大气中的非线性Rossby波和Pseudo-Rossby波——(Ⅰ)正压大气情形

本文利用相角函数和常微分方程相轨线分析方法,讨论了半地转近似下正压Rossby波的存在和求解问题;结果表明:在描述Rossby波的方程中,除了具有通常意义的Rossby波解外,还存在一支Pseudo-Rossby波解;而且正压Rossby波的频率对一定的波动有一确定上界,这个上界由大气平均厚度与地理纬度确定;同时也分析了波动特征参量与拟能及地理参数间的关系.

The Nonlinear Rossby Waves and Pseudo-Rossby Waves in A Barotrophic Atmosphere

In this paper, the existence and the solutions for steady travelling waves in the equation describing barotrophic Rossby waves under semir geostrophic approximation are discussed with the method of phase facto-function and phase orbital analysis of differential equation. It is found fhat, apart from the well-known Rossby wave solution,there is a Pseudo -Rossby wave solution which does not possess a counterpart resulting crom linear appro-ximation or quasi-geostrophic approximation and whose propagation direction is opposite to Rossby Waves'; and the phase velor tity of Rossby cnoidal wave has a upper limit.Yet, the dependence for the frequencies and the amplitudes of these waves on the pseudo-energ-and the latitude is given.