Marine Hydrography

Asymmetric influences of positive and negative IOD events on salinity transport by the fall Wyrtki Jet along the equatorial Indian Ocean

  • ZHANG Ying ,
  • DU Yan ,
  • ZHANG Yu-hong ,
  • YANG Ya-li
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  • 1. State Key Laboratory of Tropical Oceanography (South China Sea Institute of Oceanology, Chinese Academy of Sciences), Guangzhou 510301, China;
    2.University of Chinese Academy of Sciences, Beijing 100049, China;

Received date: 2014-12-10

  Revised date: 2015-03-06

  Online published: 2015-09-11

Abstract

We analyzed the interannual variability of the Wyrtki Jet and its salinity transport associated with Indian Ocean Dipole (IOD) in fall season using observations and Simple Ocean Data Assimilation (SODA). During negative IOD events, the Wyrtki Jet strengthened in the equatorial Indian Ocean, forced by enhanced equatorial westerly wind, which favors a stronger eastward transport of high-salinity water. During positive IOD events, the above-mentioned processes reversed. In addition, both the Wyrtki Jet and associated salinity transport anomalies on the strength and spatial distribution displayed significant asymmetric characteristics between the positive and negative IOD events. The amplitudes of zonal velocity and salinity anomalies were stronger during the positive IOD events. The anomalies centered in the central equatorial Indian Ocean during the positive IOD events, but they moved to the east in the negative IOD events. Moreover, the velocity anomalies reached a deeper depth during the negative IOD events, even though the salinity anomalies occurred at a rather shallow depth.

Cite this article

ZHANG Ying , DU Yan , ZHANG Yu-hong , YANG Ya-li . Asymmetric influences of positive and negative IOD events on salinity transport by the fall Wyrtki Jet along the equatorial Indian Ocean[J]. Journal of Tropical Oceanography, 2015 , 34(5) : 1 -10 . DOI: 10.11978/2014141

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