半地转近似下正压大气中的非线性波动

The Nonlinear Waves in Barotropic Atmosphere under Semi-geostrophic Approximation

本文在半地转近似下讨论了正压模式大气中的非线性 Rossby 波.结果表明:这些非线性 Rossby 波可以是椭圆函数形式的波、孤立波或冲击波;产生这些波动的条件是由一个称之为“总能量”的物理量给出的,同时还敏感地依赖于相应量的初相值;文中还求出了一支没有线性近似对应的新频率的非线性波解,它纯粹是非线性效应的产物.

In this paper,the nonlinear Rossby waves of barotropic atmosphere is discussed under semi-geostrophic approximation.The results show that these nonlinear Rossby waves may be periodic waves solitary or shock wawes. The conditions under which the waves can exist depend on a physical quan- tity called pseudo-energy and initital phase value of the physical quantity discussed.It is also found a new wave solution which has no counterpart under linear or quasi-geostrophic approximation and is purely a production of nonlinear effects.