Development and evaluation of a mosaic approach in the WRF-Noah framework

In order to assess the impact of subgrid-scale variability in land cover composition, a mosaic/tiling approach (hereafter the "mosaic" approach) is implemented into the coupled WRF-Noah modeling system. In the mosaic approach, a certain number (N) of tiles, each representing a land cover category, is considered within each grid cell.

WRF simulations of a clear sky day and a rainfall period over a heterogeneous urban/suburban setting show that the two approaches generate differences in the surface energy balance, land surface temperature, near-surface states, boundary layer growth, as well as rainfall distribution. Evaluation against a variety of observational data (including surface flux measurements, the MODIS land surface temperature product, and radar rainfall estimates) indicates that, compared to the dominant approach, the mosaic approach has a better performance.