Articles | Volume 26, issue 22
https://doi.org/10.5194/hess-26-5773-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/hess-26-5773-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
16 Nov 2022
Research article |
| 16 Nov 2022
| 16 Nov 2022
The effect of rainfall amount and timing on annual transpiration in a grazed savanna grassland
Institute for Atmospheric and Earth System Research, University of
Helsinki, Helsinki, Finland
Mika Aurela
Finnish Meteorological Institute, Helsinki, Finland
Ville Vakkari
Finnish Meteorological Institute, Helsinki, Finland
Atmospheric Chemistry Research Group, Chemical Resource Beneficiation, North-West University, Potchefstroom, South Africa
Johan P. Beukes
Atmospheric Chemistry Research Group, Chemical Resource Beneficiation, North-West University, Potchefstroom, South Africa
Juha-Pekka Tuovinen
Finnish Meteorological Institute, Helsinki, Finland
Pieter G. Van Zyl
Atmospheric Chemistry Research Group, Chemical Resource Beneficiation, North-West University, Potchefstroom, South Africa
Miroslav Josipovic
Atmospheric Chemistry Research Group, Chemical Resource Beneficiation, North-West University, Potchefstroom, South Africa
Stefan J. Siebert
Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
Tuomas Laurila
Finnish Meteorological Institute, Helsinki, Finland
Markku Kulmala
Institute for Atmospheric and Earth System Research, University of
Helsinki, Helsinki, Finland
Lauri Laakso
Finnish Meteorological Institute, Helsinki, Finland
Atmospheric Chemistry Research Group, Chemical Resource Beneficiation, North-West University, Potchefstroom, South Africa
Janne Rinne
Department of Physical Geography and Ecosystem Science, Lund
University, Lund, Sweden
Nicholas School of the Environment, Duke University, Durham, North
Carolina, USA
Department of Forest Science, University of Helsinki, Helsinki, Finland
Pratt School of Engineering, Duke University, Durham, North Carolina, USA
Gabriel Katul
Nicholas School of the Environment, Duke University, Durham, North
Carolina, USA
Department of Civil and Environmental Engineering, Duke University,
Durham, North Carolina, USA
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Ross Charles Petersen, Thomas Holst, Cheng Wu, Radovan Krejci, Jeremy Chan, Claudia Mohr, and Janne Rinne
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Hagninou Elagnon Venance Donnou, Aristide Barthélémy Akpo, Money Ossohou, Claire Delon, Véronique Yoboué, Dungall Laouali, Marie Ouafo-Leumbe, Pieter Gideon Van Zyl, Ousmane Ndiaye, Eric Gardrat, Maria Dias-Alves, and Corinne Galy-Lacaux
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Matthew Boyer, Diego Aliaga, Lauriane L. J. Quéléver, Silvia Bucci, Hélène Angot, Lubna Dada, Benjamin Heutte, Lisa Beck, Marina Duetsch, Andreas Stohl, Ivo Beck, Tiia Laurila, Nina Sarnela, Roseline C. Thakur, Branka Miljevic, Markku Kulmala, Tuukka Petäjä, Mikko Sipilä, Julia Schmale, and Tuija Jokinen
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Atmos. Chem. Phys., 24, 11737–11757, https://doi.org/10.5194/acp-24-11737-2024, https://doi.org/10.5194/acp-24-11737-2024, 2024
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Primary ice formation in clouds strongly influences their properties; hence, it is important to understand the sources of ice-nucleating particles (INPs) and their variability. We present 2 months of INP measurements in a Finnish boreal forest using a new semi-autonomous INP counting device based on gas expansion. These results show strong variability in INP concentrations, and we present a case that the INPs we observe are, at least some of the time, of biological origin.
Markku Kulmala, Santeri Tuovinen, Sander Mirme, Paap Koemets, Lauri Ahonen, Yongchun Liu, Heikki Junninen, Tuukka Petäjä, and Veli-Matti Kerminen
Aerosol Research, 2, 291–301, https://doi.org/10.5194/ar-2-291-2024, https://doi.org/10.5194/ar-2-291-2024, 2024
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With the recently developed CIC (Cluster Ion Counter) instrument, we can observe dynamics of small air ions and intermediate air ions. Furthermore, we can observe condensation sink and formation and growth rates for intermediated ions.
Zoé Brasseur, Julia Schneider, Janne Lampilahti, Ville Vakkari, Victoria A. Sinclair, Christina J. Williamson, Carlton Xavier, Dmitri Moisseev, Markus Hartmann, Pyry Poutanen, Markus Lampimäki, Markku Kulmala, Tuukka Petäjä, Katrianne Lehtipalo, Erik S. Thomson, Kristina Höhler, Ottmar Möhler, and Jonathan Duplissy
Atmos. Chem. Phys., 24, 11305–11332, https://doi.org/10.5194/acp-24-11305-2024, https://doi.org/10.5194/acp-24-11305-2024, 2024
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Ice-nucleating particles (INPs) strongly influence the formation of clouds by initiating the formation of ice crystals. However, very little is known about the vertical distribution of INPs in the atmosphere. Here, we present aircraft measurements of INP concentrations above the Finnish boreal forest. Results show that near-surface INPs are efficiently transported and mixed within the boundary layer and occasionally reach the free troposphere.
Martti Honkanen, Mika Aurela, Juha Hatakka, Lumi Haraguchi, Sami Kielosto, Timo Mäkelä, Jukka Seppälä, Simo-Matti Siiriä, Ken Stenbäck, Juha-Pekka Tuovinen, Pasi Ylöstalo, and Lauri Laakso
Biogeosciences, 21, 4341–4359, https://doi.org/10.5194/bg-21-4341-2024, https://doi.org/10.5194/bg-21-4341-2024, 2024
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The exchange of CO2 between the sea and the atmosphere was studied in the Archipelago Sea, Baltic Sea, in 2017–2021, using an eddy covariance technique. The sea acted as a net source of CO2 with an average yearly emission of 27.1 gC m-2 yr-1, indicating that the marine ecosystem respired carbon that originated elsewhere. The yearly CO2 emission varied between 18.2–39.2 gC m-2 yr-1, mostly due to the yearly variation of ecosystem carbon uptake.
Jia Sun, Markus Hermann, Kay Weinhold, Maik Merkel, Wolfram Birmili, Yifan Yang, Thomas Tuch, Harald Flentje, Björn Briel, Ludwig Ries, Cedric Couret, Michael Elsasser, Ralf Sohmer, Klaus Wirtz, Frank Meinhardt, Maik Schütze, Olaf Bath, Bryan Hellack, Veli-Matti Kerminen, Markku Kulmala, Nan Ma, and Alfred Wiedensohler
Atmos. Chem. Phys., 24, 10667–10687, https://doi.org/10.5194/acp-24-10667-2024, https://doi.org/10.5194/acp-24-10667-2024, 2024
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We investigated the characteristics of new particle formation (NPF) for various environments from urban background to high Alpine and the impacts of NPF on cloud condensation nuclei and aerosol radiative forcing. NPF features differ between site categories, implying the crucial role of local environmental factors such as the degree of emissions and meteorological conditions. The results also underscore the importance of local environments when assessing the impact of NPF on climate in models.
Romanos Foskinis, Ghislain Motos, Maria I. Gini, Olga Zografou, Kunfeng Gao, Stergios Vratolis, Konstantinos Granakis, Ville Vakkari, Kalliopi Violaki, Andreas Aktypis, Christos Kaltsonoudis, Zongbo Shi, Mika Komppula, Spyros N. Pandis, Konstantinos Eleftheriadis, Alexandros Papayannis, and Athanasios Nenes
Atmos. Chem. Phys., 24, 9827–9842, https://doi.org/10.5194/acp-24-9827-2024, https://doi.org/10.5194/acp-24-9827-2024, 2024
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Analysis of modeling, in situ, and remote sensing measurements reveals the microphysical state of orographic clouds and their response to aerosol from the boundary layer and free troposphere. We show that cloud response to aerosol is robust, as predicted supersaturation and cloud droplet number levels agree with those determined from in-cloud measurements. The ability to determine if clouds are velocity- or aerosol-limited allows for novel model constraints and remote sensing products.
Mohammad Allouche, Vladislav I. Sevostianov, Einara Zahn, Mark A. Zondlo, Nelson Luís Dias, Gabriel G. Katul, Jose D. Fuentes, and Elie Bou-Zeid
Atmos. Chem. Phys., 24, 9697–9711, https://doi.org/10.5194/acp-24-9697-2024, https://doi.org/10.5194/acp-24-9697-2024, 2024
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The significance of surface–atmosphere exchanges of aerosol species to atmospheric composition is underscored by their rising concentrations that are modulating the Earth's climate and having detrimental consequences for human health and the environment. Estimating these exchanges, using field measurements, and offering alternative models are the aims here. Limitations in measuring some species misrepresent their actual exchanges, so our proposed models serve to better quantify them.
Yusheng Zhang, Feixue Zheng, Zemin Feng, Chaofan Lian, Weigang Wang, Xiaolong Fan, Wei Ma, Zhuohui Lin, Chang Li, Gen Zhang, Chao Yan, Ying Zhang, Veli-Matti Kerminen, Federico Bianch, Tuukka Petäjä, Juha Kangasluoma, Markku Kulmala, and Yongchun Liu
Atmos. Chem. Phys., 24, 8569–8587, https://doi.org/10.5194/acp-24-8569-2024, https://doi.org/10.5194/acp-24-8569-2024, 2024
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The nitrous acid (HONO) budget was validated during a COVID-19 lockdown event. The main conclusions are (1) HONO concentrations showed a significant decrease from 0.97 to 0.53 ppb during lockdown; (2) vehicle emissions accounted for 53 % of nighttime sources, with the heterogeneous conversion of NO2 on ground surfaces more important than aerosol; and (3) the dominant daytime source shifted from the homogenous reaction between NO and OH (51 %) to nitrate photolysis (53 %) during lockdown.
Piaopiao Ke, Anna Lintunen, Pasi Kolari, Annalea Lohila, Santeri Tuovinen, Janne Lampilahti, Roseline Thakur, Maija Peltola, Otso Peräkylä, Tuomo Nieminen, Ekaterina Ezhova, Mari Pihlatie, Asta Laasonen, Markku Koskinen, Helena Rautakoski, Laura Heimsch, Tom Kokkonen, Aki Vähä, Ivan Mammarella, Steffen Noe, Jaana Bäck, Veli-Matti Kerminen, and Markku Kulmala
EGUsphere, https://doi.org/10.5194/egusphere-2024-1967, https://doi.org/10.5194/egusphere-2024-1967, 2024
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Our research explores diverse ecosystems’ role in climate cooling via the concept of CarbonSink+ Potential. We measured CO2 uptake and loaal aerosol production in forests, farms, peatlands, urban gardens, and coastal areas across Finland and Estonia. The long-term data reveal that while forests are vital regarding CarbonSink+ Potential, farms and urban gardens also play significant roles. These insights can help optimize management policy of natural resource to mitigate global warming.
Wolfgang Knorr, Matthew Williams, Tea Thum, Thomas Kaminski, Michael Voßbeck, Marko Scholze, Tristan Quaife, Luke Smallmann, Susan Steele-Dunne, Mariette Vreugdenhil, Tim Green, Sönke Zähle, Mika Aurela, Alexandre Bouvet, Emanuel Bueechi, Wouter Dorigo, Tarek El-Madany, Mirco Migliavacca, Marika Honkanen, Yann Kerr, Anna Kontu, Juha Lemmetyinen, Hannakaisa Lindqvist, Arnaud Mialon, Tuuli Miinalainen, Gaetan Pique, Amanda Ojasalo, Shaun Quegan, Peter Rayner, Pablo Reyes-Muñoz, Nemesio Rodríguez-Fernández, Mike Schwank, Jochem Verrelst, Songyan Zhu, Dirk Schüttemeyer, and Matthias Drusch
EGUsphere, https://doi.org/10.5194/egusphere-2024-1534, https://doi.org/10.5194/egusphere-2024-1534, 2024
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When it comes to climate change, the land surfaces are where the vast majority of impacts happen. The task of monitoring those across the globe is formidable and must necessarily rely on satellites – at a significant cost: the measurements are only indirect and require comprehensive physical understanding. We have created a comprehensive modelling system that we offer to the research community to explore how satellite data can be better exploited to help us see what changes on our lands.
Santeri Tuovinen, Janne Lampilahti, Veli-Matti Kerminen, and Markku Kulmala
Aerosol Research, 2, 93–105, https://doi.org/10.5194/ar-2-93-2024, https://doi.org/10.5194/ar-2-93-2024, 2024
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Atmospheric intermediate ions can be used to study atmospheric new particle formation (NPF). Here we aimed to find the optimal ion diameter for this purpose on a local scale. To fulfill our aim, we used ion size number distribution data from the SMEAR II measurement station, Hyytiälä, Finland. We found that concentrations of ions between 2.0–2.3 nm are the best suited for characterization of local intermediate ion formation and could be used to detect and evaluate the strength of local NPF.
Bjorn Stevens, Stefan Adami, Tariq Ali, Hartwig Anzt, Zafer Aslan, Sabine Attinger, Jaana Bäck, Johanna Baehr, Peter Bauer, Natacha Bernier, Bob Bishop, Hendryk Bockelmann, Sandrine Bony, Guy Brasseur, David N. Bresch, Sean Breyer, Gilbert Brunet, Pier Luigi Buttigieg, Junji Cao, Christelle Castet, Yafang Cheng, Ayantika Dey Choudhury, Deborah Coen, Susanne Crewell, Atish Dabholkar, Qing Dai, Francisco Doblas-Reyes, Dale Durran, Ayoub El Gaidi, Charlie Ewen, Eleftheria Exarchou, Veronika Eyring, Florencia Falkinhoff, David Farrell, Piers M. Forster, Ariane Frassoni, Claudia Frauen, Oliver Fuhrer, Shahzad Gani, Edwin Gerber, Debra Goldfarb, Jens Grieger, Nicolas Gruber, Wilco Hazeleger, Rolf Herken, Chris Hewitt, Torsten Hoefler, Huang-Hsiung Hsu, Daniela Jacob, Alexandra Jahn, Christian Jakob, Thomas Jung, Christopher Kadow, In-Sik Kang, Sarah Kang, Karthik Kashinath, Katharina Kleinen-von Königslöw, Daniel Klocke, Uta Kloenne, Milan Klöwer, Chihiro Kodama, Stefan Kollet, Tobias Kölling, Jenni Kontkanen, Steve Kopp, Michal Koran, Markku Kulmala, Hanna Lappalainen, Fakhria Latifi, Bryan Lawrence, June Yi Lee, Quentin Lejeun, Christian Lessig, Chao Li, Thomas Lippert, Jürg Luterbacher, Pekka Manninen, Jochem Marotzke, Satoshi Matsouoka, Charlotte Merchant, Peter Messmer, Gero Michel, Kristel Michielsen, Tomoki Miyakawa, Jens Müller, Ramsha Munir, Sandeep Narayanasetti, Ousmane Ndiaye, Carlos Nobre, Achim Oberg, Riko Oki, Tuba Özkan-Haller, Tim Palmer, Stan Posey, Andreas Prein, Odessa Primus, Mike Pritchard, Julie Pullen, Dian Putrasahan, Johannes Quaas, Krishnan Raghavan, Venkatachalam Ramaswamy, Markus Rapp, Florian Rauser, Markus Reichstein, Aromar Revi, Sonakshi Saluja, Masaki Satoh, Vera Schemann, Sebastian Schemm, Christina Schnadt Poberaj, Thomas Schulthess, Cath Senior, Jagadish Shukla, Manmeet Singh, Julia Slingo, Adam Sobel, Silvina Solman, Jenna Spitzer, Philip Stier, Thomas Stocker, Sarah Strock, Hang Su, Petteri Taalas, John Taylor, Susann Tegtmeier, Georg Teutsch, Adrian Tompkins, Uwe Ulbrich, Pier-Luigi Vidale, Chien-Ming Wu, Hao Xu, Najibullah Zaki, Laure Zanna, Tianjun Zhou, and Florian Ziemen
Earth Syst. Sci. Data, 16, 2113–2122, https://doi.org/10.5194/essd-16-2113-2024, https://doi.org/10.5194/essd-16-2113-2024, 2024
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To manage Earth in the Anthropocene, new tools, new institutions, and new forms of international cooperation will be required. Earth Virtualization Engines is proposed as an international federation of centers of excellence to empower all people to respond to the immense and urgent challenges posed by climate change.
Heidi Hellén, Rostislav Kouznetsov, Kaisa Kraft, Jukka Seppälä, Mika Vestenius, Jukka-Pekka Jalkanen, Lauri Laakso, and Hannele Hakola
Atmos. Chem. Phys., 24, 4717–4731, https://doi.org/10.5194/acp-24-4717-2024, https://doi.org/10.5194/acp-24-4717-2024, 2024
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Mixing ratios of C2-C5 NMHCs and methanethiol were measured on an island in the Baltic Sea using an in situ gas chromatograph. Shipping emissions were found to be an important source of ethene, ethyne, propene, and benzene. High summertime mixing ratios of methanethiol and dependence of mixing ratios on seawater temperature and height indicated the biogenic origin to possibly be phytoplankton or macroalgae. These emissions may have a strong impact on SO2 production and new particle formation.
Helena Rautakoski, Mika Korkiakoski, Jarmo Mäkelä, Markku Koskinen, Kari Minkkinen, Mika Aurela, Paavo Ojanen, and Annalea Lohila
Biogeosciences, 21, 1867–1886, https://doi.org/10.5194/bg-21-1867-2024, https://doi.org/10.5194/bg-21-1867-2024, 2024
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Current and future nitrous oxide (N2O) emissions are difficult to estimate due to their high variability in space and time. Several years of N2O fluxes from drained boreal peatland forest indicate high importance of summer precipitation, winter temperature, and snow conditions in controlling annual N2O emissions. The results indicate increasing year-to-year variation in N2O emissions in changing climate with more extreme seasonal weather conditions.
Christoffer Hallgren, Jeanie A. Aird, Stefan Ivanell, Heiner Körnich, Ville Vakkari, Rebecca J. Barthelmie, Sara C. Pryor, and Erik Sahlée
Wind Energ. Sci., 9, 821–840, https://doi.org/10.5194/wes-9-821-2024, https://doi.org/10.5194/wes-9-821-2024, 2024
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Knowing the wind speed across the rotor of a wind turbine is key in making good predictions of the power production. However, models struggle to capture both the speed and the shape of the wind profile. Using machine learning methods based on the model data, we show that the predictions can be improved drastically. The work focuses on three coastal sites, spread over the Northern Hemisphere (the Baltic Sea, the North Sea, and the US Atlantic coast) with similar results for all sites.
Markku Kulmala, Diego Aliaga, Santeri Tuovinen, Runlong Cai, Heikki Junninen, Chao Yan, Federico Bianchi, Yafang Cheng, Aijun Ding, Douglas R. Worsnop, Tuukka Petäjä, Katrianne Lehtipalo, Pauli Paasonen, and Veli-Matti Kerminen
Aerosol Research, 2, 49–58, https://doi.org/10.5194/ar-2-49-2024, https://doi.org/10.5194/ar-2-49-2024, 2024
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Atmospheric new particle formation (NPF), together with secondary production of particulate matter in the atmosphere, dominates aerosol particle number concentrations and submicron particle mass loads in many environments globally. In this opinion paper, we describe the paradigm shift to understand NPF in a continuous way instead of using traditional binary event–non-event analysis.
Jalisha T. Kallingal, Johan Lindström, Paul A. Miller, Janne Rinne, Maarit Raivonen, and Marko Scholze
Geosci. Model Dev., 17, 2299–2324, https://doi.org/10.5194/gmd-17-2299-2024, https://doi.org/10.5194/gmd-17-2299-2024, 2024
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By unlocking the mysteries of CH4 emissions from wetlands, our work improved the accuracy of the LPJ-GUESS vegetation model using Bayesian statistics. Via assimilation of long-term real data from a wetland, we significantly enhanced CH4 emission predictions. This advancement helps us better understand wetland contributions to atmospheric CH4, which are crucial for addressing climate change. Our method offers a promising tool for refining global climate models and guiding conservation efforts
Jian Zhao, Valter Mickwitz, Yuanyuan Luo, Ella Häkkinen, Frans Graeffe, Jiangyi Zhang, Hilkka Timonen, Manjula Canagaratna, Jordan E. Krechmer, Qi Zhang, Markku Kulmala, Juha Kangasluoma, Douglas Worsnop, and Mikael Ehn
Atmos. Meas. Tech., 17, 1527–1543, https://doi.org/10.5194/amt-17-1527-2024, https://doi.org/10.5194/amt-17-1527-2024, 2024
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Organic aerosol constitutes a significant portion of atmospheric fine particles but is less characterized due to its vast number of constituents. Recently, we developed a system for online measurements of particle-phase highly oxygenated organic molecules (HOMs). In this work, we systematically characterized the system, developed a new unit to enhance its performance, and demonstrated the essential role of thermograms in inferring volatility and quantifying HOMs in organic aerosols.
Shiyi Lai, Ximeng Qi, Xin Huang, Sijia Lou, Xuguang Chi, Liangduo Chen, Chong Liu, Yuliang Liu, Chao Yan, Mengmeng Li, Tengyu Liu, Wei Nie, Veli-Matti Kerminen, Tuukka Petäjä, Markku Kulmala, and Aijun Ding
Atmos. Chem. Phys., 24, 2535–2553, https://doi.org/10.5194/acp-24-2535-2024, https://doi.org/10.5194/acp-24-2535-2024, 2024
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By combining in situ measurements and chemical transport modeling, this study investigates new particle formation (NPF) on the southeastern Tibetan Plateau. We found that the NPF was driven by the presence of biogenic gases and the transport of anthropogenic precursors. The NPF was vertically heterogeneous and shaped by the vertical mixing. This study highlights the importance of anthropogenic–biogenic interactions and meteorological dynamics in NPF in this climate-sensitive region.
Jalisha Theanutti Kallingal, Marko Scholze, Paul Anthony Miller, Johan Lindström, Janne Rinne, Mika Aurela, Patrik Vestin, and Per Weslien
EGUsphere, https://doi.org/10.5194/egusphere-2024-373, https://doi.org/10.5194/egusphere-2024-373, 2024
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Our study employs an Adaptive MCMC algorithm (GRaB-AM) to constrain process parameters in the wetlands emission module of the LPJ-GUESS model, using CH4 EC flux observations from 14 diverse wetlands. We aim to derive a single set of parameters capable of representing the diversity of northern wetlands. By reducing uncertainties in model parameters and improving simulation accuracy, our research contributes to more reliable projections of future wetland CH4 emissions and their climate impact.
Jing Cai, Juha Sulo, Yifang Gu, Sebastian Holm, Runlong Cai, Steven Thomas, Almuth Neuberger, Fredrik Mattsson, Marco Paglione, Stefano Decesari, Matteo Rinaldi, Rujing Yin, Diego Aliaga, Wei Huang, Yuanyuan Li, Yvette Gramlich, Giancarlo Ciarelli, Lauriane Quéléver, Nina Sarnela, Katrianne Lehtipalo, Nora Zannoni, Cheng Wu, Wei Nie, Juha Kangasluoma, Claudia Mohr, Markku Kulmala, Qiaozhi Zha, Dominik Stolzenburg, and Federico Bianchi
Atmos. Chem. Phys., 24, 2423–2441, https://doi.org/10.5194/acp-24-2423-2024, https://doi.org/10.5194/acp-24-2423-2024, 2024
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By combining field measurements, simulations and recent chamber experiments, we investigate new particle formation (NPF) and growth in the Po Valley, where both haze and frequent NPF occur. Our results show that sulfuric acid, ammonia and amines are the dominant NPF precursors there. A high NPF rate and a lower condensation sink lead to a greater survival probability for newly formed particles, highlighting the importance of gas-to-particle conversion for aerosol concentrations.
Anton Rusanen, Anton Björklund, Manousos I. Manousakas, Jianhui Jiang, Markku T. Kulmala, Kai Puolamäki, and Kaspar R. Daellenbach
Atmos. Meas. Tech., 17, 1251–1277, https://doi.org/10.5194/amt-17-1251-2024, https://doi.org/10.5194/amt-17-1251-2024, 2024
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We present a Bayesian non-negative matrix factorization model that performs better on our test datasets than currently widely used models. Its advantages are better use of time information and providing a direct error estimation. We believe this could lead to better estimates of emission sources from measurements.
Juha Sulo, Joonas Enroth, Aki Pajunoja, Joonas Vanhanen, Katrianne Lehtipalo, Tuukka Petäjä, and Markku Kulmala
Aerosol Research, 2, 13–20, https://doi.org/10.5194/ar-2-13-2024, https://doi.org/10.5194/ar-2-13-2024, 2024
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We present a novel version of an aerosol number size distribution instrument, showcasing its capability to measure particle number concentration and particle number size distribution between 1 and 12 nm. Our results show that the instrument agrees well with existing instrumentation and allows for both the accurate measurement of the smallest particles and overlap with more conventional aerosol number size distribution instruments.
Ying Zhang, Duzitian Li, Xu-Cheng He, Wei Nie, Chenjuan Deng, Runlong Cai, Yuliang Liu, Yishuo Guo, Chong Liu, Yiran Li, Liangduo Chen, Yuanyuan Li, Chenjie Hua, Tingyu Liu, Zongcheng Wang, Jiali Xie, Lei Wang, Tuukka Petäjä, Federico Bianchi, Ximeng Qi, Xuguang Chi, Pauli Paasonen, Yongchun Liu, Chao Yan, Jingkun Jiang, Aijun Ding, and Markku Kulmala
Atmos. Chem. Phys., 24, 1873–1893, https://doi.org/10.5194/acp-24-1873-2024, https://doi.org/10.5194/acp-24-1873-2024, 2024
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This study conducts a long-term observation of gaseous iodine oxoacids in two Chinese megacities, revealing their ubiquitous presence with peak concentrations (up to 0.1 pptv) in summer. Our analysis suggests a mix of terrestrial and marine sources for iodine. Additionally, iodic acid is identified as a notable contributor to sub-3 nm particle growth and particle survival probability.
Viet Le, Hannah Lobo, Ewan J. O'Connor, and Ville Vakkari
Atmos. Meas. Tech., 17, 921–941, https://doi.org/10.5194/amt-17-921-2024, https://doi.org/10.5194/amt-17-921-2024, 2024
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This study offers a long-term overview of aerosol particle depolarization ratio at the wavelength of 1565 nm obtained from vertical profiling measurements by Halo Doppler lidars during 4 years at four different locations across Finland. Our observations support the long-term usage of Halo Doppler lidar depolarization ratio such as the detection of aerosols that may pose a safety risk for aviation. Long-range Saharan dust transport and pollen transport are also showcased here.
Anna-Maria Virkkala, Pekka Niittynen, Julia Kemppinen, Maija E. Marushchak, Carolina Voigt, Geert Hensgens, Johanna Kerttula, Konsta Happonen, Vilna Tyystjärvi, Christina Biasi, Jenni Hultman, Janne Rinne, and Miska Luoto
Biogeosciences, 21, 335–355, https://doi.org/10.5194/bg-21-335-2024, https://doi.org/10.5194/bg-21-335-2024, 2024
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Arctic greenhouse gas (GHG) fluxes of CO2, CH4, and N2O are important for climate feedbacks. We combined extensive in situ measurements and remote sensing data to develop machine-learning models to predict GHG fluxes at a 2 m resolution across a tundra landscape. The analysis revealed that the system was a net GHG sink and showed widespread CH4 uptake in upland vegetation types, almost surpassing the high wetland CH4 emissions at the landscape scale.
Jari-Pekka Nousu, Matthieu Lafaysse, Giulia Mazzotti, Pertti Ala-aho, Hannu Marttila, Bertrand Cluzet, Mika Aurela, Annalea Lohila, Pasi Kolari, Aaron Boone, Mathieu Fructus, and Samuli Launiainen
The Cryosphere, 18, 231–263, https://doi.org/10.5194/tc-18-231-2024, https://doi.org/10.5194/tc-18-231-2024, 2024
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The snowpack has a major impact on the land surface energy budget. Accurate simulation of the snowpack energy budget is difficult, and studies that evaluate models against energy budget observations are rare. We compared predictions from well-known models with observations of energy budgets, snow depths and soil temperatures in Finland. Our study identified contrasting strengths and limitations for the models. These results can be used for choosing the right models depending on the use cases.
Diego Aliaga, Santeri Tuovinen, Tinghan Zhang, Janne Lampilahti, Xinyang Li, Lauri Ahonen, Tom Kokkonen, Tuomo Nieminen, Simo Hakala, Pauli Paasonen, Federico Bianchi, Doug Worsnop, Veli-Matti Kerminen, and Markku Kulmala
Aerosol Research, 1, 81–92, https://doi.org/10.5194/ar-1-81-2023, https://doi.org/10.5194/ar-1-81-2023, 2023
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We introduce a novel method for evaluating days when small particles are formed in the atmosphere. Instead of the traditional binary division between event and non-event days, our method, known as "nano ranking analysis", provides a continuous, non-categorical metric for each day. By utilizing data from Hyytiälä, Finland, we show that our approach effectively quantifies these events. This innovative method paves the way for a deeper understanding of the factors influencing particle formation.
Paolo Cristofanelli, Cosimo Fratticioli, Lynn Hazan, Mali Chariot, Cedric Couret, Orestis Gazetas, Dagmar Kubistin, Antti Laitinen, Ari Leskinen, Tuomas Laurila, Matthias Lindauer, Giovanni Manca, Michel Ramonet, Pamela Trisolino, and Martin Steinbacher
Atmos. Meas. Tech., 16, 5977–5994, https://doi.org/10.5194/amt-16-5977-2023, https://doi.org/10.5194/amt-16-5977-2023, 2023
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We investigated the application of two automatic methods for detecting spikes due to local emissions in greenhouse gas (GHG) observations at a subset of sites from the ICOS Atmosphere network. We analysed the sensitivity to the spike frequency of using different methods and settings. We documented the impact of the de-spiking on different temporal aggregations (i.e. hourly, monthly and seasonal averages) of CO2, CH4 and CO 1 min time series.
Markku Kulmala, Anna Lintunen, Hanna Lappalainen, Annele Virtanen, Chao Yan, Ekaterina Ezhova, Tuomo Nieminen, Ilona Riipinen, Risto Makkonen, Johanna Tamminen, Anu-Maija Sundström, Antti Arola, Armin Hansel, Kari Lehtinen, Timo Vesala, Tuukka Petäjä, Jaana Bäck, Tom Kokkonen, and Veli-Matti Kerminen
Atmos. Chem. Phys., 23, 14949–14971, https://doi.org/10.5194/acp-23-14949-2023, https://doi.org/10.5194/acp-23-14949-2023, 2023
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To be able to meet global grand challenges, we need comprehensive open data with proper metadata. In this opinion paper, we describe the SMEAR (Station for Measuring Earth surface – Atmosphere Relations) concept and include several examples (cases), such as new particle formation and growth, feedback loops and the effect of COVID-19, and what has been learned from these investigations. The future needs and the potential of comprehensive observations of the environment are summarized.
Putian Zhou, Zhengyao Lu, Jukka-Pekka Keskinen, Qiong Zhang, Juha Lento, Jianpu Bian, Twan van Noije, Philippe Le Sager, Veli-Matti Kerminen, Markku Kulmala, Michael Boy, and Risto Makkonen
Clim. Past, 19, 2445–2462, https://doi.org/10.5194/cp-19-2445-2023, https://doi.org/10.5194/cp-19-2445-2023, 2023
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A Green Sahara with enhanced rainfall and larger vegetation cover existed in northern Africa about 6000 years ago. Biosphere–atmosphere interactions are found to be critical to explaining this wet period. Based on modeled vegetation reconstruction data, we simulated dust emissions and aerosol formation, which are key factors in biosphere–atmosphere interactions. Our results also provide a benchmark of aerosol climatology for future paleo-climate simulation experiments.
Xiaoxiao Li, Yijing Chen, Yuyang Li, Runlong Cai, Yiran Li, Chenjuan Deng, Jin Wu, Chao Yan, Hairong Cheng, Yongchun Liu, Markku Kulmala, Jiming Hao, James N. Smith, and Jingkun Jiang
Atmos. Chem. Phys., 23, 14801–14812, https://doi.org/10.5194/acp-23-14801-2023, https://doi.org/10.5194/acp-23-14801-2023, 2023
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Near-continuous measurements show the composition, sources, and seasonal variations of ultrafine particles (UFPs) in urban Beijing. Vehicle and cooking emissions and new particle formation are the main sources of UFPs, and aqueous/heterogeneous processes increase UFP mode diameters. UFPs are the highest in winter due to the highest primary particle emission rates and new particle formation rates, and CHO fractions are the highest in summer due to the strongest photooxidation.
Magdalena Okuljar, Olga Garmash, Miska Olin, Joni Kalliokoski, Hilkka Timonen, Jarkko V. Niemi, Pauli Paasonen, Jenni Kontkanen, Yanjun Zhang, Heidi Hellén, Heino Kuuluvainen, Minna Aurela, Hanna E. Manninen, Mikko Sipilä, Topi Rönkkö, Tuukka Petäjä, Markku Kulmala, Miikka Dal Maso, and Mikael Ehn
Atmos. Chem. Phys., 23, 12965–12983, https://doi.org/10.5194/acp-23-12965-2023, https://doi.org/10.5194/acp-23-12965-2023, 2023
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Highly oxygenated organic molecules (HOMs) form secondary organic aerosol that affects air quality and health. In this study, we demonstrate that in a moderately polluted city with abundant vegetation, the composition of HOMs is largely controlled by the effect of NOx on the biogenic volatile organic compound oxidation. Comparing the results from two nearby stations, we show that HOM composition and formation pathways can change considerably within small distances in urban environments.
Christoffer Hallgren, Heiner Körnich, Stefan Ivanell, Ville Vakkari, and Erik Sahlée
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2023-129, https://doi.org/10.5194/wes-2023-129, 2023
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Sometimes, the wind changes direction between the bottom and top part of a wind turbine. This affects both the power production and the loads on the turbine. In this study, a climatology of pronounced changes in wind direction across the rotor is created, focusing on Scandinavia. The weather conditions responsible for these changes in wind direction are investigated and the climatology is compared to measurements from two coastal sites, indicating an underestimation by the climatology.
Xu-Cheng He, Jiali Shen, Siddharth Iyer, Paxton Juuti, Jiangyi Zhang, Mrisha Koirala, Mikko M. Kytökari, Douglas R. Worsnop, Matti Rissanen, Markku Kulmala, Norbert M. Maier, Jyri Mikkilä, Mikko Sipilä, and Juha Kangasluoma
Atmos. Meas. Tech., 16, 4461–4487, https://doi.org/10.5194/amt-16-4461-2023, https://doi.org/10.5194/amt-16-4461-2023, 2023
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In this study, the upgraded multi-scheme chemical ionisation inlet 2 is presented. Sulfuric acid, hypoiodous acid, iodine, sulfur dioxide, and hydroperoxyl radicals are calibrated, and the improved ion optics allow us to detect sulfuric acid and iodine-containing molecules at as low as a few parts per quadrillion by volume. Additionally, we confirm the reliable detection of iodic acid using both the nitrate and bromide chemical ionisation methods under atmospherically relevant conditions.
Matti Räsänen, Risto Vesala, Petri Rönnholm, Laura Arppe, Petra Manninen, Markus Jylhä, Jouko Rikkinen, Petri Pellikka, and Janne Rinne
Biogeosciences, 20, 4029–4042, https://doi.org/10.5194/bg-20-4029-2023, https://doi.org/10.5194/bg-20-4029-2023, 2023
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Fungus-growing termites recycle large parts of dead plant material in African savannas and are significant sources of greenhouse gases. We measured CO2 and CH4 fluxes from their mounds and surrounding soils in open and closed habitats. The fluxes scale with mound volume. The results show that emissions from mounds of fungus-growing termites are more stable than those from other termites. The soil fluxes around the mound are affected by the termite colonies at up to 2 m distance from the mound.
Simo Hakala, Ville Vakkari, Heikki Lihavainen, Antti-Pekka Hyvärinen, Kimmo Neitola, Jenni Kontkanen, Veli-Matti Kerminen, Markku Kulmala, Tuukka Petäjä, Tareq Hussein, Mamdouh I. Khoder, Mansour A. Alghamdi, and Pauli Paasonen
Atmos. Chem. Phys., 23, 9287–9321, https://doi.org/10.5194/acp-23-9287-2023, https://doi.org/10.5194/acp-23-9287-2023, 2023
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Things are not always as they first seem in ambient aerosol measurements. Observations of decreasing particle sizes are often interpreted as resulting from particle evaporation. We show that such observations can counterintuitively be explained by particles that are constantly growing in size. This requires one to account for the previous movements of the observed air. Our explanation implies a larger number of larger particles, meaning more significant effects of aerosols on climate and health.
Dimitri Castarède, Zoé Brasseur, Yusheng Wu, Zamin A. Kanji, Markus Hartmann, Lauri Ahonen, Merete Bilde, Markku Kulmala, Tuukka Petäjä, Jan B. C. Pettersson, Berko Sierau, Olaf Stetzer, Frank Stratmann, Birgitta Svenningsson, Erik Swietlicki, Quynh Thu Nguyen, Jonathan Duplissy, and Erik S. Thomson
Atmos. Meas. Tech., 16, 3881–3899, https://doi.org/10.5194/amt-16-3881-2023, https://doi.org/10.5194/amt-16-3881-2023, 2023
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Clouds play a key role in Earth’s climate by influencing the surface energy budget. Certain types of atmospheric aerosols, called ice-nucleating particles (INPs), induce the formation of ice in clouds and, thus, often initiate precipitation formation. The Portable Ice Nucleation Chamber 2 (PINCii) is a new instrument developed to study ice formation and to conduct ambient measurements of INPs, allowing us to investigate the sources and properties of the atmospheric aerosols that can act as INPs.
Sophie L. Haslett, David M. Bell, Varun Kumar, Jay G. Slowik, Dongyu S. Wang, Suneeti Mishra, Neeraj Rastogi, Atinderpal Singh, Dilip Ganguly, Joel Thornton, Feixue Zheng, Yuanyuan Li, Wei Nie, Yongchun Liu, Wei Ma, Chao Yan, Markku Kulmala, Kaspar R. Daellenbach, David Hadden, Urs Baltensperger, Andre S. H. Prevot, Sachchida N. Tripathi, and Claudia Mohr
Atmos. Chem. Phys., 23, 9023–9036, https://doi.org/10.5194/acp-23-9023-2023, https://doi.org/10.5194/acp-23-9023-2023, 2023
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In Delhi, some aspects of daytime and nighttime atmospheric chemistry are inverted, and parodoxically, vehicle emissions may be limiting other forms of particle production. This is because the nighttime emissions of nitrogen oxide (NO) by traffic and biomass burning prevent some chemical processes that would otherwise create even more particles and worsen the urban haze.
Maria Filioglou, Ari Leskinen, Ville Vakkari, Ewan O'Connor, Minttu Tuononen, Pekko Tuominen, Samuli Laukkanen, Linnea Toiviainen, Annika Saarto, Xiaoxia Shang, Petri Tiitta, and Mika Komppula
Atmos. Chem. Phys., 23, 9009–9021, https://doi.org/10.5194/acp-23-9009-2023, https://doi.org/10.5194/acp-23-9009-2023, 2023
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Pollen impacts climate and public health, and it can be detected in the atmosphere by lidars which measure the linear particle depolarization ratio (PDR), a shape-relevant optical parameter. As aerosols also cause depolarization, surface aerosol and pollen observations were combined with measurements from ground-based lidars operating at different wavelengths to determine the optical properties of birch and pine pollen and quantify their relative contribution to the PDR.
Yuyang Li, Jiewen Shen, Bin Zhao, Runlong Cai, Shuxiao Wang, Yang Gao, Manish Shrivastava, Da Gao, Jun Zheng, Markku Kulmala, and Jingkun Jiang
Atmos. Chem. Phys., 23, 8789–8804, https://doi.org/10.5194/acp-23-8789-2023, https://doi.org/10.5194/acp-23-8789-2023, 2023
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We set up a new parameterization for 1.4 nm particle formation rates from sulfuric acid–dimethylamine (SA–DMA) nucleation, fully including the effects of coagulation scavenging and cluster stability. Incorporating the new parameterization into 3-D chemical transport models, we achieved better consistencies between simulation results and observation data. This new parameterization provides new insights into atmospheric nucleation simulations and its effects on atmospheric pollution or health.
Ross Petersen, Thomas Holst, Meelis Mölder, Natascha Kljun, and Janne Rinne
Atmos. Chem. Phys., 23, 7839–7858, https://doi.org/10.5194/acp-23-7839-2023, https://doi.org/10.5194/acp-23-7839-2023, 2023
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We investigate variability in the vertical distribution of volatile organic compounds (VOCs) in boreal forest, determined through multiyear measurements at several heights in a boreal forest in Sweden. VOC source/sink seasonality in canopy was explored using these vertical profiles and with measurements from a collection of sonic anemometers on the station flux tower. Our results show seasonality in the source/sink distribution for several VOCs, such as monoterpenes and water-soluble compounds.
Guangdong Niu, Ximeng Qi, Liangduo Chen, Lian Xue, Shiyi Lai, Xin Huang, Jiaping Wang, Xuguang Chi, Wei Nie, Veli-Matti Kerminen, Tuukka Petäjä, Markku Kulmala, and Aijun Ding
Atmos. Chem. Phys., 23, 7521–7534, https://doi.org/10.5194/acp-23-7521-2023, https://doi.org/10.5194/acp-23-7521-2023, 2023
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The reported below-cloud wet-scavenging coefficients (BWSCs) are much higher than theoretical data, but the reason remains unclear. Based on long-term observation, we find that air mass changing during rainfall events causes the overestimation of BWSCs. Thus, the discrepancy in BWSCs between observation and theory is not as large as currently believed. To obtain reasonable BWSCs and parameterizations from field observations, the effect of air mass changes needs to be considered.
Jonas Elm, Aladár Czitrovszky, Andreas Held, Annele Virtanen, Astrid Kiendler-Scharr, Benjamin J. Murray, Daniel McCluskey, Daniele Contini, David Broday, Eirini Goudeli, Hilkka Timonen, Joan Rosell-Llompart, Jose L. Castillo, Evangelia Diapouli, Mar Viana, Maria E. Messing, Markku Kulmala, Naděžda Zíková, and Sebastian H. Schmitt
Aerosol Research, 1, 13–16, https://doi.org/10.5194/ar-1-13-2023, https://doi.org/10.5194/ar-1-13-2023, 2023
Santeri Tuovinen, Janne Lampilahti, Veli-Matti Kerminen, and Markku Kulmala
EGUsphere, https://doi.org/10.5194/egusphere-2023-1108, https://doi.org/10.5194/egusphere-2023-1108, 2023
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Atmospheric ions can be used to characterize and detect atmospheric new particle formation. In this study we aimed to find the optimal ion diameter for this purpose within a local scale. To fulfill our aim, we used ion size number distribution data from SMEAR II measurement station, Hyytiälä, Finland. We found that negative ions between 2.0–2.3 nm are the best suited for characterization of local NPF, with minimized influence of transported ions.
Chenxi Li, Yuyang Li, Xiaoxiao Li, Runlong Cai, Yaxin Fan, Xiaohui Qiao, Rujing Yin, Chao Yan, Yishuo Guo, Yongchun Liu, Jun Zheng, Veli-Matti Kerminen, Markku Kulmala, Huayun Xiao, and Jingkun Jiang
Atmos. Chem. Phys., 23, 6879–6896, https://doi.org/10.5194/acp-23-6879-2023, https://doi.org/10.5194/acp-23-6879-2023, 2023
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New particle formation and growth in polluted environments are not fully understood despite intensive research. We applied a cluster dynamics–multicomponent sectional model to simulate the new particle formation events observed in Beijing, China. The simulation approximately captures how the events evolve. Further diagnosis shows that the oxygenated organic molecules may have been under-detected, and modulating their abundance leads to significantly improved simulation–observation agreement.
Joschka Pfeifer, Naser G. A. Mahfouz, Benjamin C. Schulze, Serge Mathot, Dominik Stolzenburg, Rima Baalbaki, Zoé Brasseur, Lucia Caudillo, Lubna Dada, Manuel Granzin, Xu-Cheng He, Houssni Lamkaddam, Brandon Lopez, Vladimir Makhmutov, Ruby Marten, Bernhard Mentler, Tatjana Müller, Antti Onnela, Maxim Philippov, Ana A. Piedehierro, Birte Rörup, Meredith Schervish, Ping Tian, Nsikanabasi S. Umo, Dongyu S. Wang, Mingyi Wang, Stefan K. Weber, André Welti, Yusheng Wu, Marcel Zauner-Wieczorek, Antonio Amorim, Imad El Haddad, Markku Kulmala, Katrianne Lehtipalo, Tuukka Petäjä, António Tomé, Sander Mirme, Hanna E. Manninen, Neil M. Donahue, Richard C. Flagan, Andreas Kürten, Joachim Curtius, and Jasper Kirkby
Atmos. Chem. Phys., 23, 6703–6718, https://doi.org/10.5194/acp-23-6703-2023, https://doi.org/10.5194/acp-23-6703-2023, 2023
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Attachment rate coefficients between ions and charged aerosol particles determine their lifetimes and may also influence cloud dynamics and aerosol processing. Here we present novel experiments that measure ion–aerosol attachment rate coefficients for multiply charged aerosol particles under atmospheric conditions in the CERN CLOUD chamber. Our results provide experimental discrimination between various theoretical models.
Yishuo Guo, Chenjuan Deng, Aino Ovaska, Feixue Zheng, Chenjie Hua, Junlei Zhan, Yiran Li, Jin Wu, Zongcheng Wang, Jiali Xie, Ying Zhang, Tingyu Liu, Yusheng Zhang, Boying Song, Wei Ma, Yongchun Liu, Chao Yan, Jingkun Jiang, Veli-Matti Kerminen, Men Xia, Tuomo Nieminen, Wei Du, Tom Kokkonen, and Markku Kulmala
Atmos. Chem. Phys., 23, 6663–6690, https://doi.org/10.5194/acp-23-6663-2023, https://doi.org/10.5194/acp-23-6663-2023, 2023
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Using the comprehensive datasets, we investigated the long-term variations of air pollutants during winter in Beijing from 2019 to 2022 and analyzed the characteristics of atmospheric pollution cocktail during different short-term special events (e.g., Beijing Winter Olympics, COVID lockdown and Chinese New Year) associated with substantial emission reductions. Our results are useful in planning more targeted and sustainable long-term pollution control plans.
Lucía Caudillo, Mihnea Surdu, Brandon Lopez, Mingyi Wang, Markus Thoma, Steffen Bräkling, Angela Buchholz, Mario Simon, Andrea C. Wagner, Tatjana Müller, Manuel Granzin, Martin Heinritzi, Antonio Amorim, David M. Bell, Zoé Brasseur, Lubna Dada, Jonathan Duplissy, Henning Finkenzeller, Xu-Cheng He, Houssni Lamkaddam, Naser G. A. Mahfouz, Vladimir Makhmutov, Hanna E. Manninen, Guillaume Marie, Ruby Marten, Roy L. Mauldin, Bernhard Mentler, Antti Onnela, Tuukka Petäjä, Joschka Pfeifer, Maxim Philippov, Ana A. Piedehierro, Birte Rörup, Wiebke Scholz, Jiali Shen, Dominik Stolzenburg, Christian Tauber, Ping Tian, António Tomé, Nsikanabasi Silas Umo, Dongyu S. Wang, Yonghong Wang, Stefan K. Weber, André Welti, Marcel Zauner-Wieczorek, Urs Baltensperger, Richard C. Flagan, Armin Hansel, Jasper Kirkby, Markku Kulmala, Katrianne Lehtipalo, Douglas R. Worsnop, Imad El Haddad, Neil M. Donahue, Alexander L. Vogel, Andreas Kürten, and Joachim Curtius
Atmos. Chem. Phys., 23, 6613–6631, https://doi.org/10.5194/acp-23-6613-2023, https://doi.org/10.5194/acp-23-6613-2023, 2023
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In this study, we present an intercomparison of four different techniques for measuring the chemical composition of nanoparticles. The intercomparison was performed based on the observed chemical composition, calculated volatility, and analysis of the thermograms. We found that the methods generally agree on the most important compounds that are found in the nanoparticles. However, they do see different parts of the organic spectrum. We suggest potential explanations for these differences.
Anton Rusanen, Kristo Hõrrak, Lauri R. Ahonen, Tuomo Nieminen, Pasi P. Aalto, Pasi Kolari, Markku Kulmala, Tuukka Petäjä, and Heikki Junninen
Atmos. Meas. Tech., 16, 2781–2793, https://doi.org/10.5194/amt-16-2781-2023, https://doi.org/10.5194/amt-16-2781-2023, 2023
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We present a framework for setting up SMEAR (Station for Measuring Ecosystem–Atmosphere Relations) type measurement station data flows. This framework, called SMEARcore, consists of modular open-source software components that can be chosen to suit various station configurations. The benefits of using this framework are automation of routine operations and real-time monitoring of measurement results.
Rujing Yin, Xiaoxiao Li, Chao Yan, Runlong Cai, Ying Zhou, Juha Kangasluoma, Nina Sarnela, Janne Lampilahti, Tuukka Petäjä, Veli-Matti Kerminen, Federico Bianchi, Markku Kulmala, and Jingkun Jiang
Atmos. Chem. Phys., 23, 5279–5296, https://doi.org/10.5194/acp-23-5279-2023, https://doi.org/10.5194/acp-23-5279-2023, 2023
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Atmospheric cluster ions are important constituents in the atmosphere. However, the quantitative research on their compositions is still limited, especially in urban environments. Here we demonstrate the feasibility of an in situ quantification method of cluster ions measured by a high-resolution mass spectrometer and reveal their governing factors, sources, and sinks in urban Beijing through quantitative analysis of cluster ions, reagent ions, neutral molecules, and condensation sink.
Qiaozhi Zha, Wei Huang, Diego Aliaga, Otso Peräkylä, Liine Heikkinen, Alkuin Maximilian Koenig, Cheng Wu, Joonas Enroth, Yvette Gramlich, Jing Cai, Samara Carbone, Armin Hansel, Tuukka Petäjä, Markku Kulmala, Douglas Worsnop, Victoria Sinclair, Radovan Krejci, Marcos Andrade, Claudia Mohr, and Federico Bianchi
Atmos. Chem. Phys., 23, 4559–4576, https://doi.org/10.5194/acp-23-4559-2023, https://doi.org/10.5194/acp-23-4559-2023, 2023
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We investigate the chemical composition of atmospheric cluster ions from January to May 2018 at the high-altitude research station Chacaltaya (5240 m a.s.l.) in the Bolivian Andes. With state-of-the-art mass spectrometers and air mass history analysis, the measured cluster ions exhibited distinct diurnal and seasonal patterns, some of which contributed to new particle formation. Our study will improve the understanding of atmospheric ions and their role in high-altitude new particle formation.
Meri Räty, Larisa Sogacheva, Helmi-Marja Keskinen, Veli-Matti Kerminen, Tuomo Nieminen, Tuukka Petäjä, Ekaterina Ezhova, and Markku Kulmala
Atmos. Chem. Phys., 23, 3779–3798, https://doi.org/10.5194/acp-23-3779-2023, https://doi.org/10.5194/acp-23-3779-2023, 2023
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We utilised back trajectories to identify the source region of air masses arriving in Hyytiälä, Finland, and their travel time over forests. Combined with atmospheric observations, they revealed how air mass transport over the Fennoscandian boreal forest during the growing season produced an accumulation of cloud condensation nuclei and humidity, promoting cloudiness and precipitation. By 55 h of transport, air masses appeared to reach a balanced state with the forest environment.
