P91 Recent RUC LSM enhancements implemented in operational WRF-based Rapid Refresh (RAP)

Smirnova, T. G., Cooperative Institute for Research in Environmental Sciences and National Oceanic and Atmospheric Administration (NOAA), John M. Brown and Stan Benjamin, NOAA

Further refinements of the RUC soil/snow/vegetation/sea-ice model (RUC LSM) implemented in Weather Research and Forecasting Model (WRF) as an officially supported physics option were performed. Most recent changes were directed towards more accurate representation of land surface sub-grid scale variabilities via implementing mosaic approach to the calculation of such surface parameters as Leaf Area Index (LAI), emissivity, roughness length and soil properties, as well. Also, seasonal variations of LAI and roughness length were introduced, and logarithmic formulation to the computation of effective roughness length in the grid cell was applied. In addition, the vertical configuration of RUC LSM was changed from 6 to 9 levels with even higher resolution near the soil/atmosphere interface. These modifi! cations were implemented in the WRF-based Rapid Refresh (RAP) and provided more realistic surface conditions through cycling of soil temperature, soil moisture, canopy water, snow depths and snow temperatures for improved wind, dew point and temperature predictions near the surface. Results from RAP surface verification will be presented in the poster.