Understanding of the formation mechanism of sea fog through numerical simulation using a Single Column Model coupled with WRF

Fog is a meteorological phenomenon that can be a great hazard in the airport. Incheon International Airport (hereafter IIA) is located on a partly reclaimed island on the west of coast of Korea so that IIA often suffers from visibility degradation due to sea fogs. The number of sea fogs occurred over the IIA area is 35 from 2002 to 2006. However, a clear guidance to forecast the sea fog is not made yet since the formation and dissipation of sea fog are complicated. Therefore in order to accomplish a clear guidance, physical mechanism for the formation and dissipation of sea fog should be primarily understood. The purposes of this study are twofold. The first is to analyze the meteorological properties related to the formation and dissipation of the classified fogs through numerical modeling. The second is to study the feasibility for the operation prediction. The numerical simulations using the 3D operation model with a very high horizontal and vertical resolution requires too expensive computation cost. Recently, 1D turbulence model with a very high vertical resolution coupled with a 3D regional model is used to reduce the computation cost to predict the fog occurrence within PBL. In this study, WRFV3.1.1 is used as a 3D regional model and PArameterized FOG (PAFOG) model is employed as a 1D model. This study uses two approaches to couple between PAFOG and WRFV3.1.1, i.e., Eulerian approach and Lagrangian approach. In the Eulerian approach, horizontal advections of heat and moisture, produced every hour from WRFV3.1.1 are provided as an external forcing into the 1D turbulence model, PAFOG. Contrary to the Eulerian approach, the Lagrangian approach considers the single column moving along with the trajectory given by WRFV3.1.1. PAFOG is designed for studying stable boundary layer as well as convective boundary layer and also supports sophisticated double moment scheme for the cloud species. Several sea fog events observed in the eastern part of the Yellow Sea near the west coast of Korea are simulated and the meteorological elements to influence on the development of sea fog will be presented in the conference.