| 摘要: |
| 利用 SODA 海洋同化资料, 分析了太平洋次表层海温异常(SOTA)年际信号变异特征与ENSO循环的联系。 结果表明, 热带太平洋的年际变率表现为以 160°W为纵轴的东西向和以 6°—8°N为横轴的南北向的跷跷板分布,南太平洋和北太平洋中高纬度海洋的 SOTA 则与热带西太平洋 SOTA同号, 但强度较弱, 这些变化都与 ENSO 事件密切相关, 是 ENSO 事件的两个主要模态, 具 57 和 44个月显著周期。 ENSO 循环期间, 热带西太平洋 SOTA 强信号中心沿赤道东传, 到达赤道东太平洋后加强并北扩, 导致 El Ni?o 或 La Ni?a 事件, 同时从热带西太平洋有较弱 SOTA 信号向东北和西南传播, 在南、 北太平洋中高纬度海域产生弱 SOTA; 同期位于热带东太平洋反号的 SOTA 强信号中心沿10°—15°N (平均 12°N)西传, 至热带西太平洋后加强并南扩, 为下次 La Ni?a 或 El Ni?o 事件准备条件, 同时在北太平洋中高纬度海洋还存在着反号弱的 SOTA。如此周而复始, 完成 ENSO 循环。太平洋次表层海温年际变化信号除在赤道及以北的热带太平洋存在一个逆时针方向的传播通道外, 同时在热带西太平洋有异常信号向南、北太平洋中高纬度海域传播, 并指出 ENSO 循环期间太平洋次表层海温异常年际变率信号传播的可能通道。
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| 关键词: 太平洋次表层海温异常, 温跃层, 年际变率信号通道, ENSO 循环 |
| DOI：10.11693/hyhz201005001001 |
| 分类号: |
| 基金项目:中国科学院知识创新工程重要方向项目, KZCX2-YW-Q11-02号； 国家重点基础研究发展(973)计划项目,2006CB403601号；国家自然科学基金项目, 40576016 号 |
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| SIGNAL PATHWAY OF INTERANNUAL VARIABILITY OF THE PACIFIC SUBSURFACE OCEAN TEMPERATURE ANOMALIES AND THE ENSO CYCLE |
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CHEN Yong-Li1,2, LI Qi1,2,3, ZHAO Yong-Ping1,2, WANG Fan1,2
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1.Institute of Oceanology, Chinese Academy of Sciences;2.Key Laboratory of Ocean Circulation and Waves(KLOCAW) Chinese Academy of Sciences;3.The Graduate School of the Chinese Academy of Sciences
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| Abstract: |
| Based on the simple ocean data assimilation (SODA) dataset, the Pacific subsurface ocean temperature anomaly (SOTA) signal on interannual timescales and its link with the ENSO cycle were analyzed. The results show that the interannual variability in tropical Pacific had special patterns as follows: west-east SOTA seesaw with cross axis at middle Pacific and south-north SOTA seesaw with longitudinal axis along 6°—8°N, with periods of 57 and 44 months.
During the ENSO cycle, strong SOTA center in western tropical pacific mainly propagated eastward along the equator. It strengthened and moved northward after it reached the eastern equatorial Pacific, and caused El Ni?o or La Ni?a events. Simultaneously, weak SOTA signal propagated northeast- and southeastward from western tropical Pacific to mid-high latitude areas of north and south Pacific. Meanwhile, strong SOTA center with contrary sign located in eastern tropical Pacific propagated westward along 10°—15°N; it strengthened and move southward after it reaches western tropical Pacific and prepares for next La Ni?a or El Ni?o event. At the same time, it isolated and weakened the SOTA in mid-high latitude area of north Pacific. The ENSO cycle will be completed under the repetition of the above processes. Finally, we sketched for the pathway of interannual variability of pacific SOTA to show its relation to ENSO cycle.
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| Key words: Pacific subsurface ocean temperature anomaly, Thermocline, Signal pathway of interannual variability, ENSO cycle |
