A Soil-Vegetation-Atmosphere Transfer model for prairie grassland

Soil-Vegetation-Atmosphere Transfer (SVAT) models provide the lower boundary forcing of atmospheric models (AMs). SVAT models are highly parameterized abstractions of energy, moisture, and momentum exchanges between the land and atmosphere. The quality of the SVAT model in capturing those exchanges greatly influences the effectiveness of the AM. The authors have developed a thermal model that includes moisture transfer in unsaturated soils. In this paper, they compare the predictions of the new model with those of their older annual model in which moisture was assumed to be fixed. They find that inclusion of moisture fluxes modifies the day-night temperature difference by as much as 11.0 K over a typical diurnal cycle in winter because of the dominant influence of moisture on soil properties