Laboratory observations for examining estimates of soil dry surface layer thickness with parsimonious models

ABSTRACT

Soil dry surface layer (DSL) thickness is often considered a key parameter for land surface resistance to gas exchange. Commonly used, simple models for DSL thickness are typically empirical in nature and based on limited observational evidence. Laboratory experiments were performed to test soil condition and boundary effects on DSL formation. DSL thickness was analyzed in soil columns with varying texture, initial water content, and potential evaporation rate. DSLs formed to greater depth in fine-textured compared to coarse-textured soils, when beginning from similar initial water content. Based on experiments, we compared a simple but physically-based mass balance DSL model to an empirical DSL model from the literature. The mass balance model performed better than the empirical relative-wetness-based model, and is similar in structure to the current DSL parameterization in the Community Land Model. Results suggest soil resistance parameterizations can be improved by employing simple, but texture-dependent, physically-based DSL formulations.

KEYWORDS:

• gas flux
• evaporation
• soil resistance

Editor K. Soulis; Associate Editor M. Newcomer

Editor K. Soulis; Associate Editor M. Newcomer

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/02626667.2024.2373249

Additional information

Funding

Research was supported by the US National Science Foundation [Grant: 1623806]. The views expressed in this article are those of the authors and do not necessarily reflect the views and policies of the US Environmental Protection Agency. Any mention of trade names, manufacturers or products does not imply an endorsement by the United States Government or the US Environmental Protection Agency. EPA and its employees do not endorse any commercial products, services, or enterprises.