EGU2020-7281
https://doi.org/10.5194/egusphere-egu2020-7281
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Atmospheric aridity and apparent soil moisture drought in European forest during heatwaves

Ryan Teuling1, Eva Lansu1, Chiel van Heerwaarden2, and Annemiek Stegehuis3
Ryan Teuling et al.
  • 1Wageningen University, Hydrology and Quantitative Water Management Group, Wageningen, Netherlands (ryan.teuling@wur.nl)
  • 2Wageningen University, Meteorology and Air Quality Group, Wageningen, Netherlands
  • 3European Forest Institute, Bonn, Germany

Land-atmosphere feedbacks, in particular the response of land evaporation to vapour pressure deficit (VPD) or the dryness of the air, remain poorly understood. Here we investigate the VPD response by analysis of a large database of eddy-covariance flux observations and simulations using a conceptual model of the atmospheric boundary layer. Data analysis reveals that under high VPD, forest in particular reduces evaporation and emits more sensible heat. In contrast, grass increases evaporation and emits less sensible heat. Simulations show that this VPD feedback can induce significant temperature increases over forest of up to 2 K during heat wave conditions. It is inferred from the simulations that the effect of the VPD feedback corresponds to an apparent soil moisture depletion of more than 50%. This suggests that previous studies may have incorrectly attributed the effects of atmospheric aridity on temperature to soil dryness.

How to cite: Teuling, R., Lansu, E., van Heerwaarden, C., and Stegehuis, A.: Atmospheric aridity and apparent soil moisture drought in European forest during heatwaves, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7281, https://doi.org/10.5194/egusphere-egu2020-7281, 2020

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