PROGRESS OF THE STUDY ON THE MESO-SCALE FLUCTUATION PHENOMENA IN THE SOUTH CHINA SEA

Kelvin wave and Rossby wave are the boundary waves that appear frequently in the ocean. The complex coastline, sharp topography and non-uniformity in spatial-temporal structure of temperature and salinity fields in the South China Sea are favor to the formation of forced Kelvin wave and topographic Rossby wave. According to the current studies, most of the meso-scale eddies in the South China Sea are formed near the major islands in the east. These eddies, after being formed, move westward by the β effect and then dissipate in the western boundary; generally speaking, the associated fluctuation propagates westward by Rossby wave. Thus, there exist some relationship between the multi-eddy structure of the South China Sea circulation and meso-scale fluctuation. In the northern South China Sea, the meso-scale eddies are mainly induced by the intrusion of Kuroshio and wind stress curl, whilst in the southern South China Sea they are induced by the wind stress curl. It is put forward that, by using a linear dynamic model to study and analyze the characteristics and rule of the wind-driven meso-scale fluctuation in the southern South China Sea, a corresponding numerical model is set up based on the above results to reveal the dynamic and thermodynamic mechanisms of the circulation in this sea area, so that the inner relationship between the seasonal variation of the current field and meso-scale fluctuation in the southern South China Sea could be understood.