热带海洋学报 ›› 2012, Vol. 31 ›› Issue (6): 1-5.doi: 10.11978/j.issn.1009-5470.2012.06.001

• 海洋水文学 •    下一篇

跨赤道经向流的不稳定性

徐昭1, 巢纪平2, 3, 冯立成3   

  1. 1. 中国海洋大学物理海洋实验室, 山东 青岛 266100;2. 国家海洋局第一海洋研究所,山东 青岛 266061;3. 国家海洋环境预报中心,北京 100081
  • 收稿日期:2011-07-18 修回日期:2011-10-19 出版日期:2012-12-01 发布日期:2013-02-06
  • 通讯作者: 冯立成(1981—),男,研究方向为短期气候预测。E-mail:fenglich@gmail.com
  • 作者简介:徐昭(1983—),男,山东省青岛市人,在读博士,研究方向为气候变化数值模拟。
  • 基金资助:
    国家基础研究规划项目(2005CB422302);高等学校创新引智计划(B07036);国际科技合作计划项目(2006DFB21250);国家自然科学基金项目(40906014);国家海洋局青年海洋科学基金项目(2010218)

An instability of cross-equatorial meridional flow

XU Zhao1, CHAO Ji-ping2, 3, FENG Li-cheng3   

  1. 1. Physical Oceanography Laboratory, Ocean University of China, Qingdao 266100, China; 2. First Institute of Oceanography,SOA,Qingdao 266061, China; 3. National Marine Environmental Forecasting Center, Beijing 100081, China
  • Received:2011-07-18 Revised:2011-10-19 Online:2012-12-01 Published:2013-02-06

摘要: 利用法国AVISO(Archiving, Validation And Interpretation Of Satellite Oceanographic Data)海平面异常数据,通过小波分析发现在索马里海流范围内比内区多存在一个30d周期的振荡,其可能原因是跨赤道流的不稳定。使用一个简单的等值浅水模式,在跨赤道背景流的情况下,分析了其中扰动的周期和不稳定性。通过将扰动速度利用Weber函数展开后保留前四阶,获得了频散关系。结果表明,在此区域有一类增长型的短波, 其频率接近30天,这一结果与观测相近。

关键词: 跨赤道经圈流, Rossby波, 不稳定性

Abstract: Our wavelet analysis of Archiving, Validation and Interpretation of Satellite Oceanographic Data (AVISO) sea surface height anomaly reveals an oscillation with a period of 30 days, which exists only inside the western boundary current region. The mechanism may be an instability of cross-equatorial current. The research tool is a simple equivalent shallow water model in the presence of background cross-equatorial current. By expanding the perturbation equation with Weber function and keeping the first four modes, the dispersion relation in the presence of cross-equatorial current is obtained. Our instability analysis demonstrates the existence of unstable modes in this boundary current region. The most unstable shortwave has a period of approximate 30 days, which is in accordance with the AVISO observations.

Key words: cross-equatorial current, Rossby wave, instability

中图分类号: 

  • P731.11