Global assessment of how averaging over spatial heterogeneity in precipitation and potential evapotranspiration affects modeled evapotranspiration rates

Rouholahnejad Freund, Elham; Fan, Ying; Kirchner, James W.

doi:https://doi.org/10.5194/hess-24-1927-2020

Articles | Volume 24, issue 4

https://doi.org/10.5194/hess-24-1927-2020

© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/hess-24-1927-2020

© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 24, issue 4

Research article

|

16 Apr 2020

Research article |

| 16 Apr 2020

Global assessment of how averaging over spatial heterogeneity in precipitation and potential evapotranspiration affects modeled evapotranspiration rates

Elham Rouholahnejad Freund, Ying Fan, and James W. Kirchner

Supplement

https://doi.org/10.5194/hess-24-1927-2020-supplement

Data sets

Average precipitation and PET over Switzerland at 500 m resolution E. Rouholahnejad Freund, J. W. Kirchner, and M. Zappa https://doi.org/10.16904/envidat.145

Short summary

Evapotranspiration (ET) rates and properties that regulate them are spatially heterogeneous. Averaging over spatial heterogeneity in precipitation (P) and potential evapotranspiration (PET) as the main drivers of ET may lead to biased estimates of energy and water fluxes from the land to the atmosphere. We show that this bias is largest in mountainous terrains, in regions with temperate climates and dry summers, and in landscapes where spatial variations in P and PET are inversely correlated.