Jing Cai, Kaspar R. Daellenbach, Cheng Wu, Yan Zheng, Feixue Zheng, Wei Du, Sophie L. Haslett, Qi Chen, Markku Kulmala, and Claudia Mohr
Atmos. Meas. Tech., 16, 1147–1165, https://doi.org/10.5194/amt-16-1147-2023, https://doi.org/10.5194/amt-16-1147-2023, 2023
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We introduce the offline application of FIGAERO-CIMS by analyzing Teflon and quartz filter samples that were collected at a typical urban site in Beijing with the deposition time varying from 30 min to 24 h. This method provides a feasible, simple, and quantitative way to investigate the molecular composition and volatility of OA compounds by using FIGAERO-CIMS to analyze offline samples.
Matti Kämäräinen, Juha-Pekka Tuovinen, Markku Kulmala, Ivan Mammarella, Juha Aalto, Henriikka Vekuri, Annalea Lohila, and Anna Lintunen
Biogeosciences, 20, 897–909, https://doi.org/10.5194/bg-20-897-2023, https://doi.org/10.5194/bg-20-897-2023, 2023
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In this study, we introduce a new method for modeling the exchange of carbon between the atmosphere and a study site located in a boreal forest in southern Finland. Our method yields more accurate results than previous approaches in this context. Accurately estimating carbon exchange is crucial for gaining a better understanding of the role of forests in regulating atmospheric carbon and addressing climate change.
Lejish Vettikkat, Pasi Miettinen, Angela Buchholz, Pekka Rantala, Hao Yu, Simon Schallhart, Tuukka Petäjä, Roger Seco, Elisa Männistö, Markku Kulmala, Eeva-Stiina Tuittila, Alex B. Guenther, and Siegfried Schobesberger
Atmos. Chem. Phys., 23, 2683–2698, https://doi.org/10.5194/acp-23-2683-2023, https://doi.org/10.5194/acp-23-2683-2023, 2023
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Wetlands cover a substantial fraction of the land mass in the northern latitudes, from northern Europe to Siberia and Canada. Yet, their isoprene and terpene emissions remain understudied. Here, we used a state-of-the-art measurement technique to quantify ecosystem-scale emissions from a boreal wetland during an unusually warm spring/summer. We found that the emissions from this wetland were (a) higher and (b) even more strongly dependent on temperature than commonly thought.
Konstantinos Matthaios Doulgeris, Ville Vakkari, Ewan J. O'Connor, Veli-Matti Kerminen, Heikki Lihavainen, and David Brus
Atmos. Chem. Phys., 23, 2483–2498, https://doi.org/10.5194/acp-23-2483-2023, https://doi.org/10.5194/acp-23-2483-2023, 2023
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We investigated how different long-range-transported air masses can affect the microphysical properties of low-level clouds in a clean subarctic environment. A connection was revealed. Higher values of cloud droplet number concentrations were related to continental air masses, whereas the lowest values of number concentrations were related to marine air masses. These were characterized by larger cloud droplets. Clouds in all regions were sensitive to increases in cloud number concentration.
Lauri Heiskanen, Juha-Pekka Tuovinen, Henriikka Vekuri, Aleksi Räsänen, Tarmo Virtanen, Sari Juutinen, Annalea Lohila, Juha Mikola, and Mika Aurela
Biogeosciences, 20, 545–572, https://doi.org/10.5194/bg-20-545-2023, https://doi.org/10.5194/bg-20-545-2023, 2023
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We measured and modelled the CO2 and CH4 fluxes of the terrestrial and aquatic ecosystems of the subarctic landscape for 2 years. The landscape was an annual CO2 sink and a CH4 source. The forest had the largest contribution to the landscape-level CO2 sink and the peatland to the CH4 emissions. The lakes released 24 % of the annual net C uptake of the landscape back to the atmosphere. The C fluxes were affected most by the rainy peak growing season of 2017 and the drought event in July 2018.
Wiebke Scholz, Jiali Shen, Diego Aliaga, Cheng Wu, Samara Carbone, Isabel Moreno, Qiaozhi Zha, Wei Huang, Liine Heikkinen, Jean Luc Jaffrezo, Gaelle Uzu, Eva Partoll, Markus Leiminger, Fernando Velarde, Paolo Laj, Patrick Ginot, Paolo Artaxo, Alfred Wiedensohler, Markku Kulmala, Claudia Mohr, Marcos Andrade, Victoria Sinclair, Federico Bianchi, and Armin Hansel
Atmos. Chem. Phys., 23, 895–920, https://doi.org/10.5194/acp-23-895-2023, https://doi.org/10.5194/acp-23-895-2023, 2023
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Dimethyl sulfide (DMS), emitted from the ocean, is the most abundant biogenic sulfur emission into the atmosphere. OH radicals, among others, can oxidize DMS to sulfuric and methanesulfonic acid, which are relevant for aerosol formation. We quantified DMS and nearly all DMS oxidation products with novel mass spectrometric instruments for gas and particle phase at the high mountain station Chacaltaya (5240 m a.s.l.) in the Bolivian Andes in free tropospheric air after long-range transport.
Matthew Boyer, Diego Aliaga, Jakob Boyd Pernov, Hélène Angot, Lauriane L. J. Quéléver, Lubna Dada, Benjamin Heutte, Manuel Dall'Osto, David C. S. Beddows, Zoé Brasseur, Ivo Beck, Silvia Bucci, Marina Duetsch, Andreas Stohl, Tiia Laurila, Eija Asmi, Andreas Massling, Daniel Charles Thomas, Jakob Klenø Nøjgaard, Tak Chan, Sangeeta Sharma, Peter Tunved, Radovan Krejci, Hans Christen Hansson, Federico Bianchi, Katrianne Lehtipalo, Alfred Wiedensohler, Kay Weinhold, Markku Kulmala, Tuukka Petäjä, Mikko Sipilä, Julia Schmale, and Tuija Jokinen
Atmos. Chem. Phys., 23, 389–415, https://doi.org/10.5194/acp-23-389-2023, https://doi.org/10.5194/acp-23-389-2023, 2023
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The Arctic is a unique environment that is warming faster than other locations on Earth. We evaluate measurements of aerosol particles, which can influence climate, over the central Arctic Ocean for a full year and compare the data to land-based measurement stations across the Arctic. Our measurements show that the central Arctic has similarities to but also distinct differences from the stations further south. We note that this may change as the Arctic warms and sea ice continues to decline.
Norbert Pirk, Kristoffer Aalstad, Sebastian Westermann, Astrid Vatne, Alouette van Hove, Lena Merete Tallaksen, Massimo Cassiani, and Gabriel Katul
Atmos. Meas. Tech., 15, 7293–7314, https://doi.org/10.5194/amt-15-7293-2022, https://doi.org/10.5194/amt-15-7293-2022, 2022
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In this study, we show how sparse and noisy drone measurements can be combined with an ensemble of turbulence-resolving wind simulations to estimate uncertainty-aware surface energy exchange. We demonstrate the feasibility of this drone data assimilation framework in a series of synthetic and real-world experiments. This new framework can, in future, be applied to estimate energy and gas exchange in heterogeneous landscapes more representatively than conventional methods.
Yao Gao, Eleanor J. Burke, Sarah E. Chadburn, Maarit Raivonen, Mika Aurela, Lawrence B. Flanagan, Krzysztof Fortuniak, Elyn Humphreys, Annalea Lohila, Tingting Li, Tiina Markkanen, Olli Nevalainen, Mats B. Nilsson, Włodzimierz Pawlak, Aki Tsuruta, Huiyi Yang, and Tuula Aalto
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-229, https://doi.org/10.5194/bg-2022-229, 2022
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We coupled a process-based peatland CH4 emission model HIMMELI with a state-of-art land surface model JULES. The performance of the coupled model was evaluated at six northern wetland sites. The coupled model is considered to be more appropriate in simulating wetland CH4 emission. In order to improve the simulated CH4 emission, the model requires better representation of the peat soil carbon and hydrologic processes in JULES and the methane production and transportation processes in HIMMELI.
Juha Sulo, Janne Lampilahti, Xuemeng Chen, Jenni Kontkanen, Tuomo Nieminen, Veli-Matti Kerminen, Tuukka Petäjä, Markku Kulmala, and Katrianne Lehtipalo
Atmos. Chem. Phys., 22, 15223–15242, https://doi.org/10.5194/acp-22-15223-2022, https://doi.org/10.5194/acp-22-15223-2022, 2022
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We measured atmospheric ion concentrations continuously in a boreal forest between 2005 and 2021 and observed an increasing interannual trend. The increase in cluster ion concentrations can be largely explained by an overall decreasing level of anthropogenic aerosols in the boreal forest. This suggests that the role of ions in atmospheric new particle formation may be more important in the future.
Santeri Tuovinen, Runlong Cai, Veli-Matti Kerminen, Jingkun Jiang, Chao Yan, Markku Kulmala, and Jenni Kontkanen
Atmos. Chem. Phys., 22, 15071–15091, https://doi.org/10.5194/acp-22-15071-2022, https://doi.org/10.5194/acp-22-15071-2022, 2022
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We compare observed survival probabilities of atmospheric particles from Beijing, China, with survival probabilities based on analytical formulae and model simulations. We find observed survival probabilities under polluted conditions at smaller sizes to be higher, while at larger sizes they are lower than or similar to theoretical survival probabilities. Uncertainties in condensation sink and growth rate are unlikely to explain higher-than-predicted survival probabilities at smaller sizes.
Runlong Cai, Chenjuan Deng, Dominik Stolzenburg, Chenxi Li, Junchen Guo, Veli-Matti Kerminen, Jingkun Jiang, Markku Kulmala, and Juha Kangasluoma
Atmos. Chem. Phys., 22, 14571–14587, https://doi.org/10.5194/acp-22-14571-2022, https://doi.org/10.5194/acp-22-14571-2022, 2022
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The survival probability of new particles is the key parameter governing their influences on the atmosphere and climate, yet the knowledge of particle survival in the atmosphere is rather limited. We propose methods to compute the size-resolved particle survival probability and validate them using simulations and measurements from diverse environments. Using these methods, we could explain particle survival from the cluster size to the cloud condensation nuclei size.
Chenjuan Deng, Yiran Li, Chao Yan, Jin Wu, Runlong Cai, Dongbin Wang, Yongchun Liu, Juha Kangasluoma, Veli-Matti Kerminen, Markku Kulmala, and Jingkun Jiang
Atmos. Chem. Phys., 22, 13569–13580, https://doi.org/10.5194/acp-22-13569-2022, https://doi.org/10.5194/acp-22-13569-2022, 2022
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The size distributions of urban atmospheric particles convey important information on their origins and impacts. This study investigates the characteristics of typical particle size distributions and key gaseous precursors in the long term in urban Beijing. A fitting function is proposed to represent and help interpret size distribution including particles and gaseous precursors. In addition to NPF (new particle formation) as the major source, vehicles can emit sub-3 nm particles as well
Loïc Gonzalez Carracedo, Katrianne Lehtipalo, Lauri R. Ahonen, Nina Sarnela, Sebastian Holm, Juha Kangasluoma, Markku Kulmala, Paul M. Winkler, and Dominik Stolzenburg
Atmos. Chem. Phys., 22, 13153–13166, https://doi.org/10.5194/acp-22-13153-2022, https://doi.org/10.5194/acp-22-13153-2022, 2022
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Fast nanoparticle growth is essential for the survival of new aerosol particles in the atmosphere and hence their contribution to the climate. We show that using naturally charged ions for growth calculations can cause a significant error. During the diurnal cycle, the importance of ion-induced and neutral nucleation varies, causing the ion population to have a slower measurable apparent growth. Results suggest that data from ion spectrometers need to be considered with great care below 3 nm.
Maiju Linkosalmi, Juha-Pekka Tuovinen, Olli Nevalainen, Mikko Peltoniemi, Cemal M. Taniş, Ali N. Arslan, Juuso Rainne, Annalea Lohila, Tuomas Laurila, and Mika Aurela
Biogeosciences, 19, 4747–4765, https://doi.org/10.5194/bg-19-4747-2022, https://doi.org/10.5194/bg-19-4747-2022, 2022
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Vegetation greenness was monitored with digital cameras in three northern peatlands during five growing seasons. The greenness index derived from the images was highest at the most nutrient-rich site. Greenness indicated the main phases of phenology and correlated with CO2 uptake, though this was mainly related to the common seasonal cycle. The cameras and Sentinel-2 satellite showed consistent results, but more frequent satellite data are needed for reliable detection of phenological phases.
Ville Leinonen, Harri Kokkola, Taina Yli-Juuti, Tero Mielonen, Thomas Kühn, Tuomo Nieminen, Simo Heikkinen, Tuuli Miinalainen, Tommi Bergman, Ken Carslaw, Stefano Decesari, Markus Fiebig, Tareq Hussein, Niku Kivekäs, Radovan Krejci, Markku Kulmala, Ari Leskinen, Andreas Massling, Nikos Mihalopoulos, Jane P. Mulcahy, Steffen M. Noe, Twan van Noije, Fiona M. O'Connor, Colin O'Dowd, Dirk Olivie, Jakob B. Pernov, Tuukka Petäjä, Øyvind Seland, Michael Schulz, Catherine E. Scott, Henrik Skov, Erik Swietlicki, Thomas Tuch, Alfred Wiedensohler, Annele Virtanen, and Santtu Mikkonen
Atmos. Chem. Phys., 22, 12873–12905, https://doi.org/10.5194/acp-22-12873-2022, https://doi.org/10.5194/acp-22-12873-2022, 2022
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We provide the first extensive comparison of detailed aerosol size distribution trends between in situ observations from Europe and five different earth system models. We investigated aerosol modes (nucleation, Aitken, and accumulation) separately and were able to show the differences between measured and modeled trends and especially their seasonal patterns. The differences in model results are likely due to complex effects of several processes instead of certain specific model features.
Malika Menoud, Carina van der Veen, Dave Lowry, Julianne M. Fernandez, Semra Bakkaloglu, James L. France, Rebecca E. Fisher, Hossein Maazallahi, Mila Stanisavljević, Jarosław Nęcki, Katarina Vinkovic, Patryk Łakomiec, Janne Rinne, Piotr Korbeń, Martina Schmidt, Sara Defratyka, Camille Yver-Kwok, Truls Andersen, Huilin Chen, and Thomas Röckmann
Earth Syst. Sci. Data, 14, 4365–4386, https://doi.org/10.5194/essd-14-4365-2022, https://doi.org/10.5194/essd-14-4365-2022, 2022
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Emission sources of methane (CH4) can be distinguished with measurements of CH4 stable isotopes. We present new measurements of isotope signatures of various CH4 sources in Europe, mainly anthropogenic, sampled from 2017 to 2020. The present database also contains the most recent update of the global signature dataset from the literature. The dataset improves CH4 source attribution and the understanding of the global CH4 budget.
Chao Yan, Yicheng Shen, Dominik Stolzenburg, Lubna Dada, Ximeng Qi, Simo Hakala, Anu-Maija Sundström, Yishuo Guo, Antti Lipponen, Tom V. Kokkonen, Jenni Kontkanen, Runlong Cai, Jing Cai, Tommy Chan, Liangduo Chen, Biwu Chu, Chenjuan Deng, Wei Du, Xiaolong Fan, Xu-Cheng He, Juha Kangasluoma, Joni Kujansuu, Mona Kurppa, Chang Li, Yiran Li, Zhuohui Lin, Yiliang Liu, Yuliang Liu, Yiqun Lu, Wei Nie, Jouni Pulliainen, Xiaohui Qiao, Yonghong Wang, Yifan Wen, Ye Wu, Gan Yang, Lei Yao, Rujing Yin, Gen Zhang, Shaojun Zhang, Feixue Zheng, Ying Zhou, Antti Arola, Johanna Tamminen, Pauli Paasonen, Yele Sun, Lin Wang, Neil M. Donahue, Yongchun Liu, Federico Bianchi, Kaspar R. Daellenbach, Douglas R. Worsnop, Veli-Matti Kerminen, Tuukka Petäjä, Aijun Ding, Jingkun Jiang, and Markku Kulmala
Atmos. Chem. Phys., 22, 12207–12220, https://doi.org/10.5194/acp-22-12207-2022, https://doi.org/10.5194/acp-22-12207-2022, 2022
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Atmospheric new particle formation (NPF) is a dominant source of atmospheric ultrafine particles. In urban environments, traffic emissions are a major source of primary pollutants, but their contribution to NPF remains under debate. During the COVID-19 lockdown, traffic emissions were significantly reduced, providing a unique chance to examine their relevance to NPF. Based on our comprehensive measurements, we demonstrate that traffic emissions alone are not able to explain the NPF in Beijing.
Outi Meinander, Pavla Dagsson-Waldhauserova, Pavel Amosov, Elena Aseyeva, Cliff Atkins, Alexander Baklanov, Clarissa Baldo, Sarah L. Barr, Barbara Barzycka, Liane G. Benning, Bojan Cvetkovic, Polina Enchilik, Denis Frolov, Santiago Gassó, Konrad Kandler, Nikolay Kasimov, Jan Kavan, James King, Tatyana Koroleva, Viktoria Krupskaya, Markku Kulmala, Monika Kusiak, Hanna K. Lappalainen, Michał Laska, Jerome Lasne, Marek Lewandowski, Bartłomiej Luks, James B. McQuaid, Beatrice Moroni, Benjamin Murray, Ottmar Möhler, Adam Nawrot, Slobodan Nickovic, Norman T. O’Neill, Goran Pejanovic, Olga Popovicheva, Keyvan Ranjbar, Manolis Romanias, Olga Samonova, Alberto Sanchez-Marroquin, Kerstin Schepanski, Ivan Semenkov, Anna Sharapova, Elena Shevnina, Zongbo Shi, Mikhail Sofiev, Frédéric Thevenet, Throstur Thorsteinsson, Mikhail Timofeev, Nsikanabasi Silas Umo, Andreas Uppstu, Darya Urupina, György Varga, Tomasz Werner, Olafur Arnalds, and Ana Vukovic Vimic
Atmos. Chem. Phys., 22, 11889–11930, https://doi.org/10.5194/acp-22-11889-2022, https://doi.org/10.5194/acp-22-11889-2022, 2022
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High-latitude dust (HLD) is a short-lived climate forcer, air pollutant, and nutrient source. Our results suggest a northern HLD belt at 50–58° N in Eurasia and 50–55° N in Canada and at >60° N in Eurasia and >58° N in Canada. Our addition to the previously identified global dust belt (GDB) provides crucially needed information on the extent of active HLD sources with both direct and indirect impacts on climate and environment in remote regions, which are often poorly understood and predicted.
Stefano Manzoni, Simone Fatichi, Xue Feng, Gabriel G. Katul, Danielle Way, and Giulia Vico
Biogeosciences, 19, 4387–4414, https://doi.org/10.5194/bg-19-4387-2022, https://doi.org/10.5194/bg-19-4387-2022, 2022
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Increasing atmospheric carbon dioxide (CO2) causes leaves to close their stomata (through which water evaporates) but also promotes leaf growth. Even if individual leaves save water, how much will be consumed by a whole plant with possibly more leaves? Using different mathematical models, we show that plant stands that are not very dense and can grow more leaves will benefit from higher CO2 by photosynthesizing more while adjusting their stomata to consume similar amounts of water.
Janne Rinne, Patryk Łakomiec, Patrik Vestin, Joel D. White, Per Weslien, Julia Kelly, Natascha Kljun, Lena Ström, and Leif Klemedtsson
Biogeosciences, 19, 4331–4349, https://doi.org/10.5194/bg-19-4331-2022, https://doi.org/10.5194/bg-19-4331-2022, 2022
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The study uses the stable isotope 13C of carbon in methane to investigate the origins of spatial and temporal variation in methane emitted by a temperate wetland ecosystem. The results indicate that methane production is more important for spatial variation than methane consumption by micro-organisms. Temporal variation on a seasonal timescale is most likely affected by more than one driver simultaneously.
Runlong Cai, Ella Häkkinen, Chao Yan, Jingkun Jiang, Markku Kulmala, and Juha Kangasluoma
Atmos. Chem. Phys., 22, 11529–11541, https://doi.org/10.5194/acp-22-11529-2022, https://doi.org/10.5194/acp-22-11529-2022, 2022
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The influences of new particle formation on the climate and air quality are governed by particle survival, which has been under debate due to uncertainties in the coagulation sink. Here we measure the coagulation coefficient of sub-10 nm particles and demonstrate that collisions between the freshly nucleated and background particles can effectively lead to coagulation. We further show that the effective coagulation sink is consistent with the new particle formation measured in urban Beijing.
Benjamin Foreback, Lubna Dada, Kaspar R. Daellenbach, Chao Yan, Lili Wang, Biwu Chu, Ying Zhou, Tom V. Kokkonen, Mona Kurppa, Rosaria E. Pileci, Yonghong Wang, Tommy Chan, Juha Kangasluoma, Lin Zhuohui, Yishou Guo, Chang Li, Rima Baalbaki, Joni Kujansuu, Xiaolong Fan, Zemin Feng, Pekka Rantala, Shahzad Gani, Federico Bianchi, Veli-Matti Kerminen, Tuukka Petäjä, Markku Kulmala, Yongchun Liu, and Pauli Paasonen
Atmos. Chem. Phys., 22, 11089–11104, https://doi.org/10.5194/acp-22-11089-2022, https://doi.org/10.5194/acp-22-11089-2022, 2022
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This study analyzed air quality in Beijing during the Chinese New Year over 7 years, including data from a new in-depth measurement station. This is one of few studies to look at long-term impacts, including the outcome of firework restrictions starting in 2018. Results show that firework pollution has gone down since 2016, indicating a positive result from the restrictions. Results of this study may be useful in making future decisions about the use of fireworks to improve air quality.
Constance K. Segakweng, Pieter G. van Zyl, Cathy Liousse, Johan P. Beukes, Jan-Stefan Swartz, Eric Gardrat, Maria Dias-Alves, Brigitte Language, Roelof P. Burger, and Stuart J. Piketh
Atmos. Chem. Phys., 22, 10291–10317, https://doi.org/10.5194/acp-22-10291-2022, https://doi.org/10.5194/acp-22-10291-2022, 2022
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A detailed size-resolved assessment of the chemical characteristics of outdoor and indoor aerosols collected in low-income urban settlements in South Africa indicated the significance of household combustion for cooking and space heating – an important source of pollutants in the developing world – to atmospheric chemical composition. The regional impact of industrial sources in the highly industrialised and densely populated north-eastern interior of South Africa was also evident.
Yishuo Guo, Chao Yan, Yuliang Liu, Xiaohui Qiao, Feixue Zheng, Ying Zhang, Ying Zhou, Chang Li, Xiaolong Fan, Zhuohui Lin, Zemin Feng, Yusheng Zhang, Penggang Zheng, Linhui Tian, Wei Nie, Zhe Wang, Dandan Huang, Kaspar R. Daellenbach, Lei Yao, Lubna Dada, Federico Bianchi, Jingkun Jiang, Yongchun Liu, Veli-Matti Kerminen, and Markku Kulmala
Atmos. Chem. Phys., 22, 10077–10097, https://doi.org/10.5194/acp-22-10077-2022, https://doi.org/10.5194/acp-22-10077-2022, 2022
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Gaseous oxygenated organic molecules (OOMs) are able to form atmospheric aerosols, which will impact on human health and climate change. Here, we find that OOMs in urban Beijing are dominated by anthropogenic sources, i.e. aromatic (29 %–41 %) and aliphatic (26 %–41 %) OOMs. They are also the main contributors to the condensational growth of secondary organic aerosols (SOAs). Therefore, the restriction on anthropogenic VOCs is crucial for the reduction of SOAs and haze formation.
Carlton Xavier, Metin Baykara, Robin Wollesen de Jonge, Barbara Altstädter, Petri Clusius, Ville Vakkari, Roseline Thakur, Lisa Beck, Silvia Becagli, Mirko Severi, Rita Traversi, Radovan Krejci, Peter Tunved, Mauro Mazzola, Birgit Wehner, Mikko Sipilä, Markku Kulmala, Michael Boy, and Pontus Roldin
Atmos. Chem. Phys., 22, 10023–10043, https://doi.org/10.5194/acp-22-10023-2022, https://doi.org/10.5194/acp-22-10023-2022, 2022
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The focus of this work is to study and improve our understanding of processes involved in the formation and growth of new particles in a remote Arctic marine environment. We run the 1D model ADCHEM along air mass trajectories arriving at Ny-Ålesund in May 2018. The model finds that ion-mediated H2SO4–NH3 nucleation can explain the observed new particle formation at Ny-Ålesund. The growth of particles is driven via H2SO4 condensation and formation of methane sulfonic acid in the aqueous phase.
Lisa J. Beck, Siegfried Schobesberger, Heikki Junninen, Janne Lampilahti, Antti Manninen, Lubna Dada, Katri Leino, Xu-Cheng He, Iida Pullinen, Lauriane L. J. Quéléver, Anna Franck, Pyry Poutanen, Daniela Wimmer, Frans Korhonen, Mikko Sipilä, Mikael Ehn, Douglas R. Worsnop, Veli-Matti Kerminen, Tuukka Petäjä, Markku Kulmala, and Jonathan Duplissy
Atmos. Chem. Phys., 22, 8547–8577, https://doi.org/10.5194/acp-22-8547-2022, https://doi.org/10.5194/acp-22-8547-2022, 2022
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The presented article introduces an overview of atmospheric ions and their composition above the boreal forest. We provide the results of an extensive airborne measurement campaign with an air ion mass spectrometer and particle measurements, showing their diurnal evolution within the boundary layer and free troposphere. In addition, we compare the airborne dataset with the co-located data from the ground at SMEAR II station, Finland.
Sari Juutinen, Mika Aurela, Juha-Pekka Tuovinen, Viktor Ivakhov, Maiju Linkosalmi, Aleksi Räsänen, Tarmo Virtanen, Juha Mikola, Johanna Nyman, Emmi Vähä, Marina Loskutova, Alexander Makshtas, and Tuomas Laurila
Biogeosciences, 19, 3151–3167, https://doi.org/10.5194/bg-19-3151-2022, https://doi.org/10.5194/bg-19-3151-2022, 2022
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We measured CO2 and CH4 fluxes in heterogenous Arctic tundra in eastern Siberia. We found that tundra wetlands with sedge and grass vegetation contributed disproportionately to the landscape's ecosystem CO2 uptake and CH4 emissions to the atmosphere. Moreover, we observed high CH4 consumption in dry tundra, particularly in barren areas, offsetting part of the CH4 emissions from the wetlands.
Miska Olin, Magdalena Okuljar, Matti P. Rissanen, Joni Kalliokoski, Jiali Shen, Lubna Dada, Markus Lampimäki, Yusheng Wu, Annalea Lohila, Jonathan Duplissy, Mikko Sipilä, Tuukka Petäjä, Markku Kulmala, and Miikka Dal Maso
Atmos. Chem. Phys., 22, 8097–8115, https://doi.org/10.5194/acp-22-8097-2022, https://doi.org/10.5194/acp-22-8097-2022, 2022
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Atmospheric new particle formation is an important source of the total particle number concentration in the atmosphere. Several parameters for predicting new particle formation events have been suggested before, but the results have been inconclusive. This study proposes an another predicting parameter, related to a specific type of highly oxidized organic molecules, especially for similar locations to the measurement site in this study, which was a coastal agricultural site in Finland.
Roseline C. Thakur, Lubna Dada, Lisa J. Beck, Lauriane L. J. Quéléver, Tommy Chan, Marjan Marbouti, Xu-Cheng He, Carlton Xavier, Juha Sulo, Janne Lampilahti, Markus Lampimäki, Yee Jun Tham, Nina Sarnela, Katrianne Lehtipalo, Alf Norkko, Markku Kulmala, Mikko Sipilä, and Tuija Jokinen
Atmos. Chem. Phys., 22, 6365–6391, https://doi.org/10.5194/acp-22-6365-2022, https://doi.org/10.5194/acp-22-6365-2022, 2022
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Every year intense cyanobacterial and macroalgal blooms occur in the Baltic Sea and in the coastal areas surrounding Helsinki, yet no studies have addressed the impact of biogenic emissions from these blooms on gas vapor concentrations, which in turn could influence new particle formation. This is the first study of its kind to address the chemistry driving new particle formation (NPF) during a bloom period in this region, highlighting the role of biogenic sulfuric acid and iodic acid.
Zoé Brasseur, Dimitri Castarède, Erik S. Thomson, Michael P. Adams, Saskia Drossaart van Dusseldorp, Paavo Heikkilä, Kimmo Korhonen, Janne Lampilahti, Mikhail Paramonov, Julia Schneider, Franziska Vogel, Yusheng Wu, Jonathan P. D. Abbatt, Nina S. Atanasova, Dennis H. Bamford, Barbara Bertozzi, Matthew Boyer, David Brus, Martin I. Daily, Romy Fösig, Ellen Gute, Alexander D. Harrison, Paula Hietala, Kristina Höhler, Zamin A. Kanji, Jorma Keskinen, Larissa Lacher, Markus Lampimäki, Janne Levula, Antti Manninen, Jens Nadolny, Maija Peltola, Grace C. E. Porter, Pyry Poutanen, Ulrike Proske, Tobias Schorr, Nsikanabasi Silas Umo, János Stenszky, Annele Virtanen, Dmitri Moisseev, Markku Kulmala, Benjamin J. Murray, Tuukka Petäjä, Ottmar Möhler, and Jonathan Duplissy
Atmos. Chem. Phys., 22, 5117–5145, https://doi.org/10.5194/acp-22-5117-2022, https://doi.org/10.5194/acp-22-5117-2022, 2022
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The present measurement report introduces the ice nucleation campaign organized in Hyytiälä, Finland, in 2018 (HyICE-2018). We provide an overview of the campaign settings, and we describe the measurement infrastructure and operating procedures used. In addition, we use results from ice nucleation instrument inter-comparison to show that the suite of these instruments deployed during the campaign reports consistent results.
Wei Ma, Zemin Feng, Junlei Zhan, Yongchun Liu, Pengfei Liu, Chengtang Liu, Qingxin Ma, Kang Yang, Yafei Wang, Hong He, Markku Kulmala, Yujing Mu, and Junfeng Liu
Atmos. Chem. Phys., 22, 4841–4851, https://doi.org/10.5194/acp-22-4841-2022, https://doi.org/10.5194/acp-22-4841-2022, 2022
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The influence of photochemical loss of volatile organic compounds (VOCS) on O3 formation is investigated using an observation-based model. The sensitivity regime of ozone formation might be misdiagnosed due to the photochemical loss of VOCs in the atmosphere. The contribution of local photochemistry is underestimated regarding O3 pollution when one does not consider the photochemical loss of VOCs.
Joel Kuula, Hilkka Timonen, Jarkko V. Niemi, Hanna E. Manninen, Topi Rönkkö, Tareq Hussein, Pak Lun Fung, Sasu Tarkoma, Mikko Laakso, Erkka Saukko, Aino Ovaska, Markku Kulmala, Ari Karppinen, Lasse Johansson, and Tuukka Petäjä
Atmos. Chem. Phys., 22, 4801–4808, https://doi.org/10.5194/acp-22-4801-2022, https://doi.org/10.5194/acp-22-4801-2022, 2022
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Modern and up-to-date policies and air quality management strategies are instrumental in tackling global air pollution. As the European Union is preparing to revise Ambient Air Quality Directive 2008/50/EC, this paper initiates discussion on selected features of the directive that we believe would benefit from a reassessment. The scientific community has the most recent and deepest understanding of air pollution; thus, its contribution is essential.
Mathew Sebastian, Sobhan Kumar Kompalli, Vasudevan Anil Kumar, Sandhya Jose, S. Suresh Babu, Govindan Pandithurai, Sachchidanand Singh, Rakesh K. Hooda, Vijay K. Soni, Jeffrey R. Pierce, Ville Vakkari, Eija Asmi, Daniel M. Westervelt, Antti-Pekka Hyvärinen, and Vijay P. Kanawade
Atmos. Chem. Phys., 22, 4491–4508, https://doi.org/10.5194/acp-22-4491-2022, https://doi.org/10.5194/acp-22-4491-2022, 2022
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Characteristics of particle number size distributions and new particle formation in six locations in India were analyzed. New particle formation occurred frequently during the pre-monsoon (spring) season and it significantly modulates the shape of the particle number size distributions. The contribution of newly formed particles to cloud condensation nuclei concentrations was ~3 times higher in urban locations than in mountain background locations.
Hanna K. Lappalainen, Tuukka Petäjä, Timo Vihma, Jouni Räisänen, Alexander Baklanov, Sergey Chalov, Igor Esau, Ekaterina Ezhova, Matti Leppäranta, Dmitry Pozdnyakov, Jukka Pumpanen, Meinrat O. Andreae, Mikhail Arshinov, Eija Asmi, Jianhui Bai, Igor Bashmachnikov, Boris Belan, Federico Bianchi, Boris Biskaborn, Michael Boy, Jaana Bäck, Bin Cheng, Natalia Chubarova, Jonathan Duplissy, Egor Dyukarev, Konstantinos Eleftheriadis, Martin Forsius, Martin Heimann, Sirkku Juhola, Vladimir Konovalov, Igor Konovalov, Pavel Konstantinov, Kajar Köster, Elena Lapshina, Anna Lintunen, Alexander Mahura, Risto Makkonen, Svetlana Malkhazova, Ivan Mammarella, Stefano Mammola, Stephany Buenrostro Mazon, Outi Meinander, Eugene Mikhailov, Victoria Miles, Stanislav Myslenkov, Dmitry Orlov, Jean-Daniel Paris, Roberta Pirazzini, Olga Popovicheva, Jouni Pulliainen, Kimmo Rautiainen, Torsten Sachs, Vladimir Shevchenko, Andrey Skorokhod, Andreas Stohl, Elli Suhonen, Erik S. Thomson, Marina Tsidilina, Veli-Pekka Tynkkynen, Petteri Uotila, Aki Virkkula, Nadezhda Voropay, Tobias Wolf, Sayaka Yasunaka, Jiahua Zhang, Yubao Qiu, Aijun Ding, Huadong Guo, Valery Bondur, Nikolay Kasimov, Sergej Zilitinkevich, Veli-Matti Kerminen, and Markku Kulmala
Atmos. Chem. Phys., 22, 4413–4469, https://doi.org/10.5194/acp-22-4413-2022, https://doi.org/10.5194/acp-22-4413-2022, 2022
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We summarize results during the last 5 years in the northern Eurasian region, especially from Russia, and introduce recent observations of the air quality in the urban environments in China. Although the scientific knowledge in these regions has increased, there are still gaps in our understanding of large-scale climate–Earth surface interactions and feedbacks. This arises from limitations in research infrastructures and integrative data analyses, hindering a comprehensive system analysis.
Elodie Salmon, Fabrice Jégou, Bertrand Guenet, Line Jourdain, Chunjing Qiu, Vladislav Bastrikov, Christophe Guimbaud, Dan Zhu, Philippe Ciais, Philippe Peylin, Sébastien Gogo, Fatima Laggoun-Défarge, Mika Aurela, M. Syndonia Bret-Harte, Jiquan Chen, Bogdan H. Chojnicki, Housen Chu, Colin W. Edgar, Eugenie S. Euskirchen, Lawrence B. Flanagan, Krzysztof Fortuniak, David Holl, Janina Klatt, Olaf Kolle, Natalia Kowalska, Lars Kutzbach, Annalea Lohila, Lutz Merbold, Włodzimierz Pawlak, Torsten Sachs, and Klaudia Ziemblińska
Geosci. Model Dev., 15, 2813–2838, https://doi.org/10.5194/gmd-15-2813-2022, https://doi.org/10.5194/gmd-15-2813-2022, 2022
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A methane model that features methane production and transport by plants, the ebullition process and diffusion in soil, oxidation to CO2, and CH4 fluxes to the atmosphere has been embedded in the ORCHIDEE-PEAT land surface model, which includes an explicit representation of northern peatlands. This model, ORCHIDEE-PCH4, was calibrated and evaluated on 14 peatland sites. Results show that the model is sensitive to temperature and substrate availability over the top 75 cm of soil depth.
Lisa J. Beck, Siegfried Schobesberger, Mikko Sipilä, Veli-Matti Kerminen, and Markku Kulmala
Atmos. Meas. Tech., 15, 1957–1965, https://doi.org/10.5194/amt-15-1957-2022, https://doi.org/10.5194/amt-15-1957-2022, 2022
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Sulfuric acid is known to be a main compound in atmospheric new particle formation. Yet, its concentration is very low, which leads to challenges in detecting it. In our study, we derive the sulfuric acid concentration from measurements of ambient ions with a mass spectrometer. Our validation shows that the theoretical approach using the bisulfate ion and its clusters with H2SO4 captures the sulfuric acid concentration very well during daytime.
Jingwei Zhang, Chaofan Lian, Weigang Wang, Maofa Ge, Yitian Guo, Haiyan Ran, Yusheng Zhang, Feixue Zheng, Xiaolong Fan, Chao Yan, Kaspar R. Daellenbach, Yongchun Liu, Markku Kulmala, and Junling An
Atmos. Chem. Phys., 22, 3275–3302, https://doi.org/10.5194/acp-22-3275-2022, https://doi.org/10.5194/acp-22-3275-2022, 2022
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This study added six potential HONO sources to the WRF-Chem model, evaluated their impact on HONO and O3 concentrations, including surface and vertical concentrations. The simulations extend our knowledge on atmospheric HONO sources, especially for nitrate photolysis. The study also explains the HONO difference in O3 formation on clean and hazy days, and reveals key potential HONO sources to O3 enhancements in haze-aggravating processes with a co-occurrence of high PM2.5 and O3 concentrations.
Marjan Marbouti, Sehyun Jang, Silvia Becagli, Gabriel Navarro, Rita Traversi, Kitack Lee, Tuomo Nieminen, Lisa J. Beck, Markku Kulmala, Veli-Matti Kerminen, and Mikko Sipilä
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2022-52, https://doi.org/10.5194/acp-2022-52, 2022
Publication in ACP not foreseen
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This research was done to understand and investigate the roles of Chl-a, PP and sea ice extent in controlling and producing the in-situ measured MSA, SA, HIO3, HOM and aerosol concentrations over the Greenland and Barents Seas. Our results provide strong support to the hypothesis that MSA, SA and small-particle concentrations in the Svalbard area are directly linked to ocean biological activity and sea ice melting during springtime.
Timo Vesala, Kukka-Maaria Kohonen, Linda M. J. Kooijmans, Arnaud P. Praplan, Lenka Foltýnová, Pasi Kolari, Markku Kulmala, Jaana Bäck, David Nelson, Dan Yakir, Mark Zahniser, and Ivan Mammarella
Atmos. Chem. Phys., 22, 2569–2584, https://doi.org/10.5194/acp-22-2569-2022, https://doi.org/10.5194/acp-22-2569-2022, 2022
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Carbonyl sulfide (COS) provides new insights into carbon cycle research. We present an easy-to-use flux parameterization and the longest existing time series of forest–atmosphere COS exchange measurements, which allow us to study both seasonal and interannual variability. We observed only uptake of COS by the forest on an annual basis, with 37 % variability between years. Upscaling the boreal COS uptake using a biosphere model indicates a significant missing COS sink at high latitudes.
Tuija Jokinen, Katrianne Lehtipalo, Roseline Cutting Thakur, Ilona Ylivinkka, Kimmo Neitola, Nina Sarnela, Totti Laitinen, Markku Kulmala, Tuukka Petäjä, and Mikko Sipilä
Atmos. Chem. Phys., 22, 2237–2254, https://doi.org/10.5194/acp-22-2237-2022, https://doi.org/10.5194/acp-22-2237-2022, 2022
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New particle formation is an important source of cloud condensation nuclei; however, long-term measurements of aerosol-forming vapors are close to nonexistent in the Arctic. Here, we report 7 months of CI-APi-TOF measurements of sulfuric acid, iodic acid, methane sulfonic acid and the sum of highly oxygenated organic molecules from the SMEAR I station in the Finnish subarctic. The results help us to understand atmospheric chemical processes and aerosol formation in this rapidly changing area.
Olli Nevalainen, Olli Niemitalo, Istem Fer, Antti Juntunen, Tuomas Mattila, Olli Koskela, Joni Kukkamäki, Layla Höckerstedt, Laura Mäkelä, Pieta Jarva, Laura Heimsch, Henriikka Vekuri, Liisa Kulmala, Åsa Stam, Otto Kuusela, Stephanie Gerin, Toni Viskari, Julius Vira, Jari Hyväluoma, Juha-Pekka Tuovinen, Annalea Lohila, Tuomas Laurila, Jussi Heinonsalo, Tuula Aalto, Iivari Kunttu, and Jari Liski
Geosci. Instrum. Method. Data Syst., 11, 93–109, https://doi.org/10.5194/gi-11-93-2022, https://doi.org/10.5194/gi-11-93-2022, 2022
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Better monitoring of soil carbon sequestration is needed to understand the best carbon farming practices in different soils and climate conditions. We, the Field Observatory Network (FiON), have therefore established a methodology for monitoring and forecasting agricultural carbon sequestration by combining offline and near-real-time field measurements, weather data, satellite imagery, and modeling. To disseminate our work, we built a website called the Field Observatory (fieldobservatory.org).
Pak Lun Fung, Martha A. Zaidan, Jarkko V. Niemi, Erkka Saukko, Hilkka Timonen, Anu Kousa, Joel Kuula, Topi Rönkkö, Ari Karppinen, Sasu Tarkoma, Markku Kulmala, Tuukka Petäjä, and Tareq Hussein
Atmos. Chem. Phys., 22, 1861–1882, https://doi.org/10.5194/acp-22-1861-2022, https://doi.org/10.5194/acp-22-1861-2022, 2022
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We developed an input-adaptive mixed-effects model, which was automatised to select the best combination of input variables, including up to three fixed effect variables and three time indictors as random effect variables. We tested the model to estimate lung-deposited surface area (LDSA), which correlates well with human health. The results show the inclusion of time indicators improved the sensitivity and the accuracy of the model so that it could serve as a network of virtual sensors.
Jing Cai, Cheng Wu, Jiandong Wang, Wei Du, Feixue Zheng, Simo Hakala, Xiaolong Fan, Biwu Chu, Lei Yao, Zemin Feng, Yongchun Liu, Yele Sun, Jun Zheng, Chao Yan, Federico Bianchi, Markku Kulmala, Claudia Mohr, and Kaspar R. Daellenbach
Atmos. Chem. Phys., 22, 1251–1269, https://doi.org/10.5194/acp-22-1251-2022, https://doi.org/10.5194/acp-22-1251-2022, 2022
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This study investigates the connection between organic aerosol (OA) molecular composition and particle absorptive properties in autumn in Beijing. We find that the molecular properties of OA compounds in different episodes influence particle light absorption properties differently: the light absorption enhancement of black carbon and light absorption coefficient of brown carbon were mostly related to more oxygenated OA (low C number and four O atoms) and aromatics/nitro-aromatics, respectively.
Peifeng Su, Jorma Joutsensaari, Lubna Dada, Martha Arbayani Zaidan, Tuomo Nieminen, Xinyang Li, Yusheng Wu, Stefano Decesari, Sasu Tarkoma, Tuukka Petäjä, Markku Kulmala, and Petri Pellikka
Atmos. Chem. Phys., 22, 1293–1309, https://doi.org/10.5194/acp-22-1293-2022, https://doi.org/10.5194/acp-22-1293-2022, 2022
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We regarded the banana shapes in the surface plots as a special kind of object (similar to cats) and applied an instance segmentation technique to automatically identify the new particle formation (NPF) events (especially the strongest ones), in addition to their growth rates, start times, and end times. The automatic method generalized well on datasets collected in different sites, which is useful for long-term data series analysis and obtaining statistical properties of NPF events.
Anna-Maria Virkkala, Susan M. Natali, Brendan M. Rogers, Jennifer D. Watts, Kathleen Savage, Sara June Connon, Marguerite Mauritz, Edward A. G. Schuur, Darcy Peter, Christina Minions, Julia Nojeim, Roisin Commane, Craig A. Emmerton, Mathias Goeckede, Manuel Helbig, David Holl, Hiroki Iwata, Hideki Kobayashi, Pasi Kolari, Efrén López-Blanco, Maija E. Marushchak, Mikhail Mastepanov, Lutz Merbold, Frans-Jan W. Parmentier, Matthias Peichl, Torsten Sachs, Oliver Sonnentag, Masahito Ueyama, Carolina Voigt, Mika Aurela, Julia Boike, Gerardo Celis, Namyi Chae, Torben R. Christensen, M. Syndonia Bret-Harte, Sigrid Dengel, Han Dolman, Colin W. Edgar, Bo Elberling, Eugenie Euskirchen, Achim Grelle, Juha Hatakka, Elyn Humphreys, Järvi Järveoja, Ayumi Kotani, Lars Kutzbach, Tuomas Laurila, Annalea Lohila, Ivan Mammarella, Yojiro Matsuura, Gesa Meyer, Mats B. Nilsson, Steven F. Oberbauer, Sang-Jong Park, Roman Petrov, Anatoly S. Prokushkin, Christopher Schulze, Vincent L. St. Louis, Eeva-Stiina Tuittila, Juha-Pekka Tuovinen, William Quinton, Andrej Varlagin, Donatella Zona, and Viacheslav I. Zyryanov
Earth Syst. Sci. Data, 14, 179–208, https://doi.org/10.5194/essd-14-179-2022, https://doi.org/10.5194/essd-14-179-2022, 2022
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The effects of climate warming on carbon cycling across the Arctic–boreal zone (ABZ) remain poorly understood due to the relatively limited distribution of ABZ flux sites. Fortunately, this flux network is constantly increasing, but new measurements are published in various platforms, making it challenging to understand the ABZ carbon cycle as a whole. Here, we compiled a new database of Arctic–boreal CO2 fluxes to help facilitate large-scale assessments of the ABZ carbon cycle.
Joel Dawson White, Lena Ström, Veiko Lehsten, Janne Rinne, and Dag Ahrén
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-353, https://doi.org/10.5194/bg-2021-353, 2022
Revised manuscript not accepted
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Microbes that produce CH4 play an important role to climate. Microbes which emit CH4 from wetlands is poorly understood. We observed that microbial community was of importance in explaining CH4 emission. We found, that microbes that produce CH4 hold the ability to produce and consume CH4 in multiple ways. This is important in terms of future climate scenarios, where wetlands are expected to shift. Therefore, we expect the community to be highly adaptive to future climate scenarios.
Arto Heitto, Kari Lehtinen, Tuukka Petäjä, Felipe Lopez-Hilfiker, Joel A. Thornton, Markku Kulmala, and Taina Yli-Juuti
Atmos. Chem. Phys., 22, 155–171, https://doi.org/10.5194/acp-22-155-2022, https://doi.org/10.5194/acp-22-155-2022, 2022
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For atmospheric aerosol particles to take part in cloud formation, they need to be at least a few tens of nanometers in diameter. By using a particle condensation model, we investigated how two types of chemical reactions, oligomerization and decomposition, of organic molecules inside the particle may affect the growth of secondary aerosol particles to these sizes. We show that the effect is potentially significant, which highlights the importance of increasing understanding of these processes.
Lukas Fischer, Martin Breitenlechner, Eva Canaval, Wiebke Scholz, Marcus Striednig, Martin Graus, Thomas G. Karl, Tuukka Petäjä, Markku Kulmala, and Armin Hansel
Atmos. Meas. Tech., 14, 8019–8039, https://doi.org/10.5194/amt-14-8019-2021, https://doi.org/10.5194/amt-14-8019-2021, 2021
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Ecosystems emit biogenic volatile organic compounds (BVOCs), which are then oxidized in the atmosphere, contributing to ozone and secondary aerosol formation. While flux measurements of BVOCs are state of the art, flux measurements of the less volatile oxidation products are difficult to achieve due to inlet losses. Here we present first flux measurements, utilizing a novel PTR3 instrument in combination with a specially designed wall-less inlet we put on top of the Hyytiälä tower in Finland.
Jari Walden, Liisa Pirjola, Tuomas Laurila, Juha Hatakka, Heidi Pettersson, Tuomas Walden, Jukka-Pekka Jalkanen, Harri Nordlund, Toivo Truuts, Miika Meretoja, and Kimmo K. Kahma
Atmos. Chem. Phys., 21, 18175–18194, https://doi.org/10.5194/acp-21-18175-2021, https://doi.org/10.5194/acp-21-18175-2021, 2021
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Ship emissions play an important role in the deposition of gaseous compounds and nanoparticles (Ntot), affecting climate, human health (especially in coastal areas), and eutrophication. Micrometeorological methods showed that ship emissions were mainly responsible for the deposition of Ntot, whereas they only accounted for a minor proportion of CO2 deposition. An uncertainty analysis applied to the fluxes and fuel sulfur content results demonstrated the reliability of the results.
Ying Zhou, Simo Hakala, Chao Yan, Yang Gao, Xiaohong Yao, Biwu Chu, Tommy Chan, Juha Kangasluoma, Shahzad Gani, Jenni Kontkanen, Pauli Paasonen, Yongchun Liu, Tuukka Petäjä, Markku Kulmala, and Lubna Dada
Atmos. Chem. Phys., 21, 17885–17906, https://doi.org/10.5194/acp-21-17885-2021, https://doi.org/10.5194/acp-21-17885-2021, 2021
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We characterized the connection between new particle formation (NPF) events in terms of frequency, intensity and growth at a near-highway location in central Beijing and at a background mountain site 80 km away. Due to the substantial contribution of NPF to the global aerosol budget, identifying the conditions that promote the occurrence of regional NPF events could help understand their contribution on a large scale and would improve their implementation in global models.
Mikko Sipilä, Nina Sarnela, Kimmo Neitola, Totti Laitinen, Deniz Kemppainen, Lisa Beck, Ella-Maria Duplissy, Salla Kuittinen, Tuuli Lehmusjärvi, Janne Lampilahti, Veli-Matti Kerminen, Katrianne Lehtipalo, Pasi P. Aalto, Petri Keronen, Erkki Siivola, Pekka A. Rantala, Douglas R. Worsnop, Markku Kulmala, Tuija Jokinen, and Tuukka Petäjä
Atmos. Chem. Phys., 21, 17559–17576, https://doi.org/10.5194/acp-21-17559-2021, https://doi.org/10.5194/acp-21-17559-2021, 2021
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Metallurgical industry in Kola peninsula is a large source of air pollution in the (sub-)Arctic domain. Sulfur dioxide emissions from the ore smelters are transported across large areas. We investigated sulfur dioxide and its transformation to sulfuric acid aerosol particles during winter months in Finnish Lapland, close to Kola industrial areas. We observed intense formation of new aerosol particles despite the low solar radiation intensity, often required for new particle formation elsewhere.
Ditte Taipale, Veli-Matti Kerminen, Mikael Ehn, Markku Kulmala, and Ülo Niinemets
Atmos. Chem. Phys., 21, 17389–17431, https://doi.org/10.5194/acp-21-17389-2021, https://doi.org/10.5194/acp-21-17389-2021, 2021
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Larval feeding and fungal infections of leaves can greatly change the emission of volatile compounds from plants and thereby influence aerosol processes in the air. We developed a model that considers the dynamics of larvae and fungi and the dependency of the emission on the severity of stress. We show that the infections can be highly atmospherically relevant during long periods of time and at times more important to consider than the parameters that are currently used in emission models.
