中尺度涡冷暖特征的理论推导

为了从理论上解释中尺度涡旋冷暖性质与涡旋旋转方向的关系,分析了涡旋的几何特征,并依据这些特征做了如下假设:中尺度涡具有对称的几何形态,涡旋中海洋要素沿径向具有线性变化的特征。从原始方程组出发,利用柱坐标系和上述假设条件,略去耗散力,不考虑涡旋切向的变化,并且忽略径向的速度,推导了中尺度涡的冷暖特征,解释了气旋式中尺度涡对应冷涡以及反气旋式中尺度涡对应暖涡等涡旋的运动特点。结果表明,中心对称形式可以作为对中尺度涡的几何特征的一个理想形态近似,在考虑上述假设条件的理想环境下,柱坐标系在研究中尺度涡的几何性质上具有一定的优势。

Derivation of mesoscale eddy cold-warm characteristics

To explain the relationship between mesoscale eddies' thermodynamic characteristics and the direction of eddies' rotation, the eddies' geometrical characteristics were analyzed, and assumption was made that mesoscale eddy has a symmetrical geometrical structure and the marine elements vary linearly along the radial direction. Starting from the primitive equations, the radial velocity and the tangential changing were ignored, the dissipative force omitted, and cylindrical coordinate and the two assumed features used. The thermodynamic characteristics for mesoscale eddies were derived and the phenomena explained that the cyclonic eddy corresponds to the warm eddy and the anti-cyclonic corresponds to the cold one. The results showed that central symmetry is an ideal approximate to the geometrical characteristics of mesoscale eddy. Using a cylindrical coordinate in an ideal environment with geometrical characteristics and assumed features has the advantage in studying the geometrical features of mesoscale eddy.