热带海洋学报 ›› 2015, Vol. 34 ›› Issue (5): 1-10.doi: 10.11978/2014141

所属专题: 海上丝绸之路专题

• 海洋水文学 •    下一篇

赤道印度洋秋季Wyrtki急流盐度输运对正、负IOD事件的不对称响应

张莹1, 2, 杜岩1, 张玉红1, 杨亚力1, 2   

  1. 1. 热带海洋环境国家重点实验室(中国科学院南海海洋研究所), 广东 广州 510301; 2. 中国科学院大学, 北京 100049;
  • 收稿日期:2014-12-10 修回日期:2015-03-06 出版日期:2015-09-11 发布日期:2015-09-11
  • 基金资助:

    国家自然科学基金项目(41176024); 中国科学院先导专项(XDA11010103); 全球变化研究国家重大科学研究计划(“973”)项目(2012CB955603)

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

ZHANG Ying1, 2, DU Yan1, ZHANG Yu-hong1, YANG Ya-li1, 2   

  1. 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:2014-12-10 Revised:2015-03-06 Online:2015-09-11 Published:2015-09-11

摘要:

采用海洋实测资料和简单海洋数据同化(SODA)模式再分析资料研究了印度洋偶极子(IOD)事件影响下赤道印度洋秋季Wyrtki急流及其盐度输运的年际变化特征。结果表明, 在正、负IOD事件盛期, 赤道流场和盐度异常不仅呈反位相特征, 在空间分布及强度上还具有显著的不对称性。正IOD事件盛期, Wyrtki急流转向为西向流, 将赤道印度洋东部低盐水向西输送; 此时赤道流场和盐度负异常显著, 影响范围大, 南北扩张明显, 盐度异常中心偏西, 影响深度较深。负IOD事件盛期, Wyrtki急流增强, 对赤道印度洋西部高盐水输送能力增强; 此时盐度及流速异常较弱, 极值范围小, 盐度异常中心偏东, 影响深度较浅, 但流速异常影响深度较正IOD事件深。

关键词: Wyrtki急流, 盐度运输, 印度洋偶极子, 不对称性

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.

Key words: Wyrtki Jet, salinity transport, Indian Ocean dipole, asymmetry