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Atmospheric Aridity and Apparent Soil Moisture Drought in European Forest During Heat Waves
Author(s) -
Lansu Eva M.,
Heerwaarden C. C.,
Stegehuis Annemiek I.,
Teuling Adriaan J.
Publication year - 2020
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2020gl087091
Subject(s) - vapour pressure deficit , sensible heat , dryness , atmospheric sciences , environmental science , eddy covariance , evaporation , potential evaporation , planetary boundary layer , water content , moisture , latent heat , heat wave , atmosphere (unit) , climatology , precipitation , aridity index , heat flux , boundary layer , climate change , heat transfer , meteorology , ecosystem , geology , transpiration , chemistry , physics , thermodynamics , ecology , oceanography , biology , biochemistry , photosynthesis , medicine , surgery , geotechnical engineering
Land‐atmosphere feedbacks, in particular the response of land evaporation to vapor 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 and corresponding high temperatures, 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.