南海罗斯贝变形半径的地理及季节变化

根据南海 1°× 1°网格的标准层季节平均温、盐度资料 ,在未引入Boussinesq近似条件下 ,采用改进的Thompson Haskell算法求解线性化斜压海洋水平大尺度波的垂直结构方程 (重力内波方程 ) ,从而得到了南海各网格点的第一斜压重力波相速度和相应的罗斯贝变形半径 ,并探讨其地理分布和季节变化特征 ,以期有助于南海环流和中尺度涡旋以及有关海洋侧边界效应的研究。

GEOGRAPHICAL AND SEASONAL VARIABILITY OF ROSSBY RADII IN SOUTH CHINA SEA

On the basis of the 1 degree girded data of the seasonal mean temperature and salinity at standard levels in the South China Sea, mean Brunt-Visl frequency profiles were derived in order to compute numerically the vertical normal-mode for different seasons in various part of the South China Sea, and the associate linearized equation for horizontal large-scale waves is solved numerically with a improved thompson-Haskell algorithm. Therefore the baroclinic gravity-wave phase speed Cn and corresponding Rossby radius of deformation (Rn) are obtained. Due to regional variations of stratification and the depth of the different basins, these parameters vary considerable, but the effect of temporal variation of the stratification can be neglected in the estimation of the first baroclinic gravity-wave phase speed (C1) and Rossby radius of deformation (R1). It is shown that the geographical distribution of C1 and R1 provide a framework for a coherent understating of the dynamics of circulation, meso-scale eddies and some boundary phenomena, such as boundary current, fronts, coastal upwelling, coastal traped waves and continental shelf waves, etc.