热带海气相互作用波及其不稳定性

THE AIR-SEA INTERACTION WAVES IN THE TROPICS AND THEIR INSTABILITIES

本文利用一个简单的海气耦合模式,讨论了热带海洋和大气中Rossby波的相互作用。结果指出,海洋和大气中向西传播的Rossby波耦合后,不仅存在着向西传播的波动,而且还可以产生一类向东传的新波。这种向东传播的波动出现在波长较长的波段范围内,这个范围的大小受海气相互作用强度的制约。另外,波动可以出现不稳定性,向西和向东传的波均有不稳定现象发生,不稳定增长率也受海气相互作用强度的制约。最后,根据所得到的海气相互作用波,对ENSO现象作了一个可能的解释。

By using a simple air-sea coupled model, the interaction of Rossby waves between the air and sea in the tropics is discussed. It is shown that the coupling of Rossby waves in the two media produces not only the westward propagating waves, but also a type of new wave which moves eastward. The eastward propagating waves exist in the scope of comparatively long wavelengths and this scope is governed by the intensity of the air-sea interaction. In addition, instability may appear in both the eastward and westward propagating waves, and the wave amplifying rates are also governed by the intensity of the air-sea interaction. In the end, a possible explanation to ENSO events is given in terms of the air-sea interaction waves.