A Numerical study for the effect of tidal parameterization scheme on the low visibility case at Incheon International Airport in South Korea

The Eastern part of the Yellow Sea near the Korean peninsula has a complicated coastline with numerous islands. And, semi-diurnal cycle of the sea level change is very drastic in this area, which results in the dynamic changes of physical and optical properties of the seawater and soil layers. Due to this tidal effects, the radiation, heat flux, moisture flux, and surface temperature near the surface can affect to land-sea breeze and sea fog in this area. The National Institute of Meteorological Research/Korean Meteorological Administration (NIMR/KMA) developed a tidal parameterization scheme implemented in the WRF model in conjunction with the Noah Land Surface Model (LSM). The primary role of tidal parameterization is to modify surface temperature by addressing the energy balance between the seawater and soil layers especially during the high tide. But, for the low tide period, there is no inflow of seawater, so that we use the water and soil temperatures from the previous time steps. Tidal information and bathymetry for each model grid are required to run the tidal parameterization. We used the tidal information from the DTU10, a global tide prediction model. For bathymetry, ETOPO2022 global data (15 arc-sec) from the National Centers for Environmental Information/National Oceanic and Atmospheric Administration (NCEI/NOAA) and bathymetry (150 m) from the Korea Hydrographic and Oceanographic Agency/Ministry of Oceans and Fisheries (KHOA/MOF) were used.

In this study, the impact of tidal range on the event of low visibility due to the sea fog (November 16, 2019) occurred at the Incheon International Airport (ICN) in a wide tidal area was analyzed through high-resolution (~200 m) WRF experiments. In this case, a low visibility warning was issued from 5 AM to 10 AM due to the fog at ICN, and the simulated surface flux and fog event were compared between the control run with (TIDE) and without the tidal parameterization (CNTL). The tide prediction of DTU10 was relatively consistent, showing a correlation of over 0.9 compared to observations from the Incheon Tide Observatory. The TIDE experiment simulated more dense fog than that in the CNTL, and the timing of the generation and dissipation of the fog event was similar to the observation in the TIDE. To analyze the influence between tidal parameterization and the PBL scheme, we performed sensitivity tests on the YSU, SH, MYNN, and no PBL scheme (LES). Finally, the detailed physical processes near the surface will be discussed in the conference.