在正压大气模式下,采用多重尺度法研究了基本气流具有弱切变的正压非线性Rossby孤立波包,得到了当波振幅和纬向波数都是缓变情况下Rossby波包振幅的演变满足带有β效应和小尺度地形作用的非线性非齐次Schrdinger方程.说明β效应和地形效应是诱导Rossby包络孤立波的重要因素.
Rossby waves are intrinsic in the large-scale systems of fluids,so Rossby waves are the most important waves in the atmosphere and ocean. In barotropic fluid,the nonlinear Rossby envelope solitary waves in a shear flow are investigated by the asymptotic method of multiple scales,Here,the β-plane approximation f = f_0+ β_0y( β_0 is a constant) is extended into f = f_0+ β( y) y,which includes a nonlinear function β( y) taking the place of β-plane approximation. Such an approximation can depict more precisely the motion of the atmosphere and ocean,especially in the middle and high latitude regions. With β effect is deduced,the terrain effect of the nonlinear Schrdinger equation. Points out that the β effect、topographic effect is induced the important factor of Schrdinger equation,illustrates the effect of topographic forcing satisfy certain conditions,Rossby envelope solitary wave in the play the nonlinear Schrdinger equation; Also pointed out that when a wave amplitude and phase are graded, still satisfied the generalized nonlinear、inhomogeneous Schrdinger equation.