An evaluation of models of bare soil evaporation formulated with different land surface boundary conditions and assumptions
Article first published online: 22 DEC 2012
©2012. American Geophysical Union. All Rights Reserved.
Water Resources Research
Volume 48, Issue 12, December 2012
How to Cite
2012), An evaluation of models of bare soil evaporation formulated with different land surface boundary conditions and assumptions, Water Resour. Res., 48, W12526, doi:10.1029/2012WR012113., , , , and (
- Issue published online: 22 DEC 2012
- Article first published online: 22 DEC 2012
- Manuscript Accepted: 1 NOV 2012
- Manuscript Revised: 31 OCT 2012
- Manuscript Received: 10 MAR 2012
- US Army Research Office. Grant Number: W911NF-04-1-0169
- Air Force Office of Scientific Research. Grant Number: W911NF-04-1-0169
- land/atmosphere interaction
 Bare soil evaporation is a key process for water exchange between the land and the atmosphere and an important component of the water balance. However, there is no agreement on the best modeling methodology to determine evaporation under different atmospheric boundary conditions. Also, there is a lack of directly measured soil evaporation data for model validation to compare these methods to establish the validity of their mathematical formulations. Thus, a need exists to systematically compare evaporation estimates using existing methods to experimental observations. The goal of this work is to test different conceptual and mathematical formulations that are used to estimate evaporation from bare soils to critically investigate various formulations and surface boundary conditions. Such a comparison required the development of a numerical model that has the ability to incorporate these boundary conditions. For this model, we modified a previously developed theory that allows nonequilibrium liquid/gas phase change with gas phase vapor diffusion to better account for dry soil conditions. Precision data under well-controlled transient heat and wind boundary conditions were generated, and results from numerical simulations were compared with experimental data. Results demonstrate that the approaches based on different boundary conditions varied in their ability to capture different stages of evaporation. All approaches have benefits and limitations, and no one approach can be deemed most appropriate for every scenario. Comparisons of different formulations of the surface boundary condition validate the need for further research on heat and vapor transport processes in soil for better modeling accuracy.