Evaluation of the impact of land surface heterogeneity representations on mesoscale fluxes

The representation of land surface heterogeneity has profound influences on the surface energy and water budgets, as well as the exchanges of water, energy, and momentum fluxes between land surface and the atmosphere. In order to provide a realistic representation of the land surface boundary in atmospheric models, discrete characterization approaches using grid box aggregations of local processes to characterize land surface heterogeneities are commonly employed. These approaches are known to produce significant variations in mesoscale fluxes when pronounced variabilities in surface heterogeneities exist. NASA's Land Information System (LIS) is a high resolution land surface modeling and data assimilation system that provides the computing and data management tools to enable land surface modeling at resolutions as fine as 1km. LIS has been coupled to the Weather Research and Forecasting (WRF) model using the evolving interoperable paradigms of the Earth System Modeling Framework (ESMF). In this study, the WRF-LIS system is employed to evaluate the impact of sub-grid scale representations on mesoscale fluxes and on the feedback mechanisms. The results using an explicit representation at 1km resolution are used to compare and evaluate the coarse resolution land surface heterogeneity representations.