Clémence Rose, Martine Collaud Coen, Elisabeth Andrews, Yong Lin, Isaline Bossert, Cathrine Lund Myhre, Thomas Tuch, Alfred Wiedensohler, Markus Fiebig, Pasi Aalto, Andrés Alastuey, Elisabeth Alonso-Blanco, Marcos Andrade, Begoña Artíñano, Todor Arsov, Urs Baltensperger, Susanne Bastian, Olaf Bath, Johan Paul Beukes, Benjamin T. Brem, Nicolas Bukowiecki, Juan Andrés Casquero-Vera, Sébastien Conil, Konstantinos Eleftheriadis, Olivier Favez, Harald Flentje, Maria I. Gini, Francisco Javier Gómez-Moreno, Martin Gysel-Beer, Anna Gannet Hallar, Ivo Kalapov, Nikos Kalivitis, Anne Kasper-Giebl, Melita Keywood, Jeong Eun Kim, Sang-Woo Kim, Adam Kristensson, Markku Kulmala, Heikki Lihavainen, Neng-Huei Lin, Hassan Lyamani, Angela Marinoni, Sebastiao Martins Dos Santos, Olga L. Mayol-Bracero, Frank Meinhardt, Maik Merkel, Jean-Marc Metzger, Nikolaos Mihalopoulos, Jakub Ondracek, Marco Pandolfi, Noemi Pérez, Tuukka Petäjä, Jean-Eudes Petit, David Picard, Jean-Marc Pichon, Veronique Pont, Jean-Philippe Putaud, Fabienne Reisen, Karine Sellegri, Sangeeta Sharma, Gerhard Schauer, Patrick Sheridan, James Patrick Sherman, Andreas Schwerin, Ralf Sohmer, Mar Sorribas, Junying Sun, Pierre Tulet, Ville Vakkari, Pieter Gideon van Zyl, Fernando Velarde, Paolo Villani, Stergios Vratolis, Zdenek Wagner, Sheng-Hsiang Wang, Kay Weinhold, Rolf Weller, Margarita Yela, Vladimir Zdimal, and Paolo Laj
Atmos. Chem. Phys., 21, 17185–17223, https://doi.org/10.5194/acp-21-17185-2021, https://doi.org/10.5194/acp-21-17185-2021, 2021
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Aerosol particles are a complex component of the atmospheric system the effects of which are among the most uncertain in climate change projections. Using data collected at 62 stations, this study provides the most up-to-date picture of the spatial distribution of particle number concentration and size distribution worldwide, with the aim of contributing to better representation of aerosols and their interactions with clouds in models and, therefore, better evaluation of their impact on climate.
Lucía Caudillo, Birte Rörup, Martin Heinritzi, Guillaume Marie, Mario Simon, Andrea C. Wagner, Tatjana Müller, Manuel Granzin, Antonio Amorim, Farnoush Ataei, Rima Baalbaki, Barbara Bertozzi, Zoé Brasseur, Randall Chiu, Biwu Chu, Lubna Dada, Jonathan Duplissy, Henning Finkenzeller, Loïc Gonzalez Carracedo, Xu-Cheng He, Victoria Hofbauer, Weimeng Kong, Houssni Lamkaddam, Chuan P. Lee, Brandon Lopez, Naser G. A. Mahfouz, Vladimir Makhmutov, Hanna E. Manninen, Ruby Marten, Dario Massabò, Roy L. Mauldin, Bernhard Mentler, Ugo Molteni, Antti Onnela, Joschka Pfeifer, Maxim Philippov, Ana A. Piedehierro, Meredith Schervish, Wiebke Scholz, Benjamin Schulze, Jiali Shen, Dominik Stolzenburg, Yuri Stozhkov, Mihnea Surdu, Christian Tauber, Yee Jun Tham, Ping Tian, António Tomé, Steffen Vogt, Mingyi Wang, Dongyu S. Wang, Stefan K. Weber, André Welti, Wang Yonghong, Wu Yusheng, Marcel Zauner-Wieczorek, Urs Baltensperger, Imad El Haddad, Richard C. Flagan, Armin Hansel, Kristina Höhler, Jasper Kirkby, Markku Kulmala, Katrianne Lehtipalo, Ottmar Möhler, Harald Saathoff, Rainer Volkamer, Paul M. Winkler, Neil M. Donahue, Andreas Kürten, and Joachim Curtius
Atmos. Chem. Phys., 21, 17099–17114, https://doi.org/10.5194/acp-21-17099-2021, https://doi.org/10.5194/acp-21-17099-2021, 2021
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We performed experiments in the CLOUD chamber at CERN at low temperatures to simulate new particle formation in the upper free troposphere (at −30 ºC and −50 ºC). We measured the particle and gas phase and found that most of the compounds present in the gas phase are detected as well in the particle phase. The major compounds in the particles are C8–10 and C18–20. Specifically, we showed that C5 and C15 compounds are detected in a mixed system with isoprene and α-pinene at −30 ºC, 20 % RH.
Anna Franck, Dmitri Moisseev, Ville Vakkari, Matti Leskinen, Janne Lampilahti, Veli-Matti Kerminen, and Ewan O'Connor
Atmos. Meas. Tech., 14, 7341–7353, https://doi.org/10.5194/amt-14-7341-2021, https://doi.org/10.5194/amt-14-7341-2021, 2021
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We proposed a method to derive a convective boundary layer height, using insects in radar observations, and we investigated the consistency of these retrievals among different radar frequencies (5, 35 and 94 GHz). This method can be applied to radars at other measurement stations and serve as additional way to estimate the boundary layer height during summer. The entrainment zone was also observed by the 5 GHz radar above the boundary layer in the form of a Bragg scatter layer.
Martti Honkanen, Jens Daniel Müller, Jukka Seppälä, Gregor Rehder, Sami Kielosto, Pasi Ylöstalo, Timo Mäkelä, Juha Hatakka, and Lauri Laakso
Ocean Sci., 17, 1657–1675, https://doi.org/10.5194/os-17-1657-2021, https://doi.org/10.5194/os-17-1657-2021, 2021
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The exchange of carbon dioxide (CO2) between the sea and the atmosphere is regulated by the gradient of CO2 partial pressure (pCO2) between the sea and the air. The daily variation of the seawater pCO2 recorded at the fixed station Utö in the Baltic Sea was found to be mainly biologically driven. Calculation of the annual net exchange of CO2 between the sea and atmosphere based on daily measurements of pCO2 carried out using the same sampling time every day could introduce a bias of up to 12 %.
Patryk Łakomiec, Jutta Holst, Thomas Friborg, Patrick Crill, Niklas Rakos, Natascha Kljun, Per-Ola Olsson, Lars Eklundh, Andreas Persson, and Janne Rinne
Biogeosciences, 18, 5811–5830, https://doi.org/10.5194/bg-18-5811-2021, https://doi.org/10.5194/bg-18-5811-2021, 2021
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Methane emission from the subarctic mire with heterogeneous permafrost status was measured for the years 2014–2016. Lower methane emission was measured from the palsa mire sector while the thawing wet sector emitted more. Both sectors have a similar annual pattern with a gentle rise during spring and a decrease during autumn. The highest emission was observed in the late summer. Winter emissions were positive during the measurement period and have a significant impact on the annual budgets.
Krista Luoma, Aki Virkkula, Pasi Aalto, Katrianne Lehtipalo, Tuukka Petäjä, and Markku Kulmala
Atmos. Meas. Tech., 14, 6419–6441, https://doi.org/10.5194/amt-14-6419-2021, https://doi.org/10.5194/amt-14-6419-2021, 2021
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The study presents a comparison of three absorption photometers that measured ambient aerosol particles at a boreal forest site. The study aims to better understand problems related to filter-based measurements. Results show how different correction algorithms, which are used to produce the data, affect the derived optical properties of aerosol particles.
Yang Liu, Simon Schallhart, Ditte Taipale, Toni Tykkä, Matti Räsänen, Lutz Merbold, Heidi Hellén, and Petri Pellikka
Atmos. Chem. Phys., 21, 14761–14787, https://doi.org/10.5194/acp-21-14761-2021, https://doi.org/10.5194/acp-21-14761-2021, 2021
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We studied the mixing ratio of biogenic volatile organic compounds (BVOCs) in a humid highland and dry lowland African ecosystem in Kenya. The mixing ratio of monoterpenoids was similar to that measured in the relevant ecosystems in western and southern Africa, while that of isoprene was lower. Modeling the emission factors (EFs) for BVOCs from the lowlands, the EFs for isoprene and β-pinene agreed well with what is assumed in the MEGAN, while those of α-pinene and limonene were higher.
Philipp G. Eger, Luc Vereecken, Rolf Sander, Jan Schuladen, Nicolas Sobanski, Horst Fischer, Einar Karu, Jonathan Williams, Ville Vakkari, Tuukka Petäjä, Jos Lelieveld, Andrea Pozzer, and John N. Crowley
Atmos. Chem. Phys., 21, 14333–14349, https://doi.org/10.5194/acp-21-14333-2021, https://doi.org/10.5194/acp-21-14333-2021, 2021
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We determine the impact of pyruvic acid photolysis on the formation of acetaldehyde and peroxy radicals during summer and autumn in the Finnish boreal forest using a data-constrained box model. Our results are dependent on the chosen scenario in which the overall quantum yield and the photolysis products are varied. We highlight that pyruvic acid photolysis can be an important contributor to acetaldehyde and peroxy radical formation in remote, forested regions.
Mao Xiao, Christopher R. Hoyle, Lubna Dada, Dominik Stolzenburg, Andreas Kürten, Mingyi Wang, Houssni Lamkaddam, Olga Garmash, Bernhard Mentler, Ugo Molteni, Andrea Baccarini, Mario Simon, Xu-Cheng He, Katrianne Lehtipalo, Lauri R. Ahonen, Rima Baalbaki, Paulus S. Bauer, Lisa Beck, David Bell, Federico Bianchi, Sophia Brilke, Dexian Chen, Randall Chiu, António Dias, Jonathan Duplissy, Henning Finkenzeller, Hamish Gordon, Victoria Hofbauer, Changhyuk Kim, Theodore K. Koenig, Janne Lampilahti, Chuan Ping Lee, Zijun Li, Huajun Mai, Vladimir Makhmutov, Hanna E. Manninen, Ruby Marten, Serge Mathot, Roy L. Mauldin, Wei Nie, Antti Onnela, Eva Partoll, Tuukka Petäjä, Joschka Pfeifer, Veronika Pospisilova, Lauriane L. J. Quéléver, Matti Rissanen, Siegfried Schobesberger, Simone Schuchmann, Yuri Stozhkov, Christian Tauber, Yee Jun Tham, António Tomé, Miguel Vazquez-Pufleau, Andrea C. Wagner, Robert Wagner, Yonghong Wang, Lena Weitz, Daniela Wimmer, Yusheng Wu, Chao Yan, Penglin Ye, Qing Ye, Qiaozhi Zha, Xueqin Zhou, Antonio Amorim, Ken Carslaw, Joachim Curtius, Armin Hansel, Rainer Volkamer, Paul M. Winkler, Richard C. Flagan, Markku Kulmala, Douglas R. Worsnop, Jasper Kirkby, Neil M. Donahue, Urs Baltensperger, Imad El Haddad, and Josef Dommen
Atmos. Chem. Phys., 21, 14275–14291, https://doi.org/10.5194/acp-21-14275-2021, https://doi.org/10.5194/acp-21-14275-2021, 2021
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Experiments at CLOUD show that in polluted environments new particle formation (NPF) is largely driven by the formation of sulfuric acid–base clusters, stabilized by amines, high ammonia concentrations or lower temperatures. While oxidation products of aromatics can nucleate, they play a minor role in urban NPF. Our experiments span 4 orders of magnitude variation of observed NPF rates in ambient conditions. We provide a framework based on NPF and growth rates to interpret ambient observations.
Christoffer Hallgren, Stefan Ivanell, Heiner Körnich, Ville Vakkari, and Erik Sahlée
Wind Energ. Sci., 6, 1205–1226, https://doi.org/10.5194/wes-6-1205-2021, https://doi.org/10.5194/wes-6-1205-2021, 2021
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As wind power becomes more popular, there is a growing demand for accurate power production forecasts. In this paper we investigated different methods to improve wind power forecasts for an offshore location in the Baltic Sea, using both simple and more advanced techniques. The performance of the methods is evaluated for different weather conditions. Smoothing the forecast was found to be the best method in general, but we recommend selecting which method to use based on the forecasted weather.
Yongchun Liu, Zemin Feng, Feixue Zheng, Xiaolei Bao, Pengfei Liu, Yanli Ge, Yan Zhao, Tao Jiang, Yunwen Liao, Yusheng Zhang, Xiaolong Fan, Chao Yan, Biwu Chu, Yonghong Wang, Wei Du, Jing Cai, Federico Bianchi, Tuukka Petäjä, Yujing Mu, Hong He, and Markku Kulmala
Atmos. Chem. Phys., 21, 13269–13286, https://doi.org/10.5194/acp-21-13269-2021, https://doi.org/10.5194/acp-21-13269-2021, 2021
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The mechanisms and kinetics of particulate sulfate formation in the atmosphere are still open questions although they have been extensively discussed. We found that uptake of SO2 is the rate-determining step for the conversion of SO2 to particulate sulfate. NH4NO3 plays an important role in AWC, the phase state of aerosol particles, and subsequently the uptake kinetics of SO2 under high-RH conditions. This work is a good example of the feedback between aerosol physics and aerosol chemistry.
Helmi Uusitalo, Jenni Kontkanen, Ilona Ylivinkka, Ekaterina Ezhova, Anastasiia Demakova, Mikhail Arshinov, Boris Denisovich Belan, Denis Davydov, Nan Ma, Tuukka Petäjä, Alfred Wiedensohler, Markku Kulmala, and Tuomo Nieminen
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2021-530, https://doi.org/10.5194/acp-2021-530, 2021
Publication in ACP not foreseen
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Characteristics of formation of atmospheric aerosol at four boreal forest sites in Finland and Russian Siberia was analyzed. Our results provide information on the governing processes of atmospheric aerosol formation in the boreal forest area, which a substantial part of the continental biosphere. Aerosol formation was occurring less frequently at Siberian than in Finnish sites, which was affected by the lower particle growth rates and higher loss rates in Siberia.
Nahid Atashi, Dariush Rahimi, Victoria A. Sinclair, Martha A. Zaidan, Anton Rusanen, Henri Vuollekoski, Markku Kulmala, Timo Vesala, and Tareq Hussein
Hydrol. Earth Syst. Sci., 25, 4719–4740, https://doi.org/10.5194/hess-25-4719-2021, https://doi.org/10.5194/hess-25-4719-2021, 2021
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Dew formation potential during a long-term period (1979–2018) was assessed in Iran to identify dew formation zones and to investigate the impacts of long-term variation in meteorological parameters on dew formation. Six dew formation zones were identified based on cluster analysis of the time series of the simulated dew yield. The distribution of dew formation zones in Iran was closely aligned with topography and sources of moisture. The dew formation trend was significantly negative.
Janne Lampilahti, Hanna E. Manninen, Tuomo Nieminen, Sander Mirme, Mikael Ehn, Iida Pullinen, Katri Leino, Siegfried Schobesberger, Juha Kangasluoma, Jenni Kontkanen, Emma Järvinen, Riikka Väänänen, Taina Yli-Juuti, Radovan Krejci, Katrianne Lehtipalo, Janne Levula, Aadu Mirme, Stefano Decesari, Ralf Tillmann, Douglas R. Worsnop, Franz Rohrer, Astrid Kiendler-Scharr, Tuukka Petäjä, Veli-Matti Kerminen, Thomas F. Mentel, and Markku Kulmala
Atmos. Chem. Phys., 21, 12649–12663, https://doi.org/10.5194/acp-21-12649-2021, https://doi.org/10.5194/acp-21-12649-2021, 2021
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We studied aerosol particle formation and growth in different parts of the planetary boundary layer at two different locations (Po Valley, Italy, and Hyytiälä, Finland). The observations consist of airborne measurements on board an instrumented Zeppelin and a small airplane combined with comprehensive ground-based measurements.
Zhuohui Lin, Yonghong Wang, Feixue Zheng, Ying Zhou, Yishuo Guo, Zemin Feng, Chang Li, Yusheng Zhang, Simo Hakala, Tommy Chan, Chao Yan, Kaspar R. Daellenbach, Biwu Chu, Lubna Dada, Juha Kangasluoma, Lei Yao, Xiaolong Fan, Wei Du, Jing Cai, Runlong Cai, Tom V. Kokkonen, Putian Zhou, Lili Wang, Tuukka Petäjä, Federico Bianchi, Veli-Matti Kerminen, Yongchun Liu, and Markku Kulmala
Atmos. Chem. Phys., 21, 12173–12187, https://doi.org/10.5194/acp-21-12173-2021, https://doi.org/10.5194/acp-21-12173-2021, 2021
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We find that ammonium nitrate and aerosol water content contributed most during low mixing layer height conditions; this may further trigger enhanced formation of sulfate and organic aerosol via heterogeneous reactions. The results of this study contribute towards a more detailed understanding of the aerosol–chemistry–radiation–boundary layer feedback that is likely to be responsible for explosive aerosol mass growth events in urban Beijing.
Kyle B. Delwiche, Sara Helen Knox, Avni Malhotra, Etienne Fluet-Chouinard, Gavin McNicol, Sarah Feron, Zutao Ouyang, Dario Papale, Carlo Trotta, Eleonora Canfora, You-Wei Cheah, Danielle Christianson, Ma. Carmelita R. Alberto, Pavel Alekseychik, Mika Aurela, Dennis Baldocchi, Sheel Bansal, David P. Billesbach, Gil Bohrer, Rosvel Bracho, Nina Buchmann, David I. Campbell, Gerardo Celis, Jiquan Chen, Weinan Chen, Housen Chu, Higo J. Dalmagro, Sigrid Dengel, Ankur R. Desai, Matteo Detto, Han Dolman, Elke Eichelmann, Eugenie Euskirchen, Daniela Famulari, Kathrin Fuchs, Mathias Goeckede, Sébastien Gogo, Mangaliso J. Gondwe, Jordan P. Goodrich, Pia Gottschalk, Scott L. Graham, Martin Heimann, Manuel Helbig, Carole Helfter, Kyle S. Hemes, Takashi Hirano, David Hollinger, Lukas Hörtnagl, Hiroki Iwata, Adrien Jacotot, Gerald Jurasinski, Minseok Kang, Kuno Kasak, John King, Janina Klatt, Franziska Koebsch, Ken W. Krauss, Derrick Y. F. Lai, Annalea Lohila, Ivan Mammarella, Luca Belelli Marchesini, Giovanni Manca, Jaclyn Hatala Matthes, Trofim Maximov, Lutz Merbold, Bhaskar Mitra, Timothy H. Morin, Eiko Nemitz, Mats B. Nilsson, Shuli Niu, Walter C. Oechel, Patricia Y. Oikawa, Keisuke Ono, Matthias Peichl, Olli Peltola, Michele L. Reba, Andrew D. Richardson, William Riley, Benjamin R. K. Runkle, Youngryel Ryu, Torsten Sachs, Ayaka Sakabe, Camilo Rey Sanchez, Edward A. Schuur, Karina V. R. Schäfer, Oliver Sonnentag, Jed P. Sparks, Ellen Stuart-Haëntjens, Cove Sturtevant, Ryan C. Sullivan, Daphne J. Szutu, Jonathan E. Thom, Margaret S. Torn, Eeva-Stiina Tuittila, Jessica Turner, Masahito Ueyama, Alex C. Valach, Rodrigo Vargas, Andrej Varlagin, Alma Vazquez-Lule, Joseph G. Verfaillie, Timo Vesala, George L. Vourlitis, Eric J. Ward, Christian Wille, Georg Wohlfahrt, Guan Xhuan Wong, Zhen Zhang, Donatella Zona, Lisamarie Windham-Myers, Benjamin Poulter, and Robert B. Jackson
Earth Syst. Sci. Data, 13, 3607–3689, https://doi.org/10.5194/essd-13-3607-2021, https://doi.org/10.5194/essd-13-3607-2021, 2021
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Methane is an important greenhouse gas, yet we lack knowledge about its global emissions and drivers. We present FLUXNET-CH4, a new global collection of methane measurements and a critical resource for the research community. We use FLUXNET-CH4 data to quantify the seasonality of methane emissions from freshwater wetlands, finding that methane seasonality varies strongly with latitude. Our new database and analysis will improve wetland model accuracy and inform greenhouse gas budgets.
Xiaolong Fan, Jing Cai, Chao Yan, Jian Zhao, Yishuo Guo, Chang Li, Kaspar R. Dällenbach, Feixue Zheng, Zhuohui Lin, Biwu Chu, Yonghong Wang, Lubna Dada, Qiaozhi Zha, Wei Du, Jenni Kontkanen, Theo Kurtén, Siddhart Iyer, Joni T. Kujansuu, Tuukka Petäjä, Douglas R. Worsnop, Veli-Matti Kerminen, Yongchun Liu, Federico Bianchi, Yee Jun Tham, Lei Yao, and Markku Kulmala
Atmos. Chem. Phys., 21, 11437–11452, https://doi.org/10.5194/acp-21-11437-2021, https://doi.org/10.5194/acp-21-11437-2021, 2021
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We observed significant concentrations of gaseous HBr and HCl throughout the winter and springtime in urban Beijing, China. Our results indicate that gaseous HCl and HBr are most likely originated from anthropogenic emissions such as burning activities, and the gas–aerosol partitioning may play a crucial role in contributing to the gaseous HCl and HBr. These observations suggest that there is an important recycling pathway of halogen species in inland megacities.
Haijie Tong, Fobang Liu, Alexander Filippi, Jake Wilson, Andrea M. Arangio, Yun Zhang, Siyao Yue, Steven Lelieveld, Fangxia Shen, Helmi-Marja K. Keskinen, Jing Li, Haoxuan Chen, Ting Zhang, Thorsten Hoffmann, Pingqing Fu, William H. Brune, Tuukka Petäjä, Markku Kulmala, Maosheng Yao, Thomas Berkemeier, Manabu Shiraiwa, and Ulrich Pöschl
Atmos. Chem. Phys., 21, 10439–10455, https://doi.org/10.5194/acp-21-10439-2021, https://doi.org/10.5194/acp-21-10439-2021, 2021
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We measured radical yields of aqueous PM2.5 extracts and found lower yields at higher concentrations of PM2.5. Abundances of water-soluble transition metals and aromatics in PM2.5 were positively correlated with the relative fraction of •OH but negatively correlated with the relative fraction of C-centered radicals among detected radicals. Composition-dependent reactive species yields may explain differences in the reactivity and health effects of PM2.5 in clean versus polluted air.
Liine Heikkinen, Mikko Äijälä, Kaspar R. Daellenbach, Gang Chen, Olga Garmash, Diego Aliaga, Frans Graeffe, Meri Räty, Krista Luoma, Pasi Aalto, Markku Kulmala, Tuukka Petäjä, Douglas Worsnop, and Mikael Ehn
Atmos. Chem. Phys., 21, 10081–10109, https://doi.org/10.5194/acp-21-10081-2021, https://doi.org/10.5194/acp-21-10081-2021, 2021
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In many locations worldwide aerosol particles have been shown to be made up of organic aerosol (OA). The boreal forest is a region where aerosol particles possess a high OA mass fraction. Here, we studied OA composition using the longest time series of OA composition ever obtained from a boreal environment. For this purpose, we tested a new analysis framework and discovered that most of the OA was highly oxidized, with strong seasonal behaviour reflecting different sources in summer and winter.
Rima Baalbaki, Michael Pikridas, Tuija Jokinen, Tiia Laurila, Lubna Dada, Spyros Bezantakos, Lauri Ahonen, Kimmo Neitola, Anne Maisser, Elie Bimenyimana, Aliki Christodoulou, Florin Unga, Chrysanthos Savvides, Katrianne Lehtipalo, Juha Kangasluoma, George Biskos, Tuukka Petäjä, Veli-Matti Kerminen, Jean Sciare, and Markku Kulmala
Atmos. Chem. Phys., 21, 9223–9251, https://doi.org/10.5194/acp-21-9223-2021, https://doi.org/10.5194/acp-21-9223-2021, 2021
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This study investigates new particle formation (NPF) in the less represented region of the Mediterranean basin using 1-year measurements of aerosol particles down to ~ 1 nm in diameter. We report a high frequency of NPF and give examples of interesting NPF features. We quantify the strength of NPF events by calculating formation rates and growth rates. We further unveil the atmospheric conditions and variables considered important for the intra-monthly and inter-monthly occurrence of NPF.
Rafael Poyatos, Víctor Granda, Víctor Flo, Mark A. Adams, Balázs Adorján, David Aguadé, Marcos P. M. Aidar, Scott Allen, M. Susana Alvarado-Barrientos, Kristina J. Anderson-Teixeira, Luiza Maria Aparecido, M. Altaf Arain, Ismael Aranda, Heidi Asbjornsen, Robert Baxter, Eric Beamesderfer, Z. Carter Berry, Daniel Berveiller, Bethany Blakely, Johnny Boggs, Gil Bohrer, Paul V. Bolstad, Damien Bonal, Rosvel Bracho, Patricia Brito, Jason Brodeur, Fernando Casanoves, Jérôme Chave, Hui Chen, Cesar Cisneros, Kenneth Clark, Edoardo Cremonese, Hongzhong Dang, Jorge S. David, Teresa S. David, Nicolas Delpierre, Ankur R. Desai, Frederic C. Do, Michal Dohnal, Jean-Christophe Domec, Sebinasi Dzikiti, Colin Edgar, Rebekka Eichstaedt, Tarek S. El-Madany, Jan Elbers, Cleiton B. Eller, Eugénie S. Euskirchen, Brent Ewers, Patrick Fonti, Alicia Forner, David I. Forrester, Helber C. Freitas, Marta Galvagno, Omar Garcia-Tejera, Chandra Prasad Ghimire, Teresa E. Gimeno, John Grace, André Granier, Anne Griebel, Yan Guangyu, Mark B. Gush, Paul J. Hanson, Niles J. Hasselquist, Ingo Heinrich, Virginia Hernandez-Santana, Valentine Herrmann, Teemu Hölttä, Friso Holwerda, James Irvine, Supat Isarangkool Na Ayutthaya, Paul G. Jarvis, Hubert Jochheim, Carlos A. Joly, Julia Kaplick, Hyun Seok Kim, Leif Klemedtsson, Heather Kropp, Fredrik Lagergren, Patrick Lane, Petra Lang, Andrei Lapenas, Víctor Lechuga, Minsu Lee, Christoph Leuschner, Jean-Marc Limousin, Juan Carlos Linares, Maj-Lena Linderson, Anders Lindroth, Pilar Llorens, Álvaro López-Bernal, Michael M. Loranty, Dietmar Lüttschwager, Cate Macinnis-Ng, Isabelle Maréchaux, Timothy A. Martin, Ashley Matheny, Nate McDowell, Sean McMahon, Patrick Meir, Ilona Mészáros, Mirco Migliavacca, Patrick Mitchell, Meelis Mölder, Leonardo Montagnani, Georgianne W. Moore, Ryogo Nakada, Furong Niu, Rachael H. Nolan, Richard Norby, Kimberly Novick, Walter Oberhuber, Nikolaus Obojes, A. Christopher Oishi, Rafael S. Oliveira, Ram Oren, Jean-Marc Ourcival, Teemu Paljakka, Oscar Perez-Priego, Pablo L. Peri, Richard L. Peters, Sebastian Pfautsch, William T. Pockman, Yakir Preisler, Katherine Rascher, George Robinson, Humberto Rocha, Alain Rocheteau, Alexander Röll, Bruno H. P. Rosado, Lucy Rowland, Alexey V. Rubtsov, Santiago Sabaté, Yann Salmon, Roberto L. Salomón, Elisenda Sánchez-Costa, Karina V. R. Schäfer, Bernhard Schuldt, Alexandr Shashkin, Clément Stahl, Marko Stojanović, Juan Carlos Suárez, Ge Sun, Justyna Szatniewska, Fyodor Tatarinov, Miroslav Tesař, Frank M. Thomas, Pantana Tor-ngern, Josef Urban, Fernando Valladares, Christiaan van der Tol, Ilja van Meerveld, Andrej Varlagin, Holm Voigt, Jeffrey Warren, Christiane Werner, Willy Werner, Gerhard Wieser, Lisa Wingate, Stan Wullschleger, Koong Yi, Roman Zweifel, Kathy Steppe, Maurizio Mencuccini, and Jordi Martínez-Vilalta
Earth Syst. Sci. Data, 13, 2607–2649, https://doi.org/10.5194/essd-13-2607-2021, https://doi.org/10.5194/essd-13-2607-2021, 2021
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Transpiration is a key component of global water balance, but it is poorly constrained from available observations. We present SAPFLUXNET, the first global database of tree-level transpiration from sap flow measurements, containing 202 datasets and covering a wide range of ecological conditions. SAPFLUXNET and its accompanying R software package
sapfluxnetrwill facilitate new data syntheses on the ecological factors driving water use and drought responses of trees and forests.
Wei Huang, Haiyan Li, Nina Sarnela, Liine Heikkinen, Yee Jun Tham, Jyri Mikkilä, Steven J. Thomas, Neil M. Donahue, Markku Kulmala, and Federico Bianchi
Atmos. Chem. Phys., 21, 8961–8977, https://doi.org/10.5194/acp-21-8961-2021, https://doi.org/10.5194/acp-21-8961-2021, 2021
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We show full characterization of gaseous organic compounds in a boreal forest. Molecular composition and volatility of gaseous organic compounds with different oxidation extents (from volatile organic compounds to highly oxygenated organic molecules) were investigated and discussed. We provide a more comprehensive understanding of atmospheric organic compounds in this boreal forest and new insights into interpreting ambient measurements or testing and improving parameterizations in models.
Laura Heimsch, Annalea Lohila, Juha-Pekka Tuovinen, Henriikka Vekuri, Jussi Heinonsalo, Olli Nevalainen, Mika Korkiakoski, Jari Liski, Tuomas Laurila, and Liisa Kulmala
Biogeosciences, 18, 3467–3483, https://doi.org/10.5194/bg-18-3467-2021, https://doi.org/10.5194/bg-18-3467-2021, 2021
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CO2 and H2O fluxes were measured at a newly established eddy covariance site in southern Finland for 2 years from 2018 to 2020. This agricultural grassland site focuses on the conversion from intensive towards more sustainable agricultural management. The first summer experienced prolonged dry periods, and notably larger fluxes were observed in the second summer. The field acted as a net carbon sink during both study years.
Mingyi Wang, Xu-Cheng He, Henning Finkenzeller, Siddharth Iyer, Dexian Chen, Jiali Shen, Mario Simon, Victoria Hofbauer, Jasper Kirkby, Joachim Curtius, Norbert Maier, Theo Kurtén, Douglas R. Worsnop, Markku Kulmala, Matti Rissanen, Rainer Volkamer, Yee Jun Tham, Neil M. Donahue, and Mikko Sipilä
Atmos. Meas. Tech., 14, 4187–4202, https://doi.org/10.5194/amt-14-4187-2021, https://doi.org/10.5194/amt-14-4187-2021, 2021
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Atmospheric iodine species are often short-lived with low abundance and have thus been challenging to measure. We show that the bromide chemical ionization mass spectrometry, compatible with both the atmospheric pressure and reduced pressure interfaces, can simultaneously detect various gas-phase iodine species. Combining calibration experiments and quantum chemical calculations, we quantify detection sensitivities to HOI, HIO3, I2, and H2SO4, giving detection limits down to < 106 molec. cm-3.
Markku Kulmala, Tom V. Kokkonen, Juha Pekkanen, Sami Paatero, Tuukka Petäjä, Veli-Matti Kerminen, and Aijun Ding
Atmos. Chem. Phys., 21, 8313–8322, https://doi.org/10.5194/acp-21-8313-2021, https://doi.org/10.5194/acp-21-8313-2021, 2021
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The eastern part of China as a whole is practically a gigacity with 650 million inhabitants. The gigacity, with its emissions, processes in the pollution cocktail and numerous feedbacks and interactions, has a crucial and big impact on regional air quality and on global climate. A large-scale research and innovation program is needed to meet the interlinked grand challenges in this gigacity and to serve as a platform for finding pathways for sustainable development of the globe.
Janne Lampilahti, Katri Leino, Antti Manninen, Pyry Poutanen, Anna Franck, Maija Peltola, Paula Hietala, Lisa Beck, Lubna Dada, Lauriane Quéléver, Ronja Öhrnberg, Ying Zhou, Madeleine Ekblom, Ville Vakkari, Sergej Zilitinkevich, Veli-Matti Kerminen, Tuukka Petäjä, and Markku Kulmala
Atmos. Chem. Phys., 21, 7901–7915, https://doi.org/10.5194/acp-21-7901-2021, https://doi.org/10.5194/acp-21-7901-2021, 2021
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Using airborne measurements we observed increased number concentrations of sub-25 nm particles in the upper residual layer. These particles may be entrained into the well-mixed boundary layer and observed at the surface. We attribute our observations to new particle formation in the topmost part of the residual layer.
Pavel Alekseychik, Gabriel Katul, Ilkka Korpela, and Samuli Launiainen
Atmos. Meas. Tech., 14, 3501–3521, https://doi.org/10.5194/amt-14-3501-2021, https://doi.org/10.5194/amt-14-3501-2021, 2021
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Drones with thermal cameras are powerful new tools with the potential to provide new insights into atmospheric turbulence and heat fluxes. In a pioneering experiment, a Matrice 210 drone with a Zenmuse XT2 thermal camera was used to record 10–20 min thermal videos at 500 m a.g.l. over the Siikaneva peatland in southern Finland. A method to visualize the turbulent structures and derive their parameters from thermal videos is developed. The study provides a novel approach for turbulence analysis.
Stephanie Bohlmann, Xiaoxia Shang, Ville Vakkari, Elina Giannakaki, Ari Leskinen, Kari E. J. Lehtinen, Sanna Pätsi, and Mika Komppula
Atmos. Chem. Phys., 21, 7083–7097, https://doi.org/10.5194/acp-21-7083-2021, https://doi.org/10.5194/acp-21-7083-2021, 2021
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Measurements of the multi-wavelength Raman polarization lidar PollyXT and a Halo Photonics StreamLine Doppler lidar have been combined with measurements of pollen type and concentration using a traditional pollen trap at the rural forest site in Vehmasmäki, Finland. Depolarization ratios were measured at three wavelengths. High depolarization ratios were detected during an event with high birch and spruce pollen concentrations and a wavelength dependence of the depolarization ratio was observed.
Ville Vakkari, Holger Baars, Stephanie Bohlmann, Johannes Bühl, Mika Komppula, Rodanthi-Elisavet Mamouri, and Ewan James O'Connor
Atmos. Chem. Phys., 21, 5807–5820, https://doi.org/10.5194/acp-21-5807-2021, https://doi.org/10.5194/acp-21-5807-2021, 2021
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The depolarization ratio is a valuable parameter for aerosol categorization from remote sensing measurements. Here, we introduce particle depolarization ratio measurements at the 1565 nm wavelength, which is substantially longer than previously utilized wavelengths and enhances our capabilities to study the wavelength dependency of the particle depolarization ratio.
Yishuo Guo, Chao Yan, Chang Li, Wei Ma, Zemin Feng, Ying Zhou, Zhuohui Lin, Lubna Dada, Dominik Stolzenburg, Rujing Yin, Jenni Kontkanen, Kaspar R. Daellenbach, Juha Kangasluoma, Lei Yao, Biwu Chu, Yonghong Wang, Runlong Cai, Federico Bianchi, Yongchun Liu, and Markku Kulmala
Atmos. Chem. Phys., 21, 5499–5511, https://doi.org/10.5194/acp-21-5499-2021, https://doi.org/10.5194/acp-21-5499-2021, 2021
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Fog, cloud and haze are very common natural phenomena. Sulfuric acid (SA) is one of the key compounds forming those suspended particles, technically called aerosols, through gas-to-particle conversion. Therefore, the concentration level, source and sink of SA is very important. Our results show that ozonolysis of alkenes plays a major role in nighttime SA formation under unpolluted conditions in urban Beijing, and nighttime cluster mode particles are probably driven by SA in urban environments.
Thomas Thorp, Stephen R. Arnold, Richard J. Pope, Dominick V. Spracklen, Luke Conibear, Christoph Knote, Mikhail Arshinov, Boris Belan, Eija Asmi, Tuomas Laurila, Andrei I. Skorokhod, Tuomo Nieminen, and Tuukka Petäjä
Atmos. Chem. Phys., 21, 4677–4697, https://doi.org/10.5194/acp-21-4677-2021, https://doi.org/10.5194/acp-21-4677-2021, 2021
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We compare modelled near-surface pollutants with surface and satellite observations to better understand the controls on the regional concentrations of pollution in western Siberia for late spring and summer in 2011. We find two commonly used emission inventories underestimate human emissions when compared to observations. Transport emissions are the main source of pollutants within the region during this period, whilst fire emissions peak during June and are only significant south of 60° N.
Clémence Rose, Matti P. Rissanen, Siddharth Iyer, Jonathan Duplissy, Chao Yan, John B. Nowak, Aurélie Colomb, Régis Dupuy, Xu-Cheng He, Janne Lampilahti, Yee Jun Tham, Daniela Wimmer, Jean-Marc Metzger, Pierre Tulet, Jérôme Brioude, Céline Planche, Markku Kulmala, and Karine Sellegri
Atmos. Chem. Phys., 21, 4541–4560, https://doi.org/10.5194/acp-21-4541-2021, https://doi.org/10.5194/acp-21-4541-2021, 2021
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Sulfuric acid (H2SO4) is commonly accepted as a key precursor for atmospheric new particle formation. However, direct measurements of [H2SO4] remain challenging, motivating the development of proxies. Using data collected in two different volcanic plumes, we show, under these specific conditions, the good performance of a proxy from the literature and also highlight the benefit of the newly developed proxies for the prediction of the highest [H2SO4] values.
Haiyan Li, Manjula R. Canagaratna, Matthieu Riva, Pekka Rantala, Yanjun Zhang, Steven Thomas, Liine Heikkinen, Pierre-Marie Flaud, Eric Villenave, Emilie Perraudin, Douglas Worsnop, Markku Kulmala, Mikael Ehn, and Federico Bianchi
Atmos. Chem. Phys., 21, 4123–4147, https://doi.org/10.5194/acp-21-4123-2021, https://doi.org/10.5194/acp-21-4123-2021, 2021
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For the first time, we performed binPMF analysis on the complex mass spectra acquired with the Vocus PTR-TOF in two European pine forests and identified various primary emission sources and secondary oxidation processes of atmospheric organic vapors, i.e., terpenes and their oxidation products, with varying oxidation degrees. Further insights were gained regarding monoterpene and sesquiterpene reactions based on the interpretation results.
Julia Schneider, Kristina Höhler, Paavo Heikkilä, Jorma Keskinen, Barbara Bertozzi, Pia Bogert, Tobias Schorr, Nsikanabasi Silas Umo, Franziska Vogel, Zoé Brasseur, Yusheng Wu, Simo Hakala, Jonathan Duplissy, Dmitri Moisseev, Markku Kulmala, Michael P. Adams, Benjamin J. Murray, Kimmo Korhonen, Liqing Hao, Erik S. Thomson, Dimitri Castarède, Thomas Leisner, Tuukka Petäjä, and Ottmar Möhler
Atmos. Chem. Phys., 21, 3899–3918, https://doi.org/10.5194/acp-21-3899-2021, https://doi.org/10.5194/acp-21-3899-2021, 2021
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By triggering the formation of ice crystals, ice-nucleating particles (INP) strongly influence cloud formation. Continuous, long-term measurements are needed to characterize the atmospheric INP variability. Here, a first long-term time series of INP spectra measured in the boreal forest for more than 1 year is presented, showing a clear seasonal cycle. It is shown that the seasonal dependency of INP concentrations and prevalent INP types is driven by the abundance of biogenic aerosol.
Imre Salma, Wanda Thén, Pasi Aalto, Veli-Matti Kerminen, Anikó Kern, Zoltán Barcza, Tuukka Petäjä, and Markku Kulmala
Atmos. Chem. Phys., 21, 2861–2880, https://doi.org/10.5194/acp-21-2861-2021, https://doi.org/10.5194/acp-21-2861-2021, 2021
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The distribution of the monthly mean nucleation frequency possessed a characteristic pattern. Its shape was compared to those of environmental variables, including vegetation-derived properties. The spring maximum in the occurrence frequency often overlapped with the positive T anomaly. The link between the heat stress and the occurrence minimum in summer could not be proven, whereas an association between the occurrence frequency and vegetation growth dynamics was clearly identified in spring.
Runlong Cai, Chao Yan, Dongsen Yang, Rujing Yin, Yiqun Lu, Chenjuan Deng, Yueyun Fu, Jiaxin Ruan, Xiaoxiao Li, Jenni Kontkanen, Qiang Zhang, Juha Kangasluoma, Yan Ma, Jiming Hao, Douglas R. Worsnop, Federico Bianchi, Pauli Paasonen, Veli-Matti Kerminen, Yongchun Liu, Lin Wang, Jun Zheng, Markku Kulmala, and Jingkun Jiang
Atmos. Chem. Phys., 21, 2457–2468, https://doi.org/10.5194/acp-21-2457-2021, https://doi.org/10.5194/acp-21-2457-2021, 2021
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Based on long-term measurements, we discovered that the collision of H2SO4–amine clusters is the governing mechanism that initializes fast new particle formation in the polluted atmospheric environment of urban Beijing. The mechanism and the governing factors for H2SO4–amine nucleation in the polluted atmosphere are quantitatively investigated in this study.
Runlong Cai, Chenxi Li, Xu-Cheng He, Chenjuan Deng, Yiqun Lu, Rujing Yin, Chao Yan, Lin Wang, Jingkun Jiang, Markku Kulmala, and Juha Kangasluoma
Atmos. Chem. Phys., 21, 2287–2304, https://doi.org/10.5194/acp-21-2287-2021, https://doi.org/10.5194/acp-21-2287-2021, 2021
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Growth rate determines the survival probability of atmospheric new particles and hence their impacts. We clarify the impacts of coagulation on the values retrieved by the appearance time method, which is widely used for growth rate evaluation. A new formula with coagulation correction is proposed based on derivation and tested using both models and atmospheric data. We show that the sub-3 nm particle growth rate in polluted environments may be overestimated without the coagulation correction.
Lauri Heiskanen, Juha-Pekka Tuovinen, Aleksi Räsänen, Tarmo Virtanen, Sari Juutinen, Annalea Lohila, Timo Penttilä, Maiju Linkosalmi, Juha Mikola, Tuomas Laurila, and Mika Aurela
Biogeosciences, 18, 873–896, https://doi.org/10.5194/bg-18-873-2021, https://doi.org/10.5194/bg-18-873-2021, 2021
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We studied ecosystem- and plant-community-level carbon (C) exchange between subarctic mire and the atmosphere during 2017–2018. We found strong spatial variation in CO2 and CH4 dynamics between the main plant communities. The earlier onset of growing season in 2018 strengthened the CO2 sink of the ecosystem, but this gain was counterbalanced by a later drought period. Variation in water table level, soil temperature and vegetation explained most of the variation in ecosystem-level C exchange.
Juha Sulo, Nina Sarnela, Jenni Kontkanen, Lauri Ahonen, Pauli Paasonen, Tiia Laurila, Tuija Jokinen, Juha Kangasluoma, Heikki Junninen, Mikko Sipilä, Tuukka Petäjä, Markku Kulmala, and Katrianne Lehtipalo
Atmos. Chem. Phys., 21, 695–715, https://doi.org/10.5194/acp-21-695-2021, https://doi.org/10.5194/acp-21-695-2021, 2021
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In this study, we analyzed over 5 years of sub-3 nm particle concentrations and their precursor vapors, identifying atmoshperic vapors important to the formation of these particles in the boreal forest. We also observed seasonal differences in both particle and precursor vapor concentrations and the formation pathways of these particles. Our results confirm the importance of organic vapors in atmospheric aerosol formation and highlight key seasonal differences that require further study.
David Brus, Jani Gustafsson, Ville Vakkari, Osku Kemppinen, Gijs de Boer, and Anne Hirsikko
Atmos. Chem. Phys., 21, 517–533, https://doi.org/10.5194/acp-21-517-2021, https://doi.org/10.5194/acp-21-517-2021, 2021
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This paper summarizes Finnish Meteorological Institute and Kansas State University unmanned aerial vehicle measurements during the summer 2018 Lower Atmospheric Process Studies at Elevation – a Remotely-piloted Aircraft Team Experiment (LAPSE-RATE) campaign in the San Luis Valley, providing an overview of the rotorcraft deployed, payloads, scientific goals and flight strategies and presenting observations of atmospheric thermodynamics and aerosol and gas parameters in the vertical column.
Oleg Sizov, Ekaterina Ezhova, Petr Tsymbarovich, Andrey Soromotin, Nikolay Prihod'ko, Tuukka Petäjä, Sergej Zilitinkevich, Markku Kulmala, Jaana Bäck, and Kajar Köster
Biogeosciences, 18, 207–228, https://doi.org/10.5194/bg-18-207-2021, https://doi.org/10.5194/bg-18-207-2021, 2021
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In changing climate, tundra is expected to turn into shrubs and trees, diminishing reindeer pasture and increasing risks of tick-borne diseases. However, this transition may require a disturbance. Fires in Siberia are increasingly widespread. We studied wildfire dynamics and tundra–forest transition over 60 years in northwest Siberia near the Arctic Circle. Based on satellite data analysis, we found that transition occurs in 40 %–85 % of burned tundra compared to 5 %–15 % in non-disturbed areas.
Marta Wenta, David Brus, Konstantinos Doulgeris, Ville Vakkari, and Agnieszka Herman
Earth Syst. Sci. Data, 13, 33–42, https://doi.org/10.5194/essd-13-33-2021, https://doi.org/10.5194/essd-13-33-2021, 2021
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Representations of the atmospheric boundary layer over sea ice are a challenge for numerical weather prediction models. To increase our understanding of the relevant processes, a field campaign was carried out over the sea ice in the Baltic Sea from 27 February to 2 March 2020. Observations included 27 unmanned aerial vehicle flights, four photogrammetry missions, and shore-based automatic weather station and lidar wind measurements. The dataset obtained is used to validate model results.
Camille Yver-Kwok, Carole Philippon, Peter Bergamaschi, Tobias Biermann, Francescopiero Calzolari, Huilin Chen, Sebastien Conil, Paolo Cristofanelli, Marc Delmotte, Juha Hatakka, Michal Heliasz, Ove Hermansen, Kateřina Komínková, Dagmar Kubistin, Nicolas Kumps, Olivier Laurent, Tuomas Laurila, Irene Lehner, Janne Levula, Matthias Lindauer, Morgan Lopez, Ivan Mammarella, Giovanni Manca, Per Marklund, Jean-Marc Metzger, Meelis Mölder, Stephen M. Platt, Michel Ramonet, Leonard Rivier, Bert Scheeren, Mahesh Kumar Sha, Paul Smith, Martin Steinbacher, Gabriela Vítková, and Simon Wyss
Atmos. Meas. Tech., 14, 89–116, https://doi.org/10.5194/amt-14-89-2021, https://doi.org/10.5194/amt-14-89-2021, 2021
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The Integrated Carbon Observation System (ICOS) is a pan-European research infrastructure which provides harmonized and high-precision scientific data on the carbon cycle and the greenhouse gas (GHG) budget. All stations have to undergo a rigorous assessment before being labeled, i.e., receiving approval to join the network. In this paper, we present the labeling process for the ICOS atmospheric network through the 23 stations that were labeled between November 2017 and November 2019.
Helmi-Marja Keskinen, Ilona Ylivinkka, Liine Heikkinen, Pasi P. Aalto, Tuomo Nieminen, Katrianne Lehtipalo, Juho Aalto, Janne Levula, Jutta Kesti, Lauri R. Ahonen, Ekaterina Ezhova, Markku Kulmala, and Tuukka Petäjä
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-447, https://doi.org/10.5194/amt-2020-447, 2020
Publication in AMT not foreseen
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Long-term (2005–2017) aerosol particulate matter (PM) concentration measurements at Finland at Station for Measuring Ecosystem-Atmosphere Relations (SMEAR II, Hyytiälä) have been measured with three different measurement equipment. The comparison revealed an equivalence among the three methods. Mass concentrations were generally highest in summer. The descending trend was visible here in spring, summer and winter. This might have resulted at least partly from air quality legislation.
Hui Zhang, Eeva-Stiina Tuittila, Aino Korrensalo, Aleksi Räsänen, Tarmo Virtanen, Mika Aurela, Timo Penttilä, Tuomas Laurila, Stephanie Gerin, Viivi Lindholm, and Annalea Lohila
Biogeosciences, 17, 6247–6270, https://doi.org/10.5194/bg-17-6247-2020, https://doi.org/10.5194/bg-17-6247-2020, 2020
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We studied the impact of a stream on peatland microhabitats and CH4 emissions in a northern boreal fen. We found that there were higher water levels, lower peat temperatures, and greater oxygen concentrations close to the stream; these supported the highest biomass production but resulted in the lowest CH4 emissions. Further from the stream, the conditions were drier and CH4 emissions were also low. CH4 emissions were highest at an intermediate distance from the stream.
Jingsha Xu, Shaojie Song, Roy M. Harrison, Congbo Song, Lianfang Wei, Qiang Zhang, Yele Sun, Lu Lei, Chao Zhang, Xiaohong Yao, Dihui Chen, Weijun Li, Miaomiao Wu, Hezhong Tian, Lining Luo, Shengrui Tong, Weiran Li, Junling Wang, Guoliang Shi, Yanqi Huangfu, Yingze Tian, Baozhu Ge, Shaoli Su, Chao Peng, Yang Chen, Fumo Yang, Aleksandra Mihajlidi-Zelić, Dragana Đorđević, Stefan J. Swift, Imogen Andrews, Jacqueline F. Hamilton, Ye Sun, Agung Kramawijaya, Jinxiu Han, Supattarachai Saksakulkrai, Clarissa Baldo, Siqi Hou, Feixue Zheng, Kaspar R. Daellenbach, Chao Yan, Yongchun Liu, Markku Kulmala, Pingqing Fu, and Zongbo Shi
Atmos. Meas. Tech., 13, 6325–6341, https://doi.org/10.5194/amt-13-6325-2020, https://doi.org/10.5194/amt-13-6325-2020, 2020
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An interlaboratory comparison was conducted for the first time to examine differences in water-soluble inorganic ions (WSIIs) measured by 10 labs using ion chromatography (IC) and by two online aerosol chemical speciation monitor (ACSM) methods. Major ions including SO42−, NO3− and NH4+ agreed well in 10 IC labs and correlated well with ACSM data. WSII interlab variability strongly affected aerosol acidity results based on ion balance, but aerosol pH computed by ISORROPIA II was very similar.
Roger Seco, Thomas Holst, Mikkel Sillesen Matzen, Andreas Westergaard-Nielsen, Tao Li, Tihomir Simin, Joachim Jansen, Patrick Crill, Thomas Friborg, Janne Rinne, and Riikka Rinnan
Atmos. Chem. Phys., 20, 13399–13416, https://doi.org/10.5194/acp-20-13399-2020, https://doi.org/10.5194/acp-20-13399-2020, 2020
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Northern ecosystems exchange climate-relevant trace gases with the atmosphere, including volatile organic compounds (VOCs). We measured VOC fluxes from a subarctic permafrost-free fen and its adjacent lake in northern Sweden. The graminoid-dominated fen emitted mainly isoprene during the peak of the growing season, with a pronounced response to increasing temperatures stronger than assumed by biogenic emission models. The lake was a sink of acetone and acetaldehyde during both periods measured.
Yongchun Liu, Yusheng Zhang, Chaofan Lian, Chao Yan, Zeming Feng, Feixue Zheng, Xiaolong Fan, Yan Chen, Weigang Wang, Biwu Chu, Yonghong Wang, Jing Cai, Wei Du, Kaspar R. Daellenbach, Juha Kangasluoma, Federico Bianchi, Joni Kujansuu, Tuukka Petäjä, Xuefei Wang, Bo Hu, Yuesi Wang, Maofa Ge, Hong He, and Markku Kulmala
Atmos. Chem. Phys., 20, 13023–13040, https://doi.org/10.5194/acp-20-13023-2020, https://doi.org/10.5194/acp-20-13023-2020, 2020
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Understanding of the chemical and physical processes leading to atmospheric aerosol particle formation is crucial to devising effective mitigation strategies to protect the public and reduce uncertainties in climate predictions. We found that the photolysis of nitrous acid could promote the formation of organic and nitrate aerosol and that traffic-related emission is a major contributor to ambient nitrous acid on haze days in wintertime in Beijing.
