| 摘要: |
| 基于在一个连续层化条件下热带海洋波动的弱非线性动力学系统中建立的最低阶Lagrange余流动力学模型及由此导出的赤道波致Lagrange余流的一般解，导出了混合Rossby惯性重力波第一斜压模态导致的最低阶Lagrange余流的表达式。从中发现，该波可产生纬向、经向和铅垂方向的Lagrange余流，其中水平分量与赤道中、东太平洋表层流速的年平均值（约5cm/s）同量级；纬向和铅垂向余流关于赤道正对称，经向余流关于赤道反对称，在赤道上为零，因而不会造成跨赤道的质量净输运；余流量值不但与零阶波的振幅平方成正比，与零阶波的频率也有关系５有振幅变化的混合波所导致的Lagrange余流的经向结构与无振幅变化波致余流不同。定性分析了该波致余流对赤道中、东太平洋环流与SST的影响，初步揭示该余流的年际变化有利于赤道中、东太平洋ElNino事件的发展。 |
| 关键词: 混合Rossby惯性重力波 波致Lagrange余流 |
| DOI：10.11693/hyhz200002009009 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目，49576276号 |
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| THE MIXED ROSSBY-INERTIA GRAVITY WAVE-INDUCED LAGRANGIAN RESIDUAL VELOCITY |
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WANG Fan1, WU De-xing2, FENG Shi-zuo2, SHI Mao-chong2
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1.Institute of Oceanology, The Chinese Academy of Sciences, Qingdao, 266071;2.Marine Environmental College, Ocean University of Qingdao, Qingdao, 266003
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| Abstract: |
| In this study expressions of the lowest order Lagrangian residual velocity induced by the 1st baroclinic mode of the mixed Rossby-inertia gravity wave were derived from a dynamic model of the lowest order Lagrangian residual velocity and its general solution of the equatorial wave induced Lagrangian residual velocity, based on a weakly non-linear dynamic system of the continuously stratified tropical oceanic wave. It was found that the wave could induce horizontal and vertical Lagrangian residual velocity, with the horizontal components being of the same order as that of annual mean velocity (about 5am/s) in the upper central and eastern Pacific. The zonal and vertical residual velocity were symmetrical with respect to the equator, while the meridional residual velocity was asymmetrical, with the value being zero at the equator and would not cause net transport across the equator. The residual velocity’s value was not only related in direct proportion to the square of the wave’s amplitude, but also to the wave’s frequency. The meridional structure of the residual velocity induced by the mixed wave decreasing amplitude was different from that of the constant amplitude wave. Finally, qualitative analysis of the effects of the wave induced residual velocity on circulation and the sea surface temperature in the central and eastern equatorial Pacific suggested that the annual variation of the residual velocity would favors the development of the E1 Nino event in the central and eastern equatorial Pacific. |
| Key words: Mixed Rossby-inertia gravity wave, Wave induced Lagrangian residual velocity |
