WRF Simulations for Stably Stratified Observation Periods of the MATERHORN Spring Field Campaign with Application to the Dividing Streamline

The Advanced Research version of the Weather Research and Forecasting (WRF) model was used to investigate the ability of a mesoscale atmospheric model to predict key atmospheric phenomena observed during the Mountain Terrain Atmospheric Modeling and Observations (MATERHORN) field programs. The two experiment, MATERHORN-X-1 and -2, had a specific emphasis on observing the weather conditions on and around Granite Mountain, (40.1°N 113.3°W) located in the US Army Dugway Proving Ground. This work aims to evaluate performance of the WRF model is two ways, namely, identification of WRF model's capability at resolving a dividing streamline and, if present, the conditions under which the previous streamline theories are valid. The mountain wakes, unsteadiness and lee and propagating waves were also of interest. The WRF simulations were run with a 0.5km horizontal grid resolution for selected Intense Observations Periods (IOPs), and the analysis was focused on periods when the atmospheric boundary layer was stably stratified and synoptically driven towards the Granite Mountain. In total, 34 dividing streamlines, corresponding to 34 different simulation time periods have been found. The simulated, real, atmospheric conditions provided an opportunity to investigate the height of the dividing streamline under different atmospheric conditions. Comparisons of the dividing streamline height, flow field surrounding the mountain, wake and wave phenomena between observations and simulations will be discussed.

This research was funded by Office of Naval Research Grant # N00014-11-1-0709.