摘要
利用简单海气耦合模式,分析了经向风应力和纬向风应力对热带太平洋不稳定海气耦合模态的相对贡献。结果表明:在局地热力平衡假设下,海气相互作用导致了海洋Kelvin波的不稳定,该不稳定模态发生在一定波长范围内,只有纬向风应力对其作出贡献;在海温仅由平流过程决定的假设下,海气相互作用导致了海洋Rossby波的不稳定,该不稳定模态在整个波长范围内都有发生,波长越大,不稳定越强,经向风应力与纬向风应力都可以对海洋Rossby波的不稳定作出贡献,但是前者贡献较小;不稳定Rossby波比不稳定Kelvin波的增长率要小;由于无论哪一种不稳定模态,都是纬向风应力在海气耦合中起着绝对的主导作用,所以在研究热带太平洋海气耦合动力学对ENSO不稳定发展的贡献时,采用忽略经向风应力作用的近似是合理可行的。
With a simple tropical coupled ocean-atmosphere model, this paper presents an analysis to understand the relative role of the meridional and zonal wind stresses in the tropical unstable air-sea interaction. The roles of the zonal wind stress, the meridional wind stress and the both are considered respectively into the coupled system. It is demonstrated that the meridional component of the wind stress does not lead to any instability under the local thermal balance assumption, but it does lead to a weak instability under the sea surface temperature advection assumption. Unstable air-sea interaction is dominated by the zonal component of the wind stress, suggesting that ignoring the meridional wind stress is approximately legitimate in studying the tropical unstable air-sea interaction.
出处
《热带气象学报》
CSCD
北大核心
2003年第1期43-52,共10页
Journal of Tropical Meteorology
基金
国家自然科学基金40075017项目资助
