Impact of Improved Land-Surface Model Coupled to NWP System on Convective Boundary Layer Variables

Abstract

Land surface parameterizations in numerical weather prediction models direct the exchange of energy between the land surface and the atmosphere. The main purpose of this paper is to gain insight into how surface heterogeneity can influence the modeled convective boundary layer, and whether the complexity of the modeled land-atmosphere interactions can improve forecasts of convective precipitation. To achieve this the NOAH land-surface model has been coupled to the Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS). Selected cases of fair weather convective conditions and convectivly produced rain episodes were used to evaluate the behavior of a land-surface model coupled to a high-resolution numerical weather prediction system. Our experiments are designed such that different surface conditions (wet soil during rain episodes and dry soil conditions during fair weather days) and different atmospheric situations could be used to further our understanding of the behavior of the model by comparing model solutions to surface observations.