A Numerical Study of Air-Sea Interaction in the Japan/East Sea

Wintertime cold-air outbreak events are the most dominant weather systems over the Japan/East Sea(JES) region. These systems develop over the Asian continent and propagate through JES. They produce surface wind gusts up to 20-25 m/s and a rapid surface air temperature drop of 5-10 ^oc in a few hours. The relatively warm sea surface in the southern JES and wind induced storm surges provide an ideal environment to study air-sea interactions. The objectives of this study are to (1) examine the impact of various physical parameterizations in PBL on model simulations of surface winds, temperature and air-sea fluxes and (2) understand the wind-wave interactions. We use the coupled PSU/NCAR nonhydrostatic mesoscale model(MM5) and the shallow water wave model(SWAN) in this study. The model simulations are validated against the surface station and buoy observations. Our preliminary results show that the surface properties are very sensitive to PBL parameterizations(e.g. the Blackdar scheme and the Burk-Thompson scheme in MM5). It is known that the surface waves can affect the surface wind fields. We are currently working on the coupled MM5/SWAN simulations to investigate the effects of the wind-wave interaction on the winter storm systems.