Local impact analysis of climate change on precipitation extremes: are high-resolution climate models needed for realistic simulations?
Hossein Tabari1,Rozemien De Troch2,5,Olivier Giot2,6,Rafiq Hamdi2,5,Piet Termonia2,5,Sajjad Saeed3,Erwan Brisson3,Nicole Van Lipzig3,and Patrick Willems1,4Hossein Tabari et al. Hossein Tabari1,Rozemien De Troch2,5,Olivier Giot2,6,Rafiq Hamdi2,5,Piet Termonia2,5,Sajjad Saeed3,Erwan Brisson3,Nicole Van Lipzig3,and Patrick Willems1,4
1Hydraulics Division, Department of Civil Engineering, KU Leuven, Kasteelpark Arenberg 40, 3001 Leuven, Belgium
2Royal Meteorological Institute of Belgium, Brussels, Belgium
3Department of Earth and Environmental Sciences, KU Leuven, Leuven, Belgium
4Department of Hydrology and Hydraulic Engineering, Vrije Universiteit Brussel, Brussels, Belgium
5Department of Physics and Astronomy, Ghent University, Ghent, Belgium
6Plant and Vegetation Ecology, University of Antwerp, Antwerp, Belgium
1Hydraulics Division, Department of Civil Engineering, KU Leuven, Kasteelpark Arenberg 40, 3001 Leuven, Belgium
2Royal Meteorological Institute of Belgium, Brussels, Belgium
3Department of Earth and Environmental Sciences, KU Leuven, Leuven, Belgium
4Department of Hydrology and Hydraulic Engineering, Vrije Universiteit Brussel, Brussels, Belgium
5Department of Physics and Astronomy, Ghent University, Ghent, Belgium
6Plant and Vegetation Ecology, University of Antwerp, Antwerp, Belgium
Received: 03 Mar 2016 – Discussion started: 07 Mar 2016 – Revised: 17 Aug 2016 – Accepted: 01 Sep 2016 – Published: 14 Sep 2016
Abstract. This study explores whether climate models with higher spatial resolutions provide higher accuracy for precipitation simulations and/or different climate change signals. The outputs from two convection-permitting climate models (ALARO and CCLM) with a spatial resolution of 3–4 km are compared with those from the coarse-scale driving models or reanalysis data for simulating/projecting daily and sub-daily precipitation quantiles. Validation of historical design precipitation statistics derived from intensity–duration–frequency (IDF) curves shows a better match of the convection-permitting model results with the observations-based IDF statistics compared to the driving GCMs and reanalysis data. This is the case for simulation of local sub-daily precipitation extremes during the summer season, while the convection-permitting models do not appear to bring added value to simulation of daily precipitation extremes. Results moreover indicate that one has to be careful in assuming spatial-scale independency of climate change signals for the delta change downscaling method, as high-resolution models may show larger changes in extreme precipitation. These larger changes appear to be dependent on the timescale, since such intensification is not observed for daily timescales for both the ALARO and CCLM models.
