沿岸风和海洋波动在北向索马里流生成中的作用  

The role of alongshore wind and ocean wave in generating the northward Somali Current

作　　者：储小青[1,2] 彭启华 CHU Xiaoqing;PENG Qihua(State Key Laboratory of Tropical Oceanography,South China Sea Institute of Oceanology,Chinese Academy of Sciences,Guangzhou 510301,China;Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou),Guangzhou 511458,China;Scripps Institution of Oceanography(University of California,San Diego),La Jolla 92093,USA)

机构地区：[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]南方海洋科学与工程广东省实验室(广州),广东广州510301 [3]斯克利普斯海洋研究所(美国加州大学圣地亚哥分校),美国加利福尼亚州拉荷亚92093

出　　处：《热带海洋学报》2023年第2期1-8,共8页Journal of Tropical Oceanography

基　　金：国家自然科学基金项目(42076021,42005035);广东省自然科学基金项目(2021A1515011534)。

摘　　要：基于同化资料和数值模式,文章研究了北向索马里流(norward Somali current,NSC)的季节特征和产生机制。NSC在5月开始出现,在8—9月向北延伸至近15°N,并形成一个强盛的反气旋式环流。10月下旬,NSC开始减弱,并于11月消失。NSC由局地沿岸风和东侧西传的海洋波动共同激发。在5—7月,在局地西南沿岸风的协助下,东非沿岸流(EACC)跨越赤道进入北印度洋,形成了NSC。在8—10月,即便无局地西南沿岸风,在来自阿拉伯海东边界的海洋波动和EACC共同作用下,依旧能形成NSC。研究表明,局地沿岸风虽能诱发近岸的环流结构,但NSC关联的影响范围较大的反气旋式环流结构则由西传的海洋波动所激发。By analyzing reanalysis data and conducting ocean modes experiments,this study investigates the seasonal variation and dynamics of the norward Somali current(NSC)in the tropical Indian Ocean.The results show that the NSC starts from May,gradually strengthens and extends norward to 15°N during August-September,and forms a strong anti-cyclonic circulation—the Great Whirl.The NSC weakens significantly in late October,and disappears in November.The NSC results from local alongshore wind forcing and westward propagational Rossby waves.During May-July,alongshore wind forcing induces the East African Coast Current(EACC)to cross the equator to form the NSC.From August to October,even without alongshore wind forcing,the Rossby waves together with EACC can still form the NSC.Further analysis suggests that,although alongshore wind forcing incudes nearshore current,the Great Whirl is caused primarily by the Rossby waves.This research reveals dynamics of the NSC,and provides substantial evidences for ocean waves modulating ocean currents.

关 键 词：北向索马里流 海洋波动 局地风场 季节变化 热带印度洋 

分 类 号：P731.2[天文地球—海洋科学]