热带海洋学报 ›› 2016, Vol. 35 ›› Issue (4): 11-20.doi: 10.11978/2015126

所属专题: 海上丝绸之路专题

• 海洋水文学 • 上一篇    下一篇

基于多套数据的印度洋深层经向翻转环流的动力特征

黄旭媚1, 2, 王卫强1, 刘海龙3   

  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;
    3. 中国科学院大气物理研究所, 大气科学和地球流体力学数值模拟国家重点实验室, 北京 100029;
  • 收稿日期:2015-10-14 出版日期:2016-07-29 发布日期:2016-08-04
  • 通讯作者: 王卫强。E-mail: weiqiang.wang@scsio.ac.cn
  • 作者简介:黄旭媚(1990—), 女, 广西壮族自治区贵港市人, 硕士研究生, 主要从事印度洋翻转环流的研究。E-mail: xmhuang@scsio.ac.cn
  • 基金资助:
    中国科学院战略性先导科技专项(A类)(XDA11010301); 国家自然科学基金(41376024); 国家重点基础研究发展计划 (2013CB956204)

The dynamic characteristics of deep meridional overturning circulation in the Indian Ocean based on six reanalysis datasets

HUANG Xumei1, 2, WANG Weiqiang1, LIU Hailong3   

  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;
    3. State Key Laboratory of Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China;
  • Received:2015-10-14 Online:2016-07-29 Published:2016-08-04
  • Contact: WANG Weiqiang, E-mail: weiqiang.wang@scsio.ac.cn
  • Supported by:
    The Strategic Priority Research Program of the Chinese Academy of Sciences (grant no; XDA11010301); the National Natural Science Foundation of China (41376024); the National Key Program for Developing Basic Sciences (2013CB956204)

摘要: 基于六套模式产品, 研究了时间平均状态下印度洋深层经向翻转环流的动力特征。时间平均状态下, 印度洋深层经向翻转环流(meridional overturning circulation, MOC)在各套数据中呈现一致的结构, 即底层和深层水体向北进入印度洋, 中上层往南流出印度洋的逆时针翻转结构。通过对经向翻转环流的动力分解, 文章分析了其各动力部分在各套数据中的异同。在各套数据中, 在南印度洋Ekman部分呈现一致的逆时针翻转结构, 在10°S强度最大; 地转和外模部分在10°S以南分别呈现相似的顺时针和逆时针的翻转结构, 在27°S强度最大且符号相反; 相对而言, Ekman部分在20°S及赤道之间, 对MOC的影响更明显, 而地转及外模部分则在25°S以南的区域更明显。基于不同的动力热力强迫, 各套数据中各动力部分流函数的空间范围及强度存在显著差异: 由于各套数据的风场相差不大, 因此Ekman部分的整体结构相似, 强度差异较小; 对于地转部分, 各数据表现出的顺时针翻转结构强度的差异主要受内区斜压流场强弱和西边界流结构的影响, 内区斜压流场越强, 翻转结构越强; 西边界流流幅越宽, 对内区斜压流场影响越大, 对翻转结构强度的削弱越大; 外模部分翻转结构的强度受西边界流强度的影响: 西边界流强度越大, 外模部分翻转结构强度越大。

关键词: 深层经向翻转环流, Ekman部分, 地转部分, 外模部分, 时间平均

Abstract: The dynamic characteristics of time-mean meridional overturning circulation in the Indian Ocean was examined using six reanalysis datasets. The results showed consistent time-mean features of the deep meridional overturning circulation, which is an anticlockwise overturning cell with inflows in the bottom and deep layers and outflows in the intermediate and upper layers. Dynamic decomposition of meridional overturning circulation was applied to examine the similarities and differences of every dynamic component. The structure of Ekman component is an anticlockwise overturning cell in the South Indian Ocean with maximum strength at ~10°S. In the region south of 10°S, geostrophic and external components show clockwise and anticlockwise overturning cells, respectively, they both reach maximum strengths at ~27°S. Based on different products of heat and momentum fluxes used, the dynamic components resulted from the six datasets show some inconsistent features as follows. The overall structures of Ekman component are similar since the wind fields of the six datasets have few differences. The discrepancies of the geostrophic component in the six datasets are due to the strength of the baroclinic flows in the interior ocean and the structure of the western boundary current: the greater the baroclinic flows in the interior ocean, the stronger the strength of the geostrophic component; the wider the western boundary current, the greater impact on the baroclinic flows in the interior ocean, and then on the strength of the geostrophic component. The strength of the external component is affected by the intensity of the western boundary current: the greater the western boundary current, the stronger the strength of the external component.

Key words: deep meridional overturning circulation, Ekman component, geostrophic component, external component, time mean

中图分类号: 

  • P731.27