Articles | Volume 24, issue 10
Research article
28 Oct 2020
Research article |  | 28 Oct 2020

Averaging over spatiotemporal heterogeneity substantially biases evapotranspiration rates in a mechanistic large-scale land evaporation model

Elham Rouholahnejad Freund, Massimiliano Zappa, and James W. Kirchner

Data sets

Daily 500 m gridded net radiation and soil moisture for Switzerland, 2004 E. Rouholahnejad Freund, M. Zappa, and J. Kirchner

Short summary
Evapotranspiration (ET) is the largest flux from the land to the atmosphere and thus contributes to Earth's energy and water balance. Due to its impact on atmospheric dynamics, ET is a key driver of droughts and heatwaves. In this paper, we demonstrate how averaging over land surface heterogeneity contributes to substantial overestimates of ET fluxes. We also demonstrate how one can correct for the effects of small-scale heterogeneity without explicitly representing it in land surface models.