Sensitivity of the Biosphere-Atmosphere Transfer Scheme ( BATS) to the inclusion of variable soil characteristics

The soils data of Wilson and Henderson-Sellers have been incorporated into the land-surface parameterization scheme of the NCAR Community Climate Model after Dickinson. The cases investigated were for conditions designed to represent a low-latitude, evergreen forest; a low-latitude sand desert; a high-latitude coniferous forest; high-latitude tundra; and prairie grasslands, each for a specified time of year. The tundra included spring snowmelt and the grassland incorporated snow accumulation.The sensitivity experiments included varying the soil texture from a coarse texture typical of sand through a medium texture typical of loam to a fine texture typical of clay. Overall, this land-surface parameterization scheme shows considerable sensitivity to the choice of soil texture. This sensitivity seems to be at least comparable to that involving changes in vegetation characteristics and it may be more important because soil characteristics are very poorly known at a resolution appropriate for global climate models. -from Authors