Jing Cai, Biwu Chu, Lei Yao, Chao Yan, Liine M. Heikkinen, Feixue Zheng, Chang Li, Xiaolong Fan, Shaojun Zhang, Daoyuan Yang, Yonghong Wang, Tom V. Kokkonen, Tommy Chan, Ying Zhou, Lubna Dada, Yongchun Liu, Hong He, Pauli Paasonen, Joni T. Kujansuu, Tuukka Petäjä, Claudia Mohr, Juha Kangasluoma, Federico Bianchi, Yele Sun, Philip L. Croteau, Douglas R. Worsnop, Veli-Matti Kerminen, Wei Du, Markku Kulmala, and Kaspar R. Daellenbach
Atmos. Chem. Phys., 20, 12721–12740, https://doi.org/10.5194/acp-20-12721-2020, https://doi.org/10.5194/acp-20-12721-2020, 2020
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By applying both OA PMF and size PMF at the same urban measurement site in Beijing, similar particle source types, including vehicular emissions, cooking emissions and secondary formation-related sources, were resolved by both frameworks and agreed well. It is also found that in the absence of new particle formation, vehicular and cooking emissions dominate the particle number concentration, while secondary particulate matter governed PM2.5 mass during spring and summer in Beijing.
Ilona Ylivinkka, Santeri Kaupinmäki, Meri Virman, Maija Peltola, Ditte Taipale, Tuukka Petäjä, Veli-Matti Kerminen, Markku Kulmala, and Ekaterina Ezhova
Atmos. Meas. Tech., 13, 5595–5619, https://doi.org/10.5194/amt-13-5595-2020, https://doi.org/10.5194/amt-13-5595-2020, 2020
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In this study, we developed a new algorithm for cloud classification using solar radiation and cloud base height measurements. Our objective was to develop a simple and inexpensive but effective algorithm for the needs of studies related to ecosystem and atmosphere interactions. In the present study, we used the algorithm for obtaining cloud statistics at a measurement station in southern Finland, and we discuss the advantages and shortcomings of the algorithm.
Janne Lampilahti, Hanna Elina Manninen, Katri Leino, Riikka Väänänen, Antti Manninen, Stephany Buenrostro Mazon, Tuomo Nieminen, Matti Leskinen, Joonas Enroth, Marja Bister, Sergej Zilitinkevich, Juha Kangasluoma, Heikki Järvinen, Veli-Matti Kerminen, Tuukka Petäjä, and Markku Kulmala
Atmos. Chem. Phys., 20, 11841–11854, https://doi.org/10.5194/acp-20-11841-2020, https://doi.org/10.5194/acp-20-11841-2020, 2020
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In this work, by using co-located airborne and ground-based measurements, we show that counter-rotating horizontal circulations in the planetary boundary layer (roll vortices) frequently enhance regional new particle formation or induce localized bursts of new particle formation. These observations can be explained by the ability of the rolls to efficiently lift low-volatile vapors emitted from the surface to the top of the boundary layer where new particle formation is more favorable.
Martin Heinritzi, Lubna Dada, Mario Simon, Dominik Stolzenburg, Andrea C. Wagner, Lukas Fischer, Lauri R. Ahonen, Stavros Amanatidis, Rima Baalbaki, Andrea Baccarini, Paulus S. Bauer, Bernhard Baumgartner, Federico Bianchi, Sophia Brilke, Dexian Chen, Randall Chiu, Antonio Dias, Josef Dommen, Jonathan Duplissy, Henning Finkenzeller, Carla Frege, Claudia Fuchs, Olga Garmash, Hamish Gordon, Manuel Granzin, Imad El Haddad, Xucheng He, Johanna Helm, Victoria Hofbauer, Christopher R. Hoyle, Juha Kangasluoma, Timo Keber, Changhyuk Kim, Andreas Kürten, Houssni Lamkaddam, Tiia M. Laurila, Janne Lampilahti, Chuan Ping Lee, Katrianne Lehtipalo, Markus Leiminger, Huajun Mai, Vladimir Makhmutov, Hanna Elina Manninen, Ruby Marten, Serge Mathot, Roy Lee Mauldin, Bernhard Mentler, Ugo Molteni, Tatjana Müller, Wei Nie, Tuomo Nieminen, Antti Onnela, Eva Partoll, Monica Passananti, Tuukka Petäjä, Joschka Pfeifer, Veronika Pospisilova, Lauriane L. J. Quéléver, Matti P. Rissanen, Clémence Rose, Siegfried Schobesberger, Wiebke Scholz, Kay Scholze, Mikko Sipilä, Gerhard Steiner, Yuri Stozhkov, Christian Tauber, Yee Jun Tham, Miguel Vazquez-Pufleau, Annele Virtanen, Alexander L. Vogel, Rainer Volkamer, Robert Wagner, Mingyi Wang, Lena Weitz, Daniela Wimmer, Mao Xiao, Chao Yan, Penglin Ye, Qiaozhi Zha, Xueqin Zhou, Antonio Amorim, Urs Baltensperger, Armin Hansel, Markku Kulmala, António Tomé, Paul M. Winkler, Douglas R. Worsnop, Neil M. Donahue, Jasper Kirkby, and Joachim Curtius
Atmos. Chem. Phys., 20, 11809–11821, https://doi.org/10.5194/acp-20-11809-2020, https://doi.org/10.5194/acp-20-11809-2020, 2020
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With experiments performed at CLOUD, we show how isoprene interferes in monoterpene oxidation via RO2 termination at atmospherically relevant concentrations. This interference shifts the distribution of highly oxygenated organic molecules (HOMs) away from C20 class dimers towards C15 class dimers, which subsequently reduces both biogenic nucleation and early growth rates. Our results may help to understand the absence of new-particle formation in isoprene-rich environments.
Lubna Dada, Ilona Ylivinkka, Rima Baalbaki, Chang Li, Yishuo Guo, Chao Yan, Lei Yao, Nina Sarnela, Tuija Jokinen, Kaspar R. Daellenbach, Rujing Yin, Chenjuan Deng, Biwu Chu, Tuomo Nieminen, Yonghong Wang, Zhuohui Lin, Roseline C. Thakur, Jenni Kontkanen, Dominik Stolzenburg, Mikko Sipilä, Tareq Hussein, Pauli Paasonen, Federico Bianchi, Imre Salma, Tamás Weidinger, Michael Pikridas, Jean Sciare, Jingkun Jiang, Yongchun Liu, Tuukka Petäjä, Veli-Matti Kerminen, and Markku Kulmala
Atmos. Chem. Phys., 20, 11747–11766, https://doi.org/10.5194/acp-20-11747-2020, https://doi.org/10.5194/acp-20-11747-2020, 2020
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We rely on sulfuric acid measurements in four contrasting environments, Hyytiälä, Finland; Agia Marina, Cyprus; Budapest, Hungary; and Beijing, China, representing semi-pristine boreal forest, rural environment in the Mediterranean area, urban environment, and heavily polluted megacity, respectively, in order to define the sources and sinks of sulfuric acid in these environments and to derive a new sulfuric acid proxy to be utilized in locations and during periods when it is not measured.
Jenni Kontkanen, Chenjuan Deng, Yueyun Fu, Lubna Dada, Ying Zhou, Jing Cai, Kaspar R. Daellenbach, Simo Hakala, Tom V. Kokkonen, Zhuohui Lin, Yongchun Liu, Yonghong Wang, Chao Yan, Tuukka Petäjä, Jingkun Jiang, Markku Kulmala, and Pauli Paasonen
Atmos. Chem. Phys., 20, 11329–11348, https://doi.org/10.5194/acp-20-11329-2020, https://doi.org/10.5194/acp-20-11329-2020, 2020
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To estimate the impacts of atmospheric aerosol particles on air quality, knowledge of size distributions of particles emitted from anthropogenic sources is needed. We introduce a new method for determining size-resolved particle number emissions from measured particle size distributions. We apply our method to data measured in Beijing, China. We find that particle number emissions at our site are dominated by emissions of particles smaller than 30 nm, originating mainly from traffic.
Tommy Chan, Runlong Cai, Lauri R. Ahonen, Yiliang Liu, Ying Zhou, Joonas Vanhanen, Lubna Dada, Yan Chao, Yongchun Liu, Lin Wang, Markku Kulmala, and Juha Kangasluoma
Atmos. Meas. Tech., 13, 4885–4898, https://doi.org/10.5194/amt-13-4885-2020, https://doi.org/10.5194/amt-13-4885-2020, 2020
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Using a particle size magnifier (PSM; Airmodus, Finland), we determined the particle size distribution using four inversion methods and compared each method to the others to establish their strengths and weaknesses. Furthermore, we provided a step-by-step procedure on how to invert measured data using the PSM. Finally, we provided recommendations, code and data related to the data inversion. This is an important paper, as no operating procedure exists regarding how to process measured PSM data.
Jan-Stefan Swartz, Pieter G. van Zyl, Johan P. Beukes, Corinne Galy-Lacaux, Avishkar Ramandh, and Jacobus J. Pienaar
Atmos. Chem. Phys., 20, 10637–10665, https://doi.org/10.5194/acp-20-10637-2020, https://doi.org/10.5194/acp-20-10637-2020, 2020
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Statistical modelling of interdependencies between local, regional and global parameters on long-term trends of atmospheric SO2, NO2 and O2 within proximity of the pollution hotspot in South Africa indicated that changes in meteorological conditions and/or variances in source influences contributed to temporal variability. The impact of increased anthropogenic activities and energy demand was evident, while the El Niño–Southern Oscillation made a significant contribution to O3 levels.
Paolo Laj, Alessandro Bigi, Clémence Rose, Elisabeth Andrews, Cathrine Lund Myhre, Martine Collaud Coen, Yong Lin, Alfred Wiedensohler, Michael Schulz, John A. Ogren, Markus Fiebig, Jonas Gliß, Augustin Mortier, Marco Pandolfi, Tuukka Petäja, Sang-Woo Kim, Wenche Aas, Jean-Philippe Putaud, Olga Mayol-Bracero, Melita Keywood, Lorenzo Labrador, Pasi Aalto, Erik Ahlberg, Lucas Alados Arboledas, Andrés Alastuey, Marcos Andrade, Begoña Artíñano, Stina Ausmeel, Todor Arsov, Eija Asmi, John Backman, Urs Baltensperger, Susanne Bastian, Olaf Bath, Johan Paul Beukes, Benjamin T. Brem, Nicolas Bukowiecki, Sébastien Conil, Cedric Couret, Derek Day, Wan Dayantolis, Anna Degorska, Konstantinos Eleftheriadis, Prodromos Fetfatzis, Olivier Favez, Harald Flentje, Maria I. Gini, Asta Gregorič, Martin Gysel-Beer, A. Gannet Hallar, Jenny Hand, Andras Hoffer, Christoph Hueglin, Rakesh K. Hooda, Antti Hyvärinen, Ivo Kalapov, Nikos Kalivitis, Anne Kasper-Giebl, Jeong Eun Kim, Giorgos Kouvarakis, Irena Kranjc, Radovan Krejci, Markku Kulmala, Casper Labuschagne, Hae-Jung Lee, Heikki Lihavainen, Neng-Huei Lin, Gunter Löschau, Krista Luoma, Angela Marinoni, Sebastiao Martins Dos Santos, Frank Meinhardt, Maik Merkel, Jean-Marc Metzger, Nikolaos Mihalopoulos, Nhat Anh Nguyen, Jakub Ondracek, Noemi Pérez, Maria Rita Perrone, Jean-Eudes Petit, David Picard, Jean-Marc Pichon, Veronique Pont, Natalia Prats, Anthony Prenni, Fabienne Reisen, Salvatore Romano, Karine Sellegri, Sangeeta Sharma, Gerhard Schauer, Patrick Sheridan, James Patrick Sherman, Maik Schütze, Andreas Schwerin, Ralf Sohmer, Mar Sorribas, Martin Steinbacher, Junying Sun, Gloria Titos, Barbara Toczko, Thomas Tuch, Pierre Tulet, Peter Tunved, Ville Vakkari, Fernando Velarde, Patricio Velasquez, Paolo Villani, Sterios Vratolis, Sheng-Hsiang Wang, Kay Weinhold, Rolf Weller, Margarita Yela, Jesus Yus-Diez, Vladimir Zdimal, Paul Zieger, and Nadezda Zikova
Atmos. Meas. Tech., 13, 4353–4392, https://doi.org/10.5194/amt-13-4353-2020, https://doi.org/10.5194/amt-13-4353-2020, 2020
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The paper establishes the fiducial reference of the GAW aerosol network providing the fully characterized value chain to the provision of four climate-relevant aerosol properties from ground-based sites. Data from almost 90 stations worldwide are reported for a reference year, 2017, providing a unique and very robust view of the variability of these variables worldwide. Current gaps in the GAW network are analysed and requirements for the Global Climate Monitoring System are proposed.
Jill S. Johnson, Leighton A. Regayre, Masaru Yoshioka, Kirsty J. Pringle, Steven T. Turnock, Jo Browse, David M. H. Sexton, John W. Rostron, Nick A. J. Schutgens, Daniel G. Partridge, Dantong Liu, James D. Allan, Hugh Coe, Aijun Ding, David D. Cohen, Armand Atanacio, Ville Vakkari, Eija Asmi, and Ken S. Carslaw
Atmos. Chem. Phys., 20, 9491–9524, https://doi.org/10.5194/acp-20-9491-2020, https://doi.org/10.5194/acp-20-9491-2020, 2020
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We use over 9000 monthly aggregated grid-box measurements of aerosol to constrain the uncertainty in the HadGEM3-UKCA climate model. Measurements of AOD, PM2.5, particle number concentrations, sulfate and organic mass concentrations are compared to 1 million
variantsof the model using an implausibility metric. Despite many compensating effects in the model, the procedure constrains the probability distributions of many parameters, and direct radiative forcing uncertainty is reduced by 34 %.
Mario Simon, Lubna Dada, Martin Heinritzi, Wiebke Scholz, Dominik Stolzenburg, Lukas Fischer, Andrea C. Wagner, Andreas Kürten, Birte Rörup, Xu-Cheng He, João Almeida, Rima Baalbaki, Andrea Baccarini, Paulus S. Bauer, Lisa Beck, Anton Bergen, Federico Bianchi, Steffen Bräkling, Sophia Brilke, Lucia Caudillo, Dexian Chen, Biwu Chu, António Dias, Danielle C. Draper, Jonathan Duplissy, Imad El-Haddad, Henning Finkenzeller, Carla Frege, Loic Gonzalez-Carracedo, Hamish Gordon, Manuel Granzin, Jani Hakala, Victoria Hofbauer, Christopher R. Hoyle, Changhyuk Kim, Weimeng Kong, Houssni Lamkaddam, Chuan P. Lee, Katrianne Lehtipalo, Markus Leiminger, Huajun Mai, Hanna E. Manninen, Guillaume Marie, Ruby Marten, Bernhard Mentler, Ugo Molteni, Leonid Nichman, Wei Nie, Andrea Ojdanic, Antti Onnela, Eva Partoll, Tuukka Petäjä, Joschka Pfeifer, Maxim Philippov, Lauriane L. J. Quéléver, Ananth Ranjithkumar, Matti P. Rissanen, Simon Schallhart, Siegfried Schobesberger, Simone Schuchmann, Jiali Shen, Mikko Sipilä, Gerhard Steiner, Yuri Stozhkov, Christian Tauber, Yee J. Tham, António R. Tomé, Miguel Vazquez-Pufleau, Alexander L. Vogel, Robert Wagner, Mingyi Wang, Dongyu S. Wang, Yonghong Wang, Stefan K. Weber, Yusheng Wu, Mao Xiao, Chao Yan, Penglin Ye, Qing Ye, Marcel Zauner-Wieczorek, Xueqin Zhou, Urs Baltensperger, Josef Dommen, Richard C. Flagan, Armin Hansel, Markku Kulmala, Rainer Volkamer, Paul M. Winkler, Douglas R. Worsnop, Neil M. Donahue, Jasper Kirkby, and Joachim Curtius
Atmos. Chem. Phys., 20, 9183–9207, https://doi.org/10.5194/acp-20-9183-2020, https://doi.org/10.5194/acp-20-9183-2020, 2020
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Highly oxygenated organic compounds (HOMs) have been identified as key vapors involved in atmospheric new-particle formation (NPF). The molecular distribution, HOM yield, and NPF from α-pinene oxidation experiments were measured at the CLOUD chamber over a wide tropospheric-temperature range. This study shows on a molecular scale that despite the sharp reduction in HOM yield at lower temperatures, the reduced volatility counteracts this effect and leads to an overall increase in the NPF rate.
Yuan Yang, Yonghong Wang, Putian Zhou, Dan Yao, Dongsheng Ji, Jie Sun, Yinghong Wang, Shuman Zhao, Wei Huang, Shuanghong Yang, Dean Chen, Wenkang Gao, Zirui Liu, Bo Hu, Renjian Zhang, Limin Zeng, Maofa Ge, Tuukka Petäjä, Veli-Matti Kerminen, Markku Kulmala, and Yuesi Wang
Atmos. Chem. Phys., 20, 8181–8200, https://doi.org/10.5194/acp-20-8181-2020, https://doi.org/10.5194/acp-20-8181-2020, 2020
Dominik Stolzenburg, Mario Simon, Ananth Ranjithkumar, Andreas Kürten, Katrianne Lehtipalo, Hamish Gordon, Sebastian Ehrhart, Henning Finkenzeller, Lukas Pichelstorfer, Tuomo Nieminen, Xu-Cheng He, Sophia Brilke, Mao Xiao, António Amorim, Rima Baalbaki, Andrea Baccarini, Lisa Beck, Steffen Bräkling, Lucía Caudillo Murillo, Dexian Chen, Biwu Chu, Lubna Dada, António Dias, Josef Dommen, Jonathan Duplissy, Imad El Haddad, Lukas Fischer, Loic Gonzalez Carracedo, Martin Heinritzi, Changhyuk Kim, Theodore K. Koenig, Weimeng Kong, Houssni Lamkaddam, Chuan Ping Lee, Markus Leiminger, Zijun Li, Vladimir Makhmutov, Hanna E. Manninen, Guillaume Marie, Ruby Marten, Tatjana Müller, Wei Nie, Eva Partoll, Tuukka Petäjä, Joschka Pfeifer, Maxim Philippov, Matti P. Rissanen, Birte Rörup, Siegfried Schobesberger, Simone Schuchmann, Jiali Shen, Mikko Sipilä, Gerhard Steiner, Yuri Stozhkov, Christian Tauber, Yee Jun Tham, António Tomé, Miguel Vazquez-Pufleau, Andrea C. Wagner, Mingyi Wang, Yonghong Wang, Stefan K. Weber, Daniela Wimmer, Peter J. Wlasits, Yusheng Wu, Qing Ye, Marcel Zauner-Wieczorek, Urs Baltensperger, Kenneth S. Carslaw, Joachim Curtius, Neil M. Donahue, Richard C. Flagan, Armin Hansel, Markku Kulmala, Jos Lelieveld, Rainer Volkamer, Jasper Kirkby, and Paul M. Winkler
Atmos. Chem. Phys., 20, 7359–7372, https://doi.org/10.5194/acp-20-7359-2020, https://doi.org/10.5194/acp-20-7359-2020, 2020
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Sulfuric acid is a major atmospheric vapour for aerosol formation. If new particles grow fast enough, they can act as cloud droplet seeds or affect air quality. In a controlled laboratory set-up, we demonstrate that van der Waals forces enhance growth from sulfuric acid. We disentangle the effects of ammonia, ions and particle hydration, presenting a complete picture of sulfuric acid growth from molecular clusters onwards. In a climate model, we show its influence on the global aerosol budget.
Heidi Hellén, Simon Schallhart, Arnaud P. Praplan, Toni Tykkä, Mika Aurela, Annalea Lohila, and Hannele Hakola
Atmos. Chem. Phys., 20, 7021–7034, https://doi.org/10.5194/acp-20-7021-2020, https://doi.org/10.5194/acp-20-7021-2020, 2020
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We studied biogenic volatile organic compound emissions and their ambient concentrations in a sub-Arctic wetland. Although isoprene was the main terpenoid emitted, sesquiterpene emissions were also highly significant, especially in early summer. Sesquiterpenes have much higher potential to form secondary organic aerosol than isoprenes. High sesquiterpene emissions during early summer suggested that melting snow and thawing soil could be an important source of these compounds.
Nataliia Kozii, Kersti Haahti, Pantana Tor-ngern, Jinshu Chi, Eliza Maher Hasselquist, Hjalmar Laudon, Samuli Launiainen, Ram Oren, Matthias Peichl, Jörgen Wallerman, and Niles J. Hasselquist
Hydrol. Earth Syst. Sci., 24, 2999–3014, https://doi.org/10.5194/hess-24-2999-2020, https://doi.org/10.5194/hess-24-2999-2020, 2020
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The hydrologic cycle is one of the greatest natural processes on Earth and strongly influences both regional and global climate as well as ecosystem functioning. Results from this study clearly show the central role trees play in regulating the water cycle of boreal catchments, implying that forest management impacts on stand structure as well as climate change effects on tree growth are likely to have large cascading effects on the way water moves through boreal forested landscapes.
Dean Chen, Putian Zhou, Tuomo Nieminen, Pontus Roldin, Ximeng Qi, Petri Clusius, Carlton Xavier, Lukas Pichelstorfer, Markku Kulmala, Pekka Rantala, Juho Aalto, Nina Sarnela, Pasi Kolari, Petri Keronen, Matti P. Rissanen, Metin Baykara, and Michael Boy
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-128, https://doi.org/10.5194/acp-2020-128, 2020
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Atmospheric oxidants OH, O3 and NO3 dominate the atmospheric oxidation capacity, and sulfuric acid (H2SO4) is considered as a main driver for new particle formation events. We studied how the trends of these atmospheric oxidants and H2SO4 changed in southern Finland during the past 12 years and discussed how these trends related to decreasing emissions of air pollutants in Europe. Our results showed that OH increased by 1.56 % yr−1 at daytime and NO3 decreased by 3.92 % yr−1 at nighttime.
Sheila Wachiye, Lutz Merbold, Timo Vesala, Janne Rinne, Matti Räsänen, Sonja Leitner, and Petri Pellikka
Biogeosciences, 17, 2149–2167, https://doi.org/10.5194/bg-17-2149-2020, https://doi.org/10.5194/bg-17-2149-2020, 2020
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Limited data on emissions in Africa translate into uncertainty during GHG budgeting. We studied annual CO2, N2O, and CH4 emissions in four land-use types in Kenyan savanna using static chambers and gas chromatography. CO2 emissions varied between seasons and land-use types. Soil moisture and vegetation explained the seasonal variation, while soil temperature was insignificant. N2O and CH4 emissions did not vary at all sites. Our results are useful in climate change mitigation interventions.
Chris R. Flechard, Andreas Ibrom, Ute M. Skiba, Wim de Vries, Marcel van Oijen, David R. Cameron, Nancy B. Dise, Janne F. J. Korhonen, Nina Buchmann, Arnaud Legout, David Simpson, Maria J. Sanz, Marc Aubinet, Denis Loustau, Leonardo Montagnani, Johan Neirynck, Ivan A. Janssens, Mari Pihlatie, Ralf Kiese, Jan Siemens, André-Jean Francez, Jürgen Augustin, Andrej Varlagin, Janusz Olejnik, Radosław Juszczak, Mika Aurela, Daniel Berveiller, Bogdan H. Chojnicki, Ulrich Dämmgen, Nicolas Delpierre, Vesna Djuricic, Julia Drewer, Eric Dufrêne, Werner Eugster, Yannick Fauvel, David Fowler, Arnoud Frumau, André Granier, Patrick Gross, Yannick Hamon, Carole Helfter, Arjan Hensen, László Horváth, Barbara Kitzler, Bart Kruijt, Werner L. Kutsch, Raquel Lobo-do-Vale, Annalea Lohila, Bernard Longdoz, Michal V. Marek, Giorgio Matteucci, Marta Mitosinkova, Virginie Moreaux, Albrecht Neftel, Jean-Marc Ourcival, Kim Pilegaard, Gabriel Pita, Francisco Sanz, Jan K. Schjoerring, Maria-Teresa Sebastià, Y. Sim Tang, Hilde Uggerud, Marek Urbaniak, Netty van Dijk, Timo Vesala, Sonja Vidic, Caroline Vincke, Tamás Weidinger, Sophie Zechmeister-Boltenstern, Klaus Butterbach-Bahl, Eiko Nemitz, and Mark A. Sutton
Biogeosciences, 17, 1583–1620, https://doi.org/10.5194/bg-17-1583-2020, https://doi.org/10.5194/bg-17-1583-2020, 2020
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Experimental evidence from a network of 40 monitoring sites in Europe suggests that atmospheric nitrogen deposition to forests and other semi-natural vegetation impacts the carbon sequestration rates in ecosystems, as well as the net greenhouse gas balance including other greenhouse gases such as nitrous oxide and methane. Excess nitrogen deposition in polluted areas also leads to other environmental impacts such as nitrogen leaching to groundwater and other pollutant gaseous emissions.
Chris R. Flechard, Marcel van Oijen, David R. Cameron, Wim de Vries, Andreas Ibrom, Nina Buchmann, Nancy B. Dise, Ivan A. Janssens, Johan Neirynck, Leonardo Montagnani, Andrej Varlagin, Denis Loustau, Arnaud Legout, Klaudia Ziemblińska, Marc Aubinet, Mika Aurela, Bogdan H. Chojnicki, Julia Drewer, Werner Eugster, André-Jean Francez, Radosław Juszczak, Barbara Kitzler, Werner L. Kutsch, Annalea Lohila, Bernard Longdoz, Giorgio Matteucci, Virginie Moreaux, Albrecht Neftel, Janusz Olejnik, Maria J. Sanz, Jan Siemens, Timo Vesala, Caroline Vincke, Eiko Nemitz, Sophie Zechmeister-Boltenstern, Klaus Butterbach-Bahl, Ute M. Skiba, and Mark A. Sutton
Biogeosciences, 17, 1621–1654, https://doi.org/10.5194/bg-17-1621-2020, https://doi.org/10.5194/bg-17-1621-2020, 2020
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Nitrogen deposition from the atmosphere to unfertilized terrestrial vegetation such as forests can increase carbon dioxide uptake and favour carbon sequestration by ecosystems. However the data from observational networks are difficult to interpret in terms of a carbon-to-nitrogen response, because there are a number of other confounding factors, such as climate, soil physical properties and fertility, and forest age. We propose a model-based method to untangle the different influences.
Liine Heikkinen, Mikko Äijälä, Matthieu Riva, Krista Luoma, Kaspar Dällenbach, Juho Aalto, Pasi Aalto, Diego Aliaga, Minna Aurela, Helmi Keskinen, Ulla Makkonen, Pekka Rantala, Markku Kulmala, Tuukka Petäjä, Douglas Worsnop, and Mikael Ehn
Atmos. Chem. Phys., 20, 3151–3180, https://doi.org/10.5194/acp-20-3151-2020, https://doi.org/10.5194/acp-20-3151-2020, 2020
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Atmospheric aerosols are solid or liquid particles suspended in the air. They are known as a health risk, but they also influence the Earth's climate. The composition of aerosols becomes important when predicting their effect on climate. We show both seasonal and year-to-year variability of aerosol chemical composition in the boreal forest of Finland. We observed a consistent bimodal seasonal trend: a biogenic summertime maximum and an anthropogenic wintertime maximum in the mass concentration.
Haiyan Li, Matthieu Riva, Pekka Rantala, Liine Heikkinen, Kaspar Daellenbach, Jordan E. Krechmer, Pierre-Marie Flaud, Douglas Worsnop, Markku Kulmala, Eric Villenave, Emilie Perraudin, Mikael Ehn, and Federico Bianchi
Atmos. Chem. Phys., 20, 1941–1959, https://doi.org/10.5194/acp-20-1941-2020, https://doi.org/10.5194/acp-20-1941-2020, 2020
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We deployed the recently developed Vocus PTR-TOF in the French Landes forest during summertime to gain insights into terpene chemistry. In addition to isoprene, monoterpenes, sesquiterpenes, and the low-volatility diterpenes, various terpene reaction products are characterized. Through the analysis of terpene chemistry, we demonstrate the capability of the Vocus PTR-TOF for the detection of oxidized reaction products, highlighting its importance in investigating atmospheric oxidation processes.
Ditte Taipale, Juho Aalto, Pauliina Schiestl-Aalto, Markku Kulmala, and Jaana Bäck
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-502, https://doi.org/10.5194/bg-2019-502, 2020
Preprint withdrawn
Ying Zhou, Lubna Dada, Yiliang Liu, Yueyun Fu, Juha Kangasluoma, Tommy Chan, Chao Yan, Biwu Chu, Kaspar R. Daellenbach, Federico Bianchi, Tom V. Kokkonen, Yongchun Liu, Joni Kujansuu, Veli-Matti Kerminen, Tuukka Petäjä, Lin Wang, Jingkun Jiang, and Markku Kulmala
Atmos. Chem. Phys., 20, 1201–1216, https://doi.org/10.5194/acp-20-1201-2020, https://doi.org/10.5194/acp-20-1201-2020, 2020
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In this study, we focus on explaining the concentration variations in the observed particle modes, by relating them to the potential aerosol sources and sinks, and on understanding the connections between these modes. Interestingly, even in the atmospheric cocktail in urban Beijing, secondary new particle formation (NPF) drives the particle number concentration, especially in the sub-3 nm range. We found that the total number concentration is ~ 4 times higher on NPF days than on haze days.
Marja Hemmilä, Ulla Makkonen, Aki Virkkula, Georgia Panagiotopoulou, Juho Aalto, Markku Kulmala, Tuukka Petäjä, Hannele Hakola, and Heidi Hellén
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2019-1157, https://doi.org/10.5194/acp-2019-1157, 2020
Publication in ACP not foreseen
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Amines are atmospheric bases, which can affect to nucleation of aerosols. Lately, a computational study showed that guanidine could be even more effective to stabilize sulphuric acid clusters. In this paper we used a a dynamic flow-through chamber with an online ion chromatograph MARGA coupled with a mass spectrometer (MARGA-MS). We studied amine and guanidine emission from a boreal forest floor in Finland, and find out, that the boreal forest floor is a source of amines and guanidine.
Matti Räsänen, Mika Aurela, Ville Vakkari, Johan P. Beukes, Juha-Pekka Tuovinen, Pieter G. Van Zyl, Miroslav Josipovic, Stefan J. Siebert, Tuomas Laurila, Markku Kulmala, Lauri Laakso, Janne Rinne, Ram Oren, and Gabriel Katul
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2019-651, https://doi.org/10.5194/hess-2019-651, 2020
Revised manuscript not accepted
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The annual ET is approximately equal to precipitation during six measured years for grazed savanna grassland. The computed annual transpiration was highly constrained when rainfall was near or above the long-term mean but was reduced during severe drought year. The developed methodologies can be used in a wide range of arid and semi-arid ecosystems.
Yonghong Wang, Miao Yu, Yuesi Wang, Guiqian Tang, Tao Song, Putian Zhou, Zirui Liu, Bo Hu, Dongsheng Ji, Lili Wang, Xiaowan Zhu, Chao Yan, Mikael Ehn, Wenkang Gao, Yuepeng Pan, Jinyuan Xin, Yang Sun, Veli-Matti Kerminen, Markku Kulmala, and Tuukka Petäjä
Atmos. Chem. Phys., 20, 45–53, https://doi.org/10.5194/acp-20-45-2020, https://doi.org/10.5194/acp-20-45-2020, 2020
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We found a positive particle matter-mixing layer height feedback at three observation platforms at the 325 m Beijing meteorology tower, which is characterized by a shallower mixing layer height and a higher particle matter concentration. Measurements of solar radiation, aerosol chemical composition, meteorology parameters, trace gases and turbulent kinetic energy (TKE) could explain the feedback mechanism to some extent.
Yicheng Shen, Aki Virkkula, Aijun Ding, Krista Luoma, Helmi Keskinen, Pasi P. Aalto, Xuguang Chi, Ximeng Qi, Wei Nie, Xin Huang, Tuukka Petäjä, Markku Kulmala, and Veli-Matti Kerminen
Atmos. Chem. Phys., 19, 15483–15502, https://doi.org/10.5194/acp-19-15483-2019, https://doi.org/10.5194/acp-19-15483-2019, 2019
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Long-term cloud condensation nuclei (CCN) number concentration (NCCN) data are scarce; there are a lot more data on aerosol optical properties (AOPs). It is therefore valuable to derive parameterizations for estimating NCCN from AOP measurements. With the new parameterization NCCN can be estimated from backscatter fraction, scattering Ångström exponent, and total light-scattering coefficient. The NCCN–AOP relationships depend on the geometric mean diameter and the width of the size distribution.
Arnaud P. Praplan, Toni Tykkä, Dean Chen, Michael Boy, Ditte Taipale, Ville Vakkari, Putian Zhou, Tuukka Petäjä, and Heidi Hellén
Atmos. Chem. Phys., 19, 14431–14453, https://doi.org/10.5194/acp-19-14431-2019, https://doi.org/10.5194/acp-19-14431-2019, 2019
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Our study shows that, despite our best efforts and recent progress, our knowledge of the chemical composition of the air under the canopy of a boreal forest still cannot be fully characterized. The discrepancy between the measured total reactivity of the air and the reactivity derived from the known chemical composition highlights the need to better understand the emissions from vegetation, but also other sources, such as the forest soil.
Jingda Liu, Lili Wang, Mingge Li, Zhiheng Liao, Yang Sun, Tao Song, Wenkang Gao, Yonghong Wang, Yan Li, Dongsheng Ji, Bo Hu, Veli-Matti Kerminen, Yuesi Wang, and Markku Kulmala
Atmos. Chem. Phys., 19, 14477–14492, https://doi.org/10.5194/acp-19-14477-2019, https://doi.org/10.5194/acp-19-14477-2019, 2019
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We analyzed the surface ozone variation characteristics and quantified the impact of synoptic and local meteorological factors on northern China during the warm season based on multi-city, in situ ozone and meteorological data, as well as meteorological reanalysis. The results of quantitative exploration on synoptic and local meteorological factors influencing both interannual and day-to-day ozone variations will provide the scientific basis for evaluating emission reduction measures.
Simonas Kecorius, Teresa Vogl, Pauli Paasonen, Janne Lampilahti, Daniel Rothenberg, Heike Wex, Sebastian Zeppenfeld, Manuela van Pinxteren, Markus Hartmann, Silvia Henning, Xianda Gong, Andre Welti, Markku Kulmala, Frank Stratmann, Hartmut Herrmann, and Alfred Wiedensohler
Atmos. Chem. Phys., 19, 14339–14364, https://doi.org/10.5194/acp-19-14339-2019, https://doi.org/10.5194/acp-19-14339-2019, 2019
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Arctic sea-ice retreat, atmospheric new particle formation (NPF), and aerosol–cloud interaction may all be linked via a positive feedback mechanism. Understanding the sources of cloud condensation nuclei (CCN) is an important piece in the Arctic amplification puzzle. We show that Arctic newly formed particles do not have to grow beyond the Aitken mode to act as CCN. This is important, because NPF occurrence in the Arctic is expected to increase, making it a significant contributor to CCN budget.
Mika Korkiakoski, Juha-Pekka Tuovinen, Timo Penttilä, Sakari Sarkkola, Paavo Ojanen, Kari Minkkinen, Juuso Rainne, Tuomas Laurila, and Annalea Lohila
Biogeosciences, 16, 3703–3723, https://doi.org/10.5194/bg-16-3703-2019, https://doi.org/10.5194/bg-16-3703-2019, 2019
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We measured greenhouse gas and energy fluxes for 2 years after clear-cutting in a peatland forest. We found high carbon dioxide and nitrous oxide emissions. However, in the second year after clear-cutting, the carbon dioxide emissions had already decreased by 33 % from the first year. Also, clear-cutting turned the site from a methane sink into a methane source. We conclude that clear-cutting peatland forests exerts a strong climatic warming effect through accelerated emission of greenhouse gas.
Jarmo Mäkelä, Jürgen Knauer, Mika Aurela, Andrew Black, Martin Heimann, Hideki Kobayashi, Annalea Lohila, Ivan Mammarella, Hank Margolis, Tiina Markkanen, Jouni Susiluoto, Tea Thum, Toni Viskari, Sönke Zaehle, and Tuula Aalto
Geosci. Model Dev., 12, 4075–4098, https://doi.org/10.5194/gmd-12-4075-2019, https://doi.org/10.5194/gmd-12-4075-2019, 2019
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We assess the differences of six stomatal conductance formulations, embedded into a land–vegetation model JSBACH, on 10 boreal coniferous evergreen forest sites. We calibrate the model parameters using all six functions in a multi-year experiment, as well as for a separate drought event at one of the sites, using the adaptive population importance sampler. The analysis reveals weaknesses in the stomatal conductance formulation-dependent model behaviour that we are able to partially amend.
Krista Luoma, Aki Virkkula, Pasi Aalto, Tuukka Petäjä, and Markku Kulmala
Atmos. Chem. Phys., 19, 11363–11382, https://doi.org/10.5194/acp-19-11363-2019, https://doi.org/10.5194/acp-19-11363-2019, 2019
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We present an over 10-year-long time series of aerosol optical properties (AOPs) measured at a rural boreal forest site. Knowledge of AOPs is needed in determining the direct effect of aerosol particles on climate. We observed decreasing trends in scattering and absorption and increasing trends in backscattering fraction and single-scattering albedo. Trends of single-scattering albedo and backscattering fraction increased the efficiency of aerosol particles to scatter radiation back into space.
Olli Peltola, Timo Vesala, Yao Gao, Olle Räty, Pavel Alekseychik, Mika Aurela, Bogdan Chojnicki, Ankur R. Desai, Albertus J. Dolman, Eugenie S. Euskirchen, Thomas Friborg, Mathias Göckede, Manuel Helbig, Elyn Humphreys, Robert B. Jackson, Georg Jocher, Fortunat Joos, Janina Klatt, Sara H. Knox, Natalia Kowalska, Lars Kutzbach, Sebastian Lienert, Annalea Lohila, Ivan Mammarella, Daniel F. Nadeau, Mats B. Nilsson, Walter C. Oechel, Matthias Peichl, Thomas Pypker, William Quinton, Janne Rinne, Torsten Sachs, Mateusz Samson, Hans Peter Schmid, Oliver Sonnentag, Christian Wille, Donatella Zona, and Tuula Aalto
Earth Syst. Sci. Data, 11, 1263–1289, https://doi.org/10.5194/essd-11-1263-2019, https://doi.org/10.5194/essd-11-1263-2019, 2019
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Here we develop a monthly gridded dataset of northern (> 45 N) wetland methane (CH4) emissions. The data product is derived using a random forest machine-learning technique and eddy covariance CH4 fluxes from 25 wetland sites. Annual CH4 emissions from these wetlands calculated from the derived data product are comparable to prior studies focusing on these areas. This product is an independent estimate of northern wetland CH4 emissions and hence could be used, e.g. for process model evaluation.
Simo Hakala, Mansour A. Alghamdi, Pauli Paasonen, Ville Vakkari, Mamdouh I. Khoder, Kimmo Neitola, Lubna Dada, Ahmad S. Abdelmaksoud, Hisham Al-Jeelani, Ibrahim I. Shabbaj, Fahd M. Almehmadi, Anu-Maija Sundström, Heikki Lihavainen, Veli-Matti Kerminen, Jenni Kontkanen, Markku Kulmala, Tareq Hussein, and Antti-Pekka Hyvärinen
Atmos. Chem. Phys., 19, 10537–10555, https://doi.org/10.5194/acp-19-10537-2019, https://doi.org/10.5194/acp-19-10537-2019, 2019
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Atmospheric aerosols have significant effects on human health and the climate. A large fraction of these aerosols originate from new particle formation, where atmospheric vapors form small nanosized particles that grow into larger sizes, thus becoming climatically relevant. We show that large amounts of fast-growing particles are formed frequently at a site located in western Saudi Arabia and that these particles are likely connected to strong nearby emissions from human activities.
Yonghong Wang, Yuesi Wang, Lili Wang, Tuukka Petäjä, Qiaozhi Zha, Chongshui Gong, Sixuan Li, Yuepeng Pan, Bo Hu, Jinyuan Xin, and Markku Kulmala
Atmos. Chem. Phys., 19, 5881–5888, https://doi.org/10.5194/acp-19-5881-2019, https://doi.org/10.5194/acp-19-5881-2019, 2019
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Satellite observations combined with in situ measurements demonstrate that increased inorganic aerosol fractions of NO2 and SO2 contribute to air pollution and frequently occurring haze in China from 1980 to 2010. Currently, the reduction of nitrate, sulfate and their precursor gases would contribute towards better visibility in China.
Matthieu Riva, Pekka Rantala, Jordan E. Krechmer, Otso Peräkylä, Yanjun Zhang, Liine Heikkinen, Olga Garmash, Chao Yan, Markku Kulmala, Douglas Worsnop, and Mikael Ehn
Atmos. Meas. Tech., 12, 2403–2421, https://doi.org/10.5194/amt-12-2403-2019, https://doi.org/10.5194/amt-12-2403-2019, 2019
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The impact of aerosol particles on climate and air quality remains poorly understood due to multiple factors. One of the current limitations is the incomplete understanding of the contribution of oxygenated species, formed from the oxidation of volatile organic compounds (VOCs) to aerosol formation. Taking advantage of recent mass spectrometric developments, we have evaluated and compared the capability of multiple state-of-the-art mass spectrometers to detect a wide variety of oxygenated VOCs.
Katri Leino, Janne Lampilahti, Pyry Poutanen, Riikka Väänänen, Antti Manninen, Stephany Buenrostro Mazon, Lubna Dada, Anna Franck, Daniela Wimmer, Pasi P. Aalto, Lauri R. Ahonen, Joonas Enroth, Juha Kangasluoma, Petri Keronen, Frans Korhonen, Heikki Laakso, Teemu Matilainen, Erkki Siivola, Hanna E. Manninen, Katrianne Lehtipalo, Veli-Matti Kerminen, Tuukka Petäjä, and Markku Kulmala
Atmos. Chem. Phys., 19, 4127–4138, https://doi.org/10.5194/acp-19-4127-2019, https://doi.org/10.5194/acp-19-4127-2019, 2019
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This study presents airborne observations of particles, starting from 1.5 nm in diameter, above the boreal forest from 100 m up to 2700 m. The aim was to study the extent of NPF and likely places for nucleation. We found that the highest concentrations of 1.5–3 nm particles were above the forest canopy top on NPF event mornings, and the concentration decreased with increasing altitude. This would indicate the importance of gaseous precursors from vegetation for NPF processes in this area.
Mikko Äijälä, Kaspar R. Daellenbach, Francesco Canonaco, Liine Heikkinen, Heikki Junninen, Tuukka Petäjä, Markku Kulmala, André S. H. Prévôt, and Mikael Ehn
Atmos. Chem. Phys., 19, 3645–3672, https://doi.org/10.5194/acp-19-3645-2019, https://doi.org/10.5194/acp-19-3645-2019, 2019
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Aerosol mass spectrometry produces large amounts of complex data, the analysis of which necessitates chemometrics – the application of advanced statistical and mathematical tools to chemical data. Here, we perform a data-driven analysis of multiple aerosol mass spectrometric data sets, to show that the traditional separation of organics and inorganics is not necessary. The resulting 7-component aerosol speciation explains 83 % to 96 % of observed variability at our boreal forest experiment site.
Nikos Kalivitis, Veli-Matti Kerminen, Giorgos Kouvarakis, Iasonas Stavroulas, Evaggelia Tzitzikalaki, Panayiotis Kalkavouras, Nikos Daskalakis, Stelios Myriokefalitakis, Aikaterini Bougiatioti, Hanna E. Manninen, Pontus Roldin, Tuukka Petäjä, Michael Boy, Markku Kulmala, Maria Kanakidou, and Nikolaos Mihalopoulos
Atmos. Chem. Phys., 19, 2671–2686, https://doi.org/10.5194/acp-19-2671-2019, https://doi.org/10.5194/acp-19-2671-2019, 2019
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New particle formation (NPF) is an important source of atmospheric aerosols. For the Mediterranean atmosphere, only few studies exist. In this study we present one of the longest series of NPF by analyzing 10 years of data from Crete, Greece. NPF took place on 27 % of the available days; it was more frequent in spring and less so in late summer. Model simulations showed that NPF in the subtropical environment may differ greatly from that in the boreal environment.
Michael Boy, Erik S. Thomson, Juan-C. Acosta Navarro, Olafur Arnalds, Ekaterina Batchvarova, Jaana Bäck, Frank Berninger, Merete Bilde, Zoé Brasseur, Pavla Dagsson-Waldhauserova, Dimitri Castarède, Maryam Dalirian, Gerrit de Leeuw, Monika Dragosics, Ella-Maria Duplissy, Jonathan Duplissy, Annica M. L. Ekman, Keyan Fang, Jean-Charles Gallet, Marianne Glasius, Sven-Erik Gryning, Henrik Grythe, Hans-Christen Hansson, Margareta Hansson, Elisabeth Isaksson, Trond Iversen, Ingibjorg Jonsdottir, Ville Kasurinen, Alf Kirkevåg, Atte Korhola, Radovan Krejci, Jon Egill Kristjansson, Hanna K. Lappalainen, Antti Lauri, Matti Leppäranta, Heikki Lihavainen, Risto Makkonen, Andreas Massling, Outi Meinander, E. Douglas Nilsson, Haraldur Olafsson, Jan B. C. Pettersson, Nønne L. Prisle, Ilona Riipinen, Pontus Roldin, Meri Ruppel, Matthew Salter, Maria Sand, Øyvind Seland, Heikki Seppä, Henrik Skov, Joana Soares, Andreas Stohl, Johan Ström, Jonas Svensson, Erik Swietlicki, Ksenia Tabakova, Throstur Thorsteinsson, Aki Virkkula, Gesa A. Weyhenmeyer, Yusheng Wu, Paul Zieger, and Markku Kulmala
Atmos. Chem. Phys., 19, 2015–2061, https://doi.org/10.5194/acp-19-2015-2019, https://doi.org/10.5194/acp-19-2015-2019, 2019
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The Nordic Centre of Excellence CRAICC (Cryosphere–Atmosphere Interactions in a Changing Arctic Climate), funded by NordForsk in the years 2011–2016, is the largest joint Nordic research and innovation initiative to date and aimed to strengthen research and innovation regarding climate change issues in the Nordic region. The paper presents an overview of the main scientific topics investigated and provides a state-of-the-art comprehensive summary of what has been achieved in CRAICC.
Timo Vihma, Petteri Uotila, Stein Sandven, Dmitry Pozdnyakov, Alexander Makshtas, Alexander Pelyasov, Roberta Pirazzini, Finn Danielsen, Sergey Chalov, Hanna K. Lappalainen, Vladimir Ivanov, Ivan Frolov, Anna Albin, Bin Cheng, Sergey Dobrolyubov, Viktor Arkhipkin, Stanislav Myslenkov, Tuukka Petäjä, and Markku Kulmala
Atmos. Chem. Phys., 19, 1941–1970, https://doi.org/10.5194/acp-19-1941-2019, https://doi.org/10.5194/acp-19-1941-2019, 2019
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The Arctic marine climate system, ecosystems, and socio-economic systems are changing rapidly. This calls for the establishment of a marine Arctic component of the Pan-Eurasian Experiment (MA-PEEX), for which we present a plan. The program will promote international collaboration; sustainable marine meteorological, sea ice, and oceanographic observations; advanced data management; and multidisciplinary research on the marine Arctic and its interaction with the Eurasian continent.
Yiqun Lu, Chao Yan, Yueyun Fu, Yan Chen, Yiliang Liu, Gan Yang, Yuwei Wang, Federico Bianchi, Biwu Chu, Ying Zhou, Rujing Yin, Rima Baalbaki, Olga Garmash, Chenjuan Deng, Weigang Wang, Yongchun Liu, Tuukka Petäjä, Veli-Matti Kerminen, Jingkun Jiang, Markku Kulmala, and Lin Wang
Atmos. Chem. Phys., 19, 1971–1983, https://doi.org/10.5194/acp-19-1971-2019, https://doi.org/10.5194/acp-19-1971-2019, 2019
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Gaseous sulfuric acid is one of the key precursors for atmospheric new particle formation processes, but its measurement remains challenging. This work develops an estimation method for the gaseous sulfuric acid concentration in an urban environment in China using multiple atmospheric variables that are easier to measure. The consideration of the heterogeneous formation of HONO and the subsequent photo-production of OH radicals improves the performance of the estimation method.
Ville Vakkari, Antti J. Manninen, Ewan J. O'Connor, Jan H. Schween, Pieter G. van Zyl, and Eleni Marinou
Atmos. Meas. Tech., 12, 839–852, https://doi.org/10.5194/amt-12-839-2019, https://doi.org/10.5194/amt-12-839-2019, 2019
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Commercially available Doppler lidars have been proven to be efficient tools for studying winds and turbulence in the planetary boundary layer. However, in many cases low signal is still a limiting factor for utilising measurements by these devices. Here, we present a novel post-processing algorithm for Halo Stream Line Doppler lidars, which enables an improvement in sensitivity of a factor of 5 or more.
Juha-Pekka Tuovinen, Mika Aurela, Juha Hatakka, Aleksi Räsänen, Tarmo Virtanen, Juha Mikola, Viktor Ivakhov, Vladimir Kondratyev, and Tuomas Laurila
Biogeosciences, 16, 255–274, https://doi.org/10.5194/bg-16-255-2019, https://doi.org/10.5194/bg-16-255-2019, 2019
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We analysed ecosystem-scale measurements of methane exchange between Arctic tundra and the atmosphere, taking into account the large variations in vegetation and soil properties. The measurements are spatial averages, but using meteorological and statistical modelling techniques we could estimate methane emissions for different land cover types and quantify how well the measurements correspond to the spatial variability. This provides a more accurate estimate of the regional methane emission.
Biwu Chu, Veli-Matti Kerminen, Federico Bianchi, Chao Yan, Tuukka Petäjä, and Markku Kulmala
Atmos. Chem. Phys., 19, 115–138, https://doi.org/10.5194/acp-19-115-2019, https://doi.org/10.5194/acp-19-115-2019, 2019
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The characteristics of new particle formation (NPF) in China, including frequency, formation rate, and particle growth rate, were summarized comprehensively and were compared among observations in different environments. The interactions between air pollution and NPF are discussed, as well as the possible reasons for more frequent NPF under heavy pollution conditions than in our current understanding. Significant and future research directions for NPF studies in China are also summarized.
Lubna Dada, Robert Chellapermal, Stephany Buenrostro Mazon, Pauli Paasonen, Janne Lampilahti, Hanna E. Manninen, Heikki Junninen, Tuukka Petäjä, Veli-Matti Kerminen, and Markku Kulmala
Atmos. Chem. Phys., 18, 17883–17893, https://doi.org/10.5194/acp-18-17883-2018, https://doi.org/10.5194/acp-18-17883-2018, 2018
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Our paper provides an automatic method to classify new particle formation events into four classes based on the accompanying air ion concentrations. The method is applied to 10 years of data measured within the SMEAR II station and was capable of eliminating the undefined class as well as defining the start, peak and end times of a regional event by monitoring the initial steps of cluster formation. Our method can be modified and applied to different locations where particle formation occurs.
