Impact of land surface processes on boundary layer evolution

The Naval Research Laboratory's Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS®) is currently being utilized to simulate cases from the International H2O Project (IHOP 2002). Our objective in this work is to evaluate surface properties from the land surface model (LSM) and to investigate the impact of the LSM on boundary layer structure. COAMPS® uses the NOAH LSM as implemented in the Weather Research and Forecast model (WRF). Our preliminary findings indicate that certain shortcomings of the standard COAMPS® forecast diurnal temperature wave have been significantly reduced by inclusion of the LSM. In particular, the LSM responds very quickly to sunrise and compares more favorably to the observations in the early morning hours. In addition, we find that under prediction of soil moisture significantly reduces the quality of forecasts from both the standard COAMPS® and the LSM, resulting in (not surprisingly) over prediction of the amplitude of the diurnal temperature wave and the sensible heat flux and under prediction of the latent heat flux. We plan to continue to analyze results from IHOP 2002 simulations and to investigate sensitivity to the horizontal resolution of the initial soil moisture field.