The influence of a Soil–Vegetation–Atmosphere Transfer scheme on the simulated climate of LLNL/UCLA AGCM

Abstract

The sensitivity of the Lawrence Livermore National Laboratory (LLNL)/University of California, Los Angeles (UCLA) Atmospheric General Circulation Model (AGCM) to coupling with a Soil–Vegetation–Atmosphere Transfer (SVAT) scheme is investigated in this paper. The SVAT leads to general warming of the climate over continents in association with enhanced sensible heat fluxes. The wetness bias of AGCM is reduced drastically with reductions in latent heat fluxes and precipitation. There is reduction in cloudiness when the SVAT is coupled which results in increased solar radiation at the surface. Upward long wave radiation increases in association with increases in land surface temperature. Although the coupling of SVAT improves surface fluxes of heat and water vapor, these changes are mainly offset by changes in solar and infrared radiative fluxes. Global mean energy balance at the surface and the top of atmosphere is improved marginally.