Ekaterina Ezhova, Ilona Ylivinkka, Joel Kuusk, Kaupo Komsaare, Marko Vana, Alisa Krasnova, Steffen Noe, Mikhail Arshinov, Boris Belan, Sung-Bin Park, Jošt Valentin Lavrič, Martin Heimann, Tuukka Petäjä, Timo Vesala, Ivan Mammarella, Pasi Kolari, Jaana Bäck, Üllar Rannik, Veli-Matti Kerminen, and Markku Kulmala
Atmos. Chem. Phys., 18, 17863–17881, https://doi.org/10.5194/acp-18-17863-2018, https://doi.org/10.5194/acp-18-17863-2018, 2018
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Understanding the connections between aerosols, solar radiation and photosynthesis in terrestrial ecosystems is important for estimates of the CO2 balance in the atmosphere. Atmospheric aerosols and clouds influence solar radiation. In this study, we quantify the aerosol effect on solar radiation in boreal forests and study forest ecosystems response to this change in the radiation conditions. The analysis is based on atmospheric observations from several remote stations in Eurasian forests.
Liqing Hao, Olga Garmash, Mikael Ehn, Pasi Miettinen, Paola Massoli, Santtu Mikkonen, Tuija Jokinen, Pontus Roldin, Pasi Aalto, Taina Yli-Juuti, Jorma Joutsensaari, Tuukka Petäjä, Markku Kulmala, Kari E. J. Lehtinen, Douglas R. Worsnop, and Annele Virtanen
Atmos. Chem. Phys., 18, 17705–17716, https://doi.org/10.5194/acp-18-17705-2018, https://doi.org/10.5194/acp-18-17705-2018, 2018
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An aerosol mass spectrometer was used to characterize aerosol chemical composition during new particle formation periods. The time profiles of mass concentrations and chemical composition of observed aerosol particles are subjected to joint effects of boundary layer dilution, atmospheric chemistry and aerosol mixing in different boundary layers. During the nighttime, the increase in organic aerosol mass correlated well with the increase in condensed highly oxygenated organic molecules' mass.
Qiaozhi Zha, Chao Yan, Heikki Junninen, Matthieu Riva, Nina Sarnela, Juho Aalto, Lauriane Quéléver, Simon Schallhart, Lubna Dada, Liine Heikkinen, Otso Peräkylä, Jun Zou, Clémence Rose, Yonghong Wang, Ivan Mammarella, Gabriel Katul, Timo Vesala, Douglas R. Worsnop, Markku Kulmala, Tuukka Petäjä, Federico Bianchi, and Mikael Ehn
Atmos. Chem. Phys., 18, 17437–17450, https://doi.org/10.5194/acp-18-17437-2018, https://doi.org/10.5194/acp-18-17437-2018, 2018
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Vertical measurements of highly oxygenated molecules (HOMs) below and above the forest canopy were performed for the first time in a boreal forest during September 2016. Our results highlight that near-ground HOM measurements may only be representative of a small fraction of the entire nocturnal boundary layer, which may sequentially influence the growth of newly formed particles and SOA formation close to ground surface, where the majority of measurements are conducted.
Cristina Carnerero, Noemí Pérez, Cristina Reche, Marina Ealo, Gloria Titos, Hong-Ku Lee, Hee-Ram Eun, Yong-Hee Park, Lubna Dada, Pauli Paasonen, Veli-Matti Kerminen, Enrique Mantilla, Miguel Escudero, Francisco J. Gómez-Moreno, Elisabeth Alonso-Blanco, Esther Coz, Alfonso Saiz-Lopez, Brice Temime-Roussel, Nicolas Marchand, David C. S. Beddows, Roy M. Harrison, Tuukka Petäjä, Markku Kulmala, Kang-Ho Ahn, Andrés Alastuey, and Xavier Querol
Atmos. Chem. Phys., 18, 16601–16618, https://doi.org/10.5194/acp-18-16601-2018, https://doi.org/10.5194/acp-18-16601-2018, 2018
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The vertical distribution of new particle formation events was studied using tethered balloons carrying miniaturized instrumentation. Results show that new particle formation and growth occurs only in the lower layer of the atmosphere, where aerosols are mixed due to convection, especially when the atmosphere is clean. A comparison of urban and suburban surface stations was also made, suggesting that such events may have a significant impact on ultrafine particle concentrations in a wide area.
Tracey Leah Laban, Pieter Gideon van Zyl, Johan Paul Beukes, Ville Vakkari, Kerneels Jaars, Nadine Borduas-Dedekind, Miroslav Josipovic, Anne Mee Thompson, Markku Kulmala, and Lauri Laakso
Atmos. Chem. Phys., 18, 15491–15514, https://doi.org/10.5194/acp-18-15491-2018, https://doi.org/10.5194/acp-18-15491-2018, 2018
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Surface O3 was measured at four sites in the north-eastern interior of South Africa, which revealed that O3 is a regional problem in continental South Africa, with elevated O3 levels found at rural background and industrial sites. Increased O3 concentrations were associated with high CO levels predominantly related to regional biomass burning, while the O3 production regime was established to be predominantly VOC limited. Increased O3 is associated with strong seasonality of precursor sources.
Ulpu Leijala, Jan-Victor Björkqvist, Milla M. Johansson, Havu Pellikka, Lauri Laakso, and Kimmo K. Kahma
Nat. Hazards Earth Syst. Sci., 18, 2785–2799, https://doi.org/10.5194/nhess-18-2785-2018, https://doi.org/10.5194/nhess-18-2785-2018, 2018
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The coastal flooding risks based on the combined effect of sea level variations and wind-generated waves are estimated for the present, 2050 and 2100. The variability of the wave conditions between the two case study locations in the Helsinki archipelago leads to a difference in the safe building levels of up to 1 m. The rising mean sea level in the Gulf of Finland and the uncertainty of the associated scenarios contribute to the flooding risks notably in 2100.
Tuomo Nieminen, Veli-Matti Kerminen, Tuukka Petäjä, Pasi P. Aalto, Mikhail Arshinov, Eija Asmi, Urs Baltensperger, David C. S. Beddows, Johan Paul Beukes, Don Collins, Aijun Ding, Roy M. Harrison, Bas Henzing, Rakesh Hooda, Min Hu, Urmas Hõrrak, Niku Kivekäs, Kaupo Komsaare, Radovan Krejci, Adam Kristensson, Lauri Laakso, Ari Laaksonen, W. Richard Leaitch, Heikki Lihavainen, Nikolaos Mihalopoulos, Zoltán Németh, Wei Nie, Colin O'Dowd, Imre Salma, Karine Sellegri, Birgitta Svenningsson, Erik Swietlicki, Peter Tunved, Vidmantas Ulevicius, Ville Vakkari, Marko Vana, Alfred Wiedensohler, Zhijun Wu, Annele Virtanen, and Markku Kulmala
Atmos. Chem. Phys., 18, 14737–14756, https://doi.org/10.5194/acp-18-14737-2018, https://doi.org/10.5194/acp-18-14737-2018, 2018
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Atmospheric aerosols have diverse effects on air quality, human health, and global climate. One important source of aerosols is their formation via nucleation and growth in the atmosphere. We have analyzed long-term observations of regional new particle formation events around the globe and provide a comprehensive view on the characteristics of this phenomenon in diverse environments. The results are useful in developing more realistic representation of atmospheric aerosols in global models.
Heidi Hellén, Arnaud P. Praplan, Toni Tykkä, Ilona Ylivinkka, Ville Vakkari, Jaana Bäck, Tuukka Petäjä, Markku Kulmala, and Hannele Hakola
Atmos. Chem. Phys., 18, 13839–13863, https://doi.org/10.5194/acp-18-13839-2018, https://doi.org/10.5194/acp-18-13839-2018, 2018
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Exceptionally large ambient air concentration datasets of VOCs were measured in a boreal forest. For the first time concentration of the main sesquiterpene (β-caryophyllene) emitted by the local trees was also measured. Sesquiterpenes were found to have a major impact on local atmospheric chemistry, even though their concentrations were 30 times lower than the monoterpene concentrations. In addition, sesquiterpenes are expected to have a high impact on local secondary organic aerosol production.
David Patoulias, Christos Fountoukis, Ilona Riipinen, Ari Asmi, Markku Kulmala, and Spyros N. Pandis
Atmos. Chem. Phys., 18, 13639–13654, https://doi.org/10.5194/acp-18-13639-2018, https://doi.org/10.5194/acp-18-13639-2018, 2018
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PMCAMx-UF, a 3-D chemical transport model focusing on the simulation of ultrafine particles, has been extended with the addition of the volatility basis set (VBS) approach for the simulation of organic aerosol. The model was applied in Europe and its predictions were evaluated against field observations collected during the PEGASOS 2012 campaign. The condensation of organics led to an increase (50–120 %) in the larger particles but the total number concentration decreased by 10–30 %.
Jenni Kontkanen, Tinja Olenius, Markku Kulmala, and Ilona Riipinen
Atmos. Chem. Phys., 18, 13733–13754, https://doi.org/10.5194/acp-18-13733-2018, https://doi.org/10.5194/acp-18-13733-2018, 2018
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New particle formation involving sulfuric acid, bases and organic compounds is an important source of atmospheric aerosol particles. We investigate the capability of nano-Köhler theory to describe this process by simulating the dynamics of atmospheric molecular clusters. We find that nano-Köhler-type behavior occurs in our simulations when the saturation ratio of the organic vapor and the ratio between organic and inorganic vapor concentrations are in a suitable range.
Martti Honkanen, Juha-Pekka Tuovinen, Tuomas Laurila, Timo Mäkelä, Juha Hatakka, Sami Kielosto, and Lauri Laakso
Atmos. Meas. Tech., 11, 5335–5350, https://doi.org/10.5194/amt-11-5335-2018, https://doi.org/10.5194/amt-11-5335-2018, 2018
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The exchange rate of carbon dioxide (CO2) between the atmosphere and the sea is typically small compared to the fluxes observed in the terrestrial ecosystems, causing technical challenges for the measurements of the CO2 sea–air fluxes. In this paper, we examine CO2 sea–air flux measurements carried out on a fixed station on an island. The problems generated by water vapor interference and unmet theoretical assumptions of the eddy covariance method are addressed.
Pertti Hari, Steffen Noe, Sigrid Dengel, Jan Elbers, Bert Gielen, Veli-Matti Kerminen, Bart Kruijt, Liisa Kulmala, Anders Lindroth, Ivan Mammarella, Tuukka Petäjä, Guy Schurgers, Anni Vanhatalo, Markku Kulmala, and Jaana Bäck
Atmos. Chem. Phys., 18, 13321–13328, https://doi.org/10.5194/acp-18-13321-2018, https://doi.org/10.5194/acp-18-13321-2018, 2018
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The development of eddy-covariance measurements of ecosystem CO2 fluxes began a new era in the field studies of photosynthesis. The interpretation of the very variable CO2 fluxes in evergreen forests has been problematic especially in seasonal transition times. We apply two theoretical needle-level equations and show they can predict photosynthetic CO2 flux between the atmosphere and Scots pine forests. This has strong implications for the interpretation of the global change and boreal forests.
Daniela Wimmer, Stephany Buenrostro Mazon, Hanna Elina Manninen, Juha Kangasluoma, Alessandro Franchin, Tuomo Nieminen, John Backman, Jian Wang, Chongai Kuang, Radovan Krejci, Joel Brito, Fernando Goncalves Morais, Scot Turnbull Martin, Paulo Artaxo, Markku Kulmala, Veli-Matti Kerminen, and Tuukka Petäjä
Atmos. Chem. Phys., 18, 13245–13264, https://doi.org/10.5194/acp-18-13245-2018, https://doi.org/10.5194/acp-18-13245-2018, 2018
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This work focuses on understanding the production of very small airborne particles in the undisturbed environment of the Amazon basin. Computer models have shown that up to 70 % of these tiny particles are responsible for cloud formation on a global scale. The processes behind the production of these very small particles have been studied intensely recently. Their appearance has been observed almost all over the world. We directly measure sub-3 nm aerosols for the first time in the Amazon basin.
Chao Yan, Lubna Dada, Clémence Rose, Tuija Jokinen, Wei Nie, Siegfried Schobesberger, Heikki Junninen, Katrianne Lehtipalo, Nina Sarnela, Ulla Makkonen, Olga Garmash, Yonghong Wang, Qiaozhi Zha, Pauli Paasonen, Federico Bianchi, Mikko Sipilä, Mikael Ehn, Tuukka Petäjä, Veli-Matti Kerminen, Douglas R. Worsnop, and Markku Kulmala
Atmos. Chem. Phys., 18, 13231–13243, https://doi.org/10.5194/acp-18-13231-2018, https://doi.org/10.5194/acp-18-13231-2018, 2018
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Ions can play an important role in atmospheric new particle formation by stabilizing the embryonic clusters. Such a process is called ion-induced nucleation (IIN). We found two distinct IIN mechanisms – driven by H2SO4-NH3 clusters and by organic vapors, respectively. The concentration ratio of organic vapors to H2SO4 regulates via which pathway the IIN occur. As the organic vapor concentration is influenced by temperature, a seasonal variation in the main IIN mechanism can be expected.
Martha A. Zaidan, Ville Haapasilta, Rishi Relan, Pauli Paasonen, Veli-Matti Kerminen, Heikki Junninen, Markku Kulmala, and Adam S. Foster
Atmos. Chem. Phys., 18, 12699–12714, https://doi.org/10.5194/acp-18-12699-2018, https://doi.org/10.5194/acp-18-12699-2018, 2018
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This article promotes the use of the mutual information method for finding any non-linear associations among atmospheric variables. We demonstrate that the same results from previous studies are obtained by this method, which operates without supervision and without the need of understanding the physics deeply. This suggests that the method is suitable to be implemented widely in the atmospheric field to discover other interesting phenomena and their relevant variables.
Pauli Paasonen, Maija Peltola, Jenni Kontkanen, Heikki Junninen, Veli-Matti Kerminen, and Markku Kulmala
Atmos. Chem. Phys., 18, 12085–12103, https://doi.org/10.5194/acp-18-12085-2018, https://doi.org/10.5194/acp-18-12085-2018, 2018
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We determine aerosol growth rates in diameter ranges from below 10 to over 300 nm from long-term data with a novel automatic method. We show that aerosol growth rate in boreal forest increases with increasing particle diameter from 10 nm to cloud condensation nuclei (CCN) sizes and that the growth rate of sub-CCN particles is not suppressed by increasing condensation sink. Our findings suggest that aerosol growth to CCN sizes is a faster and less self-regulated process than previously estimated.
Ximeng Qi, Aijun Ding, Pontus Roldin, Zhengning Xu, Putian Zhou, Nina Sarnela, Wei Nie, Xin Huang, Anton Rusanen, Mikael Ehn, Matti P. Rissanen, Tuukka Petäjä, Markku Kulmala, and Michael Boy
Atmos. Chem. Phys., 18, 11779–11791, https://doi.org/10.5194/acp-18-11779-2018, https://doi.org/10.5194/acp-18-11779-2018, 2018
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In this study we simulate the HOM concentrations and discuss their roles in NPF at a remote boreal forest site in Finland and a suburban site in eastern China. We found that sulfuric acid and HOM organonitrate concentrations in the gas phase are significantly higher but other HOM monomers and dimers from monoterpene oxidation are lower in eastern China. This study highlights the need for molecular-scale measurements in improving the understanding of NPF mechanisms in polluted areas.
Anna Nikandrova, Ksenia Tabakova, Antti Manninen, Riikka Väänänen, Tuukka Petäjä, Markku Kulmala, Veli-Matti Kerminen, and Ewan O'Connor
Atmos. Chem. Phys., 18, 10575–10591, https://doi.org/10.5194/acp-18-10575-2018, https://doi.org/10.5194/acp-18-10575-2018, 2018
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We investigated temporal and vertical aerosol properties in a rural environment during BAECC (Biogenic Aerosols – Effects on Cloud and Climate) campaign. Differences were observed in aerosol number size distribution, variability and mixing in the layers between two case studies: clear-sky and partly cloudy case. We also conclude that care should be taken in selecting appropriate arrival heights of backward trajectories, since the modelled and observed layer heights did not always coincide.
Luciana Varanda Rizzo, Pontus Roldin, Joel Brito, John Backman, Erik Swietlicki, Radovan Krejci, Peter Tunved, Tukka Petäjä, Markku Kulmala, and Paulo Artaxo
Atmos. Chem. Phys., 18, 10255–10274, https://doi.org/10.5194/acp-18-10255-2018, https://doi.org/10.5194/acp-18-10255-2018, 2018
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Aerosols are tiny particles suspended in the air that can interact with sunlight and form clouds, which in turn affect the climate. They can also recycle nutrients in forest environments. Aerosols are naturally emitted at the surface in the Amazon forest, in addition to being brought down from above the boundary layer by intense air movements. In this work, we describe how the particle size number concentrations of aerosols change over hours, days and seasons in a multi-year study in Amazonia.
Filippo Xausa, Pauli Paasonen, Risto Makkonen, Mikhail Arshinov, Aijun Ding, Hugo Denier Van Der Gon, Veli-Matti Kerminen, and Markku Kulmala
Atmos. Chem. Phys., 18, 10039–10054, https://doi.org/10.5194/acp-18-10039-2018, https://doi.org/10.5194/acp-18-10039-2018, 2018
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Our project describes the feasibility of implementing particle number emissions taken from the GAINS model in global climate modeling through a simulation with the ECHAM-HAM global climate model. The results from the simulations have important implications regarding modeled particle number concentrations and future climate effects. Our findings represent an important starting point for further simulations concerning climate effects derived from anthropogenic particle emissions on a global scale.
Lauri Laakso, Santtu Mikkonen, Achim Drebs, Anu Karjalainen, Pentti Pirinen, and Pekka Alenius
Ocean Sci., 14, 617–632, https://doi.org/10.5194/os-14-617-2018, https://doi.org/10.5194/os-14-617-2018, 2018
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Meteorological observations at Utö Atmospheric and Marine Research Station, the Baltic Sea, started in 1881 and seawater temperature and salinity observations in 1900. Based on the dataset of more than 100 years of observations, we see an increase in atmospheric temperature after the 1980s, in line with reduced sea ice cover. We also found an increase in seawater temperatures, modulated by changes in salinities. The results indicate that the climate at Utö may have shifted into a new phase.
Kari Minkkinen, Paavo Ojanen, Timo Penttilä, Mika Aurela, Tuomas Laurila, Juha-Pekka Tuovinen, and Annalea Lohila
Biogeosciences, 15, 3603–3624, https://doi.org/10.5194/bg-15-3603-2018, https://doi.org/10.5194/bg-15-3603-2018, 2018
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Drainage often turns peatlands into C sources. We measured C dynamics of a drained forested boreal peatland over 4 years, including one with a drought during growing season. The drained peatland ecosystem was a strong sink of C in all studied years. Also, the peat soil sequestered C. A drought period in one summer significantly decreased C sequestration through decreased gross primary production, but since the drought also decreased ecosystem respiration, the site remained a C sink.
Marco Pandolfi, Lucas Alados-Arboledas, Andrés Alastuey, Marcos Andrade, Christo Angelov, Begoña Artiñano, John Backman, Urs Baltensperger, Paolo Bonasoni, Nicolas Bukowiecki, Martine Collaud Coen, Sébastien Conil, Esther Coz, Vincent Crenn, Vadimas Dudoitis, Marina Ealo, Kostas Eleftheriadis, Olivier Favez, Prodromos Fetfatzis, Markus Fiebig, Harald Flentje, Patrick Ginot, Martin Gysel, Bas Henzing, Andras Hoffer, Adela Holubova Smejkalova, Ivo Kalapov, Nikos Kalivitis, Giorgos Kouvarakis, Adam Kristensson, Markku Kulmala, Heikki Lihavainen, Chris Lunder, Krista Luoma, Hassan Lyamani, Angela Marinoni, Nikos Mihalopoulos, Marcel Moerman, José Nicolas, Colin O'Dowd, Tuukka Petäjä, Jean-Eudes Petit, Jean Marc Pichon, Nina Prokopciuk, Jean-Philippe Putaud, Sergio Rodríguez, Jean Sciare, Karine Sellegri, Erik Swietlicki, Gloria Titos, Thomas Tuch, Peter Tunved, Vidmantas Ulevicius, Aditya Vaishya, Milan Vana, Aki Virkkula, Stergios Vratolis, Ernest Weingartner, Alfred Wiedensohler, and Paolo Laj
Atmos. Chem. Phys., 18, 7877–7911, https://doi.org/10.5194/acp-18-7877-2018, https://doi.org/10.5194/acp-18-7877-2018, 2018
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This investigation presents the variability in near-surface in situ aerosol particle light-scattering measurements obtained over the past decade at 28 measuring atmospheric observatories which are part of the ACTRIS Research Infrastructure, and most of them belong to the GAW network. This paper provides a comprehensive picture of the spatial and temporal variability of aerosol particles optical properties in Europe.
Juha Mikola, Tarmo Virtanen, Maiju Linkosalmi, Emmi Vähä, Johanna Nyman, Olga Postanogova, Aleksi Räsänen, D. Johan Kotze, Tuomas Laurila, Sari Juutinen, Vladimir Kondratyev, and Mika Aurela
Biogeosciences, 15, 2781–2801, https://doi.org/10.5194/bg-15-2781-2018, https://doi.org/10.5194/bg-15-2781-2018, 2018
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To support C exchange measurements, we examined plant and soil attributes in Siberian Arctic tundra. Our results illustrate a typical tundra ecosystem with great spatial variation. Mosses dominate plant biomass and control many soil attributes such as temperature, but variation in moss biomass is difficult to capture by remote sensing. This indicates challenges in spatial extrapolation of some of those plant and soil attributes that are relevant for regional ecosystem and global climate models.
Vladimir Melnikov, Viktor Gennadinik, Markku Kulmala, Hanna K. Lappalainen, Tuukka Petäjä, and Sergej Zilitinkevich
Atmos. Chem. Phys., 18, 6535–6542, https://doi.org/10.5194/acp-18-6535-2018, https://doi.org/10.5194/acp-18-6535-2018, 2018
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The cryosphere of the Earth overlaps with the atmosphere, hydrosphere and lithosphere over vast areas with temperatures below zero C and pronounced H2O phase changes. The cryosphere plays the role of a global thermostat; however, the processes related to the cryosphere attract insufficient attention from research communities. We call attention to crucial importance of cryogenic anomalies, which make the Earth atmosphere and the entire Earth system unique.
Marja Hemmilä, Heidi Hellén, Aki Virkkula, Ulla Makkonen, Arnaud P. Praplan, Jenni Kontkanen, Lauri Ahonen, Markku Kulmala, and Hannele Hakola
Atmos. Chem. Phys., 18, 6367–6380, https://doi.org/10.5194/acp-18-6367-2018, https://doi.org/10.5194/acp-18-6367-2018, 2018
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We measured gas- and particle-phase amine and ammonia concentrations in a boreal forest site in 2015 with online ion chromatography coupled with mass spectrometry. We wanted to know how much and which kinds of amines there are, and how they behave and could affect nucleation. We observed seasonal and diurnal variations for different amines. Amines turned out to be a heterogeneous group of compounds. To our best knowledge, our amine measurements are the longest time series that has been made.
Yicheng Shen, Aki Virkkula, Aijun Ding, Jiaping Wang, Xuguang Chi, Wei Nie, Ximeng Qi, Xin Huang, Qiang Liu, Longfei Zheng, Zheng Xu, Tuukka Petäjä, Pasi P. Aalto, Congbin Fu, and Markku Kulmala
Atmos. Chem. Phys., 18, 5265–5292, https://doi.org/10.5194/acp-18-5265-2018, https://doi.org/10.5194/acp-18-5265-2018, 2018
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Aerosol optical properties (AOPs) were measured at SORPES, a regional background station in Nanjing, China from June 2013 to May 2015. The aerosol was highly scattering. The single-scattering albedo in Nanjing appears to be slightly higher than at several other sites. The data do not suggest any significant contribution to absorption by brown carbon. The sources of high values are mainly in eastern China. During pollution episodes, pollutant concentrations increased gradually but decreased fast.
Joonas Enroth, Jyri Mikkilä, Zoltán Németh, Markku Kulmala, and Imre Salma
Atmos. Chem. Phys., 18, 4533–4548, https://doi.org/10.5194/acp-18-4533-2018, https://doi.org/10.5194/acp-18-4533-2018, 2018
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The urban aerosol particles in central Budapest consist of two externally mixed classes – nearly hydrophobic and less volatile particles, which were assigned to vehicle emissions (large mass fractions of soot likely coated with water-insoluble organic compounds) – and of less hygroscopic and volatile particles (moderately transformed aged combustion particles composed of partly oxygenated organics and inorganic salts internally mixed).
Aino Korrensalo, Elisa Männistö, Pavel Alekseychik, Ivan Mammarella, Janne Rinne, Timo Vesala, and Eeva-Stiina Tuittila
Biogeosciences, 15, 1749–1761, https://doi.org/10.5194/bg-15-1749-2018, https://doi.org/10.5194/bg-15-1749-2018, 2018
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We measured methane fluxes of a boreal bog from six different plant community types in 2012–2014. We found only little variation in methane fluxes among plant community types. Peat temperature as well as both leaf area of plant species with air channels and of all vegetation are important factors controlling the fluxes. We also detected negative net fluxes indicating methane consumption each year. Our results can be used to improve the models of peatland methane dynamics under climate change.
Julia Schmale, Silvia Henning, Stefano Decesari, Bas Henzing, Helmi Keskinen, Karine Sellegri, Jurgita Ovadnevaite, Mira L. Pöhlker, Joel Brito, Aikaterini Bougiatioti, Adam Kristensson, Nikos Kalivitis, Iasonas Stavroulas, Samara Carbone, Anne Jefferson, Minsu Park, Patrick Schlag, Yoko Iwamoto, Pasi Aalto, Mikko Äijälä, Nicolas Bukowiecki, Mikael Ehn, Göran Frank, Roman Fröhlich, Arnoud Frumau, Erik Herrmann, Hartmut Herrmann, Rupert Holzinger, Gerard Kos, Markku Kulmala, Nikolaos Mihalopoulos, Athanasios Nenes, Colin O'Dowd, Tuukka Petäjä, David Picard, Christopher Pöhlker, Ulrich Pöschl, Laurent Poulain, André Stephan Henry Prévôt, Erik Swietlicki, Meinrat O. Andreae, Paulo Artaxo, Alfred Wiedensohler, John Ogren, Atsushi Matsuki, Seong Soo Yum, Frank Stratmann, Urs Baltensperger, and Martin Gysel
Atmos. Chem. Phys., 18, 2853–2881, https://doi.org/10.5194/acp-18-2853-2018, https://doi.org/10.5194/acp-18-2853-2018, 2018
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Collocated long-term observations of cloud condensation nuclei (CCN) number concentrations, particle number size distributions and chemical composition from 12 sites are synthesized. Observations cover coastal environments, the Arctic, the Mediterranean, the boreal and rain forest, high alpine and continental background sites, and Monsoon-influenced areas. We interpret regional and seasonal variability. CCN concentrations are predicted with the κ–Köhler model and compared to the measurements.
Nina Sarnela, Tuija Jokinen, Jonathan Duplissy, Chao Yan, Tuomo Nieminen, Mikael Ehn, Siegfried Schobesberger, Martin Heinritzi, Sebastian Ehrhart, Katrianne Lehtipalo, Jasmin Tröstl, Mario Simon, Andreas Kürten, Markus Leiminger, Michael J. Lawler, Matti P. Rissanen, Federico Bianchi, Arnaud P. Praplan, Jani Hakala, Antonio Amorim, Marc Gonin, Armin Hansel, Jasper Kirkby, Josef Dommen, Joachim Curtius, James N. Smith, Tuukka Petäjä, Douglas R. Worsnop, Markku Kulmala, Neil M. Donahue, and Mikko Sipilä
Atmos. Chem. Phys., 18, 2363–2380, https://doi.org/10.5194/acp-18-2363-2018, https://doi.org/10.5194/acp-18-2363-2018, 2018
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Atmospheric trace gases can form small molecular clusters, which can grow to larger sizes through the condensation of vapours. This process is called new particle formation. In this paper we studied the formation of sulfuric acid and highly oxygenated molecules, the key compounds in atmospheric new particle formation, in chamber experiments and introduced a way to simulate these ozonolysis products of α-pinene in a simple manner.
Ekaterina Ezhova, Veli-Matti Kerminen, Kari E. J. Lehtinen, and Markku Kulmala
Atmos. Chem. Phys., 18, 2431–2442, https://doi.org/10.5194/acp-18-2431-2018, https://doi.org/10.5194/acp-18-2431-2018, 2018
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A condensation sink (CS) quantifies the rate of uptake of condensing vapours by pre-existing aerosol and can be used as well to quantify losses of monomers/clusters. An analytical solution of the condensation equation valid in a wide range of particle diameters is presented. We describe the dynamics of atmospheric CS, test the formulas against field observations and further use them to develop a simplified model of the coupled dynamics of aerosol and condensing vapours in the atmosphere.
Luís Miguel Feijó Barreira, Geoffroy Duporté, Tuukka Rönkkö, Jevgeni Parshintsev, Kari Hartonen, Lydia Hyrsky, Enna Heikkinen, Matti Jussila, Markku Kulmala, and Marja-Liisa Riekkola
Atmos. Meas. Tech., 11, 881–893, https://doi.org/10.5194/amt-11-881-2018, https://doi.org/10.5194/amt-11-881-2018, 2018
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Our results demonstrated the benefits and challenges of using new SPME Arrow over SPME fiber for the sampling of BVOCs emitted by terrestrial vegetation in the atmosphere. The new SPME Arrow system showed significant improvement on sampling capacity, with collected amounts being approximately 2 times higher for monoterpenes and 7–8 times higher for aldehydes than with SPME fiber. Higher extraction efficiencies were obtained with dynamic collection prior to equilibrium regime.
Johannes Größ, Amar Hamed, André Sonntag, Gerald Spindler, Hanna Elina Manninen, Tuomo Nieminen, Markku Kulmala, Urmas Hõrrak, Christian Plass-Dülmer, Alfred Wiedensohler, and Wolfram Birmili
Atmos. Chem. Phys., 18, 1835–1861, https://doi.org/10.5194/acp-18-1835-2018, https://doi.org/10.5194/acp-18-1835-2018, 2018
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This paper revisits the atmospheric new particle formation (NPF) process in the polluted troposphere. Novel aspects include a new NPF classification, which aims at more objectivity, and a long-term analysis of neutral cluster and air ion spectrometer data. Intense NPF events were associated with enhanced sulfur dioxide concentrations and solar radiation, while no significant relationships were observed with the condensation sink, surface-measured turbulence parameters, or ammonia.
Chunjing Qiu, Dan Zhu, Philippe Ciais, Bertrand Guenet, Gerhard Krinner, Shushi Peng, Mika Aurela, Christian Bernhofer, Christian Brümmer, Syndonia Bret-Harte, Housen Chu, Jiquan Chen, Ankur R. Desai, Jiří Dušek, Eugénie S. Euskirchen, Krzysztof Fortuniak, Lawrence B. Flanagan, Thomas Friborg, Mateusz Grygoruk, Sébastien Gogo, Thomas Grünwald, Birger U. Hansen, David Holl, Elyn Humphreys, Miriam Hurkuck, Gerard Kiely, Janina Klatt, Lars Kutzbach, Chloé Largeron, Fatima Laggoun-Défarge, Magnus Lund, Peter M. Lafleur, Xuefei Li, Ivan Mammarella, Lutz Merbold, Mats B. Nilsson, Janusz Olejnik, Mikaell Ottosson-Löfvenius, Walter Oechel, Frans-Jan W. Parmentier, Matthias Peichl, Norbert Pirk, Olli Peltola, Włodzimierz Pawlak, Daniel Rasse, Janne Rinne, Gaius Shaver, Hans Peter Schmid, Matteo Sottocornola, Rainer Steinbrecher, Torsten Sachs, Marek Urbaniak, Donatella Zona, and Klaudia Ziemblinska
Geosci. Model Dev., 11, 497–519, https://doi.org/10.5194/gmd-11-497-2018, https://doi.org/10.5194/gmd-11-497-2018, 2018
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Northern peatlands store large amount of soil carbon and are vulnerable to climate change. We implemented peatland hydrological and carbon accumulation processes into the ORCHIDEE land surface model. The model was evaluated against EC measurements from 30 northern peatland sites. The model generally well reproduced the spatial gradient and temporal variations in GPP and NEE at these sites. Water table depth was not well predicted but had only small influence on simulated NEE.
Mikko Peltoniemi, Mika Aurela, Kristin Böttcher, Pasi Kolari, John Loehr, Jouni Karhu, Maiju Linkosalmi, Cemal Melih Tanis, Juha-Pekka Tuovinen, and Ali Nadir Arslan
Earth Syst. Sci. Data, 10, 173–184, https://doi.org/10.5194/essd-10-173-2018, https://doi.org/10.5194/essd-10-173-2018, 2018
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Monitoring ecosystems using low-cost time lapse cameras has gained wide interest among researchers worldwide. Quantitative information stored in image pixels can be analysed automatically to track time-dependent phenomena, e.g. seasonal course of leaves in the canopies or snow on ground. As such, cameras can provide valuable ground references to earth observation. Here we document the ecosystem camera network we established to Finland and publish time series of images recorded between 2014–2016.
Simon Schallhart, Pekka Rantala, Maija K. Kajos, Juho Aalto, Ivan Mammarella, Taina M. Ruuskanen, and Markku Kulmala
Atmos. Chem. Phys., 18, 815–832, https://doi.org/10.5194/acp-18-815-2018, https://doi.org/10.5194/acp-18-815-2018, 2018
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Emissions of volatile organic compounds (VOCs) have impact to air quality, human health and climate. We investigated the development of VOC exchange in a boreal forest between April and June 2013. VOC exchange and diversity increased towards summer, but over 75 % of the biogenic net exchange was driven by methanol, monoterpenes and acetone only. The boreal forest emitted less than 0.2 % carbon in form of VOCs in relation to the carbon uptake.
Andreas Kürten, Chenxi Li, Federico Bianchi, Joachim Curtius, António Dias, Neil M. Donahue, Jonathan Duplissy, Richard C. Flagan, Jani Hakala, Tuija Jokinen, Jasper Kirkby, Markku Kulmala, Ari Laaksonen, Katrianne Lehtipalo, Vladimir Makhmutov, Antti Onnela, Matti P. Rissanen, Mario Simon, Mikko Sipilä, Yuri Stozhkov, Jasmin Tröstl, Penglin Ye, and Peter H. McMurry
Atmos. Chem. Phys., 18, 845–863, https://doi.org/10.5194/acp-18-845-2018, https://doi.org/10.5194/acp-18-845-2018, 2018
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A recent laboratory study (CLOUD) showed that new particles nucleate efficiently from sulfuric acid and dimethylamine (DMA). The reanalysis of previously published data reveals that the nucleation rates are even faster than previously assumed, i.e., nucleation can proceed at rates that are compatible with collision-controlled new particle formation for atmospheric conditions. This indicates that sulfuric acid–DMA nucleation is likely an important source of particles in the boundary layer.
Carla Frege, Ismael K. Ortega, Matti P. Rissanen, Arnaud P. Praplan, Gerhard Steiner, Martin Heinritzi, Lauri Ahonen, António Amorim, Anne-Kathrin Bernhammer, Federico Bianchi, Sophia Brilke, Martin Breitenlechner, Lubna Dada, António Dias, Jonathan Duplissy, Sebastian Ehrhart, Imad El-Haddad, Lukas Fischer, Claudia Fuchs, Olga Garmash, Marc Gonin, Armin Hansel, Christopher R. Hoyle, Tuija Jokinen, Heikki Junninen, Jasper Kirkby, Andreas Kürten, Katrianne Lehtipalo, Markus Leiminger, Roy Lee Mauldin, Ugo Molteni, Leonid Nichman, Tuukka Petäjä, Nina Sarnela, Siegfried Schobesberger, Mario Simon, Mikko Sipilä, Dominik Stolzenburg, António Tomé, Alexander L. Vogel, Andrea C. Wagner, Robert Wagner, Mao Xiao, Chao Yan, Penglin Ye, Joachim Curtius, Neil M. Donahue, Richard C. Flagan, Markku Kulmala, Douglas R. Worsnop, Paul M. Winkler, Josef Dommen, and Urs Baltensperger
Atmos. Chem. Phys., 18, 65–79, https://doi.org/10.5194/acp-18-65-2018, https://doi.org/10.5194/acp-18-65-2018, 2018
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It was recently shown that biogenic highly oxygenated molecules (HOMs) form particles in the absence of sulfuric acid and ions enhance the nucleation rate. Here we compare the molecular composition of positive and negative HOM clusters at 25, 5 and −25 °C. At lower temperatures the HOM average oxygen-to-carbon ratio decreases indicating a reduction in the rate of autoxidation due to rather high activation energy. The experimental findings are supported by quantum chemical calculations.
Xuemeng Chen, Lauriane L. J. Quéléver, Pak L. Fung, Jutta Kesti, Matti P. Rissanen, Jaana Bäck, Petri Keronen, Heikki Junninen, Tuukka Petäjä, Veli-Matti Kerminen, and Markku Kulmala
Atmos. Chem. Phys., 18, 49–63, https://doi.org/10.5194/acp-18-49-2018, https://doi.org/10.5194/acp-18-49-2018, 2018
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We analysed a 20-year-long dataset collected in a Finnish boreal forest at SMEAR II station to investigate the frequency and strength of ozone depletion events. We could identify a number of ozone depletion events that lasted for more than 3 h, mainly in the autumn and winter months. Their occurrence was likely related to the formation of a low mixing layer under the conditions of low temperatures, low wind speeds, high relative humidities and limited intensity of solar radiation.
Maarit Raivonen, Sampo Smolander, Leif Backman, Jouni Susiluoto, Tuula Aalto, Tiina Markkanen, Jarmo Mäkelä, Janne Rinne, Olli Peltola, Mika Aurela, Annalea Lohila, Marin Tomasic, Xuefei Li, Tuula Larmola, Sari Juutinen, Eeva-Stiina Tuittila, Martin Heimann, Sanna Sevanto, Thomas Kleinen, Victor Brovkin, and Timo Vesala
Geosci. Model Dev., 10, 4665–4691, https://doi.org/10.5194/gmd-10-4665-2017, https://doi.org/10.5194/gmd-10-4665-2017, 2017
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Wetlands are one of the most significant natural sources of the strong greenhouse gas methane. We developed a model that can be used within a larger wetland carbon model to simulate the methane emissions. In this study, we present the model and results of its testing. We found that the model works well with different settings and that the results depend primarily on the rate of input anoxic soil respiration and also on factors that affect the simulated oxygen concentrations in the wetland soil.
Robert Wagner, Chao Yan, Katrianne Lehtipalo, Jonathan Duplissy, Tuomo Nieminen, Juha Kangasluoma, Lauri R. Ahonen, Lubna Dada, Jenni Kontkanen, Hanna E. Manninen, Antonio Dias, Antonio Amorim, Paulus S. Bauer, Anton Bergen, Anne-Kathrin Bernhammer, Federico Bianchi, Sophia Brilke, Stephany Buenrostro Mazon, Xuemeng Chen, Danielle C. Draper, Lukas Fischer, Carla Frege, Claudia Fuchs, Olga Garmash, Hamish Gordon, Jani Hakala, Liine Heikkinen, Martin Heinritzi, Victoria Hofbauer, Christopher R. Hoyle, Jasper Kirkby, Andreas Kürten, Alexander N. Kvashnin, Tiia Laurila, Michael J. Lawler, Huajun Mai, Vladimir Makhmutov, Roy L. Mauldin III, Ugo Molteni, Leonid Nichman, Wei Nie, Andrea Ojdanic, Antti Onnela, Felix Piel, Lauriane L. J. Quéléver, Matti P. Rissanen, Nina Sarnela, Simon Schallhart, Kamalika Sengupta, Mario Simon, Dominik Stolzenburg, Yuri Stozhkov, Jasmin Tröstl, Yrjö Viisanen, Alexander L. Vogel, Andrea C. Wagner, Mao Xiao, Penglin Ye, Urs Baltensperger, Joachim Curtius, Neil M. Donahue, Richard C. Flagan, Martin Gallagher, Armin Hansel, James N. Smith, António Tomé, Paul M. Winkler, Douglas Worsnop, Mikael Ehn, Mikko Sipilä, Veli-Matti Kerminen, Tuukka Petäjä, and Markku Kulmala
Atmos. Chem. Phys., 17, 15181–15197, https://doi.org/10.5194/acp-17-15181-2017, https://doi.org/10.5194/acp-17-15181-2017, 2017
Pertti Hari, Veli-Matti Kerminen, Liisa Kulmala, Markku Kulmala, Steffen Noe, Tuukka Petäjä, Anni Vanhatalo, and Jaana Bäck
Atmos. Chem. Phys., 17, 15045–15053, https://doi.org/10.5194/acp-17-15045-2017, https://doi.org/10.5194/acp-17-15045-2017, 2017
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We developed a theory on the seasonal behaviour of photosynthesis in natural conditions and tested the theory with intensive measurements. Light, temperature, water vapor and CO2 concentration explained the daily variation in photosynthesis, and the physiological state of the photosynthetic machinery explained the annual pattern of photosynthesis. The theory explained about 95 % of the variance of photosynthesis measured with chambers in the field in northern Finland.
Xuemeng Chen, Aki Virkkula, Veli-Matti Kerminen, Hanna E. Manninen, Maurizio Busetto, Christian Lanconelli, Angelo Lupi, Vito Vitale, Massimo Del Guasta, Paolo Grigioni, Riikka Väänänen, Ella-Maria Duplissy, Tuukka Petäjä, and Markku Kulmala
Atmos. Chem. Phys., 17, 13783–13800, https://doi.org/10.5194/acp-17-13783-2017, https://doi.org/10.5194/acp-17-13783-2017, 2017
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An air ion spectrometer was deployed for characterizing air ions for the first time at the Concordia station at Dome C on the Antarctic Plateau. We observed different ion processes: new particle formation (NPF), wind-induced ion production, and ion formation related to cloud and/or fog formation. Insights into these phenomena are presented. Additionally, the analysis on the growth of NPF events showed a size dependency of growth rates (GRs), i.e. GRs increase with particle sizes.
Federico Bianchi, Olga Garmash, Xucheng He, Chao Yan, Siddharth Iyer, Ida Rosendahl, Zhengning Xu, Matti P. Rissanen, Matthieu Riva, Risto Taipale, Nina Sarnela, Tuukka Petäjä, Douglas R. Worsnop, Markku Kulmala, Mikael Ehn, and Heikki Junninen
Atmos. Chem. Phys., 17, 13819–13831, https://doi.org/10.5194/acp-17-13819-2017, https://doi.org/10.5194/acp-17-13819-2017, 2017
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Naturally charged highly oxidised molecules (HOMs) were characterized using advanced mass spectrometers. Two different classes of compounds, clustered with the nitrate and bisulfate ions, were identified: HOMs containing only carbon, hydrogen and oxygen and nitrogen-containing HOMs or organonitrates (ONs). They exhibit strong diurnal variations where HOMs peak during night and ONs during day. Finally, large clusters containing up to 40 carbon atoms (four oxidized
α-pinene units) were observed.
Elham Baranizadeh, Tuomo Nieminen, Taina Yli-Juuti, Markku Kulmala, Tuukka Petäjä, Ari Leskinen, Mika Komppula, Ari Laaksonen, and Kari E. J. Lehtinen
Atmos. Chem. Phys., 17, 13361–13371, https://doi.org/10.5194/acp-17-13361-2017, https://doi.org/10.5194/acp-17-13361-2017, 2017
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Extrapolation of the particle formation rates from one measured larger size (e.g., 7 nm) to smaller sizes (e.g., 3 nm) based on simplified growth-scavenging dynamics works fairly well to estimate mean daily formation rates, but it fails to predict the time evolution of the particle population. This points to the challenges in predicting atmospheric nucleation rates for locations where the particle growth and loss rates are size- and time-dependent.
Yao Gao, Tiina Markkanen, Mika Aurela, Ivan Mammarella, Tea Thum, Aki Tsuruta, Huiyi Yang, and Tuula Aalto
Biogeosciences, 14, 4409–4422, https://doi.org/10.5194/bg-14-4409-2017, https://doi.org/10.5194/bg-14-4409-2017, 2017
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We investigated the response of water use efficiency (WUE) to summer drought in a boreal Scots pine forest (Pinus sylvestris) on the daily time scale mainly using EC flux data from the Hyytiälä (southern Finland) flux site. Simulation results from the JSBACH land surface model were also evaluated against the observed results. The performance of three WUE metrics at the ecosystem level (EWUE, IWUE, and uWUE) during the severe summer drought were studied and showed different results.
Georgios Tsagkogeorgas, Pontus Roldin, Jonathan Duplissy, Linda Rondo, Jasmin Tröstl, Jay G. Slowik, Sebastian Ehrhart, Alessandro Franchin, Andreas Kürten, Antonio Amorim, Federico Bianchi, Jasper Kirkby, Tuukka Petäjä, Urs Baltensperger, Michael Boy, Joachim Curtius, Richard C. Flagan, Markku Kulmala, Neil M. Donahue, and Frank Stratmann
Atmos. Chem. Phys., 17, 8923–8938, https://doi.org/10.5194/acp-17-8923-2017, https://doi.org/10.5194/acp-17-8923-2017, 2017
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The H2SO4 vapour pressure plays key role in Earth's and Venus' atmospheres. In regions where RH is low and stabilising bases are scarce, H2SO4 can evaporate from particles; however the H2SO4 vapour pressure at low RH is uncertain. To address this, we measured H2SO4 evaporation versus T and RH in the CLOUD chamber and constrained the equilibrium constants for dissociation and dehydration of H2SO4. This study is important for nucleation, particle growth and H2SO4 formation occurring in atmosphere.
Thibaud Thonat, Marielle Saunois, Philippe Bousquet, Isabelle Pison, Zeli Tan, Qianlai Zhuang, Patrick M. Crill, Brett F. Thornton, David Bastviken, Ed J. Dlugokencky, Nikita Zimov, Tuomas Laurila, Juha Hatakka, Ove Hermansen, and Doug E. J. Worthy
Atmos. Chem. Phys., 17, 8371–8394, https://doi.org/10.5194/acp-17-8371-2017, https://doi.org/10.5194/acp-17-8371-2017, 2017
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Atmospheric methane simulations in the Arctic have been made for 2012 and compared to continuous observations at six measurement sites. All methane sources significantly affect the measurements at all stations, at least at the synoptic scale, except for biomass burning. An appropriate modelling framework combined with continuous observations of atmospheric methane enables us to gain knowledge on regional methane sources, including those which are usually poorly represented, such as freshwater.
Juha Kangasluoma, Susanne Hering, David Picard, Gregory Lewis, Joonas Enroth, Frans Korhonen, Markku Kulmala, Karine Sellegri, Michel Attoui, and Tuukka Petäjä
Atmos. Meas. Tech., 10, 2271–2281, https://doi.org/10.5194/amt-10-2271-2017, https://doi.org/10.5194/amt-10-2271-2017, 2017
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The manuscript presents a characterization of three new particle counters able to detect airborne nanoparticles smaller than 3 nm in diameter. We explored some of the parameters affecting the smallest detectable particle size, such as sample flow relative humidity, the particle chemical composition and the electrical charging state. The characterization results help one to select a suitable particle counter for a given application.
Lubna Dada, Pauli Paasonen, Tuomo Nieminen, Stephany Buenrostro Mazon, Jenni Kontkanen, Otso Peräkylä, Katrianne Lehtipalo, Tareq Hussein, Tuukka Petäjä, Veli-Matti Kerminen, Jaana Bäck, and Markku Kulmala
Atmos. Chem. Phys., 17, 6227–6241, https://doi.org/10.5194/acp-17-6227-2017, https://doi.org/10.5194/acp-17-6227-2017, 2017
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We studied new particle formation under clear-sky conditions in the boreal forest in southern Finland. We compared varying conditions between new particle events and nonevents. We then formulated a threshold value that separates new particle events from nonevents and reached a probability distribution for the frequency of new particle formation. This study serves as the basis for scientists aiming to improve their understanding of new particle formation.
Kgaugelo Euphinia Chiloane, Johan Paul Beukes, Pieter Gideon van Zyl, Petra Maritz, Ville Vakkari, Miroslav Josipovic, Andrew Derick Venter, Kerneels Jaars, Petri Tiitta, Markku Kulmala, Alfred Wiedensohler, Catherine Liousse, Gabisile Vuyisile Mkhatshwa, Avishkar Ramandh, and Lauri Laakso
Atmos. Chem. Phys., 17, 6177–6196, https://doi.org/10.5194/acp-17-6177-2017, https://doi.org/10.5194/acp-17-6177-2017, 2017
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This paper presents atmospheric black carbon (BC) data collected in South Africa (SA). In general, BC level were higher than in the developed world. At one site, five sources were identified, with household combustion as well as savannah and grassland fires the most significant sources during winter and spring, while coal-fired power stations, pyrometallurgical smelters and traffic contributed year round.
Eero Nikinmaa, Tuomo Kalliokoski, Kari Minkkinen, Jaana Bäck, Michael Boy, Yao Gao, Nina Janasik-Honkela, Janne I. Hukkinen, Maarit Kallio, Markku Kulmala, Nea Kuusinen, Annikki Mäkelä, Brent D. Matthies, Mikko Peltoniemi, Risto Sievänen, Ditte Taipale, Lauri Valsta, Anni Vanhatalo, Martin Welp, Luxi Zhou, Putian Zhou, and Frank Berninger
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-141, https://doi.org/10.5194/bg-2017-141, 2017
Manuscript not accepted for further review
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We estimated the impact of boreal forest management on climate, considering the effects of carbon, albedo, aerosols, and effects of industrial wood use. We made analyses both in current and warmer climate of 2050. The aerosol effect was comparable to that of carbon sequestration. Deciduous trees may have a large potential for mitigation due to their high albedo and aerosol effects. If the forests will be used more intensively and mainly for pulp and energy, the warming influence is clear.
Yuqin Liu, Gerrit de Leeuw, Veli-Matti Kerminen, Jiahua Zhang, Putian Zhou, Wei Nie, Ximeng Qi, Juan Hong, Yonghong Wang, Aijun Ding, Huadong Guo, Olaf Krüger, Markku Kulmala, and Tuukka Petäjä
Atmos. Chem. Phys., 17, 5623–5641, https://doi.org/10.5194/acp-17-5623-2017, https://doi.org/10.5194/acp-17-5623-2017, 2017
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The aerosol effects on warm cloud parameters over the Yangtze River Delta are systematically examined using multi-sensor retrievals. This study shows that the COT–CDR and CWP–CDR relationships are not unique, but are affected by atmospheric aerosol loading. CDR and cloud fraction show different behaviours for low and high AOD. Aerosol–cloud interaction (ACI) is stronger for clouds mixed with smoke aerosol than for clouds mixed with dust. Meteorological conditions play an important role in ACI.
Tea Thum, Sönke Zaehle, Philipp Köhler, Tuula Aalto, Mika Aurela, Luis Guanter, Pasi Kolari, Tuomas Laurila, Annalea Lohila, Federico Magnani, Christiaan Van Der Tol, and Tiina Markkanen
Biogeosciences, 14, 1969–1987, https://doi.org/10.5194/bg-14-1969-2017, https://doi.org/10.5194/bg-14-1969-2017, 2017
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Modelling seasonal cycle at the coniferous forests poses a challenge. We implemented a model for sun-induced chlorophyll fluorescence (SIF) to a land surface model JSBACH. It was used to study the seasonality of the carbon cycle in the Fenno-Scandinavian region. Comparison was made to direct CO2 flux measurements and satellite observations of SIF. SIF proved to be a better proxy for photosynthesis than the fraction of absorbed photosynthetically active radiation.
