南海中尺度波动现象研究进展

Kelvin波和Rossby波是经常出现于海洋中的边界波；南海的复杂岸线、陡变地形和热盐场时空结构的不均匀性具有形成强迫Kelvin波和地形Rossby波的条件。现有研究表明，南海大部分中尺度涡形成于东部一些较大岛屿附近；这些中尺度涡一旦形成后，就在β效应作用下向西移动并最终耗散于西边界，且其波动一般以Rossby波的形式向西传播。因此，南海环流的多涡结构与中尺度波动之间存在着一定的联系。在南海北部，中尺度涡主要由黑潮入侵和风应力旋度所诱生，而在南海南部而以风应力旋度为主要成因。提出了利用线性波动动力学模式来研究南海南部中尺度波动、分析风应力强迫所产生的中尺度波动特征和规律，并据此建立相应的数值模式来揭示该海区环流的动力学和热动力学机制的思路，以便了解该海区流场季节性变化与中尺度波动之间的内在关系。

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.