海洋学研究 ›› 2021, Vol. 39 ›› Issue (3): 1-11.DOI: 10.3969/j.issn.1001-909X.2021.03.001

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苏门答腊岛西北海域中尺度涡源区特征与形成机制

张家赢1,2，周锋*1,2,3，田娣1,2，黄挺1,2,3   

  1. 1.卫星海洋环境动力学国家重点实验室，浙江 杭州 310012；
    2.自然资源部 第二海洋研究所，浙江 杭州 310012；
    3.上海交通大学 海洋学院，上海 200030
  • 出版日期:2021-09-15 发布日期:2021-09-15
  • 基金资助:
    “全球变化与海气相互作用”(二期)专项(GASI-04-WLHY-03，GASI-04-WLHY-01，GASI-01-EIND-STwin)；中央级公益性科研院所基本科研业务费专项资金资助项目(JG2008)；浙江省万人计划科技创新领军人才项目(2020R52038)；浙江省自然科学杰出青年基金(LR16D060001)；中国东盟国家蓝色伙伴关系建设项目

The characteristics and formation mechanism of the oceanic mesoscale eddy origin in northwest of Sumatra

ZHANG Jiaying1,2, ZHOU Feng*1,2,3, TIAN Di1,2, HUANG Ting1,2,3   

  1. 1.State Key Laboratory of Satellite Ocean Environment Dynamics, Hangzhou 310012, China; 
    2.Second Institute of Oceanography, Ministry of NaturalＲesources, Hangzhou 310012, China; 
    3.School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China
  • Online:2021-09-15 Published:2021-09-15

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摘要： 孟加拉湾内和湾口附近有丰富的中尺度现象，本文利用2.0版可分辨低纬地区中尺度涡的Chelton数据集，通过溯源的方法得到中尺度涡的源地分布。苏门答腊岛西北海域(以5°N，94°E为核心的区域)是中尺度涡重要源区之一。通过拉格朗日方法的涡旋追踪表明，1993—2017年该海域(3°N—6°N、92°E—95°E)，分别有57个气旋式和40个反气旋式中尺度涡。频谱分析显示海表面高度异常存在180 d和360 d两个显著周期。地形和风场的共同作用是该海域产生中尺度涡的动力机制：沿5°N西传的罗斯贝波在海岭地形的作用下触发了中尺度涡的生成；赤道风场是源区重要的能量来源，局地风场能诱发中尺度涡的极性。本研究也揭示了以往文献虽刻画了苏门答腊岛西北部海域为高涡动能区，却没有识别出较多中尺度涡的原因。

关键词: 中尺度涡, 源区, 涡旋识别, 统计特征, 罗斯贝波, 孟加拉湾

Abstract: There are abundant mesoscale phenomena in the Bay of Bengal and near the mouth of the bay. In this study, a 2.0 version of the Chelton's data set was used, which can distinguish mesoscale eddies in low-latitude regions, and obtain the genesis distribution of mesoscale eddies by tracing. The northwest sea off Sumatra (the area with 5 °N,94 °E as the core) is an important origin of mesoscale eddies. The eddy tracking of Lagrangian method shows that there were 57 cyclonic and 40 anticyclonic mesoscale eddies in the origin (3°N—6°N, 92°E—95°E) during 19932017. Spectrum analysis indicates that there are two significant periods of 180-day and 360-day in sea surface height anomalies. The dynamic mechanism of mesoscale eddies in this origin is the combined effect of topography and wind field, the Rossby wave propagating westward along 5°N increases instability and triggers the mesoscale eddy generation under the action of the ridge topography. The equatorial wind field is an important source of energy in the origin, and the local wind field can induce the polarity of the mesoscale eddy. This study also reveals the reason why the previous literatures described the northwest sea area off Sumatra as a high eddy kinetic area, but failed to identify many mesoscale eddies.

Key words: mesoscale eddy, eddy origin, eddy identification, statistical characteristic analysis, Rossby wave, Bay of Bengal

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