Mika Korkiakoski, Juha-Pekka Tuovinen, Mika Aurela, Markku Koskinen, Kari Minkkinen, Paavo Ojanen, Timo Penttilä, Juuso Rainne, Tuomas Laurila, and Annalea Lohila
Biogeosciences, 14, 1947–1967, https://doi.org/10.5194/bg-14-1947-2017, https://doi.org/10.5194/bg-14-1947-2017, 2017
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We measured methane exchange rates at the forest floor of a nutrient-rich drained peatland in southern Finland. The forest floor acted mainly as a small methane sink, but emission peaks were occasionally observed during spring and rainfall events. The strength of the sink correlated best with groundwater level and soil temperatures at 20 and 30 cm depths. Diurnal variations were also observed but they were caused by changes in ambient wind speed and not by biological processes.
Juan Hong, Mikko Äijälä, Silja A. K. Häme, Liqing Hao, Jonathan Duplissy, Liine M. Heikkinen, Wei Nie, Jyri Mikkilä, Markku Kulmala, Nønne L. Prisle, Annele Virtanen, Mikael Ehn, Pauli Paasonen, Douglas R. Worsnop, Ilona Riipinen, Tuukka Petäjä, and Veli-Matti Kerminen
Atmos. Chem. Phys., 17, 4387–4399, https://doi.org/10.5194/acp-17-4387-2017, https://doi.org/10.5194/acp-17-4387-2017, 2017
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Estimates of volatility of secondary organic aerosols was characterized in a boreal forest environment of Hyytiälä, southern Finland. This was done by interpreting field measurements using a volatility tandem differential mobility analyzer (VTDMA) with a kinetic evaporation model and by applying positive matrix factorization (PMF) to high-resolution aerosol mass spectrometer data. About 16 % of the variation can be explained by the linear regression between the results from these two methods.
Andrew D. Venter, Pieter G. van Zyl, Johan P. Beukes, Micky Josipovic, Johan Hendriks, Ville Vakkari, and Lauri Laakso
Atmos. Chem. Phys., 17, 4251–4263, https://doi.org/10.5194/acp-17-4251-2017, https://doi.org/10.5194/acp-17-4251-2017, 2017
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Size-resolved trace metal concentrations were determined at a regional background site impacted by the major pollutant source regions in the interior of South Africa, which include a region holding a large number of pyrometallurgical smelters. ≥70% of trace metal species were in the smaller size fractions, indicating the influence of industrial activities, while the influence of wind-blown dust was reflected in the PM2.5–10 size fraction. Annual average Ni and As exceeded European standards.
Wei Nie, Juan Hong, Silja A. K. Häme, Aijun Ding, Yugen Li, Chao Yan, Liqing Hao, Jyri Mikkilä, Longfei Zheng, Yuning Xie, Caijun Zhu, Zheng Xu, Xuguang Chi, Xin Huang, Yang Zhou, Peng Lin, Annele Virtanen, Douglas R. Worsnop, Markku Kulmala, Mikael Ehn, Jianzhen Yu, Veli-Matti Kerminen, and Tuukka Petäjä
Atmos. Chem. Phys., 17, 3659–3672, https://doi.org/10.5194/acp-17-3659-2017, https://doi.org/10.5194/acp-17-3659-2017, 2017
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HULIS are demonstrated to be important low-volatility, or even extremely low volatility, compounds in the organic aerosol phase. This sheds new light on the connection between atmospheric HULIS and ELVOCs. The interaction between HULIS and ammonium sulfate was found to decrease the volatility of the HULIS part in HULIS-AS mixed samples, indicating multiphase processes have the potential to lower the volatility of organic compounds in the aerosol phase.
Hannele Hakola, Virpi Tarvainen, Arnaud P. Praplan, Kerneels Jaars, Marja Hemmilä, Markku Kulmala, Jaana Bäck, and Heidi Hellén
Atmos. Chem. Phys., 17, 3357–3370, https://doi.org/10.5194/acp-17-3357-2017, https://doi.org/10.5194/acp-17-3357-2017, 2017
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We present spring and summer VOC emission rate measurements from Norway spruce using an in situ gas chromatograph. Monoterpene and C4–C10 aldehyde emission rates reached maxima in July. SQT emissions increased at the end of July and in August SQT were the most abundant group. The MT emission pattern varied a lot from tree to tree and therefore emission fluxes on canopy level should be conducted for more representative measurements. However, leaf level measurements produce more reliable SQT data.
Antti-Jussi Kieloaho, Mari Pihlatie, Samuli Launiainen, Markku Kulmala, Marja-Liisa Riekkola, Jevgeni Parshintsev, Ivan Mammarella, Timo Vesala, and Jussi Heinonsalo
Biogeosciences, 14, 1075–1091, https://doi.org/10.5194/bg-14-1075-2017, https://doi.org/10.5194/bg-14-1075-2017, 2017
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The alkylamines are important precursors in secondary aerosol formation in boreal forests. We quantified alkylamine concentrations in fungal species present in boreal forests in order to estimate soil as a source of atmospheric alkylamines. Based on our knowledge we estimated possible soil–atmosphere exchange of these compounds. The results shows that the boreal forest soil could act as a source of alkylamines depending on environmental conditions and studied compound.
Matti Räsänen, Mika Aurela, Ville Vakkari, Johan P. Beukes, Juha-Pekka Tuovinen, Pieter G. Van Zyl, Miroslav Josipovic, Andrew D. Venter, Kerneels Jaars, Stefan J. Siebert, Tuomas Laurila, Janne Rinne, and Lauri Laakso
Biogeosciences, 14, 1039–1054, https://doi.org/10.5194/bg-14-1039-2017, https://doi.org/10.5194/bg-14-1039-2017, 2017
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This study presents measurements of carbon dioxide exchange between the atmosphere and a grazed savanna grassland ecosystem for 3 years. We find that the yearly variation in carbon dioxide balance is largely determined by the changes in the early wet season balance (September to November) and in the mid-growing season balance (December to January).
Mikko Äijälä, Liine Heikkinen, Roman Fröhlich, Francesco Canonaco, André S. H. Prévôt, Heikki Junninen, Tuukka Petäjä, Markku Kulmala, Douglas Worsnop, and Mikael Ehn
Atmos. Chem. Phys., 17, 3165–3197, https://doi.org/10.5194/acp-17-3165-2017, https://doi.org/10.5194/acp-17-3165-2017, 2017
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Mass spectrometric measurements commonly yield data on hundreds of variables over thousands of points in time. Refining and synthesising this “raw” data into chemical information necessitates the use of advanced, statistics-based data analysis techniques. Here we present an example of combining data dimensionality reduction (factorisation) with exploratory classification (clustering) and show that the results complement and broaden our current perspectives on aerosol chemical classification.
Kerry J. Dinsmore, Julia Drewer, Peter E. Levy, Charles George, Annalea Lohila, Mika Aurela, and Ute M. Skiba
Biogeosciences, 14, 799–815, https://doi.org/10.5194/bg-14-799-2017, https://doi.org/10.5194/bg-14-799-2017, 2017
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Release of greenhouse gases from northern soils contributes significantly to the global atmosphere and plays an important role in regulating climate. This study, based in N. Finland, aimed to measure and understand release of CH4 and N2O, and using satellite imagery, upscale our results to a 2 × 2 km area. Wetlands released large amounts of CH4, with emissions linked to temperature and the presence of Sphagnum; landscape emissions were 2.05 mg C m−2 hr−1. N2O fluxes were consistently near-zero.
Carla Frege, Federico Bianchi, Ugo Molteni, Jasmin Tröstl, Heikki Junninen, Stephan Henne, Mikko Sipilä, Erik Herrmann, Michel J. Rossi, Markku Kulmala, Christopher R. Hoyle, Urs Baltensperger, and Josef Dommen
Atmos. Chem. Phys., 17, 2613–2629, https://doi.org/10.5194/acp-17-2613-2017, https://doi.org/10.5194/acp-17-2613-2017, 2017
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We present measurements of the chemical composition of atmospheric ions at high altitude (3450 m a.s.l.) during a 9-month campaign. We detected remarkably high correlation between methanesulfonic acid (MSA) and SO5−. Halogenated species were also detected frequently at this continental location. New-particle formation events occurred via the condensation of highly oxygenated molecules (HOMs) at very low sulfuric acid concentration or, less frequently, due to ammonia–sulfuric acid clusters.
Jenni Kontkanen, Katrianne Lehtipalo, Lauri Ahonen, Juha Kangasluoma, Hanna E. Manninen, Jani Hakala, Clémence Rose, Karine Sellegri, Shan Xiao, Lin Wang, Ximeng Qi, Wei Nie, Aijun Ding, Huan Yu, Shanhu Lee, Veli-Matti Kerminen, Tuukka Petäjä, and Markku Kulmala
Atmos. Chem. Phys., 17, 2163–2187, https://doi.org/10.5194/acp-17-2163-2017, https://doi.org/10.5194/acp-17-2163-2017, 2017
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The concentrations of ~1–3 nm particles were investigated at nine sites around the world. Sub-3 nm particle concentrations were highest at the sites with strong anthropogenic influence. Electrically neutral particles dominated sub-3 nm particle concentrations in polluted environments and in boreal forest during spring and summer. Sub-3 nm particle concentrations were observed to be determined by the availability of precursor vapors rather than the sink caused by preexisting aerosol particles.
Aino Korrensalo, Pavel Alekseychik, Tomáš Hájek, Janne Rinne, Timo Vesala, Lauri Mehtätalo, Ivan Mammarella, and Eeva-Stiina Tuittila
Biogeosciences, 14, 257–269, https://doi.org/10.5194/bg-14-257-2017, https://doi.org/10.5194/bg-14-257-2017, 2017
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Photosynthetic parameters of peatland plant species were measured over one growing season in an ombrotrophic bog. Based on these measurements, ecosystem-level photosynthesis was calculated for the whole growing season and compared with an estimate derived from micrometeorological measurements. These two estimates corresponded well. Species with low areal cover at the site but high photosynthetic efficiency appeared to be potentially important for the ecosystem-level carbon balance.
Kerneels Jaars, Pieter G. van Zyl, Johan P. Beukes, Heidi Hellén, Ville Vakkari, Micky Josipovic, Andrew D. Venter, Matti Räsänen, Leandra Knoetze, Dirk P. Cilliers, Stefan J. Siebert, Markku Kulmala, Janne Rinne, Alex Guenther, Lauri Laakso, and Hannele Hakola
Atmos. Chem. Phys., 16, 15665–15688, https://doi.org/10.5194/acp-16-15665-2016, https://doi.org/10.5194/acp-16-15665-2016, 2016
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Biogenic volatile organic compounds (BVOCs) – important in tropospheric ozone and secondary organic aerosol formation – were measured at a savannah grassland in South Africa. Results presented are the most extensive for this type of landscape. Compared to other parts of the world, monoterpene levels were similar, while very low isoprene levels led to significantly lower total BVOC levels. BVOC levels were an order of magnitude lower compared to anthropogenic VOC levels measured at Welgegund.
Jarmo Mäkelä, Jouni Susiluoto, Tiina Markkanen, Mika Aurela, Heikki Järvinen, Ivan Mammarella, Stefan Hagemann, and Tuula Aalto
Nonlin. Processes Geophys., 23, 447–465, https://doi.org/10.5194/npg-23-447-2016, https://doi.org/10.5194/npg-23-447-2016, 2016
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The land-based hydrological cycle is one of the key processes controlling the growth and wilting of plants and the amount of carbon vegetation can assimilate. Recent studies have shown that many land surface models have biases in this area. We optimized parameters in one such model (JSBACH) and were able to enhance the model performance in many respects, but the response to drought remained unaffected. Further studies into this aspect should include alternative stomatal conductance formulations.
Hanna K. Lappalainen, Veli-Matti Kerminen, Tuukka Petäjä, Theo Kurten, Aleksander Baklanov, Anatoly Shvidenko, Jaana Bäck, Timo Vihma, Pavel Alekseychik, Meinrat O. Andreae, Stephen R. Arnold, Mikhail Arshinov, Eija Asmi, Boris Belan, Leonid Bobylev, Sergey Chalov, Yafang Cheng, Natalia Chubarova, Gerrit de Leeuw, Aijun Ding, Sergey Dobrolyubov, Sergei Dubtsov, Egor Dyukarev, Nikolai Elansky, Kostas Eleftheriadis, Igor Esau, Nikolay Filatov, Mikhail Flint, Congbin Fu, Olga Glezer, Aleksander Gliko, Martin Heimann, Albert A. M. Holtslag, Urmas Hõrrak, Juha Janhunen, Sirkku Juhola, Leena Järvi, Heikki Järvinen, Anna Kanukhina, Pavel Konstantinov, Vladimir Kotlyakov, Antti-Jussi Kieloaho, Alexander S. Komarov, Joni Kujansuu, Ilmo Kukkonen, Ella-Maria Duplissy, Ari Laaksonen, Tuomas Laurila, Heikki Lihavainen, Alexander Lisitzin, Alexsander Mahura, Alexander Makshtas, Evgeny Mareev, Stephany Mazon, Dmitry Matishov, Vladimir Melnikov, Eugene Mikhailov, Dmitri Moisseev, Robert Nigmatulin, Steffen M. Noe, Anne Ojala, Mari Pihlatie, Olga Popovicheva, Jukka Pumpanen, Tatjana Regerand, Irina Repina, Aleksei Shcherbinin, Vladimir Shevchenko, Mikko Sipilä, Andrey Skorokhod, Dominick V. Spracklen, Hang Su, Dmitry A. Subetto, Junying Sun, Arkady Y. Terzhevik, Yuri Timofeyev, Yuliya Troitskaya, Veli-Pekka Tynkkynen, Viacheslav I. Kharuk, Nina Zaytseva, Jiahua Zhang, Yrjö Viisanen, Timo Vesala, Pertti Hari, Hans Christen Hansson, Gennady G. Matvienko, Nikolai S. Kasimov, Huadong Guo, Valery Bondur, Sergej Zilitinkevich, and Markku Kulmala
Atmos. Chem. Phys., 16, 14421–14461, https://doi.org/10.5194/acp-16-14421-2016, https://doi.org/10.5194/acp-16-14421-2016, 2016
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After kick off in 2012, the Pan-Eurasian Experiment (PEEX) program has expanded fast and today the multi-disciplinary research community covers ca. 80 institutes and a network of ca. 500 scientists from Europe, Russia, and China. Here we introduce scientific topics relevant in this context. This is one of the first multi-disciplinary overviews crossing scientific boundaries, from atmospheric sciences to socio-economics and social sciences.
Laura Riuttanen, Marja Bister, Veli-Matti Kerminen, Viju O. John, Anu-Maija Sundström, Miikka Dal Maso, Jouni Räisänen, Victoria A. Sinclair, Risto Makkonen, Filippo Xausa, Gerrit de Leeuw, and Markku Kulmala
Atmos. Chem. Phys., 16, 14331–14342, https://doi.org/10.5194/acp-16-14331-2016, https://doi.org/10.5194/acp-16-14331-2016, 2016
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Here we show observational evidence that aerosols increase upper tropospheric humidity (UTH) via changes in the microphysics of deep convection. Using remote sensing data over the ocean east of China in summer, we show that increased aerosol loads are associated with an UTH increase of 2.2 ± 1.5 in units of relative humidity. We show that humidification of aerosols or other meteorological covariation is very unlikely to be the cause for this result indicating relevance for the global climate.
Xuemeng Chen, Veli-Matti Kerminen, Jussi Paatero, Pauli Paasonen, Hanna E. Manninen, Tuomo Nieminen, Tuukka Petäjä, and Markku Kulmala
Atmos. Chem. Phys., 16, 14297–14315, https://doi.org/10.5194/acp-16-14297-2016, https://doi.org/10.5194/acp-16-14297-2016, 2016
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Ionising radiation is responsible for air ion production. However, minor efforts have been invested in understanding the connection of observed air ions to ionising radiation in the lower atmosphere and underlying processes therein. In this work, we analysed 4 years of ambient data collected in a Finnish boreal forest and found that gamma radiation dominates air ion production in the lower atmosphere and demonstrated clear promotion effects of the ionising radiation on air ion production.
Jenni Kontkanen, Pauli Paasonen, Juho Aalto, Jaana Bäck, Pekka Rantala, Tuukka Petäjä, and Markku Kulmala
Atmos. Chem. Phys., 16, 13291–13307, https://doi.org/10.5194/acp-16-13291-2016, https://doi.org/10.5194/acp-16-13291-2016, 2016
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We developed proxies for estimating the concentrations of monoterpenes and their oxidation products at a boreal forest site in Hyytiälä, Finland. The proxies for the monoterpene concentration include temperature-controlled emissions, dilution and different oxidation processes. The proxies were observed to capture the seasonal and diurnal variation of the monoterpene concentration reasonably well. Our proxies can be used in the analysis of new particle formation and growth in boreal environments.
Chao Yan, Wei Nie, Mikko Äijälä, Matti P. Rissanen, Manjula R. Canagaratna, Paola Massoli, Heikki Junninen, Tuija Jokinen, Nina Sarnela, Silja A. K. Häme, Siegfried Schobesberger, Francesco Canonaco, Lei Yao, André S. H. Prévôt, Tuukka Petäjä, Markku Kulmala, Mikko Sipilä, Douglas R. Worsnop, and Mikael Ehn
Atmos. Chem. Phys., 16, 12715–12731, https://doi.org/10.5194/acp-16-12715-2016, https://doi.org/10.5194/acp-16-12715-2016, 2016
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Highly oxidized multifunctional compounds (HOMs) are known to have a significant contribution to secondary aerosol formation, yet their dominating formation pathways remain unclear in the atmosphere. We apply positive matrix factorization (PMF) on HOM data, and successfully retrieve factors representing different formation pathways. The results improve our understanding of HOM formation, and provide new perspectives on using PMF to study the variation of short-lived specie.
Maiju Linkosalmi, Mika Aurela, Juha-Pekka Tuovinen, Mikko Peltoniemi, Cemal M. Tanis, Ali N. Arslan, Pasi Kolari, Kristin Böttcher, Tuula Aalto, Juuso Rainne, Juha Hatakka, and Tuomas Laurila
Geosci. Instrum. Method. Data Syst., 5, 417–426, https://doi.org/10.5194/gi-5-417-2016, https://doi.org/10.5194/gi-5-417-2016, 2016
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Digital photography has become a widely used tool for monitoring the vegetation phenology. The seasonal cycle of the greenness index obtained from photographs correlated well with the CO2 exchange of the plants at our wetland and Scots pine forest sites. While the seasonal changes in the greenness were more obvious for the ecosystem dominated by annual plants, clear seasonal patterns were also observed for the evergreen forest.
Luís Miguel Feijó Barreira, Yu Xue, Geoffroy Duporté, Jevgeni Parshintsev, Kari Hartonen, Matti Jussila, Markku Kulmala, and Marja-Liisa Riekkola
Atmos. Meas. Tech., 9, 3661–3671, https://doi.org/10.5194/amt-9-3661-2016, https://doi.org/10.5194/amt-9-3661-2016, 2016
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Volatile organic compounds play a key role in atmospheric chemistry and physics by influencing the climate. Trace concentrations need to be determined, even at remote locations, like forests. In this research, an easy and fast method using a portable device was developed for determination of relevant atmospheric compounds. Links between these compounds and meteorological factors were observed. Also, accumulation of volatiles in the snow was measured.
Hanna E. Manninen, Sander Mirme, Aadu Mirme, Tuukka Petäjä, and Markku Kulmala
Atmos. Meas. Tech., 9, 3577–3605, https://doi.org/10.5194/amt-9-3577-2016, https://doi.org/10.5194/amt-9-3577-2016, 2016
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This paper reports a standard operation procedure (SOP) for a Neutral cluster and Air Ion Spectrometer (NAIS) to detect small clusters and nucleation mode particles. The NAIS measures number size distributions of charged and neutral aerosol particles. The SOP is needed to provide comparable results measured by NAIS users around the world. The work is based on discussions between the NAIS users (lead by University of Helsinki, Finland) and the NAIS manufacturer (Airel Ltd., Estonia).
Imre Salma, Zoltán Németh, Veli-Matti Kerminen, Pasi Aalto, Tuomo Nieminen, Tamás Weidinger, Ágnes Molnár, Kornélia Imre, and Markku Kulmala
Atmos. Chem. Phys., 16, 8715–8728, https://doi.org/10.5194/acp-16-8715-2016, https://doi.org/10.5194/acp-16-8715-2016, 2016
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We revealed that NPF seen in a central large city of the Carpathian Basin, Budapest, and its regional background occur in a consistent and spatially coherent way as a result of a joint atmospheric phenomenon taking place on large horizontal scales.
Riikka Väänänen, Radovan Krejci, Hanna E. Manninen, Antti Manninen, Janne Lampilahti, Stephany Buenrostro Mazon, Tuomo Nieminen, Taina Yli-Juuti, Jenni Kontkanen, Ari Asmi, Pasi P. Aalto, Petri Keronen, Toivo Pohja, Ewan O'Connor, Veli-Matti Kerminen, Tuukka Petäjä, and Markku Kulmala
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2016-556, https://doi.org/10.5194/acp-2016-556, 2016
Revised manuscript has not been submitted
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A light aircraft was used as a platform to explore the horizontal and vertical variability of the aerosol particles over a boreal forest in Central Finland. This information is needed when data measured at ground level station is extrapolated and parameterized to represent the
conditions of the larger scale. The measurements showed that despite local fluctuations there was a good agreement between the on-ground and airborne measurements inside the planetary boundary layer.
Juha Kangasluoma, Alessandro Franchin, Jonahtan Duplissy, Lauri Ahonen, Frans Korhonen, Michel Attoui, Jyri Mikkilä, Katrianne Lehtipalo, Joonas Vanhanen, Markku Kulmala, and Tuukka Petäjä
Atmos. Meas. Tech., 9, 2977–2988, https://doi.org/10.5194/amt-9-2977-2016, https://doi.org/10.5194/amt-9-2977-2016, 2016
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The paper describes technical aspects of using the Airmodus A11 nCNC at various inlet pressures and how temperature selection affects the performance of the instrument. We also present a sampling box to minimize the inlet losses and make use of the instrument more convenient.
Elina Giannakaki, Pieter G. van Zyl, Detlef Müller, Dimitris Balis, and Mika Komppula
Atmos. Chem. Phys., 16, 8109–8123, https://doi.org/10.5194/acp-16-8109-2016, https://doi.org/10.5194/acp-16-8109-2016, 2016
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Optical and microphysical properties of different aerosol types over South Africa measured with a multi-wavelength polarization Raman lidar are presented. Aerosol characterization of elevated layers was performed. This study could assist in bridging existing gaps relating to aerosol properties over South Africa.
Pekka Rantala, Leena Järvi, Risto Taipale, Terhi K. Laurila, Johanna Patokoski, Maija K. Kajos, Mona Kurppa, Sami Haapanala, Erkki Siivola, Tuukka Petäjä, Taina M. Ruuskanen, and Janne Rinne
Atmos. Chem. Phys., 16, 7981–8007, https://doi.org/10.5194/acp-16-7981-2016, https://doi.org/10.5194/acp-16-7981-2016, 2016
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Fluxes of volatile organic compounds (VOCs) were measured above an urban landscape in Helsinki, northern Europe. We found that traffic was a major source for many oxygenated and aromatic VOCs, whereas isoprene originated mostly from the urban vegetation. Overall, the VOC fluxes were quite small in comparison with the earlier urban VOC flux measurements.
Alessandro Franchin, Andy Downard, Juha Kangasluoma, Tuomo Nieminen, Katrianne Lehtipalo, Gerhard Steiner, Hanna E. Manninen, Tuukka Petäjä, Richard C. Flagan, and Markku Kulmala
Atmos. Meas. Tech., 9, 2709–2720, https://doi.org/10.5194/amt-9-2709-2016, https://doi.org/10.5194/amt-9-2709-2016, 2016
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High transmission efficiency is key for classifying and counting atmospheric aerosol below 10 nm. We developed a new high-transmission inlet for the Caltech nano-radial DMA (nRDMA) and successfully deployed the nRDMA, equipped with the new inlet, in chamber measurements, using a particle size magnifier (PSM) and a booster CPC as a counter. With this setup, we were able to measure size distributions of ions between 1.3 and 6 nm in mobility diameter.
Fanni Mylläri, Eija Asmi, Tatu Anttila, Erkka Saukko, Ville Vakkari, Liisa Pirjola, Risto Hillamo, Tuomas Laurila, Anna Häyrinen, Jani Rautiainen, Heikki Lihavainen, Ewan O'Connor, Ville Niemelä, Jorma Keskinen, Miikka Dal Maso, and Topi Rönkkö
Atmos. Chem. Phys., 16, 7485–7496, https://doi.org/10.5194/acp-16-7485-2016, https://doi.org/10.5194/acp-16-7485-2016, 2016
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The primary emissions of a coal-fired power plant were highly affected by the flue-gas cleaning technologies. The primary emission results were used as input values for a Gaussian plume model and the model correlated well with the atmospheric measurements from the flue-gas plume. Concentrations of newly formed particles in the flue gas plume were higher than the primary particle concentration, and thus the source of particle-forming precursors should be characterized in more detail.
Simon Schallhart, Pekka Rantala, Eiko Nemitz, Ditte Taipale, Ralf Tillmann, Thomas F. Mentel, Benjamin Loubet, Giacomo Gerosa, Angelo Finco, Janne Rinne, and Taina M. Ruuskanen
Atmos. Chem. Phys., 16, 7171–7194, https://doi.org/10.5194/acp-16-7171-2016, https://doi.org/10.5194/acp-16-7171-2016, 2016
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We present ecosystem exchange fluxes from a mixed oak–hornbeam forest in the Po Valley, Italy. Detectable fluxes were observed for 29 compounds, dominated by isoprene, which comprised over 60 % of the upward flux. Methanol seemed to be deposited to dew, as the deposition happened in the early morning. We estimated that up to 30 % of the upward flux of methyl vinyl ketone and methacrolein originated from atmospheric oxidation of isoprene.
Karoliina Ignatius, Thomas B. Kristensen, Emma Järvinen, Leonid Nichman, Claudia Fuchs, Hamish Gordon, Paul Herenz, Christopher R. Hoyle, Jonathan Duplissy, Sarvesh Garimella, Antonio Dias, Carla Frege, Niko Höppel, Jasmin Tröstl, Robert Wagner, Chao Yan, Antonio Amorim, Urs Baltensperger, Joachim Curtius, Neil M. Donahue, Martin W. Gallagher, Jasper Kirkby, Markku Kulmala, Ottmar Möhler, Harald Saathoff, Martin Schnaiter, Antonio Tomé, Annele Virtanen, Douglas Worsnop, and Frank Stratmann
Atmos. Chem. Phys., 16, 6495–6509, https://doi.org/10.5194/acp-16-6495-2016, https://doi.org/10.5194/acp-16-6495-2016, 2016
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Viscous solid or semi-solid secondary organic aerosol (SOA) may influence cloud properties through ice nucleation in the atmosphere. Here, we observed heterogeneous ice nucleation of viscous α-pinene SOA at temperatures between −39 °C and −37.2 °C with ice saturation ratios significantly below the homogeneous freezing limit. Global modelling suggests that viscous biogenic SOA are present in regions where cirrus formation takes place and could contribute to the global ice nuclei budget.
Jenni Kontkanen, Tinja Olenius, Katrianne Lehtipalo, Hanna Vehkamäki, Markku Kulmala, and Kari E. J. Lehtinen
Atmos. Chem. Phys., 16, 5545–5560, https://doi.org/10.5194/acp-16-5545-2016, https://doi.org/10.5194/acp-16-5545-2016, 2016
Holger Baars, Thomas Kanitz, Ronny Engelmann, Dietrich Althausen, Birgit Heese, Mika Komppula, Jana Preißler, Matthias Tesche, Albert Ansmann, Ulla Wandinger, Jae-Hyun Lim, Joon Young Ahn, Iwona S. Stachlewska, Vassilis Amiridis, Eleni Marinou, Patric Seifert, Julian Hofer, Annett Skupin, Florian Schneider, Stephanie Bohlmann, Andreas Foth, Sebastian Bley, Anne Pfüller, Eleni Giannakaki, Heikki Lihavainen, Yrjö Viisanen, Rakesh Kumar Hooda, Sérgio Nepomuceno Pereira, Daniele Bortoli, Frank Wagner, Ina Mattis, Lucja Janicka, Krzysztof M. Markowicz, Peggy Achtert, Paulo Artaxo, Theotonio Pauliquevis, Rodrigo A. F. Souza, Ved Prakesh Sharma, Pieter Gideon van Zyl, Johan Paul Beukes, Junying Sun, Erich G. Rohwer, Ruru Deng, Rodanthi-Elisavet Mamouri, and Felix Zamorano
Atmos. Chem. Phys., 16, 5111–5137, https://doi.org/10.5194/acp-16-5111-2016, https://doi.org/10.5194/acp-16-5111-2016, 2016
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The findings from more than 10 years of global aerosol lidar measurements with Polly systems are summarized, and a data set of optical properties for specific aerosol types is given. An automated data retrieval algorithm for continuous Polly lidar observations is presented and discussed by means of a Saharan dust advection event in Leipzig, Germany. Finally, a statistic on the vertical aerosol distribution including the seasonal variability at PollyNET locations around the globe is presented.
Emma Järvinen, Karoliina Ignatius, Leonid Nichman, Thomas B. Kristensen, Claudia Fuchs, Christopher R. Hoyle, Niko Höppel, Joel C. Corbin, Jill Craven, Jonathan Duplissy, Sebastian Ehrhart, Imad El Haddad, Carla Frege, Hamish Gordon, Tuija Jokinen, Peter Kallinger, Jasper Kirkby, Alexei Kiselev, Karl-Heinz Naumann, Tuukka Petäjä, Tamara Pinterich, Andre S. H. Prevot, Harald Saathoff, Thea Schiebel, Kamalika Sengupta, Mario Simon, Jay G. Slowik, Jasmin Tröstl, Annele Virtanen, Paul Vochezer, Steffen Vogt, Andrea C. Wagner, Robert Wagner, Christina Williamson, Paul M. Winkler, Chao Yan, Urs Baltensperger, Neil M. Donahue, Rick C. Flagan, Martin Gallagher, Armin Hansel, Markku Kulmala, Frank Stratmann, Douglas R. Worsnop, Ottmar Möhler, Thomas Leisner, and Martin Schnaiter
Atmos. Chem. Phys., 16, 4423–4438, https://doi.org/10.5194/acp-16-4423-2016, https://doi.org/10.5194/acp-16-4423-2016, 2016
Markku Kangas, Laura Rontu, Carl Fortelius, Mika Aurela, and Antti Poikonen
Geosci. Instrum. Method. Data Syst., 5, 75–84, https://doi.org/10.5194/gi-5-75-2016, https://doi.org/10.5194/gi-5-75-2016, 2016
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Sodankylä, in the heart of the Arctic Research Centre of the Finnish Meteorological Institute in northern Finland with temperatures ranging from −50 to +30 °C, provides a challenging location for numerical weather forecasting (NWP) models. In this article, the use of measurements performed in Sodankylä for near-real time online verification of NWP models is described. A more specific case study of three different radiation schemes, applicable in NWP model HARMONIE-AROME, is also presented.
Antoine Berchet, Philippe Bousquet, Isabelle Pison, Robin Locatelli, Frédéric Chevallier, Jean-Daniel Paris, Ed J. Dlugokencky, Tuomas Laurila, Juha Hatakka, Yrjo Viisanen, Doug E. J. Worthy, Euan Nisbet, Rebecca Fisher, James France, David Lowry, Viktor Ivakhov, and Ove Hermansen
Atmos. Chem. Phys., 16, 4147–4157, https://doi.org/10.5194/acp-16-4147-2016, https://doi.org/10.5194/acp-16-4147-2016, 2016
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We propose insights based on atmospheric observations around the Arctic circle to evaluate estimates of methane emissions to the atmosphere from the East Siberian Arctic Shelf. Based on a comprehensive statistical analysis of the observations and of high-resolution transport simulations, annual methane emissions from ESAS are estimated to range from 0.0 to 4.5 TgCH4 yr−1, with a maximum in summer and very low emissions in winter.
Antti J. Manninen, Ewan J. O'Connor, Ville Vakkari, and Tuukka Petäjä
Atmos. Meas. Tech., 9, 817–827, https://doi.org/10.5194/amt-9-817-2016, https://doi.org/10.5194/amt-9-817-2016, 2016
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Current commercially available Doppler lidars provide a cost-effective solution for measuring vertical and horizontal wind velocities, and the co- and cross-polarised backscatter profiles. However, the background noise behaviour becomes a limiting factor for the instrument sensitivity in low aerosol load regions. In this paper we present a correction method which can improve the data availability up to 50 % and greatly improves the calculation of turbulent properties in weak signal regimes.
Xin Huang, Luxi Zhou, Aijun Ding, Ximeng Qi, Wei Nie, Minghuai Wang, Xuguang Chi, Tuukka Petäjä, Veli-Matti Kerminen, Pontus Roldin, Anton Rusanen, Markku Kulmala, and Michael Boy
Atmos. Chem. Phys., 16, 2477–2492, https://doi.org/10.5194/acp-16-2477-2016, https://doi.org/10.5194/acp-16-2477-2016, 2016
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By combining a regional model and a box model, this study simulates new particle formation in Nanjing, China, when the air masses were affected by anthropogenic activities, biogenic emissions, or mixed ocean and continental sources. The simulations reveal that biogenic organic compounds play a vital role in growth of newly formed clusters. This novel combination of two models makes it possible to accomplish new particle formation simulation without direct measurements of all chemical species.
M. Dal Maso, L. Liao, J. Wildt, A. Kiendler-Scharr, E. Kleist, R. Tillmann, M. Sipilä, J. Hakala, K. Lehtipalo, M. Ehn, V.-M. Kerminen, M. Kulmala, D. Worsnop, and T. Mentel
Atmos. Chem. Phys., 16, 1955–1970, https://doi.org/10.5194/acp-16-1955-2016, https://doi.org/10.5194/acp-16-1955-2016, 2016
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In this paper, we present the first direct laboratory observations of nanoparticle formation from sulfuric acid and realistic BVOC precursor vapour mixtures performed at atmospherically relevant concentration levels. We found that the formation rate was proportional to the product of sulphuric acid and biogenic VOC emission strength, and that the formation rates were consistent with a mechanism in which nucleating BVOC oxidation products are rapidly formed and activate with sulfuric acid.
Jenni Kontkanen, Emma Järvinen, Hanna E. Manninen, Katrianne Lehtipalo, Juha Kangasluoma, Stefano Decesari, Gian Paolo Gobbi, Ari Laaksonen, Tuukka Petäjä, and Markku Kulmala
Atmos. Chem. Phys., 16, 1919–1935, https://doi.org/10.5194/acp-16-1919-2016, https://doi.org/10.5194/acp-16-1919-2016, 2016
S. Osterwalder, J. Fritsche, C. Alewell, M. Schmutz, M. B. Nilsson, G. Jocher, J. Sommar, J. Rinne, and K. Bishop
Atmos. Meas. Tech., 9, 509–524, https://doi.org/10.5194/amt-9-509-2016, https://doi.org/10.5194/amt-9-509-2016, 2016
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Human activities have increased mercury (Hg) cycling between land and atmosphere. To define landscapes as sinks or sources of Hg we have developed an advanced REA system for long-term measurements of gaseous elemental Hg exchange. It was tested in two contrasting environments: above Basel, Switzerland, and a peatland in Sweden. Both landscapes showed net Hg emission (15 and 3 ng m−2 h−1, respectively). The novel system will help to advance our understanding of Hg exchange on an ecosystem scale.
C. R. Hoyle, C. Fuchs, E. Järvinen, H. Saathoff, A. Dias, I. El Haddad, M. Gysel, S. C. Coburn, J. Tröstl, A.-K. Bernhammer, F. Bianchi, M. Breitenlechner, J. C. Corbin, J. Craven, N. M. Donahue, J. Duplissy, S. Ehrhart, C. Frege, H. Gordon, N. Höppel, M. Heinritzi, T. B. Kristensen, U. Molteni, L. Nichman, T. Pinterich, A. S. H. Prévôt, M. Simon, J. G. Slowik, G. Steiner, A. Tomé, A. L. Vogel, R. Volkamer, A. C. Wagner, R. Wagner, A. S. Wexler, C. Williamson, P. M. Winkler, C. Yan, A. Amorim, J. Dommen, J. Curtius, M. W. Gallagher, R. C. Flagan, A. Hansel, J. Kirkby, M. Kulmala, O. Möhler, F. Stratmann, D. R. Worsnop, and U. Baltensperger
Atmos. Chem. Phys., 16, 1693–1712, https://doi.org/10.5194/acp-16-1693-2016, https://doi.org/10.5194/acp-16-1693-2016, 2016
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A significant portion of sulphate, an important constituent of atmospheric aerosols, is formed via the aqueous phase oxidation of sulphur dioxide by ozone. The rate of this reaction has previously only been measured over a relatively small temperature range. Here, we use the state of the art CLOUD chamber at CERN to perform the first measurements of this reaction rate in super-cooled droplets, confirming that the existing extrapolation of the reaction rate to sub-zero temperatures is accurate.
J.-V. Björkqvist, H. Pettersson, L. Laakso, K. K. Kahma, H. Jokinen, and P. Kosloff
Geosci. Instrum. Method. Data Syst., 5, 17–25, https://doi.org/10.5194/gi-5-17-2016, https://doi.org/10.5194/gi-5-17-2016, 2016
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We identified a previously unknown artefact in the Datawell DWR-G4 wave buoy, which measures the GPS signal to resolve surface water waves. The artefact interferes with the part of the measurements containing information about the longer waves and must be removed to obtain accurate readings. We presented a correction method and found it to be accurate based on a comparison to measurements from a larger wave buoy that measures the movements of the device without using the GPS signal.
E. Asmi, V. Kondratyev, D. Brus, T. Laurila, H. Lihavainen, J. Backman, V. Vakkari, M. Aurela, J. Hatakka, Y. Viisanen, T. Uttal, V. Ivakhov, and A. Makshtas
Atmos. Chem. Phys., 16, 1271–1287, https://doi.org/10.5194/acp-16-1271-2016, https://doi.org/10.5194/acp-16-1271-2016, 2016
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Aerosol number size distributions were measured in Arctic Russia continuously during 4 years. The particles' seasonal characteristics and sources were identified based on these data. In early spring, elevated concentrations were detected during episodes of Arctic haze and during days of secondary particle formation. In summer, Siberian forests biogenic emissions had a significant impact on particle number and mass. These are the first such results obtained from the region.
P. Hari, T. Petäjä, J. Bäck, V.-M. Kerminen, H. K. Lappalainen, T. Vihma, T. Laurila, Y. Viisanen, T. Vesala, and M. Kulmala
Atmos. Chem. Phys., 16, 1017–1028, https://doi.org/10.5194/acp-16-1017-2016, https://doi.org/10.5194/acp-16-1017-2016, 2016
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This manuscript introduces a conceptual design of a global, hierarchical observation network which provides tools and increased understanding to tackle the inter-connected environmental and societal challenges that we will face in the coming decades. Each ecosystem type on the globe has its own characteristic features that need to be taken into consideration. The hierarchical network is able to tackle problems related to large spatial scales, heterogeneity of ecosystems and their complexity.
E. W. Butt, A. Rap, A. Schmidt, C. E. Scott, K. J. Pringle, C. L. Reddington, N. A. D. Richards, M. T. Woodhouse, J. Ramirez-Villegas, H. Yang, V. Vakkari, E. A. Stone, M. Rupakheti, P. S. Praveen, P. G. van Zyl, J. P. Beukes, M. Josipovic, E. J. S. Mitchell, S. M. Sallu, P. M. Forster, and D. V. Spracklen
Atmos. Chem. Phys., 16, 873–905, https://doi.org/10.5194/acp-16-873-2016, https://doi.org/10.5194/acp-16-873-2016, 2016
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We estimate the impact of residential emissions (cooking and heating) on atmospheric aerosol, human health, and climate. We find large contributions to annual mean ambient PM2.5 in residential sources regions resulting in significant but uncertain global premature mortality when key uncertainties in emission flux are considered. We show that residential emissions exert an uncertain global radiative effect and suggest more work is needed to characterise residential emissions climate importance.
J. Kim, L. Ahlm, T. Yli-Juuti, M. Lawler, H. Keskinen, J. Tröstl, S. Schobesberger, J. Duplissy, A. Amorim, F. Bianchi, N. M. Donahue, R. C. Flagan, J. Hakala, M. Heinritzi, T. Jokinen, A. Kürten, A. Laaksonen, K. Lehtipalo, P. Miettinen, T. Petäjä, M. P. Rissanen, L. Rondo, K. Sengupta, M. Simon, A. Tomé, C. Williamson, D. Wimmer, P. M. Winkler, S. Ehrhart, P. Ye, J. Kirkby, J. Curtius, U. Baltensperger, M. Kulmala, K. E. J. Lehtinen, J. N. Smith, I. Riipinen, and A. Virtanen
Atmos. Chem. Phys., 16, 293–304, https://doi.org/10.5194/acp-16-293-2016, https://doi.org/10.5194/acp-16-293-2016, 2016
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The hygroscopicity of nucleated nanoparticles was measured in the presence of sulfuric acid, sulfuric acid-dimethylamine, and sulfuric acid-organics derived from α-pinene oxidation during CLOUD7 at CERN in 2012. The hygroscopicity parameter κ decreased with increasing particle size, indicating decreasing acidity of particles.
Y. Gao, T. Markkanen, T. Thum, M. Aurela, A. Lohila, I. Mammarella, M. Kämäräinen, S. Hagemann, and T. Aalto
Hydrol. Earth Syst. Sci., 20, 175–191, https://doi.org/10.5194/hess-20-175-2016, https://doi.org/10.5194/hess-20-175-2016, 2016
R. L. Mauldin III, M. P. Rissanen, T. Petäjä, and M. Kulmala
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2015-398, https://doi.org/10.5194/amt-2015-398, 2016
Revised manuscript not accepted
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The manuscript describes a novel instrument for the measurement of OH, HO2+RO2, and other atmospheric species. The instrument described combines the chemical ionization techniques of nitrate CIMS, OH conversion to H2SO4, HO2+RO2 conversion to H2SO4, and high resolution time of flight mass spectroscopy into one system. By using one instrument to obtain spectra it is possible to compare spectra from the different modes and gain further chemical information towards peak identification.
V. N. Dos Santos, E. Herrmann, H. E. Manninen, T. Hussein, J. Hakala, T. Nieminen, P. P. Aalto, M. Merkel, A. Wiedensohler, M. Kulmala, T. Petäjä, and K. Hämeri
Atmos. Chem. Phys., 15, 13717–13737, https://doi.org/10.5194/acp-15-13717-2015, https://doi.org/10.5194/acp-15-13717-2015, 2015
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Atmospheric charged particles, i.e. air ions, contribute to secondary aerosol formation and have an effect on global climate as potential cloud condensation nuclei. We aimed to evaluate air ion concentrations and characteristics during new particle formation (NPF) events in the megacity Paris, France. We analyzed frequency and seasonal variations of NPF events, diurnal and seasonal cycles of ions, and aerosol particles.
J. Patokoski, T. M. Ruuskanen, M. K. Kajos, R. Taipale, P. Rantala, J. Aalto, T. Ryyppö, T. Nieminen, H. Hakola, and J. Rinne
Atmos. Chem. Phys., 15, 13413–13432, https://doi.org/10.5194/acp-15-13413-2015, https://doi.org/10.5194/acp-15-13413-2015, 2015
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In this study, main source areas for long-lived VOCs at the boreal forest in SMEAR II were determined. Air masses arriving from eastern and western directions were more polluted than those arriving from the northern direction. The biogenic and anthropogenic influences of three different source profiles were determined. The elevated trace gas concentrations from forest fire episodes were observed clearly in the trajectory analysis.
M. Kulmala, H. K. Lappalainen, T. Petäjä, T. Kurten, V.-M. Kerminen, Y. Viisanen, P. Hari, S. Sorvari, J. Bäck, V. Bondur, N. Kasimov, V. Kotlyakov, G. Matvienko, A. Baklanov, H. D. Guo, A. Ding, H.-C. Hansson, and S. Zilitinkevich
Atmos. Chem. Phys., 15, 13085–13096, https://doi.org/10.5194/acp-15-13085-2015, https://doi.org/10.5194/acp-15-13085-2015, 2015
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The Pan-European Experiment (PEEX) is introduced. PEEX is a multidisciplinary, multiscale and multicomponent research, research infrastructure and capacity-building program. This paper outlines the mission, vision and objectives of PEEX and introduces its main components, including the research agenda, research infrastructure, knowledge transfer and potential impacts on society. The paper also summarizes the main scientific questions that PEEX is going to tackle in the future.
C. E. Scott, D. V. Spracklen, J. R. Pierce, I. Riipinen, S. D. D'Andrea, A. Rap, K. S. Carslaw, P. M. Forster, P. Artaxo, M. Kulmala, L. V. Rizzo, E. Swietlicki, G. W. Mann, and K. J. Pringle
Atmos. Chem. Phys., 15, 12989–13001, https://doi.org/10.5194/acp-15-12989-2015, https://doi.org/10.5194/acp-15-12989-2015, 2015
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To understand the radiative effects of biogenic secondary organic aerosol (SOA) it is necessary to consider the manner in which it is distributed across the existing aerosol size distribution. We explore the importance of the approach taken by global-scale models to do this, when calculating the direct radiative effect (DRE) & first aerosol indirect effect (AIE) due to biogenic SOA. This choice has little effect on the DRE, but a substantial impact on the magnitude and even sign of the first AIE
T. Nieminen, T. Yli-Juuti, H. E. Manninen, T. Petäjä, V.-M. Kerminen, and M. Kulmala
Atmos. Chem. Phys., 15, 12385–12396, https://doi.org/10.5194/acp-15-12385-2015, https://doi.org/10.5194/acp-15-12385-2015, 2015
M. Paramonov, V.-M. Kerminen, M. Gysel, P. P. Aalto, M. O. Andreae, E. Asmi, U. Baltensperger, A. Bougiatioti, D. Brus, G. P. Frank, N. Good, S. S. Gunthe, L. Hao, M. Irwin, A. Jaatinen, Z. Jurányi, S. M. King, A. Kortelainen, A. Kristensson, H. Lihavainen, M. Kulmala, U. Lohmann, S. T. Martin, G. McFiggans, N. Mihalopoulos, A. Nenes, C. D. O'Dowd, J. Ovadnevaite, T. Petäjä, U. Pöschl, G. C. Roberts, D. Rose, B. Svenningsson, E. Swietlicki, E. Weingartner, J. Whitehead, A. Wiedensohler, C. Wittbom, and B. Sierau
Atmos. Chem. Phys., 15, 12211–12229, https://doi.org/10.5194/acp-15-12211-2015, https://doi.org/10.5194/acp-15-12211-2015, 2015
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The research paper presents the first comprehensive overview of field measurements with the CCN Counter performed at a large number of locations around the world within the EUCAARI framework. The paper sheds light on the CCN number concentrations and activated fractions around the world and their dependence on the water vapour supersaturation ratio, the dependence of aerosol hygroscopicity on particle size, and seasonal and diurnal variation of CCN activation and hygroscopic properties.
M. K. Kajos, P. Rantala, M. Hill, H. Hellén, J. Aalto, J. Patokoski, R. Taipale, C. C. Hoerger, S. Reimann, T. M. Ruuskanen, J. Rinne, and T. Petäjä
Atmos. Meas. Tech., 8, 4453–4473, https://doi.org/10.5194/amt-8-4453-2015, https://doi.org/10.5194/amt-8-4453-2015, 2015
B. Wehner, F. Werner, F. Ditas, R. A. Shaw, M. Kulmala, and H. Siebert
Atmos. Chem. Phys., 15, 11701–11711, https://doi.org/10.5194/acp-15-11701-2015, https://doi.org/10.5194/acp-15-11701-2015, 2015
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During the CARRIBA campaign on Barbados, 91 cases with increased aerosol particle number concentrations near clouds were detected from helicopter-borne measurements. Most of these cases are correlated with enhanced irradiance in the ultraviolet range. The events have a mean length of 100m, corresponding to a lifetime of 300s, meaning a growth of several nm/h. Such high values cannot be explained by sulfuric acid alone; thus extremely low volatility organic compounds are probably involved here.
A. Virkkula, X. Chi, A. Ding, Y. Shen, W. Nie, X. Qi, L. Zheng, X. Huang, Y. Xie, J. Wang, T. Petäjä, and M. Kulmala
Atmos. Meas. Tech., 8, 4415–4427, https://doi.org/10.5194/amt-8-4415-2015, https://doi.org/10.5194/amt-8-4415-2015, 2015
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Aerosol optical properties were measured with a seven-wavelength aethalometer and a three-wavelength nephelometer in Nanjing, China, in September 2013–January 2015. The aethalometer compensation parameter k depended on the backscatter fraction, measured with an independent method, the integrating nephelometer. The compensation parameter decreased with increasing single-scattering albedo.
P. Rantala, J. Aalto, R. Taipale, T. M. Ruuskanen, and J. Rinne
Biogeosciences, 12, 5753–5770, https://doi.org/10.5194/bg-12-5753-2015, https://doi.org/10.5194/bg-12-5753-2015, 2015
A. Kürten, S. Münch, L. Rondo, F. Bianchi, J. Duplissy, T. Jokinen, H. Junninen, N. Sarnela, S. Schobesberger, M. Simon, M. Sipilä, J. Almeida, A. Amorim, J. Dommen, N. M. Donahue, E. M. Dunne, R. C. Flagan, A. Franchin, J. Kirkby, A. Kupc, V. Makhmutov, T. Petäjä, A. P. Praplan, F. Riccobono, G. Steiner, A. Tomé, G. Tsagkogeorgas, P. E. Wagner, D. Wimmer, U. Baltensperger, M. Kulmala, D. R. Worsnop, and J. Curtius
Atmos. Chem. Phys., 15, 10701–10721, https://doi.org/10.5194/acp-15-10701-2015, https://doi.org/10.5194/acp-15-10701-2015, 2015
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New particle formation (NPF) is an important atmospheric process. At cold temperatures in the upper troposphere the binary (H2SO4-H2O) and ternary (H2SO4-H2O-NH3) system are thought to be important for NPF. Sulfuric acid monomer (H2SO4) and sulfuric acid dimer ((H2SO4)2) concentrations were measured between 208 and 248K for these systems and dimer evaporation rates were derived. These data will help to better understand and predict binary and ternary nucleation at low temperatures.
A. D. Venter, J. P. Beukes, P. G. van Zyl, E.-G. Brunke, C. Labuschagne, F. Slemr, R. Ebinghaus, and H. Kock
Atmos. Chem. Phys., 15, 10271–10280, https://doi.org/10.5194/acp-15-10271-2015, https://doi.org/10.5194/acp-15-10271-2015, 2015
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Statistical techniques applied to continuous high-resolution Hg data and back-trajectory analyses showed lower GEM concentrations originating from the sparsely populated semi-arid interior of SA and the marine environment, whereas higher GEM concentrations coincided with trade routes and industrial activities along the coast. Multi-linear regression indicated the relation of GEM with other atmospheric parameters. Measured and MLR data confirm a decline in GEM concentrations at CPT GAW station.
M. Pikridas, J. Sciare, F. Freutel, S. Crumeyrolle, S.-L. von der Weiden-Reinmüller, A. Borbon, A. Schwarzenboeck, M. Merkel, M. Crippa, E. Kostenidou, M. Psichoudaki, L. Hildebrandt, G. J. Engelhart, T. Petäjä, A. S. H. Prévôt, F. Drewnick, U. Baltensperger, A. Wiedensohler, M. Kulmala, M. Beekmann, and S. N. Pandis
Atmos. Chem. Phys., 15, 10219–10237, https://doi.org/10.5194/acp-15-10219-2015, https://doi.org/10.5194/acp-15-10219-2015, 2015
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Aerosol size distribution measurements from three ground sites, two mobile laboratories, and one airplane are combined to investigate the spatial and temporal variability of ultrafine particles in and around Paris during the summer and winter MEGAPOLI campaigns. The role of nucleation as a particle source and the influence of Paris emissions on their surroundings are examined.
