제주도에서 대기-해양 상호작용에 의한 중규모 순환장의 변화

Abstract

Numerical studies on the influence of interaction between atmosphere and ocean on the variation of Karman vortex at the lee side of Jeju island were carried out. Karman vortex tends to be occurred at limited height associated with Halla mountain. And we can find clear Karman vortex at 900 hPa height in this study. One big vortex cell occurred at lee side of Jeju island in the beginning stage of its development and the cell was divided into three small cells as time goes by. And the strength and lifetime of small vortexes depend on the distribution of SST(Sea Surface Temperature):. Weak gradient of SST makes long-lasting Karman vortex but produces weak potential vorticity at lee side of Jeju island in comparison with the vortex under strong SST gradient. Strong SST gradient also increases not only the mixing depth but also the mixing ratio at lower level of troposphere. And the increased atmospheric mixing decreases the mechanical forcing due to isolated topography. Then the strength of Karman vortex at lee side of Jeju island becomes weak under strong gradient of SST. Thus the evolution of Karman vortex is closely related to distribution of SST around the isolated island.