Sensitivity of Numerical Simulations of an Ice Fog Event to Snow Depth and Surface Albedo

This study examines the sensitivity of numerical simulations of near surface atmosphere conditions during an ice fog event occurred in Heber Valley, Utah to the initial surface albedo and snow depth with the WRF model. Results indicate that the near-surface cooling during the nighttime that closely relates to the fog event is much underestimated by WRF model. In addition, WRF model also overestimates the temperature during the daytime period. These could be improved by increasing initial surface albedo and snow depth, which act a role in cooling the near surface atmosphere by increasing the reflection of downward shortwave radiation and decreasing the heat from soil layer. The inability of WRF model on the representation and prediction of atmospheric conditions in the near-surface and lower boundary layers over the mountainous region reflects the complexity and uncertainty among the parameterization of surface radiative cooling, turbulent mixing, and ice crystal condensation number in the near surface atmosphere.