Effect of latent heat transfer on diurnal and annual prediction of temperature and radiobrightness of northern prairie

Prairie Biophere-Atmosphere Interchange (BAI) fluxes of energy and moisture influence mid-continent atmospheric circulation. The energy fluxes of radiant heat, sensible heat, and latent heat are strongly coupled to soil temperature and moisture content, and through these to radiobrightness. Our long term objective is to develop a BAI model that will reliably predict radiobrightness based upon radiation and weather forcing. Here we present an element of such a BAI model - an improved annual model for soil temperature. We use the bulk transfer approach to model sensible heat transfer and the Bowen ratio approach to model latent heat transfer. A finite element method is then used to track isotherms within the soil. From these isotherms we find surface temperature and temperature gradient - parameters needed in the computation of radiobrightness. The model predicts that soil temperatures are weakly dependent on latent heat transfer in frozen regions and strongly dependent in thawed regions.