大地形对Rossby波波射线的影响

本文利用Ｒｕｎｇｅ－Ｋｕｔｔａ方法计算了大地形对定常、非定常低频Ｒｏｓｓｂｙ波波射线的影响，计算结果显示，地形对Ｒｏｓｓｂｙ波波射线有重要影响。对位于地形上游的波源，定常波波射线在传播过程中，遇到地形时，会绕过地形偏向高纬度传播并加密波射线，地形起阻挡屏障作用；波源位于地形中心时，东西走向的地形使波射线发生分支现象，南北走向地形没有这种现象产生。文中还计算了地形存在下，周期为５０ｄ的低频Ｒｏｓｓｂｙ波波射线。结果显示，地形对低频波波射线的影响似乎更复杂。

THE EFFECT OF TOPOGRAPHY ON WAVE RAYS OF ROSSBY WAVES

The effects of topography on the rays of stationary and low-frequency Rossby waves are discussed by using a fourth-order Runge-Kutta scheme. The results show that topography has great effects on the propagation and rays of Rossby waves. The mountain plays a barrier role for the propagation of stationary Rossby waves. and causes concentrating and moving towards higher latitude of wave rays. In the case of wave source to be located at the mountain center, the rays exhibit splitting structure for the mountain elongated in the westeast direction. and there is no splitting structure of rays for the mountain with the south direction stretching. The influence of topography on the energy propagation of lowfrequency Rossby waves seems more complicated than that of stationary Rossby waves.