A CASE STUDY OF NUMERICAL SIMULATION OF SEA FOG ON THE SOUTHERN CHINA COAST

Abstract:

This study uses numerical simulations to examine a case of sea fog that was observed from 20 to 22 March 2011 on the southern China coast. The observation dataset includes observatory data, cloud-top temperature from MODIS, GPS sonde, and data from the Integrated Observation Platform for Marine Meteorology (IOPMM). The simulations are based on the Weather Research and Forecasting (WRF) model with four distinct parameter settings. Both the observations and simulations focus on the characteristics of the fog extent, boundary layer structure, and meteorological elements near the air-sea interface. Our main results are as follows: (1) The extent of mesoscale sea fog can be well simulated when the sea surface temperature has at least 0.5×0.5 horizontal resolution. (2) To accurately model the vertical structure of the sea fog, particularly the surface-based inversion, vertical levels must be added in the boundary layer. (3) When these model conditions are met, the simulations faithfully reproduce the measured downward shortwave radiation, downward longwave radiation, and surface sensible heat flux during the sea fog period.