N. Kalivitis, V.-M. Kerminen, G. Kouvarakis, I. Stavroulas, A. Bougiatioti, A. Nenes, H. E. Manninen, T. Petäjä, M. Kulmala, and N. Mihalopoulos
Atmos. Chem. Phys., 15, 9203–9215, https://doi.org/10.5194/acp-15-9203-2015, https://doi.org/10.5194/acp-15-9203-2015, 2015
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Cloud condensation nuclei (CCN) production associated with atmospheric new particle formation (NPF) is presented, and this is the first direct evidence of CCN production resulting from NPF in the eastern Mediterranean atmosphere. We show that condensation of both gaseous sulfuric acid and organic compounds from multiple sources leads to the rapid growth of nucleated particles. Sub-100nm particles were found to be substantially less hygroscopic than larger particles during the active NPF period.
F. Kuik, A. Lauer, J. P. Beukes, P. G. Van Zyl, M. Josipovic, V. Vakkari, L. Laakso, and G. T. Feig
Atmos. Chem. Phys., 15, 8809–8830, https://doi.org/10.5194/acp-15-8809-2015, https://doi.org/10.5194/acp-15-8809-2015, 2015
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The numerical model WRF-Chem is used to estimate the contribution of anthropogenic emissions to BC, aerosol optical depth and atmospheric heating rates over southern Africa. An evaluation of the model with observational data including long-term BC measurements shows that the basic meteorology is reproduced reasonably well but simulated near-surface BC concentrations are underestimated by up to 50%. It is found that up to 100% of the BC in highly industrialized regions is of anthropogenic origin.
L. Zhou, R. Gierens, A. Sogachev, D. Mogensen, J. Ortega, J. N. Smith, P. C. Harley, A. J. Prenni, E. J. T. Levin, A. Turnipseed, A. Rusanen, S. Smolander, A. B. Guenther, M. Kulmala, T. Karl, and M. Boy
Atmos. Chem. Phys., 15, 8643–8656, https://doi.org/10.5194/acp-15-8643-2015, https://doi.org/10.5194/acp-15-8643-2015, 2015
D. Wimmer, K. Lehtipalo, T. Nieminen, J. Duplissy, S. Ehrhart, J. Almeida, L. Rondo, A. Franchin, F. Kreissl, F. Bianchi, H. E. Manninen, M. Kulmala, J. Curtius, and T. Petäjä
Atmos. Chem. Phys., 15, 7547–7555, https://doi.org/10.5194/acp-15-7547-2015, https://doi.org/10.5194/acp-15-7547-2015, 2015
Z. Z. Zhang, P. Zhao, R. Oren, H. R. McCarthy, J. F. Niu, L. W. Zhu, G. Y. Ni, and Y. Q. Huang
Biogeosciences Discuss., https://doi.org/10.5194/bgd-12-10469-2015, https://doi.org/10.5194/bgd-12-10469-2015, 2015
Manuscript not accepted for further review
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a) More dramatically decreased hydralic conductivity when stomatal conductance was decreasing may shed some light on the mechanism of the high WUE of Eucalyptus when exposed to drought conditions. b) As tree grows, ks is more sensitive to water loss. c) The decrease in stomatal sensitivity of GSref to D along the radiation gradient accounted for an important aspect of “plastic characteristics” for E. urophylla.
F. Minunno, M. Peltoniemi, S. Launiainen, M. Aurela, A. Lindroth, A. Lohila, I. Mammarella, K. Minkkinen, and A. Mäkelä
Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmdd-8-5089-2015, https://doi.org/10.5194/gmdd-8-5089-2015, 2015
Revised manuscript not accepted
A. Franchin, S. Ehrhart, J. Leppä, T. Nieminen, S. Gagné, S. Schobesberger, D. Wimmer, J. Duplissy, F. Riccobono, E. M. Dunne, L. Rondo, A. Downard, F. Bianchi, A. Kupc, G. Tsagkogeorgas, K. Lehtipalo, H. E. Manninen, J. Almeida, A. Amorim, P. E. Wagner, A. Hansel, J. Kirkby, A. Kürten, N. M. Donahue, V. Makhmutov, S. Mathot, A. Metzger, T. Petäjä, R. Schnitzhofer, M. Sipilä, Y. Stozhkov, A. Tomé, V.-M. Kerminen, K. Carslaw, J. Curtius, U. Baltensperger, and M. Kulmala
Atmos. Chem. Phys., 15, 7203–7216, https://doi.org/10.5194/acp-15-7203-2015, https://doi.org/10.5194/acp-15-7203-2015, 2015
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The ion-ion recombination coefficient was measured at different temperatures, relative humidities and concentrations of ozone and sulfur dioxide. The experiments were carried out using the CLOUD chamber at CERN.
We observed a strong dependency on temperature and on relative humidity, which has not been reported previously. No dependency of the ion-ion recombination coefficient on ozone concentration was observed and a weak variation with sulfur dioxide concentration was also observed.
E. Giannakaki, A. Pfüller, K. Korhonen, T. Mielonen, L. Laakso, V. Vakkari, H. Baars, R. Engelmann, J. P. Beukes, P. G. Van Zyl, M. Josipovic, P. Tiitta, K. Chiloane, S. Piketh, H. Lihavainen, K. E. J. Lehtinen, and M. Komppula
Atmos. Chem. Phys., 15, 5429–5442, https://doi.org/10.5194/acp-15-5429-2015, https://doi.org/10.5194/acp-15-5429-2015, 2015
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In this study we summarize 1 year of Raman lidar observations over South Africa. The analyses of lidar measurements presented here could assist in bridging existing gaps in the knowledge of vertical distribution of aerosols above South Africa, since limited long-term data of this type are available for this region. For the first time, we have been able to cover the full seasonal cycle on geometrical characteristics and optical properties of free tropospheric aerosol layers in the region.
A.-M. Sundström, A. Nikandrova, K. Atlaskina, T. Nieminen, V. Vakkari, L. Laakso, J. P. Beukes, A. Arola, P. G. van Zyl, M. Josipovic, A. D. Venter, K. Jaars, J. J. Pienaar, S. Piketh, A. Wiedensohler, E. K. Chiloane, G. de Leeuw, and M. Kulmala
Atmos. Chem. Phys., 15, 4983–4996, https://doi.org/10.5194/acp-15-4983-2015, https://doi.org/10.5194/acp-15-4983-2015, 2015
V. Vakkari, E. J. O'Connor, A. Nisantzi, R. E. Mamouri, and D. G. Hadjimitsis
Atmos. Meas. Tech., 8, 1875–1885, https://doi.org/10.5194/amt-8-1875-2015, https://doi.org/10.5194/amt-8-1875-2015, 2015
A. P. Praplan, S. Schobesberger, F. Bianchi, M. P. Rissanen, M. Ehn, T. Jokinen, H. Junninen, A. Adamov, A. Amorim, J. Dommen, J. Duplissy, J. Hakala, A. Hansel, M. Heinritzi, J. Kangasluoma, J. Kirkby, M. Krapf, A. Kürten, K. Lehtipalo, F. Riccobono, L. Rondo, N. Sarnela, M. Simon, A. Tomé, J. Tröstl, P. M. Winkler, C. Williamson, P. Ye, J. Curtius, U. Baltensperger, N. M. Donahue, M. Kulmala, and D. R. Worsnop
Atmos. Chem. Phys., 15, 4145–4159, https://doi.org/10.5194/acp-15-4145-2015, https://doi.org/10.5194/acp-15-4145-2015, 2015
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Our study shows, based on data from three atmospheric pressure interface time-of-flight mass spectrometers measuring in parallel charged and neutral molecules and molecular clusters, how oxidised organic compounds bind to inorganic ions (e.g. bisulfate, nitrate, ammonium). This ionisation is selective for compounds with lower molar mass due to their limited amount and variety of functional groups. We also found that extremely low volatile organic compounds (ELVOCs) can be formed immediately.
D. Mogensen, R. Gierens, J. N. Crowley, P. Keronen, S. Smolander, A. Sogachev, A. C. Nölscher, L. Zhou, M. Kulmala, M. J. Tang, J. Williams, and M. Boy
Atmos. Chem. Phys., 15, 3909–3932, https://doi.org/10.5194/acp-15-3909-2015, https://doi.org/10.5194/acp-15-3909-2015, 2015
K. Neitola, D. Brus, U. Makkonen, M. Sipilä, R. L. Mauldin III, N. Sarnela, T. Jokinen, H. Lihavainen, and M. Kulmala
Atmos. Chem. Phys., 15, 3429–3443, https://doi.org/10.5194/acp-15-3429-2015, https://doi.org/10.5194/acp-15-3429-2015, 2015
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A discrepancy of 2 orders of magnitude was found between the measured sulfuric acid monomer concentration and total sulfate, when measured with independent methods (mass spectrometry and ion chromatography) with the same source of sulphuric acid vapor. The ion chromatography method produces the exact concentrations predicted by empirical equations, and the mass spectrometry method shows significantly lower values. The discrepancy is investigated thoroughly from different points of views.
C. Rose, K. Sellegri, E. Asmi, M. Hervo, E. Freney, A. Colomb, H. Junninen, J. Duplissy, M. Sipilä, J. Kontkanen, K. Lehtipalo, and M. Kulmala
Atmos. Chem. Phys., 15, 3413–3428, https://doi.org/10.5194/acp-15-3413-2015, https://doi.org/10.5194/acp-15-3413-2015, 2015
S. Xiao, M. Y. Wang, L. Yao, M. Kulmala, B. Zhou, X. Yang, J. M. Chen, D. F. Wang, Q. Y. Fu, D. R. Worsnop, and L. Wang
Atmos. Chem. Phys., 15, 1769–1781, https://doi.org/10.5194/acp-15-1769-2015, https://doi.org/10.5194/acp-15-1769-2015, 2015
W. Nie, A. J. Ding, Y. N. Xie, Z. Xu, H. Mao, V.-M. Kerminen, L. F. Zheng, X. M. Qi, X. Huang, X.-Q. Yang, J. N. Sun, E. Herrmann, T. Petäjä, M. Kulmala, and C. B. Fu
Atmos. Chem. Phys., 15, 1147–1159, https://doi.org/10.5194/acp-15-1147-2015, https://doi.org/10.5194/acp-15-1147-2015, 2015
H. Vuollekoski, M. Vogt, V. A. Sinclair, J. Duplissy, H. Järvinen, E.-M. Kyrö, R. Makkonen, T. Petäjä, N. L. Prisle, P. Räisänen, M. Sipilä, J. Ylhäisi, and M. Kulmala
Hydrol. Earth Syst. Sci., 19, 601–613, https://doi.org/10.5194/hess-19-601-2015, https://doi.org/10.5194/hess-19-601-2015, 2015
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The global potential for collecting usable water from dew on an
artificial collector sheet was investigated by utilising 34 years of
meteorological reanalysis data as input to a dew formation model. Continental dew formation was found to be frequent and common, but daily yields were
mostly below 0.1mm.
A.-M. Sundström, A. Arola, P. Kolmonen, Y. Xue, G. de Leeuw, and M. Kulmala
Atmos. Chem. Phys., 15, 505–518, https://doi.org/10.5194/acp-15-505-2015, https://doi.org/10.5194/acp-15-505-2015, 2015
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In this work, a satellite-based approach to derive the aerosol direct shortwave (SW) radiative effect (ADRE) is studied. The method is based on using coincident satellite observations of SW fluxes and aerosol optical depths (AODs). The key findings of this study are that using normalized values of observed fluxes improves the estimates of ADRE and aerosol-free TOA fluxes as compared to a model. The method was applied over eastern China where the satellite-based mean ADRE of -5Wm-2 was obtained.
C. Metzger, P.-E. Jansson, A. Lohila, M. Aurela, T. Eickenscheidt, L. Belelli-Marchesini, K. J. Dinsmore, J. Drewer, J. van Huissteden, and M. Drösler
Biogeosciences, 12, 125–146, https://doi.org/10.5194/bg-12-125-2015, https://doi.org/10.5194/bg-12-125-2015, 2015
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To identify site specific differences in CO2-related processes in open peatlands, we calibrated a process oriented model to fit to detailed measurements of carbon fluxes and compared the resulting parameter ranges between the sites. For most processes a common configuration could be applied. Site specific differences were identified for soil respiration coefficients, plant radiation-use efficiencies and plant storage fractions for spring regrowth.
S. Schobesberger, A. Franchin, F. Bianchi, L. Rondo, J. Duplissy, A. Kürten, I. K. Ortega, A. Metzger, R. Schnitzhofer, J. Almeida, A. Amorim, J. Dommen, E. M. Dunne, M. Ehn, S. Gagné, L. Ickes, H. Junninen, A. Hansel, V.-M. Kerminen, J. Kirkby, A. Kupc, A. Laaksonen, K. Lehtipalo, S. Mathot, A. Onnela, T. Petäjä, F. Riccobono, F. D. Santos, M. Sipilä, A. Tomé, G. Tsagkogeorgas, Y. Viisanen, P. E. Wagner, D. Wimmer, J. Curtius, N. M. Donahue, U. Baltensperger, M. Kulmala, and D. R. Worsnop
Atmos. Chem. Phys., 15, 55–78, https://doi.org/10.5194/acp-15-55-2015, https://doi.org/10.5194/acp-15-55-2015, 2015
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We used an ion mass spectrometer at CERN's CLOUD chamber to investigate the detailed composition of ammonia--sulfuric acid ion clusters (of both polarities) as they initially form and then grow into aerosol particles, at atmospherically relevant conditions. We found that these clusters’ composition is mainly determined by the ratio of the precursor vapors and ranges from ammonia-free clusters to clusters containing > 1 ammonia per sulfuric acid. Acid--base bindings are a key formation mechanism.
S. J. O'Shea, G. Allen, M. W. Gallagher, K. Bower, S. M. Illingworth, J. B. A. Muller, B. T. Jones, C. J. Percival, S. J-B. Bauguitte, M. Cain, N. Warwick, A. Quiquet, U. Skiba, J. Drewer, K. Dinsmore, E. G. Nisbet, D. Lowry, R. E. Fisher, J. L. France, M. Aurela, A. Lohila, G. Hayman, C. George, D. B. Clark, A. J. Manning, A. D. Friend, and J. Pyle
Atmos. Chem. Phys., 14, 13159–13174, https://doi.org/10.5194/acp-14-13159-2014, https://doi.org/10.5194/acp-14-13159-2014, 2014
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This paper presents airborne measurements of greenhouse gases collected in the European Arctic. Regional scale flux estimates for the northern Scandinavian wetlands are derived. These fluxes are found to be in excellent agreement with coincident surface measurements within the aircraft's sampling domain. This has allowed a significant low bias to be identified in two commonly used process-based land surface models.
J. Backman, A. Virkkula, V. Vakkari, J. P. Beukes, P. G. Van Zyl, M. Josipovic, S. Piketh, P. Tiitta, K. Chiloane, T. Petäjä, M. Kulmala, and L. Laakso
Atmos. Meas. Tech., 7, 4285–4298, https://doi.org/10.5194/amt-7-4285-2014, https://doi.org/10.5194/amt-7-4285-2014, 2014
M. Sipilä, T. Jokinen, T. Berndt, S. Richters, R. Makkonen, N. M. Donahue, R. L. Mauldin III, T. Kurtén, P. Paasonen, N. Sarnela, M. Ehn, H. Junninen, M. P. Rissanen, J. Thornton, F. Stratmann, H. Herrmann, D. R. Worsnop, M. Kulmala, V.-M. Kerminen, and T. Petäjä
Atmos. Chem. Phys., 14, 12143–12153, https://doi.org/10.5194/acp-14-12143-2014, https://doi.org/10.5194/acp-14-12143-2014, 2014
M. K. Sporre, E. Swietlicki, P. Glantz, and M. Kulmala
Atmos. Chem. Phys., 14, 12167–12179, https://doi.org/10.5194/acp-14-12167-2014, https://doi.org/10.5194/acp-14-12167-2014, 2014
J.-P. Pietikäinen, S. Mikkonen, A. Hamed, A. I. Hienola, W. Birmili, M. Kulmala, and A. Laaksonen
Atmos. Chem. Phys., 14, 11711–11729, https://doi.org/10.5194/acp-14-11711-2014, https://doi.org/10.5194/acp-14-11711-2014, 2014
K. Tsigaridis, N. Daskalakis, M. Kanakidou, P. J. Adams, P. Artaxo, R. Bahadur, Y. Balkanski, S. E. Bauer, N. Bellouin, A. Benedetti, T. Bergman, T. K. Berntsen, J. P. Beukes, H. Bian, K. S. Carslaw, M. Chin, G. Curci, T. Diehl, R. C. Easter, S. J. Ghan, S. L. Gong, A. Hodzic, C. R. Hoyle, T. Iversen, S. Jathar, J. L. Jimenez, J. W. Kaiser, A. Kirkevåg, D. Koch, H. Kokkola, Y. H Lee, G. Lin, X. Liu, G. Luo, X. Ma, G. W. Mann, N. Mihalopoulos, J.-J. Morcrette, J.-F. Müller, G. Myhre, S. Myriokefalitakis, N. L. Ng, D. O'Donnell, J. E. Penner, L. Pozzoli, K. J. Pringle, L. M. Russell, M. Schulz, J. Sciare, Ø. Seland, D. T. Shindell, S. Sillman, R. B. Skeie, D. Spracklen, T. Stavrakou, S. D. Steenrod, T. Takemura, P. Tiitta, S. Tilmes, H. Tost, T. van Noije, P. G. van Zyl, K. von Salzen, F. Yu, Z. Wang, Z. Wang, R. A. Zaveri, H. Zhang, K. Zhang, Q. Zhang, and X. Zhang
Atmos. Chem. Phys., 14, 10845–10895, https://doi.org/10.5194/acp-14-10845-2014, https://doi.org/10.5194/acp-14-10845-2014, 2014
S. G. Gonser, F. Klein, W. Birmili, J. Größ, M. Kulmala, H. E. Manninen, A. Wiedensohler, and A. Held
Atmos. Chem. Phys., 14, 10547–10563, https://doi.org/10.5194/acp-14-10547-2014, https://doi.org/10.5194/acp-14-10547-2014, 2014
S. Smolander, Q. He, D. Mogensen, L. Zhou, J. Bäck, T. Ruuskanen, S. Noe, A. Guenther, H. Aaltonen, M. Kulmala, and M. Boy
Biogeosciences, 11, 5425–5443, https://doi.org/10.5194/bg-11-5425-2014, https://doi.org/10.5194/bg-11-5425-2014, 2014
H. N. Mbufong, M. Lund, M. Aurela, T. R. Christensen, W. Eugster, T. Friborg, B. U. Hansen, E. R. Humphreys, M. Jackowicz-Korczynski, L. Kutzbach, P. M. Lafleur, W. C. Oechel, F. J. W. Parmentier, D. P. Rasse, A. V. Rocha, T. Sachs, M. K. van der Molen, and M. P. Tamstorf
Biogeosciences, 11, 4897–4912, https://doi.org/10.5194/bg-11-4897-2014, https://doi.org/10.5194/bg-11-4897-2014, 2014
L. Liao, V.-M. Kerminen, M. Boy, M. Kulmala, and M. Dal Maso
Atmos. Chem. Phys., 14, 8295–8308, https://doi.org/10.5194/acp-14-8295-2014, https://doi.org/10.5194/acp-14-8295-2014, 2014
M. Vestenius, H. Hellén, J. Levula, P. Kuronen, K.J. Helminen, T. Nieminen, M. Kulmala, and H. Hakola
Atmos. Chem. Phys., 14, 7883–7893, https://doi.org/10.5194/acp-14-7883-2014, https://doi.org/10.5194/acp-14-7883-2014, 2014
K. Jaars, J. P. Beukes, P. G. van Zyl, A. D. Venter, M. Josipovic, J. J. Pienaar, V. Vakkari, H. Aaltonen, H. Laakso, M. Kulmala, P. Tiitta, A. Guenther, H. Hellén, L. Laakso, and H. Hakola
Atmos. Chem. Phys., 14, 7075–7089, https://doi.org/10.5194/acp-14-7075-2014, https://doi.org/10.5194/acp-14-7075-2014, 2014
M. Crippa, F. Canonaco, V. A. Lanz, M. Äijälä, J. D. Allan, S. Carbone, G. Capes, D. Ceburnis, M. Dall'Osto, D. A. Day, P. F. DeCarlo, M. Ehn, A. Eriksson, E. Freney, L. Hildebrandt Ruiz, R. Hillamo, J. L. Jimenez, H. Junninen, A. Kiendler-Scharr, A.-M. Kortelainen, M. Kulmala, A. Laaksonen, A. A. Mensah, C. Mohr, E. Nemitz, C. O'Dowd, J. Ovadnevaite, S. N. Pandis, T. Petäjä, L. Poulain, S. Saarikoski, K. Sellegri, E. Swietlicki, P. Tiitta, D. R. Worsnop, U. Baltensperger, and A. S. H. Prévôt
Atmos. Chem. Phys., 14, 6159–6176, https://doi.org/10.5194/acp-14-6159-2014, https://doi.org/10.5194/acp-14-6159-2014, 2014
O. Peltola, A. Hensen, C. Helfter, L. Belelli Marchesini, F. C. Bosveld, W. C. M. van den Bulk, J. A. Elbers, S. Haapanala, J. Holst, T. Laurila, A. Lindroth, E. Nemitz, T. Röckmann, A. T. Vermeulen, and I. Mammarella
Biogeosciences, 11, 3163–3186, https://doi.org/10.5194/bg-11-3163-2014, https://doi.org/10.5194/bg-11-3163-2014, 2014
A. Hirsikko, E. J. O'Connor, M. Komppula, K. Korhonen, A. Pfüller, E. Giannakaki, C. R. Wood, M. Bauer-Pfundstein, A. Poikonen, T. Karppinen, H. Lonka, M. Kurri, J. Heinonen, D. Moisseev, E. Asmi, V. Aaltonen, A. Nordbo, E. Rodriguez, H. Lihavainen, A. Laaksonen, K. E. J. Lehtinen, T. Laurila, T. Petäjä, M. Kulmala, and Y. Viisanen
Atmos. Meas. Tech., 7, 1351–1375, https://doi.org/10.5194/amt-7-1351-2014, https://doi.org/10.5194/amt-7-1351-2014, 2014
G. W. Mann, K. S. Carslaw, C. L. Reddington, K. J. Pringle, M. Schulz, A. Asmi, D. V. Spracklen, D. A. Ridley, M. T. Woodhouse, L. A. Lee, K. Zhang, S. J. Ghan, R. C. Easter, X. Liu, P. Stier, Y. H. Lee, P. J. Adams, H. Tost, J. Lelieveld, S. E. Bauer, K. Tsigaridis, T. P. C. van Noije, A. Strunk, E. Vignati, N. Bellouin, M. Dalvi, C. E. Johnson, T. Bergman, H. Kokkola, K. von Salzen, F. Yu, G. Luo, A. Petzold, J. Heintzenberg, A. Clarke, J. A. Ogren, J. Gras, U. Baltensperger, U. Kaminski, S. G. Jennings, C. D. O'Dowd, R. M. Harrison, D. C. S. Beddows, M. Kulmala, Y. Viisanen, V. Ulevicius, N. Mihalopoulos, V. Zdimal, M. Fiebig, H.-C. Hansson, E. Swietlicki, and J. S. Henzing
Atmos. Chem. Phys., 14, 4679–4713, https://doi.org/10.5194/acp-14-4679-2014, https://doi.org/10.5194/acp-14-4679-2014, 2014
J. Hong, S. A. K. Häkkinen, M. Paramonov, M. Äijälä, J. Hakala, T. Nieminen, J. Mikkilä, N. L. Prisle, M. Kulmala, I. Riipinen, M. Bilde, V.-M. Kerminen, and T. Petäjä
Atmos. Chem. Phys., 14, 4733–4748, https://doi.org/10.5194/acp-14-4733-2014, https://doi.org/10.5194/acp-14-4733-2014, 2014
A. Virkkula, J. Levula, T. Pohja, P. P. Aalto, P. Keronen, S. Schobesberger, C. B. Clements, L. Pirjola, A.-J. Kieloaho, L. Kulmala, H. Aaltonen, J. Patokoski, J. Pumpanen, J. Rinne, T. Ruuskanen, M. Pihlatie, H. E. Manninen, V. Aaltonen, H. Junninen, T. Petäjä, J. Backman, M. Dal Maso, T. Nieminen, T. Olsson, T. Grönholm, J. Aalto, T. H. Virtanen, M. Kajos, V.-M. Kerminen, D. M. Schultz, J. Kukkonen, M. Sofiev, G. De Leeuw, J. Bäck, P. Hari, and M. Kulmala
Atmos. Chem. Phys., 14, 4473–4502, https://doi.org/10.5194/acp-14-4473-2014, https://doi.org/10.5194/acp-14-4473-2014, 2014
E.-M. Kyrö, R. Väänänen, V.-M. Kerminen, A. Virkkula, T. Petäjä, A. Asmi, M. Dal Maso, T. Nieminen, S. Juhola, A. Shcherbinin, I. Riipinen, K. Lehtipalo, P. Keronen, P. P. Aalto, P. Hari, and M. Kulmala
Atmos. Chem. Phys., 14, 4383–4396, https://doi.org/10.5194/acp-14-4383-2014, https://doi.org/10.5194/acp-14-4383-2014, 2014
K. Korhonen, E. Giannakaki, T. Mielonen, A. Pfüller, L. Laakso, V. Vakkari, H. Baars, R. Engelmann, J. P. Beukes, P. G. Van Zyl, A. Ramandh, L. Ntsangwane, M. Josipovic, P. Tiitta, G. Fourie, I. Ngwana, K. Chiloane, and M. Komppula
Atmos. Chem. Phys., 14, 4263–4278, https://doi.org/10.5194/acp-14-4263-2014, https://doi.org/10.5194/acp-14-4263-2014, 2014
D. C. S. Beddows, M. Dall'Osto, R. M. Harrison, M. Kulmala, A. Asmi, A. Wiedensohler, P. Laj, A.M. Fjaeraa, K. Sellegri, W. Birmili, N. Bukowiecki, E. Weingartner, U. Baltensperger, V. Zdimal, N. Zikova, J.-P. Putaud, A. Marinoni, P. Tunved, H.-C. Hansson, M. Fiebig, N. Kivekäs, E. Swietlicki, H. Lihavainen, E. Asmi, V. Ulevicius, P. P. Aalto, N. Mihalopoulos, N. Kalivitis, I. Kalapov, G. Kiss, G. de Leeuw, B. Henzing, C. O'Dowd, S. G. Jennings, H. Flentje, F. Meinhardt, L. Ries, H. A. C. Denier van der Gon, and A. J. H. Visschedijk
Atmos. Chem. Phys., 14, 4327–4348, https://doi.org/10.5194/acp-14-4327-2014, https://doi.org/10.5194/acp-14-4327-2014, 2014
J. D. Watts, J. S. Kimball, F. J. W. Parmentier, T. Sachs, J. Rinne, D. Zona, W. Oechel, T. Tagesson, M. Jackowicz-Korczyński, and M. Aurela
Biogeosciences, 11, 1961–1980, https://doi.org/10.5194/bg-11-1961-2014, https://doi.org/10.5194/bg-11-1961-2014, 2014
J. Aalto, P. Kolari, P. Hari, V.-M. Kerminen, P. Schiestl-Aalto, H. Aaltonen, J. Levula, E. Siivola, M. Kulmala, and J. Bäck
Biogeosciences, 11, 1331–1344, https://doi.org/10.5194/bg-11-1331-2014, https://doi.org/10.5194/bg-11-1331-2014, 2014
J. Kangasluoma, C. Kuang, D. Wimmer, M. P. Rissanen, K. Lehtipalo, M. Ehn, D. R. Worsnop, J. Wang, M. Kulmala, and T. Petäjä
Atmos. Meas. Tech., 7, 689–700, https://doi.org/10.5194/amt-7-689-2014, https://doi.org/10.5194/amt-7-689-2014, 2014
I. Kourtchev, S. J. Fuller, C. Giorio, R. M. Healy, E. Wilson, I. O'Connor, J. C. Wenger, M. McLeod, J. Aalto, T. M. Ruuskanen, W. Maenhaut, R. Jones, D. S. Venables, J. R. Sodeau, M. Kulmala, and M. Kalberer
Atmos. Chem. Phys., 14, 2155–2167, https://doi.org/10.5194/acp-14-2155-2014, https://doi.org/10.5194/acp-14-2155-2014, 2014
P. Tiitta, V. Vakkari, P. Croteau, J. P. Beukes, P. G. van Zyl, M. Josipovic, A. D. Venter, K. Jaars, J. J. Pienaar, N. L. Ng, M. R. Canagaratna, J. T. Jayne, V.-M. Kerminen, H. Kokkola, M. Kulmala, A. Laaksonen, D. R. Worsnop, and L. Laakso
Atmos. Chem. Phys., 14, 1909–1927, https://doi.org/10.5194/acp-14-1909-2014, https://doi.org/10.5194/acp-14-1909-2014, 2014
M. Koskinen, K. Minkkinen, P. Ojanen, M. Kämäräinen, T. Laurila, and A. Lohila
Biogeosciences, 11, 347–363, https://doi.org/10.5194/bg-11-347-2014, https://doi.org/10.5194/bg-11-347-2014, 2014
C. E. Scott, A. Rap, D. V. Spracklen, P. M. Forster, K. S. Carslaw, G. W. Mann, K. J. Pringle, N. Kivekäs, M. Kulmala, H. Lihavainen, and P. Tunved
Atmos. Chem. Phys., 14, 447–470, https://doi.org/10.5194/acp-14-447-2014, https://doi.org/10.5194/acp-14-447-2014, 2014
A. L. Corrigan, L. M. Russell, S. Takahama, M. Äijälä, M. Ehn, H. Junninen, J. Rinne, T. Petäjä, M. Kulmala, A. L. Vogel, T. Hoffmann, C. J. Ebben, F. M. Geiger, P. Chhabra, J. H. Seinfeld, D. R. Worsnop, W. Song, J. Auld, and J. Williams
Atmos. Chem. Phys., 13, 12233–12256, https://doi.org/10.5194/acp-13-12233-2013, https://doi.org/10.5194/acp-13-12233-2013, 2013
A. I. Partanen, A. Laakso, A. Schmidt, H. Kokkola, T. Kuokkanen, J.-P. Pietikäinen, V.-M. Kerminen, K. E. J. Lehtinen, L. Laakso, and H. Korhonen
Atmos. Chem. Phys., 13, 12059–12071, https://doi.org/10.5194/acp-13-12059-2013, https://doi.org/10.5194/acp-13-12059-2013, 2013
S. Dengel, D. Zona, T. Sachs, M. Aurela, M. Jammet, F. J. W. Parmentier, W. Oechel, and T. Vesala
Biogeosciences, 10, 8185–8200, https://doi.org/10.5194/bg-10-8185-2013, https://doi.org/10.5194/bg-10-8185-2013, 2013
C. J. Schumacher, C. Pöhlker, P. Aalto, V. Hiltunen, T. Petäjä, M. Kulmala, U. Pöschl, and J. A. Huffman
Atmos. Chem. Phys., 13, 11987–12001, https://doi.org/10.5194/acp-13-11987-2013, https://doi.org/10.5194/acp-13-11987-2013, 2013
A. J. Ding, C. B. Fu, X. Q. Yang, J. N. Sun, T. Petäjä, V.-M. Kerminen, T. Wang, Y. Xie, E. Herrmann, L. F. Zheng, W. Nie, Q. Liu, X. L. Wei, and M. Kulmala
Atmos. Chem. Phys., 13, 10545–10554, https://doi.org/10.5194/acp-13-10545-2013, https://doi.org/10.5194/acp-13-10545-2013, 2013
N. Unger, K. Harper, Y. Zheng, N. Y. Kiang, I. Aleinov, A. Arneth, G. Schurgers, C. Amelynck, A. Goldstein, A. Guenther, B. Heinesch, C. N. Hewitt, T. Karl, Q. Laffineur, B. Langford, K. A. McKinney, P. Misztal, M. Potosnak, J. Rinne, S. Pressley, N. Schoon, and D. Serça
Atmos. Chem. Phys., 13, 10243–10269, https://doi.org/10.5194/acp-13-10243-2013, https://doi.org/10.5194/acp-13-10243-2013, 2013
M. R. Pennington, B. R. Bzdek, J. W. DePalma, J. N. Smith, A.-M. Kortelainen, L. Hildebrandt Ruiz, T. Petäjä, M. Kulmala, D. R. Worsnop, and M. V. Johnston
Atmos. Chem. Phys., 13, 10215–10225, https://doi.org/10.5194/acp-13-10215-2013, https://doi.org/10.5194/acp-13-10215-2013, 2013
S. A. K. Häkkinen, H. E. Manninen, T. Yli-Juuti, J. Merikanto, M. K. Kajos, T. Nieminen, S. D. D'Andrea, A. Asmi, J. R. Pierce, M. Kulmala, and I. Riipinen
Atmos. Chem. Phys., 13, 7665–7682, https://doi.org/10.5194/acp-13-7665-2013, https://doi.org/10.5194/acp-13-7665-2013, 2013
E. Järvinen, A. Virkkula, T. Nieminen, P. P. Aalto, E. Asmi, C. Lanconelli, M. Busetto, A. Lupi, R. Schioppo, V. Vitale, M. Mazzola, T. Petäjä, V.-M. Kerminen, and M. Kulmala
Atmos. Chem. Phys., 13, 7473–7487, https://doi.org/10.5194/acp-13-7473-2013, https://doi.org/10.5194/acp-13-7473-2013, 2013
A. Berchet, I. Pison, F. Chevallier, P. Bousquet, S. Conil, M. Geever, T. Laurila, J. Lavrič, M. Lopez, J. Moncrieff, J. Necki, M. Ramonet, M. Schmidt, M. Steinbacher, and J. Tarniewicz
Atmos. Chem. Phys., 13, 7115–7132, https://doi.org/10.5194/acp-13-7115-2013, https://doi.org/10.5194/acp-13-7115-2013, 2013
D. Wimmer, K. Lehtipalo, A. Franchin, J. Kangasluoma, F. Kreissl, A. Kürten, A. Kupc, A. Metzger, J. Mikkilä, T. Petäjä, F. Riccobono, J. Vanhanen, M. Kulmala, and J. Curtius
Atmos. Meas. Tech., 6, 1793–1804, https://doi.org/10.5194/amt-6-1793-2013, https://doi.org/10.5194/amt-6-1793-2013, 2013
M. K. Kajos, H. Hakola, T. Holst, T. Nieminen, V. Tarvainen, T. Maximov, T. Petäjä, A. Arneth, and J. Rinne
Biogeosciences, 10, 4705–4719, https://doi.org/10.5194/bg-10-4705-2013, https://doi.org/10.5194/bg-10-4705-2013, 2013
A. J. Ding, C. B. Fu, X. Q. Yang, J. N. Sun, L. F. Zheng, Y. N. Xie, E. Herrmann, W. Nie, T. Petäjä, V.-M. Kerminen, and M. Kulmala
Atmos. Chem. Phys., 13, 5813–5830, https://doi.org/10.5194/acp-13-5813-2013, https://doi.org/10.5194/acp-13-5813-2013, 2013
A. Hirsikko, V. Vakkari, P. Tiitta, J. Hatakka, V.-M. Kerminen, A.-M. Sundström, J. P. Beukes, H. E. Manninen, M. Kulmala, and L. Laakso
Atmos. Chem. Phys., 13, 5523–5532, https://doi.org/10.5194/acp-13-5523-2013, https://doi.org/10.5194/acp-13-5523-2013, 2013
V. Vakkari, J. P. Beukes, H. Laakso, D. Mabaso, J. J. Pienaar, M. Kulmala, and L. Laakso
Atmos. Chem. Phys., 13, 1751–1770, https://doi.org/10.5194/acp-13-1751-2013, https://doi.org/10.5194/acp-13-1751-2013, 2013
L. Riuttanen, M. Dal Maso, G. de Leeuw, I. Riipinen, L. Sogacheva, V. Vakkari, L. Laakso, and M. Kulmala
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acpd-13-4289-2013, https://doi.org/10.5194/acpd-13-4289-2013, 2013
Revised manuscript has not been submitted
J. Leppä, S. Gagné, L. Laakso, H. E. Manninen, K. E. J. Lehtinen, M. Kulmala, and V.-M. Kerminen
Atmos. Chem. Phys., 13, 463–486, https://doi.org/10.5194/acp-13-463-2013, https://doi.org/10.5194/acp-13-463-2013, 2013
A.-P. Hyvärinen, V. Vakkari, L. Laakso, R. K. Hooda, V. P. Sharma, T. S. Panwar, J. P. Beukes, P. G. van Zyl, M. Josipovic, R. M. Garland, M. O. Andreae, U. Pöschl, and A. Petzold
Atmos. Meas. Tech., 6, 81–90, https://doi.org/10.5194/amt-6-81-2013, https://doi.org/10.5194/amt-6-81-2013, 2013
V.-M. Kerminen, M. Paramonov, T. Anttila, I. Riipinen, C. Fountoukis, H. Korhonen, E. Asmi, L. Laakso, H. Lihavainen, E. Swietlicki, B. Svenningsson, A. Asmi, S. N. Pandis, M. Kulmala, and T. Petäjä
Atmos. Chem. Phys., 12, 12037–12059, https://doi.org/10.5194/acp-12-12037-2012, https://doi.org/10.5194/acp-12-12037-2012, 2012
H. Hakola, H. Hellén, M. Hemmilä, J. Rinne, and M. Kulmala
Atmos. Chem. Phys., 12, 11665–11678, https://doi.org/10.5194/acp-12-11665-2012, https://doi.org/10.5194/acp-12-11665-2012, 2012
Related subject area
Subject: Ecohydrology | Techniques and Approaches: Instruments and observation techniques
Technical note: a Weighing Forest Floor Grid-Lysimeter
Seasonal shifts in depth-to-water uptake by young thinned and overstocked lodgepole pine (Pinus contorta) forests under drought conditions in the Okanagan Valley, British Columbia, Canada
Hydrological and pedological effects of combining Italian alder and blackberries in an agroforestry windbreak system in South Africa
Rainfall redistribution in subtropical Chinese forests changes over 22 years
Effects of subsurface water infiltration systems on land movement dynamics in Dutch peat meadows
The influence of hillslope topography on beech water use: a comparative study in two different climates
Real-time biological early-warning system based on freshwater mussels’ valvometry data
Root water uptake patterns are controlled by tree species interactions and soil water variability
The seasonal origins and ages of water provisioning streams and trees in a tropical montane cloud forest
Benefits of a robotic chamber system for determining evapotranspiration in an erosion-affected, heterogeneous cropland
Quantifying river water contributions to the transpiration of riparian trees along a losing river: lessons from stable isotopes and an iteration method
Dye-tracer-aided investigation of xylem water transport velocity distributions
Technical note: Lessons from and best practices for the deployment of the Soil Water Isotope Storage System
Throughfall spatial patterns translate into spatial patterns of soil moisture dynamics – empirical evidence
Routing stemflow water through the soil via preferential flow: a dual-labelling approach with artificial tracers
Improving soil aquifer treatment efficiency using air injection into the subsurface
Dynamic root growth in response to depth-varying soil moisture availability: a rhizobox study
Controls on leaf water hydrogen and oxygen isotopes: a local investigation across seasons and altitude
Resolving seasonal and diel dynamics of non-rainfall water inputs in a Mediterranean ecosystem using lysimeters
Inter- and intra-event rainfall partitioning dynamics of two typical xerophytic shrubs in the Loess Plateau of China
A comparative study of plant water extraction methods for isotopic analyses: Scholander-type pressure chamber vs. cryogenic vacuum distillation
Technical note: Conservative storage of water vapour – practical in situ sampling of stable isotopes in tree stems
Xylem water in riparian willow trees (Salix alba) reveals shallow sources of root water uptake by in situ monitoring of stable water isotopes
Technical note: High-accuracy weighing micro-lysimeter system for long-term measurements of non-rainfall water inputs to grasslands
Response of water fluxes and biomass production to climate change in permanent grassland soil ecosystems
Ecohydrological travel times derived from in situ stable water isotope measurements in trees during a semi-controlled pot experiment
Insights into the isotopic mismatch between bulk soil water and Salix matsudana Koidz trunk water from root water stable isotope measurements
The role of dew and radiation fog inputs in the local water cycling of a temperate grassland during dry spells in central Europe
Co-evolution of xylem water and soil water stable isotopic composition in a northern mixed forest biome
Vapor plumes in a tropical wet forest: spotting the invisible evaporation
Rapid reduction in ecosystem productivity caused by flash droughts based on decade-long FLUXNET observations
Throughfall isotopic composition in relation to drop size at the intra-event scale in a Mediterranean Scots pine stand
Rainfall interception and redistribution by a common North American understory and pasture forb, Eupatorium capillifolium (Lam. dogfennel)
In situ measurements of soil and plant water isotopes: a review of approaches, practical considerations and a vision for the future
Coalescence of bacterial groups originating from urban runoffs and artificial infiltration systems among aquifer microbiomes
A combination of soil water extraction methods quantifies the isotopic mixing of waters held at separate tensions in soil
Using water stable isotopes to understand evaporation, moisture stress, and re-wetting in catchment forest and grassland soils of the summer drought of 2018
Partitioning growing season water balance within a forested boreal catchment using sap flux, eddy covariance, and a process-based model
Technical note: Long-term probe misalignment and proposed quality control using the heat pulse method for transpiration estimations
Contribution of understory evaporation in a tropical wet forest during the dry season
Coffee and shade trees show complementary use of soil water in a traditional agroforestry ecosystem
Responses of soil water storage and crop water use efficiency to changing climatic conditions: a lysimeter-based space-for-time approach
Neighbourhood and stand structure affect stemflow generation in a heterogeneous deciduous temperate forest
Technical Note: A global database of the stable isotopic ratios of meteoric and terrestrial waters
Temporally dependent effects of rainfall characteristics on inter- and intra-event branch-scale stemflow variability in two xerophytic shrubs
Dissolved organic carbon driven by rainfall events from a semi-arid catchment during concentrated rainfall season in the Loess Plateau, China
Dew frequency across the US from a network of in situ radiometers
Seasonal origins of soil water used by trees
Forest harvesting impacts on microclimate conditions and sediment transport activities in a humid periglacial environment
Hydrogeochemical controls on brook trout spawning habitats in a coastal stream
Heinke Paulsen and Markus Weiler
EGUsphere, https://doi.org/10.5194/egusphere-2024-3503, https://doi.org/10.5194/egusphere-2024-3503, 2024
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This technical note describes the development of the weighing Forest Floor Grid-Lysimeter. The device is needed to investigate the dynamics of the water balance components of the organic layer in forests. Quantifying precipitation, drainage, evaporation and storage. We designed a setup that can be easily rebuild and is cost-effective, which allows for customized applications. Performance metrics from laboratory results and initial field data are presented.
Emory C. Ellis, Robert D. Guy, and Xiaohua A. Wei
Hydrol. Earth Syst. Sci., 28, 4667–4684, https://doi.org/10.5194/hess-28-4667-2024, https://doi.org/10.5194/hess-28-4667-2024, 2024
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This study analyzes water-stable isotope composition by analyzing the impact of forest thinning on lodgepole pine depth-to-water uptake and water-use strategies. Lodgepole pine's primary source is spring snowmelt and shifts to rely on deeper soil water to maintain water uptake. There was no effect of decreased stand density on depth-to-water uptake. It will become more critical that we know how much water forests are using and which strategies trees use to sustain their water supply.
Svenja Hoffmeister, Rafael Bohn Reckziegel, Ben du Toit, Sibylle K. Hassler, Florian Kestel, Rebekka Maier, Jonathan P. Sheppard, and Erwin Zehe
Hydrol. Earth Syst. Sci., 28, 3963–3982, https://doi.org/10.5194/hess-28-3963-2024, https://doi.org/10.5194/hess-28-3963-2024, 2024
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We studied a tree–crop ecosystem consisting of a blackberry field and an alder windbreak. In the water-scarce region, irrigation provides sufficient water for plant growth. The windbreak lowers the irrigation amount by reducing wind speed and therefore water transport into the atmosphere. These ecosystems could provide sustainable use of water-scarce landscapes, and we studied the complex interactions by observing several aspects (e.g. soil, nutrients, carbon assimilation, water).
Wanjun Zhang, Thomas Scholten, Steffen Seitz, Qianmei Zhang, Guowei Chu, Linhua Wang, Xin Xiong, and Juxiu Liu
Hydrol. Earth Syst. Sci., 28, 3837–3854, https://doi.org/10.5194/hess-28-3837-2024, https://doi.org/10.5194/hess-28-3837-2024, 2024
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Rainfall input generally controls soil water and plant growth. We focus on rainfall redistribution in succession sequence forests over 22 years. Some changes in rainwater volume and chemistry in the throughfall and stemflow and drivers were investigated. Results show that shifted open rainfall over time and forest factors induced remarkable variability in throughfall and stemflow, which potentially makes forecasting future changes in water resources in the forest ecosystems more difficult.
Sanneke van Asselen, Gilles Erkens, Christian Fritz, Rudi Hessel, and Jan J. H. van den Akker
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2024-152, https://doi.org/10.5194/hess-2024-152, 2024
Revised manuscript accepted for HESS
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In general, water infiltration systems in peat meadows reduce groundwater level lowering and yearly vertical soil dynamics. Groundwater level fluctuations induce soil volume decreases and increases in both the saturated and unsaturated zone, causing yearly soil dynamics of up to 10 cm. Multi-year subsidence rates are in the order of mm/yr. Such research is vital to increase knowledge on subsidence processes and to develop effective measures to reduce land subsidence and greenhouse gas emission.
Ginevra Fabiani, Julian Klaus, and Daniele Penna
Hydrol. Earth Syst. Sci., 28, 2683–2703, https://doi.org/10.5194/hess-28-2683-2024, https://doi.org/10.5194/hess-28-2683-2024, 2024
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There is a limited understanding of the role that topography and climate play in tree water use. Through a cross-site comparison in Luxembourg and Italy, we investigated beech water use along slopes in different climates. Our findings indicate that in landscapes characterized by stronger hydraulic and climatic gradients there is greater spatial variation in tree physiological responses. This highlights how differing growing conditions across landscapes can lead to contrasting tree performances.
Ashkan Pilbala, Nicoletta Riccardi, Nina Benistati, Vanessa Modesto, Donatella Termini, Dario Manca, Augusto Benigni, Cristiano Corradini, Tommaso Lazzarin, Tommaso Moramarco, Luigi Fraccarollo, and Sebastiano Piccolroaz
Hydrol. Earth Syst. Sci., 28, 2297–2311, https://doi.org/10.5194/hess-28-2297-2024, https://doi.org/10.5194/hess-28-2297-2024, 2024
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This study investigates the impact of floods on the aquatic ecosystem using freshwater mussels instrumented with sensors to monitor the opening of their valves. Signal analysis techniques were used to gain insight into their responses in terms of changes in the intensity and frequency of valve opening. The approach used in the study enables the development of real-time monitoring systems for ecological purposes and provides a pathway for practical biological early-warning systems.
Gökben Demir, Andrew J. Guswa, Janett Filipzik, Johanna Clara Metzger, Christine Römermann, and Anke Hildebrandt
Hydrol. Earth Syst. Sci., 28, 1441–1461, https://doi.org/10.5194/hess-28-1441-2024, https://doi.org/10.5194/hess-28-1441-2024, 2024
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Experimental evidence is scarce to understand how the spatial variation in below-canopy precipitation affects root water uptake patterns. Here, we conducted field measurements to investigate drivers of root water uptake patterns while accounting for canopy induced heterogeneity in water input. We found that tree species interactions and soil moisture variability, rather than below-canopy precipitation patterns, control root water uptake patterns in a mixed unmanaged forest.
Emily I. Burt, Gregory R. Goldsmith, Roxanne M. Cruz-de Hoyos, Adan Julian Ccahuana Quispe, and A. Joshua West
Hydrol. Earth Syst. Sci., 27, 4173–4186, https://doi.org/10.5194/hess-27-4173-2023, https://doi.org/10.5194/hess-27-4173-2023, 2023
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When it rains, water remains in the ground for variable amounts of time before it is taken up by plants or becomes streamflow. Understanding how long water stays in the ground before it is taken up by plants or becomes streamflow helps predict what will happen to the water cycle in future climates. Some studies suggest that plants take up water that has been in the ground for a long time; in contrast, we find that plants take up a significant amount of recent rain.
Adrian Dahlmann, Mathias Hoffmann, Gernot Verch, Marten Schmidt, Michael Sommer, Jürgen Augustin, and Maren Dubbert
Hydrol. Earth Syst. Sci., 27, 3851–3873, https://doi.org/10.5194/hess-27-3851-2023, https://doi.org/10.5194/hess-27-3851-2023, 2023
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Evapotranspiration (ET) plays a pivotal role in terrestrial water cycling, returning up to 90 % of precipitation to the atmosphere. We studied impacts of soil type and management on an agroecosystem using an automated system with modern modeling approaches. We modeled ET at high spatial and temporal resolution to highlight differences in heterogeneous soils on an hourly basis. Our results show significant differences in yield and smaller differences in ET overall, impacting water use efficiency.
Yue Li, Ying Ma, Xianfang Song, Qian Zhang, and Lixin Wang
Hydrol. Earth Syst. Sci., 27, 3405–3425, https://doi.org/10.5194/hess-27-3405-2023, https://doi.org/10.5194/hess-27-3405-2023, 2023
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We proposed an iteration method in combination with the MixSIAR model and water isotopes to quantify the river water contribution (RWC) to riparian deep-rooted trees nearby a losing river. River water can indirectly contribute by 20.3 % to water uptake of riparian trees. River recharged riparian groundwater rapidly with a short groundwater residence time (no more than 0.28 d). The RWC to riparian trees was negatively correlated with the water table depth and leaf δ13C in linear functions.
Stefan Seeger and Markus Weiler
Hydrol. Earth Syst. Sci., 27, 3393–3404, https://doi.org/10.5194/hess-27-3393-2023, https://doi.org/10.5194/hess-27-3393-2023, 2023
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This study proposes a low-budget method to quantify the radial distribution of water transport velocities within trees at a high spatial resolution. We observed a wide spread of water transport velocities within a tree stem section, which were on average 3 times faster than the flux velocity. The distribution of transport velocities has implications for studies that use water isotopic signatures to study root water uptake and usually assume uniform or even implicitly infinite velocities.
Rachel E. Havranek, Kathryn Snell, Sebastian Kopf, Brett Davidheiser-Kroll, Valerie Morris, and Bruce Vaughn
Hydrol. Earth Syst. Sci., 27, 2951–2971, https://doi.org/10.5194/hess-27-2951-2023, https://doi.org/10.5194/hess-27-2951-2023, 2023
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We present an automated, field-ready system that collects soil water vapor for stable isotope analysis. This system can be used to determine soil water evolution through time, which is helpful for understanding crop water use, water vapor fluxes to the atmosphere, and geologic proxy development. Our system can automatically collect soil water vapor and then store it for up to 30 d, which allows researchers to collect datasets from historically understudied, remote locations.
Christine Fischer-Bedtke, Johanna Clara Metzger, Gökben Demir, Thomas Wutzler, and Anke Hildebrandt
Hydrol. Earth Syst. Sci., 27, 2899–2918, https://doi.org/10.5194/hess-27-2899-2023, https://doi.org/10.5194/hess-27-2899-2023, 2023
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Canopies change how rain reaches the soil: some spots receive more and others less water. It has long been debated whether this also leads to locally wetter and drier soil. We checked this using measurements of canopy drip and soil moisture. We found that the increase in soil water content after rain was aligned with canopy drip. Independently, the soil storage reaction was dampened in locations prone to drainage, like hig-macroporosity areas, suggesting that canopy drip enhances bypass flow.
