A BASIC STUDY ON THE DEVOLOPMENT OF A SATELLITE DATA ASSIMILATION OF A LAND-ATMOSPHERE COUPLED SYSTEM

抄録

The objective of this study is to develop a new downscaling approach, which can take into account atmospheric and land surface heterogeneities for a better precipitation prediction. We address the effect of land surface heterogeneity on the land-atmosphere interactions through coupling a land data assimilation system with a land-atmosphere coupled model. This system relies on a mesoscale model as atmospheric part, a Land Surface Scheme as a model operator, a Radiative Transfer Model as an observation operator, satellite data and the Simulated Annealing method for minimization. To assess the effectiveness of the new system, a 2-dimensional numerical experiment was carried out in a mesoscale area of the Tibetan Plateau. The results showed significant differences compared with standard regional atmospheric model outputs and were more consistent with satellite microwave brightness temperature observations that improved the spatial distribution of soil moisture, which strongly affected the convection systems.