Satellite‐based assessment of the impact of sea‐surface winds on regional atmospheric circulations over the Korean Peninsula

Abstract

In order to clarify the impact of sea‐wind satellite‐data assimilation under fair and calm weather conditions over the Korean Peninsula, several numerical experiments were carried out. The numerical model used in this study was the Fifth Mesoscale Model (MM5), verified by many previous studies; satellite data of sea winds were gathered by the QuikSCAT sensor launched on ADEOS II. During the daytime, the change in mesoscale circulations according to the assimilation of sea‐wind data increased in the coastal area and decreased deep inland. Although variations in mesoscale circulations due to satellite‐based sea‐wind data assimilation occurred near the coastal area, the mixing height far inland over the Korean Peninsula often changed according to the intensity of inflow from the surrounding seas and that of the topographic effect. In this study, a lower mixing height inland was generated by a numerical simulation using QuikSCAT sea‐wind data assimilation. The lower mixing height was caused by strong westerly and weak easterly winds from the Yellow Sea and the East Sea, respectively. The validation of the sea‐wind influence was verified quantitatively by RMSD and IOA analyses. The accuracy of weather forecasting increased at the East Sea and Korea Strait and decreased at the Yellow Sea. These different accuracy levels were caused by the inhomogeneity of sea‐wind data quality. The maintenance of the uniform quality of satellite‐based data on sea wind is an important factor in the reasonable forecasting of mesoscale circulations.