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Cite this paper: |
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MA Xiao, SUN Che. Equatorward shift of annual Rossby waves in the Equatorial Pacifi c Ocean[J]. Journal of Oceanology and Limnology, 2016, 34(1): 212-218 |
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Equatorward shift of annual Rossby waves in the Equatorial Pacifi c Ocean |
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| MA Xiao1,2, SUN Che1, |
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1 Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China;
2 University of Chinese Academy of Sciences, Beijing 100049, China |
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| Abstract: |
| Annual Rossby wave is a key component of the ENSO phenomenon in the equatorial Pacifi c Ocean. Due to the paucity and seasonal bias in historical hydrographic data, previous studies on equatorial Rossby waves only gave qualitative description. The accumulation of Argo measurements in recent years has greatly alleviated the data problem. In this study, seasonal variation of the equatorial Pacifi c Ocean is examined with annual harmonic analysis of Argo gridded data. Results show that strong seasonal signal is present in the western equatorial Pacifi c and explains more than 50% of the thermal variance below 500 m. Lag-correlation tracing further shows that this sub-thermocline seasonal signal originates from the eastern equatorial Pacifi c via downward and southwestward propagation of annual Rossby waves. Possible mechanisms for the equatorward shift of Rossby wave path are also discussed. |
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| Key words:
equatorial Pacifi c|annual Rossby wave|equatorward shift|Argo profi les|MOAA-GPV gridded data
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| Received: 2015-01-13 Revised: 2015-03-02 |
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