Juan Pinos, Markus Flury, Jérôme Latron, and Pilar Llorens
Hydrol. Earth Syst. Sci., 27, 2865–2881, https://doi.org/10.5194/hess-27-2865-2023, https://doi.org/10.5194/hess-27-2865-2023, 2023
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We investigated how stemflow (intercepted rainwater by the tree crown that travels down the stem) infiltrates within the soil. We simulated stemflow, applying coloured water along a tree trunk. Coloured patterns, observed when we excavated the soil after the experiment, were used to view and quantify preferential flow in the soil. We found that stemflow was mainly funnelled belowground along tree roots and macropores. Soil moisture near the trunk was affected both vertically and horizontally.
Ido Arad, Aviya Ziner, Shany Ben Moshe, Noam Weisbrod, and Alex Furman
Hydrol. Earth Syst. Sci., 27, 2509–2522, https://doi.org/10.5194/hess-27-2509-2023, https://doi.org/10.5194/hess-27-2509-2023, 2023
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In a series of long-column experiments, subsurface air injection in soil aquifer treatment (Air-SAT) was tested as an alternative to conventional flooding–drying operation (FDO) in tertiary wastewater (WW) treatment. Our results show that Air-SAT allows for the treatment of increased WW volumes and results in similar or better effluent quality compared with FDO. These results highlight the possibility of using air injection to treat more effluent and alleviate the pressure on existing SAT sites.
Cynthia Maan, Marie-Claire ten Veldhuis, and Bas J. H. van de Wiel
Hydrol. Earth Syst. Sci., 27, 2341–2355, https://doi.org/10.5194/hess-27-2341-2023, https://doi.org/10.5194/hess-27-2341-2023, 2023
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Their flexible growth provides the plants with a strong ability to adapt and develop resilience to droughts and climate change. But this adaptability is badly included in crop and climate models. To model plant development in changing environments, we need to include the survival strategies of plants. Based on experimental data, we set up a simple model for soil-moisture-driven root growth. The model performance suggests that soil moisture is a key parameter determining root growth.
Jinzhao Liu, Chong Jiang, Huawu Wu, Li Guo, Haiwei Zhang, and Ying Zhao
Hydrol. Earth Syst. Sci., 27, 599–612, https://doi.org/10.5194/hess-27-599-2023, https://doi.org/10.5194/hess-27-599-2023, 2023
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What controls leaf water isotopes? We answered the question from two perspectives: respective and dual isotopes. On the one hand, the δ18O and δ2H values of leaf water responded to isotopes of potential source water (i.e., twig water, soil water, and precipitation) and meteorological parameters (i.e., temperature, RH, and precipitation) differently. On the other hand, dual δ18O and δ2H values of leaf water yielded a significant linear relationship associated with altitude and seasonality.
Sinikka Jasmin Paulus, Tarek Sebastian El-Madany, René Orth, Anke Hildebrandt, Thomas Wutzler, Arnaud Carrara, Gerardo Moreno, Oscar Perez-Priego, Olaf Kolle, Markus Reichstein, and Mirco Migliavacca
Hydrol. Earth Syst. Sci., 26, 6263–6287, https://doi.org/10.5194/hess-26-6263-2022, https://doi.org/10.5194/hess-26-6263-2022, 2022
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In this study, we analyze small inputs of water to ecosystems such as fog, dew, and adsorption of vapor. To measure them, we use a scaling system and later test our attribution of different water fluxes to weight changes. We found that they occur frequently during 1 year in a dry summer ecosystem. In each season, a different flux seems dominant, but they all mainly occur during the night. Therefore, they could be important for the biosphere because rain is unevenly distributed over the year.
Jinxia An, Guangyao Gao, Chuan Yuan, Juan Pinos, and Bojie Fu
Hydrol. Earth Syst. Sci., 26, 3885–3900, https://doi.org/10.5194/hess-26-3885-2022, https://doi.org/10.5194/hess-26-3885-2022, 2022
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An in-depth investigation was conducted of all rainfall-partitioning components at inter- and intra-event scales for two xerophytic shrubs. Inter-event rainfall partitioning amount and percentage depended more on rainfall amount, and rainfall intensity and duration controlled intra-event rainfall-partitioning variables. One shrub has larger branch angle, small branch and smaller canopy area to produce stemflow more efficiently, and the other has larger biomass to intercept more rainfall.
Giulia Zuecco, Anam Amin, Jay Frentress, Michael Engel, Chiara Marchina, Tommaso Anfodillo, Marco Borga, Vinicio Carraro, Francesca Scandellari, Massimo Tagliavini, Damiano Zanotelli, Francesco Comiti, and Daniele Penna
Hydrol. Earth Syst. Sci., 26, 3673–3689, https://doi.org/10.5194/hess-26-3673-2022, https://doi.org/10.5194/hess-26-3673-2022, 2022
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We analyzed the variability in the isotopic composition of plant water extracted by two different methods, i.e., cryogenic vacuum distillation (CVD) and Scholander-type pressure chamber (SPC). Our results indicated that the isotopic composition of plant water extracted by CVD and SPC was significantly different. We concluded that plant water extraction by SPC is not an alternative for CVD as SPC mostly extracts the mobile plant water whereas CVD retrieves all water stored in the sampled tissue.
Ruth-Kristina Magh, Benjamin Gralher, Barbara Herbstritt, Angelika Kübert, Hyungwoo Lim, Tomas Lundmark, and John Marshall
Hydrol. Earth Syst. Sci., 26, 3573–3587, https://doi.org/10.5194/hess-26-3573-2022, https://doi.org/10.5194/hess-26-3573-2022, 2022
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We developed a method of sampling and storing water vapour for isotope analysis, allowing us to infer plant water uptake depth. Measurements can be made at high temporal and spatial resolution even in remote areas. We ensured that all necessary components are easily available, making this method cost efficient and simple to implement. We found our method to perform well in the lab and in the field, enabling it to become a tool for everyone aiming to resolve questions regarding the water cycle.
Jessica Landgraf, Dörthe Tetzlaff, Maren Dubbert, David Dubbert, Aaron Smith, and Chris Soulsby
Hydrol. Earth Syst. Sci., 26, 2073–2092, https://doi.org/10.5194/hess-26-2073-2022, https://doi.org/10.5194/hess-26-2073-2022, 2022
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Using water stable isotopes, we studied from which water source (lake water, stream water, groundwater, or soil water) two willows were taking their water. We monitored the environmental conditions (e.g. air temperature and soil moisture) and the behaviour of the trees (water flow in the stem). We found that the most likely water sources of the willows were the upper soil layers but that there were seasonal dynamics.
Andreas Riedl, Yafei Li, Jon Eugster, Nina Buchmann, and Werner Eugster
Hydrol. Earth Syst. Sci., 26, 91–116, https://doi.org/10.5194/hess-26-91-2022, https://doi.org/10.5194/hess-26-91-2022, 2022
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The aim of this study was to develop a high-accuracy micro-lysimeter system for the quantification of non-rainfall water inputs that overcomes existing drawbacks. The micro-lysimeter system had a high accuracy and allowed us to quantify and distinguish between different types of non-rainfall water inputs, like dew and fog. Non-rainfall water inputs occurred frequently in a Swiss Alpine grassland ecosystem. These water inputs can be an important water source for grasslands during dry periods.
Veronika Forstner, Jannis Groh, Matevz Vremec, Markus Herndl, Harry Vereecken, Horst H. Gerke, Steffen Birk, and Thomas Pütz
Hydrol. Earth Syst. Sci., 25, 6087–6106, https://doi.org/10.5194/hess-25-6087-2021, https://doi.org/10.5194/hess-25-6087-2021, 2021
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Lysimeter-based manipulative and observational experiments were used to identify responses of water fluxes and aboveground biomass (AGB) to climatic change in permanent grassland. Under energy-limited conditions, elevated temperature actual evapotranspiration (ETa) increased, while seepage, dew, and AGB decreased. Elevated CO2 mitigated the effect on ETa. Under water limitation, elevated temperature resulted in reduced ETa, and AGB was negatively correlated with an increasing aridity.
David Mennekes, Michael Rinderer, Stefan Seeger, and Natalie Orlowski
Hydrol. Earth Syst. Sci., 25, 4513–4530, https://doi.org/10.5194/hess-25-4513-2021, https://doi.org/10.5194/hess-25-4513-2021, 2021
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In situ stable water isotope measurements are a recently developed method to measure water movement from the soil through the plant to the atmosphere in high resolution and precision. Here, we present important advantages of the new method in comparison to commonly used measurement methods in an experimental setup. Overall, this method can help to answer research questions such as plant responses to climate change with potentially shifting water availability or temperatures.
Ying Zhao and Li Wang
Hydrol. Earth Syst. Sci., 25, 3975–3989, https://doi.org/10.5194/hess-25-3975-2021, https://doi.org/10.5194/hess-25-3975-2021, 2021
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At our study site during the experimental period, trunk water was only isotopically similar to root water at 100–160 cm depths. The isotopic composition of root water deviated from that of bulk soil water but overlapped with the composition derived for less mobile water. These findings suggest that the isotopic offset between bulk soil water and trunk water was due to the isotopic mismatch between root water and bulk soil water associated with soil water heterogeneity.
Yafei Li, Franziska Aemisegger, Andreas Riedl, Nina Buchmann, and Werner Eugster
Hydrol. Earth Syst. Sci., 25, 2617–2648, https://doi.org/10.5194/hess-25-2617-2021, https://doi.org/10.5194/hess-25-2617-2021, 2021
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During dry spells, dew and fog potentially play an increasingly important role in temperate grasslands. Research on the combined mechanisms of dew and fog inputs to ecosystems and distillation of water vapor from soil to plant surfaces is rare. Our results using stable water isotopes highlight the importance of dew and fog inputs to temperate grasslands during dry spells and reveal the complexity of the local water cycling in such conditions, including different pathways of dew and fog inputs.
Jenna R. Snelgrove, James M. Buttle, Matthew J. Kohn, and Dörthe Tetzlaff
Hydrol. Earth Syst. Sci., 25, 2169–2186, https://doi.org/10.5194/hess-25-2169-2021, https://doi.org/10.5194/hess-25-2169-2021, 2021
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Co-evolution of plant and soil water isotopic composition throughout the growing season in a little-studied northern mixed forest landscape was explored. Marked inter-specific differences in the isotopic composition of xylem water relative to surrounding soil water occurred, despite thin soil cover constraining inter-species differences in rooting depths. We provide potential explanations for differences in temporal evolution of xylem water isotopic composition in this northern landscape.
César Dionisio Jiménez-Rodríguez, Miriam Coenders-Gerrits, Bart Schilperoort, Adriana del Pilar González-Angarita, and Hubert Savenije
Hydrol. Earth Syst. Sci., 25, 619–635, https://doi.org/10.5194/hess-25-619-2021, https://doi.org/10.5194/hess-25-619-2021, 2021
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During rainfall events, evaporation from tropical forests is usually ignored. However, the water retained in the canopy during rainfall increases the evaporation despite the high-humidity conditions. In a tropical wet forest in Costa Rica, it was possible to depict vapor plumes rising from the forest canopy during rainfall. These plumes are evidence of forest evaporation. Also, we identified the conditions that allowed this phenomenon to happen using time-lapse videos and meteorological data.
Miao Zhang and Xing Yuan
Hydrol. Earth Syst. Sci., 24, 5579–5593, https://doi.org/10.5194/hess-24-5579-2020, https://doi.org/10.5194/hess-24-5579-2020, 2020
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We identify flash drought events by considering the decline rate of soil moisture and the drought persistency, and we detect the response of ecosystem carbon and water fluxes to flash droughts based on FLUXNET observations. We find rapid declines in carbon assimilation within 16–24 d of flash drought onset, where savannas show the highest sensitivity. Water use efficiency increases for forests but decreases for herbaceous ecosystems during the recovery stage of flash droughts.
Juan Pinos, Jérôme Latron, Kazuki Nanko, Delphis F. Levia, and Pilar Llorens
Hydrol. Earth Syst. Sci., 24, 4675–4690, https://doi.org/10.5194/hess-24-4675-2020, https://doi.org/10.5194/hess-24-4675-2020, 2020
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Water that drips or splashes from a canopy or passes through it is termed throughfall. This is the first known study to examine interrelationships between throughfall isotopic fractionation and throughfall drop size. Working in a mountainous Scots pine forest, we found that throughfall splash droplets were more prevalent at the onset of rain when vapour pressure deficits were larger. This finding has important implications for water mixing in the canopy and for theories of canopy interception.
D. Alex R. Gordon, Miriam Coenders-Gerrits, Brent A. Sellers, S. M. Moein Sadeghi, and John T. Van Stan II
Hydrol. Earth Syst. Sci., 24, 4587–4599, https://doi.org/10.5194/hess-24-4587-2020, https://doi.org/10.5194/hess-24-4587-2020, 2020
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Where plants exist, rain must pass through canopies to reach soils. We studied how rain interacts with dogfennel – a highly problematic weed that is abundant in pastures, grasslands, rangelands, urban forests and along highways. Dogfennels evaporated large portions (approx. one-fifth) of rain and drained significant (at times > 25 %) rain (and dew) down their stems to their roots (via stemflow). This may explain how dogfennel survives and even invades managed landscapes during extended droughts.
Matthias Beyer, Kathrin Kühnhammer, and Maren Dubbert
Hydrol. Earth Syst. Sci., 24, 4413–4440, https://doi.org/10.5194/hess-24-4413-2020, https://doi.org/10.5194/hess-24-4413-2020, 2020
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Water isotopes are a scientific tool that can be used to identify sources of water and answer questions such as
From which soil depths do plants take up water?, which are highly relevant under changing climatic conditions. In the past, the measurement of water isotopes required tremendous effort. In the last decade methods have advanced and can now be applied in the field. Herein, we review the current status of direct field measurements of water isotopes and discuss future applications.
Yannick Colin, Rayan Bouchali, Laurence Marjolet, Romain Marti, Florian Vautrin, Jérémy Voisin, Emilie Bourgeois, Veronica Rodriguez-Nava, Didier Blaha, Thierry Winiarski, Florian Mermillod-Blondin, and Benoit Cournoyer
Hydrol. Earth Syst. Sci., 24, 4257–4273, https://doi.org/10.5194/hess-24-4257-2020, https://doi.org/10.5194/hess-24-4257-2020, 2020
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Stormwater infiltration systems (SISs) are a source of pollution that may have adverse ecological and sanitary impacts. The incidence of a SIS on the coalescence of microbial communities from runoff waters and aboveground sediments with those of an aquifer was investigated. Aquifer waters showed lower coalescence with aboveground bacterial taxa than aquifer biofilms. These biofilms were colonized by bacterial hydrocarbon degraders and harboured undesirable human-opportunistic pathogens.
William H. Bowers, Jason J. Mercer, Mark S. Pleasants, and David G. Williams
Hydrol. Earth Syst. Sci., 24, 4045–4060, https://doi.org/10.5194/hess-24-4045-2020, https://doi.org/10.5194/hess-24-4045-2020, 2020
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Determining the chemical composition of soil water can help to address questions concerning water transport and use. However, there are many observations of incompletely mixed soil water within various soil pore domains. We applied two contrasting waters to soil samples and then removed water from the soils with three sequential and increasing applied energy steps to assess soil water mixing and equilibration over time. We found it took more than 3 d for soil water to mix and equilibrate.
Lukas Kleine, Doerthe Tetzlaff, Aaron Smith, Hailong Wang, and Chris Soulsby
Hydrol. Earth Syst. Sci., 24, 3737–3752, https://doi.org/10.5194/hess-24-3737-2020, https://doi.org/10.5194/hess-24-3737-2020, 2020
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We investigated the effects of the 2018 drought on water partitioning in a lowland catchment under grassland and forest in north-eastern Germany. Conditions resulted in drying up of streams, yield losses, and lower groundwater levels. Oak trees continued to transpire during the drought. We used stable isotopes to assess the fluxes and ages of water. Sustainable use of resource water requires such understanding of ecohydrological water partitioning.
Nataliia Kozii, Kersti Haahti, Pantana Tor-ngern, Jinshu Chi, Eliza Maher Hasselquist, Hjalmar Laudon, Samuli Launiainen, Ram Oren, Matthias Peichl, Jörgen Wallerman, and Niles J. Hasselquist
Hydrol. Earth Syst. Sci., 24, 2999–3014, https://doi.org/10.5194/hess-24-2999-2020, https://doi.org/10.5194/hess-24-2999-2020, 2020
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The hydrologic cycle is one of the greatest natural processes on Earth and strongly influences both regional and global climate as well as ecosystem functioning. Results from this study clearly show the central role trees play in regulating the water cycle of boreal catchments, implying that forest management impacts on stand structure as well as climate change effects on tree growth are likely to have large cascading effects on the way water moves through boreal forested landscapes.
Elisabeth K. Larsen, Jose Luis Palau, Jose Antonio Valiente, Esteban Chirino, and Juan Bellot
Hydrol. Earth Syst. Sci., 24, 2755–2767, https://doi.org/10.5194/hess-24-2755-2020, https://doi.org/10.5194/hess-24-2755-2020, 2020
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To improve long-term sap flow measurements when using the heat ratio method, this study introduces a dynamic probe misalignment correction method. This work uses sap flow data from four Aleppo pines from April 2017 to December 2018 and shows how a classical probe correction approach declines in accuracy over time. Additionally, it is proposed that a new set of statistical information be recorded along with the sap flow readings to ensure the quality of the raw data.
César Dionisio Jiménez-Rodríguez, Miriam Coenders-Gerrits, Jochen Wenninger, Adriana Gonzalez-Angarita, and Hubert Savenije
Hydrol. Earth Syst. Sci., 24, 2179–2206, https://doi.org/10.5194/hess-24-2179-2020, https://doi.org/10.5194/hess-24-2179-2020, 2020
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Tropical forest ecosystems are able to export a lot of water to the atmosphere by means of evaporation. However, little is known on how their complex structure affects this water flux. This paper analyzes the contribution of three canopy layers in terms of water fluxes and stable water isotope signatures. During the dry season in 2018 the two lower canopy layers provide 20 % of measured evaporation, highlighting the importance of knowing how forest structure can affect the hydrological cycle.
Lyssette Elena Muñoz-Villers, Josie Geris, María Susana Alvarado-Barrientos, Friso Holwerda, and Todd Dawson
Hydrol. Earth Syst. Sci., 24, 1649–1668, https://doi.org/10.5194/hess-24-1649-2020, https://doi.org/10.5194/hess-24-1649-2020, 2020
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Our research showed, consistently, a complementary use of soil water sources between coffee (Coffea Arabica var. typica) plants and shade tree species during the dry and wet seasons in a traditional agroforestry ecosystem in central Veracruz, Mexico. However, more variability in plant water sources was observed among species in the rainy season when higher soil moisture conditions were present and water stress was largely absent.
Jannis Groh, Jan Vanderborght, Thomas Pütz, Hans-Jörg Vogel, Ralf Gründling, Holger Rupp, Mehdi Rahmati, Michael Sommer, Harry Vereecken, and Horst H. Gerke
Hydrol. Earth Syst. Sci., 24, 1211–1225, https://doi.org/10.5194/hess-24-1211-2020, https://doi.org/10.5194/hess-24-1211-2020, 2020
Johanna C. Metzger, Jens Schumacher, Markus Lange, and Anke Hildebrandt
Hydrol. Earth Syst. Sci., 23, 4433–4452, https://doi.org/10.5194/hess-23-4433-2019, https://doi.org/10.5194/hess-23-4433-2019, 2019
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Variation in stemflow (rain water running down the stem) enhances the formation of flow hot spots at the forest floor. Investigating drivers based on detailed measurements, we find that forest structure affects stemflow, both for individual trees and small communities. Densely packed forest patches received more stemflow, due to a higher proportion of woody structure and canopy morphology adjustments, which increase the potential for flow path generation connecting crowns and soil.
Annie L. Putman and Gabriel J. Bowen
Hydrol. Earth Syst. Sci., 23, 4389–4396, https://doi.org/10.5194/hess-23-4389-2019, https://doi.org/10.5194/hess-23-4389-2019, 2019
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We describe an open-access, global database of stable water isotope ratios of various water types. The database facilitates data archiving, supports standardized metadata collection, and decreases the time investment for metanalyses. To promote data discovery and collaboration, the database exposes metadata and data owner contact information for private data but only permits download of public data. Two companion apps support digital data collection and processing and upload of analyzed data.
Chuan Yuan, Guangyao Gao, Bojie Fu, Daming He, Xingwu Duan, and Xiaohua Wei
Hydrol. Earth Syst. Sci., 23, 4077–4095, https://doi.org/10.5194/hess-23-4077-2019, https://doi.org/10.5194/hess-23-4077-2019, 2019
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The stemflow dynamics of two xerophytic shrubs were investigated at the inter- and intra-event scales with high-temporal-resolution data in 54 rain events. Stemflow process was depicted by intensity, duration and time lags to rain events. Funneling ratio was calculated as the ratio of stemflow to rainfall intensities. Rainfall intensity and raindrop momentum controlled stemflow intensity and time lags. Influences of rainfall characteristics on stemflow variables showed temporal dependence.
Linhua Wang, Haw Yen, Xinhui E, Liding Chen, and Yafeng Wang
Hydrol. Earth Syst. Sci., 23, 3141–3153, https://doi.org/10.5194/hess-23-3141-2019, https://doi.org/10.5194/hess-23-3141-2019, 2019
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A high-frequency approach was used to monitor dynamic changes of DOC exported during the concentrated rainfall season in LPR, China. DOC concentration and flux from an ecologically restored catchment in the LPR was investigated. Hysteresis analysis indicated non-linear relationships between DOC concentration and discharge rate in a rainfall event. DOC export is substantially affected by the interaction of rainfall and antecedent conditions for a rainfall event.
François Ritter, Max Berkelhammer, and Daniel Beysens
Hydrol. Earth Syst. Sci., 23, 1179–1197, https://doi.org/10.5194/hess-23-1179-2019, https://doi.org/10.5194/hess-23-1179-2019, 2019
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There currently is no standardized approach for measuring dew formation, making it difficult to compare its frequency and importance across ecosystems. Recently, canopy surface temperature data from 30 sites in the US were measured continuously using in situ infrared radiometers. The analysis presented here provides the first continental-scale standardized synthesis of dew formation. This work provides a basis for considering how changing climate and land use will influence dew formation.
Scott T. Allen, James W. Kirchner, Sabine Braun, Rolf T. W. Siegwolf, and Gregory R. Goldsmith
Hydrol. Earth Syst. Sci., 23, 1199–1210, https://doi.org/10.5194/hess-23-1199-2019, https://doi.org/10.5194/hess-23-1199-2019, 2019
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We used stable isotopes of xylem water to study differences in the seasonal origin of water in more than 900 individual trees from three dominant species in 182 Swiss forested sites. We discovered that midsummer transpiration was mostly supplied by winter precipitation across diverse humid climates. Our findings provide new insights into tree vulnerability to droughts, transport of water (and thus solutes) in soils, and the climatic information conveyed by plant-tissue isotopes.
Fumitoshi Imaizumi, Ryoko Nishii, Kenichi Ueno, and Kousei Kurobe
Hydrol. Earth Syst. Sci., 23, 155–170, https://doi.org/10.5194/hess-23-155-2019, https://doi.org/10.5194/hess-23-155-2019, 2019
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We investigated seasonal changes in sediment transport activities following forest harvesting in a humid periglacial area. Removal of the forest canopy by forest harvesting alters the type of winter soil creep. Winter creep velocity of the ground surface sediment in the harvested site was significantly higher than that in the non-harvested site. Meanwhile, sediment flux on the hillslopes decreased in the harvested site because of capture of sediment by branches of harvested trees.
Martin A. Briggs, Judson W. Harvey, Stephen T. Hurley, Donald O. Rosenberry, Timothy McCobb, Dale Werkema, and John W. Lane Jr.
Hydrol. Earth Syst. Sci., 22, 6383–6398, https://doi.org/10.5194/hess-22-6383-2018, https://doi.org/10.5194/hess-22-6383-2018, 2018
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Brook trout are known to seek out groundwater-discharge zones for spawning. However, in a groundwater-dominated system, we observed trout using a few locations for repeatedly laying eggs. To improve the management of this cold-water species, we wanted to know why these specific groundwater-discharge zones were desirable. Through a combination of geophysical and chemical measurements, we found that locations where the stream intersects the sandy valley wall create oxygen-rich seepage zones.
Cited articles
Archibald, S. and Scholes, R. J.: Leaf green-up in a semi-arid African
savanna – separating tree and grass responses to environmental cues, J.
Veg. Sci., 18, 583–594, https://doi.org/10.1111/j.1654-1103.2007.tb02572.x, 2007.
Aurela, M., Lohila, A., Tuovinen, J.-P., Hatakka, J., Riutta, T., and Laurila, T.: Carbon dioxide exchange on a northern boreal fen, Boreal Environ. Res., 14, 699–710, 2009.
Baldocchi, D., Falge, E., Gu, L., Olson, R., Hollinger, D., Running, S.,
Anthoni, P., Bernhofer, C., Davis, K., Evans, R., Fuentes, J., Goldstein,
A., Katul, G., Law, B., Lee, X., Malhi, Y., Meyers, T., Munger, W., Oechel,
W., U, K. T. P., Pilegaard, K., Schmid, H. P., Valentini, R., Verma, S.,
Vesala, T., Wilson, K., and Wofsy, S.: FLUXNET: A new tool to study the
temporal and spatial variability of ecosystem-scale carbon dioxide, water
vapor, and energy flux densities, B. Am. Meteorol. Soc., 82, 2415–2434, 2001.
Barnes, R. D., Fagg, C. W., and Milton, S. J.: Acacia Erioloba: Monograph
and Annotated Bibliography, Oxford Forestry Institute, University of Oxford,
https://ora.ox.ac.uk/objects/uuid:9f260e92-d72d-4fff-988d-5ef95e716f94 (last access: 15 November 2022), 1997.
Bengtsson, J., Bullock, J. M., Egoh, B., Everson, C., Everson, T., O'Connor,
T., O'Farrell, P. J., Smith, H. G., and Lindborg, R.: Grasslands – more
important for ecosystem services than you might think, Ecosphere, 10, e02582, https://doi.org/10.1002/ecs2.2582, 2019.
Ben Neriah, A., Assouline, S., Shavit, U., and Weisbrod, N.: Impact of ambient conditions on evaporation from porous media, Water Resour. Res., 50, 6696–6712, https://doi.org/10.1002/2014WR015523, 2014.
Berkelhammer, M., Noone, D. C., Wong, T. E., Burns, S. P., Knowles, J. F.,
Kaushik, A., Blanken, P. D., and Williams, M. W.: Convergent approaches to
determine an ecosystem's transpiration fraction, Global Biogeoch. Cy., 30, 933–951, https://doi.org/10.1002/2016GB005392, 2016.
Beukes, J. P., Venter, A. D., Josipovic, M., Zyl, P. G. V., Vakkari, V.,
Jaars, K., Dunn, M., and Laakso, L.: Chapter 6 – Automated Continuous Air
Monitoring, in: Monitoring of Air Pollutants, vol. 70, edited by: Forbes, P.
B. C., Elsevier, 183–208, https://doi.org/10.1016/bs.coac.2015.09.006, 2015.
Beyer, M., Hamutoko, J. T., Wanke, H., Gaj, M., and Koeniger, P.: Examination
of deep root water uptake using anomalies of soil water stable isotopes,
depth-controlled isotopic labeling and mixing models, J. Hydrol., 566, 122–136, https://doi.org/10.1016/j.jhydrol.2018.08.060, 2018.
Braaten, J. D., Cohen, W. B., and Yang, Z.: Automated cloud and cloud shadow
identification in Landsat MSS imagery for temperate ecosystems, Remote
Sens. Environ., 169, 128–138, https://doi.org/10.1016/j.rse.2015.08.006, 2015.
Brutsaert, W. and Chen, D.: Desorption and the two Stages of Drying of Natural Tallgrass Prairie, Water Resour. Res., 31, 1305–1313,
https://doi.org/10.1029/95WR00323, 1995.
Bulcock, H. H. and Jewitt, G. P. W.: Modelling canopy and litter interception in commercial forest plantations in South Africa using the Variable Storage Gash model and idealised drying curves, Hydrol. Earth Syst. Sci., 16, 4693–4705, https://doi.org/10.5194/hess-16-4693-2012, 2012.
Didan, K.: MOD13Q1 MODIS/Terra Vegetation Indices 16-Day L3 Global 250 m SIN
Grid V006, NASA EOSDIS Land Processes DAAC, https://doi.org/10.5067/MODIS/MOD13Q1.006, 2015.
Do, F. C., Rocheteau, A., Diagne, A. L., Goudiaby, V., Granier, A., and Lhomme, J.-P.: Stable annual pattern of water use by Acacia tortilis in Sahelian Africa, Tree Physiol., 28, 95–104, https://doi.org/10.1093/treephys/28.1.95, 2008.
D'Onofrio, D., Sweeney, L., von Hardenberg, J., and Baudena, M.: Grass and
tree cover responses to intra-seasonal rainfall variability vary along a
rainfall gradient in African tropical grassy biomes, Scient. Rep., 9, 2334, https://doi.org/10.1038/s41598-019-38933-9, 2019.
Foken, T. and Wichura, B.: Tools for quality assessment of surface-based flux measurements, Agr. Forest Meteorol., 78, 83–105, https://doi.org/10.1016/0168-1923(95)02248-1, 1996.
Gash, J. H. C., Lloyd, C. R., and Lachaud, G.: Estimating sparse forest rainfall interception with an analytical model, J. Hydrol., 170, 79–86, https://doi.org/10.1016/0022-1694(95)02697-N, 1995.
Godde, C. M., Boone, R. B., Ash, A. J., Waha, K., Sloat, L. L., Thornton, P.
K., and Herrero, M.: Global rangeland production systems and livelihoods at
threat under climate change and variability, Environ. Res. Lett., 15, 044021, https://doi.org/10.1088/1748-9326/ab7395, 2020.
Guan, K., Wood, E. F., Medvigy, D., Kimball, J., Pan, M., Caylor, K. K.,
Sheffield, J., Xu, X., and Jones, M. O.: Terrestrial hydrological controls on
land surface phenology of African savannas and woodlands, J. Geophys. Res.-Biogeo., 119, 1652–1669, https://doi.org/10.1002/2013JG002572, 2014.
Gwate, O., Mantel, S. K., Gibson, L. A., Munch, Z., and Palmer, A. R.:
Exploring dynamics of evapotranspiration in selected land cover classes in a
sub-humid grassland: A case study in quaternary catchment S50E, South
Africa, J. Arid Environ., 157, 66–76, https://doi.org/10.1016/j.jaridenv.2018.05.011, 2018.
Hari, P., Mäkelä, A., and Pohja, T.: Surprising implications of the
optimality hypothesis of stomatal regulation gain support in a field test,
Funct. Plant Biol., 27, 77–80, 2000.
Hu, H., Chen, L., Liu, H., Ali Khan, M. Y., Tie, Q., Zhang, X., and Tian, F.:
Comparison of the vegetation effect on et partitioning based on eddy
covariance method at five different sites of Northern China, Remote Sens., 10, 1755, https://doi.org/10.3390/rs10111755, 2018.
Hu, X. and Lei, H.: Evapotranspiration partitioning and its interannual
variability over a winter wheat-summer maize rotation system in the North
China Plain, Agr. Forest Meteorol., 310, 108635,
https://doi.org/10.1016/j.agrformet.2021.108635, 2021.
Hubert, M. and Vandervieren, E.: An adjusted boxplot for skewed distributions, Comput. Stat. Data Anal., 52, 5186–5201, https://doi.org/10.1016/j.csda.2007.11.008, 2008.
Hutley, L. B., O'Grady, A. P., and Eamus, D.: Monsoonal Influences on
Evapotranspiration of Savanna Vegetation of Northern Australia, Oecologia,
126, 434–443, 2001.
Jaars, K., van Zyl, P. G., Beukes, J. P., Hellén, H., Vakkari, V.,
Josipovic, M., Venter, A. D., Räsänen, M., Knoetze, L., Cilliers, D.
P., Siebert, S. J., Kulmala, M., Rinne, J., Guenther, A., Laakso, L., and
Hakola, H.: Measurements of biogenic volatile organic compounds at a grazed
savannah grassland agricultural landscape in South Africa, Atmos. Chem. Phys., 16, 15665–15688, https://doi.org/10.5194/acp-16-15665-2016, 2016.
Jackisch, C., Knoblauch, S., Blume, T., Zehe, E., and Hassler, S. K.:
Estimates of tree root water uptake from soil moisture profile dynamics,
Biogeosciences, 17, 5787–5808, https://doi.org/10.5194/bg-17-5787-2020, 2020.
Jennings, C. M. H.: The hydrology of botswana, PhD thesis, University of Natal, http://hdl.handle.net/10413/8524 (last access: 15 November 2022), 1974.
Katul, G., Manzoni, S., Palmroth, S., and Oren, R.: A stomatal optimization
theory to describe the effects of atmospheric CO2 on leaf photosynthesis and transpiration, Ann. Bot., 105, 431–442, 2010.
Katul, G. G., Palmroth, S., and Oren, R.: Leaf stomatal responses to vapour
pressure deficit under current and CO2-enriched atmosphere explained by the economics of gas exchange, Plant Cell Environ., 32, 968–979, 2009.
Kljun, N., Calanca, P., Rotach, M. W., and Schmid, H. P.: A simple
two-dimensional parameterisation for Flux Footprint Prediction (FFP), Geosci. Model Dev., 8, 3695–3713, https://doi.org/10.5194/gmd-8-3695-2015, 2015.
Mamadou, O., Cohard, J. M., Galle, S., Awanou, C. N., Diedhiou, A., Kounouhewa, B., and Peugeot, C.: Energy fluxes and surface characteristics
over a cultivated area in Benin: Daily and seasonal dynamics, Hydrol.
Earth Syst. Sci., 18, 893–914, https://doi.org/10.5194/hess-18-893-2014, 2014.
Mamadou, O., Galle, S., Cohard, J.-M., Peugeot, C., Kounouhewa, B., Biron,
R., Hector, B., and Zannou, A. B.: Dynamics of water vapor and energy exchanges above two contrasting Sudanian climate ecosystems in Northern Benin (West Africa), J. Geophys. Res.-Atmos., 121, 11269–11286, https://doi.org/10.1002/2016JD024749, 2016.
Merbold, L., Ardö, J., Arneth, A., Scholes, R. J., Nouvellon, Y., de Grandcourt, A., Archibald, S., Bonnefond, J. M., Boulain, N., Brueggemann, N., Bruemmer, C., Cappelaere, B., Ceschia, E., El-Khidir, H. A. M., El-Tahir, B. A., Falk, U., Lloyd, J., Kergoat, L., Le Dantec, V., Mougin, E., Muchinda, M., Mukelabai, M. M., Ramier, D., Roupsard, O., Timouk, F., Veenendaal, E. M., and Kutsch, W. L.: Precipitation as driver of carbon fluxes in 11 African ecosystems, Biogeosciences, 6, 1027–1041, https://doi.org/10.5194/bg-6-1027-2009, 2009.
Moene, A. F. and Van Dam, J. C.: Transport in the atmosphere-vegetation-soil
continuum, Cambridge University Press, ISBN 9780521195683, 2014.
Montaldo, N., Curreli, M., Corona, R., and Oren, R.: Fixed and variable
components of evapotranspiration in a Mediterranean wild-olive – grass
landscape mosaic, Agr.d Forest Meteorol., 280, 107769,
https://doi.org/10.1016/j.agrformet.2019.107769, 2020.
Moore, C. J.: Frequency response corrections for eddy correlation systems,
Bound.-Lay. Meteorol., 37, 17–35, https://doi.org/10.1007/BF00122754, 1986.
Nelson, J. A., Carvalhais, N., Cuntz, M., Delpierre, N., Knauer, J., Ogée, J., Migliavacca, M., Reichstein, M., and Jung, M.: Coupling water
and carbon fluxes to constrain estimates of transpiration: The TEA algorithm, J. Geophys. Res.-Biogeo., 123, 3617–3632, https://doi.org/10.1029/2018JG004727, 2018.
Nelson, J. A., Pérez-Priego, O., Zhou, S., Poyatos, R., Zhang, Y.,
Blanken, P. D., Gimeno, T. E., Wohlfahrt, G., Desai, A. R., Gioli, B.,
Limousin, J.-M., Bonal, D., Paul-Limoges, E., Scott, R. L., Varlagin, A.,
Fuchs, K., Montagnani, L., Wolf, S., Delpierre, N., Berveiller, D., Gharun,
M., Marchesini, L. B., Gianelle, D., Šigut, L., Mammarella, I., Siebicke, L., Black, T. A., Knohl, A., Hörtnagl, L., Magliulo, V., Besnard, S., Weber, U., Carvalhais, N., Migliavacca, M., Reichstein, M., and Jung, M.: Ecosystem transpiration and evaporation: Insights from three water flux partitioning methods across FLUXNET sites, Global Change Biol., 26,
6916–6930, https://doi.org/10.1111/gcb.15314, 2020.
Novick, K. A., Oren, R., Stoy, P. C., Siqueira, M. B. S., and Katul, G. G.:
Nocturnal evapotranspiration in eddy-covariance records from three co-located ecosystems in the Southeastern U.S.: Implications for annual fluxes, Agr. Forest Meteorol., 149, 1491–1504, https://doi.org/10.1016/j.agrformet.2009.04.005, 2009.
Oishi, A. C., Oren, R., Novick, K. A., Palmroth, S., and Katul, G. G.:
Interannual Invariability of Forest Evapotranspiration and Its Consequence to Water Flow Downstream, Ecosystems, 13, 421–436, https://doi.org/10.1007/s10021-010-9328-3, 2010.
Perez-Priego, O., Katul, G., Reichstein, M., El-Madany, T. S., Ahrens, B.,
Carrara, A., Scanlon, T. M., and Migliavacca, M.: Partitioning eddy covariance water flux components using physiological and micrometeorological
approaches, J. Geophys. Res.-Biogeo., 123, 3353–3370, https://doi.org/10.1029/2018JG004637, 2018.
Petäjä, T., Vakkari, V., Pohja, T., Nieminen, T., Laakso, H., Aalto,
P. P., Keronen, P., Siivola, E., Kerminen, V.-M., Kulmala, M., and Laakso,
L.: Transportable Aerosol Characterization Trailer with Trace Gas Chemistry:
Design, Instruments and Verification, Aerosol Air Qual. Res., 13, 421–435,
https://doi.org/10.4209/aaqr.2012.08.0207, 2013.
Pollock, M. D., O'Donnell, G., Quinn, P., Dutton, M., Black, A., Wilkinson,
M. E., Colli, M., Stagnaro, M., Lanza, L. G., Lewis, E., Kilsby, C. G., and
O'Connell, P. E.: Quantifying and mitigating wind-induced undercatch in rainfall measurements, Water Resour. Res., 54, 3863–3875, https://doi.org/10.1029/2017WR022421, 2018.
Priestley, C. H. B. and Taylor, R. J.: On the assessment of surface heat flux and evaporation using large-scale parameters, Mon. Weather Rev., 100, 81–92, https://doi.org/10.1175/1520-0493(1972)100<0081:OTAOSH>2.3.CO;2, 1972.
Priyadarshini, K. V. R., Prins, H. H. T., de Bie, S., Heitkönig, I. M.
A., Woodborne, S., Gort, G., Kirkman, K., Ludwig, F., Dawson, T. E., and de Kroon, H.: Seasonality of hydraulic redistribution by trees to grasses and
changes in their water-source use that change tree–grass interactions,
Ecohydrology, 9, 218–228, https://doi.org/10.1002/eco.1624, 2016.
Räsänen, M., Aurela, M., Vakkari, V., Beukes, J. P., Tuovinen, J.-P., Van Zyl, P. G., Josipovic, M., Venter, A. D., Jaars, K., Siebert, S. J., Laurila, T., Rinne, J., and Laakso, L.: Carbon balance of a grazed savanna grassland ecosystem in South Africa, Biogeosciences, 14, 1039–1054, https://doi.org/10.5194/bg-14-1039-2017, 2017.
Räsänen, M., Aurela, M., Vakkari, V., Beukes, P., Tuovinen, J.-P.,
Siebert, S., Zyl, P. V., Josipovic, M., Laurila, T., Kulmala, M., Laakso,
L., Rinne, J., Oren, R., and Katul, G. G.: Dataset for “The effect of
rainfall amount and timing on annual transpiration in grazed savanna grassland”, figshare [data set], https://doi.org/10.6084/m9.figshare.11322464, 2019.
Reichstein, M., Falge, E., Baldocchi, D., Papale, D., Aubinet, M., Berbigier, P., Bernhofer, C., Buchmann, N., Gilmanov, T., Granier, A., Grünwald, T., Havránková, K., Ilvesniemi, H., Janous, D., Knohl, A., Laurila, T., Lohila, A., Loustau, D., Matteucci, G., Meyers, T., Miglietta, F., Ourcival, J.-M., Pumpanen, J., Rambal, S., Rotenberg, E., Sanz, M., Tenhunen, J., Seufert, G., Vaccari, F., Vesala, T., Yakir, D., and Valentini, R.: On the separation of net ecosystem exchange into assimilation and ecosystem respiration: Review and improved algorithm, Global Change Biol., 11, 1424–1439, https://doi.org/10.1111/j.1365-2486.2005.001002.x, 2005.
Ripley, B., Frole, K., and Gilbert, M.: Differences in drought sensitivities
and photosynthetic limitations between co-occurring C3 and C4 (NADP-ME) Panicoid grasses, Ann. Bot., 105, 493–503, https://doi.org/10.1093/aob/mcp307, 2010.
Sankaran, M.: Droughts and the ecological future of tropical savanna vegetation, J. Ecol., 107, 1531–1549, https://doi.org/10.1111/1365-2745.13195, 2019.
Sankaran, M., Ratnam, J., and Hanan, N. P.: Tree–grass coexistence in
savannas revisited–insights from an examination of assumptions and mechanisms invoked in existing models, Ecol. Lett., 7, 480–490, 2004.
Scanlon, T. M., Albertson, J. D., Caylor, K. K., and Williams, C. A.: Determining land surface fractional cover from NDVI and rainfall time series
for a savanna ecosystem, Remote Sens. Environ., 82, 376–388, 2002.
Scanlon, T. M., Caylor, K. K., Manfreda, S., Levin, S. A., and Rodriguez-Iturbe, I.: Dynamic response of grass cover to rainfall variability: Implications for the function and persistence of savanna ecosystems, Adv. Water Resour., 28, 291–302, 2005.
Scholes, R. and Archer, S.: Tree-grass interactions in savannas, Annu. Rev. Ecol. System., 28, 517–544, 1997.
Scholes, R. and Walker, H.: An African Savanna: Synthesis of the Nylsvley
study, Cambridge University Press, ISBN 9780511565472, 1993.
Scott, R. L. and Biederman, J. A.: Partitioning evapotranspiration using
long-term carbon dioxide and water vapor fluxes, Geophys. Res. Lett., 44, 6833–6840, https://doi.org/10.1002/2017GL074324, 2017.
Scott, R. L. and Biederman, J. A.: Critical Zone Water Balance Over 13 Years
in a Semiarid Savanna, Water Resour. Res., 55, 574–588, https://doi.org/10.1029/2018WR023477, 2019.
Scott, R. L., Knowles, J. F., Nelson, J. A., Gentine, P., Li, X., Barron-Gafford, G., Bryant, R., and Biederman, J. A.: Water availability
impacts on evapotranspiration partitioning, Agr. Forest Meteorol., 297, 108251, https://doi.org/10.1016/j.agrformet.2020.108251, 2021.
Scott-Shaw, B. C. and Everson, C. S.: Water-use dynamics of an alien-invaded riparian forest within the summer rainfall zone of South Africa, Hydrol. Earth Syst. Sci., 23, 1553–1565, https://doi.org/10.5194/hess-23-1553-2019, 2019.
Steenkamp, C. J., Vogel, J. C., Fuls, A., van Rooyen, N., and van Rooyen, M.
W.: Age determination of Acacia erioloba trees in the Kalahari, J. Arid Environ., 72, 302–313, https://doi.org/10.1016/j.jaridenv.2007.07.015, 2008.
Stoy, P. C., Mauder, M., Foken, T., Marcolla, B., Boegh, E., Ibrom, A., Arain, M. A., Arneth, A., Aurela, M., Bernhofer, C., Cescatti, A., Dellwik, E., Duce, P., Gianelle, D., van Gorsel, E., Kiely, G., Knohl, A., Margolis, H., McCaughey, H., Merbold, L., Montagnani, L., Papale, D., Reichstein, M., Saunders, M., Serrano-Ortiz, P., Sottocornola, M., Spano, D., Vaccari, F., and Varlagin, A.: A data-driven analysis of energy balance closure across fluxnet research sites: The role of landscape scale heterogeneity, Agr. Forest Meteorol., 171, 137–152, 2013.
Stoy, P. C., El-Madany, T. S., Fisher, J. B., Gentine, P., Gerken, T., Good,
S. P., Klosterhalfen, A., Liu, S., Miralles, D. G., Perez-Priego, O., Rigden, A. J., Skaggs, T. H., Wohlfahrt, G., Anderson, R. G., Coenders-Gerrits, A. M. J., Jung, M., Maes, W. H., Mammarella, I., Mauder, M., Migliavacca, M., Nelson, J. A., Poyatos, R., Reichstein, M., Scott, R. L., and Wolf, S.: Reviews and syntheses: Turning the challenges of partitioning ecosystem evaporation and transpiration into opportunities, Biogeosciences, 16, 3747–3775, https://doi.org/10.5194/bg-16-3747-2019, 2019.
Swemmer, A. M., Knapp, A. K., and Snyman, H. A.: Intra-seasonal precipitation patterns and above-ground productivity in three perennial grasslands, J. Ecol., 95, 780–788, https://doi.org/10.1111/j.1365-2745.2007.01237.x, 2007.
Taylor, S. H., Ripley, B. S., Martin, T., De-Wet, L.-A., Woodward, F. I., and
Osborne, C. P.: Physiological advantages of C4 grasses in the field: A comparative experiment demonstrating the importance of drought, Global Change Biol., 20, 1992–2003, https://doi.org/10.1111/gcb.12498, 2014.
Tfwala, C. M., van Rensburg, L. D., Bello, Z. A., and Zietsman, P. C.:
Transpiration dynamics and water sources for selected indigenous trees under
varying soil water content, Agr. Forest Meteorol., 275, 296–304, https://doi.org/10.1016/j.agrformet.2019.05.030, 2019.
Tor-ngern, P., Oren, R., Oishi, A. C., Uebelherr, J. M., Palmroth, S.,
Tarvainen, L., Ottosson-Löfvenius, M., Linder, S., Domec, J.-C., and
Näsholm, T.: Ecophysiological variation of transpiration of pine forests: synthesis of new and published results, Ecol. Appl., 27, 118–133, 2017.
Urban, M., Berger, C., Mudau, T. E., Heckel, K., Truckenbrodt, J., Onyango
Odipo, V., Smit, I. P. J., and Schmullius, C.: Surface moisture and vegetation cover analysis for drought monitoring in the southern Kruger National Park using Sentinel-1, Sentinel-2, and Landsat-8, Remote Sens., 10, 1482, https://doi.org/10.3390/rs10091482, 2018.
Volder, A., Briske, D. D., and Tjoelker, M. G.: Climate warming and precipitation redistribution modify tree–grass interactions and tree species establishment in a warm-temperate savanna, Global Change Biol., 19, 843–857, 2013.
Wang, L., D'Odorico, P., Ringrose, S., Coetzee, S., and Macko, S. A.: Biogeochemistry of Kalahari sands, J. Arid Environ., 71, 259–279, https://doi.org/10.1016/j.jaridenv.2007.03.016, 2007.
Ward, E. J., Oren, R., Kim, H. S., Kim, D., Tor-ngern, P., Ewers, B. E.,
McCarthy, H. R., Oishi, A. C., Pataki, D. E., Palmroth, S., Phillips, N. G.,
and Schäfer, K. V. R.: Evapotranspiration and water yield of a pine-broadleaf forest are not altered by long-term atmospheric [CO2] enrichment under native or enhanced soil fertility, Global Change Biol., 24, 4841–4856, https://doi.org/10.1111/gcb.14363, 2018.
Webb, E. K., Pearman, G. I., and Leuning, R.: Correction of flux measurements
for density effects due to heat and water vapour transfer, Q. J. Roy. Meteorol. Soc., 106, 85–100, 1980.
Wei, Z., Yoshimura, K., Wang, L., Miralles, D. G., Jasechko, S., and Lee, X.:
Revisiting the contribution of transpiration to global terrestrial evapotranspiration, Geophys. Res. Lett., 44, 2792–2801,
https://doi.org/10.1002/2016GL072235, 2017.
Wigley-Coetsee, C. and Staver, A. C.: Grass community responses to drought
in an African savanna, Afr. J. Range Forage Sci., 37, 43–52, https://doi.org/10.2989/10220119.2020.1716072, 2020.
Williams, C. A. and Albertson, J. D.: Soil moisture controls on canopy-scale
water and carbon fluxes in an African savanna, Water Resour. Res., 40, W09302, https://doi.org/10.1029/2004WR003208, 2004.
Williams, C. A. and Albertson, J. D.: Contrasting short- and long-timescale
effects of vegetation dynamics on water and carbon fluxes in water-limited
ecosystems: vegetation controls on dryland fluxes, Water Resour. Res., 41, W06005, https://doi.org/10.1029/2004WR003750, 2005.
Wilson, K., Goldstein, A., Falge, E., Aubinet, M., Baldocchi, D., Berbigier, P., Bernhofer, C., Ceulemans, R., Dolman, H., Field, C., Grelle, A., Ibrom, A., Law, B. E., Kowalski, A., Meyers, T., Moncrieff, J., Monson, R., Oechel, W., Tenhunen, J., Valentini, R., and Verma, S.: Energy balance closure at fluxnet sites, Agr. Forest Meteorol., 113, 223–243, 2002.
Wutzler, T., Lucas-Moffat, A., Migliavacca, M., Knauer, J., Sickel, K.,
Šigut, L., Menzer, O., and Reichstein, M.: Basic and extensible post-processing of eddy covariance flux data with REddyProc, Biogeosciences,
15, 5015–5030, https://doi.org/10.5194/bg-15-5015-2018, 2018.
Xu, X., Medvigy, D., and Rodriguez-Iturbe, I.: Relation between rainfall
intensity and savanna tree abundance explained by water use strategies, P. Natl. Acad. Sci. USA, 112, 12992–12996, 2015.
Yu, K. and D'Odorico, P.: Hydraulic lift as a determinant of tree–grass
coexistence on savannas, New Phytol., 207, 1038–1051, 2015.
Zhang, L., Dawes, W. R., and Walker, G. R.: Response of mean annual evapotranspiration to vegetation changes at catchment scale, Water Resour. Res., 37, 701–708, https://doi.org/10.1029/2000WR900325, 2001.
Zhou, S., Yu, B., Zhang, Y., Huang, Y., and Wang, G.: Partitioning evapotranspiration based on the concept of underlying water use efficiency,
Water Resour. Res., 52, 1160–1175, https://doi.org/10.1002/2015WR017766, 2016.
Zhou, S., Yu, B., Zhang, Y., Huang, Y., and Wang, G.: Water use efficiency
and evapotranspiration partitioning for three typical ecosystems in the
Heihe River Basin, northwestern China, Agr. Forest Meteorol., 253–254, 261–273, https://doi.org/10.1016/j.agrformet.2018.02.002, 2018.
Short summary
The productivity of semiarid grazed grasslands is linked to the variation in rainfall and transpiration. By combining carbon dioxide and water flux measurements, we show that the annual transpiration is nearly constant during wet years while grasses react quickly to dry spells and drought, which reduce transpiration. The planning of annual grazing strategies could consider the early-season rainfall frequency that was linked to the portion of annual transpiration.
The productivity of semiarid grazed grasslands is linked to the variation in rainfall and...
