A WRF Modeling Study on the Effects of Land Use Changes on Fog Off the West Coast of the Korean Peninsula

This study investigates, for the purpose of fog forecasting, the impacts of topography and land use changes on the characteristics of turbulence that directly contribute to the formation and dissipation of fog off the west coast of the Korean Peninsula using the Weather Research and Forecasting model version 3.5.1. During the investigation period, there are 59 coastal ground fog and 29 sea fog events. Local meteorological characteristics of coastal ground fog were similar to those of radiation fog typically seen over the land surface since the reclaimed island was constructed. After the sun rises, relative humidity over the land surface decreases rapidly—within a couple of hours—due to surface heating, which is controlled directly by shortwave radiation. Over the sea surface, however, the sea fog remains, with the relative humidity higher than 95% even during the daytime. For two selected cases, topography and land use were modified to identify turbulence characteristics through numerical modeling. This modification contributed to better forecasting the formation and dissipation of fog by changing characteristics of sensible and latent heat flux in the land surface model and then planetary boundary layer over the reclaimed island.