台风右侧暖涡对台风“鲇鱼”的响应  

Responses of a warm mesoscale eddy to bypassed typhoon Megi in the South China Sea

作　　者：李晟[1,2,3,4] 宣基亮 黄大吉 LI Sheng;XUAN Jiliang;HUANG Daji(Ocean College,Zhejiang University,Zhoushan 316021,China;State Key Laboratory of Satellite Ocean Environment Dynamics,Second Institute of Oceanography,MNR,Hangzhou 310012,China;Guangxi Key Laboratory of Beibu Gulf Marine Resources,Environment and Sustainable Development,Fourth Institute of Oceanography,MNR,Beihai 536015,China;Lishui Water Resources Bureau,Lishui 323000,China)

机构地区：[1]浙江大学海洋学院,浙江舟山316021 [2]卫星海洋环境动力学国家重点实验室,自然资源部第二海洋研究所,浙江杭州310012 [3]广西北部湾海洋资源环境与可持续发展重点实验室,自然资源部第四海洋研究所,广西北海536015 [4]丽水市水利局,浙江丽水323000

出　　处：《海洋学研究》2024年第2期1-14,共14页Journal of Marine Sciences

基　　金：国家自然科学基金项目(42276021);自然资源部全球变化与海气相互作用(二期)项目(GASI-04-WLHY-03);浙江省万人计划科技创新领军人才项目(2020R52038)。

摘　　要：基于多源观测数据,分析了台风右侧暖涡对2010年南海台风“鲇鱼”的响应,发现了意料之外的暖涡增强和海水下沉现象。台风“鲇鱼”过境期间,暖涡海面高度距平(SLA)最大值从30 cm增加至36 cm、半径从78 km增大至116 km、涡动能从166 m^(2)s^(2)增加至303 m^(2)s^(2)、振幅从3 cm增大至9 cm,台风右侧暖涡边缘的Argo站位处温跃层海水下沉20~40 m。为此,诊断分析了台风风应力旋度对暖涡的单独作用,结果显示暖涡及暖涡边缘的Argo站位处总体受正风应力旋度作用,正风应力旋度将使暖涡减弱、温跃层抬升,与观测到的暖涡增强和海水下沉结果不符。而基于实际海面流场的诊断分析表明,台风“鲇鱼”过境期间台风路径下方的海水辐散,路径右侧暖涡区域海水辐聚,暖涡SLA最大值、涡旋振幅均与辐聚强度呈正相关,Argo站位处海水下沉29 m,都与观测结果相符。个例分析研究表明,位于台风路径外围的中尺度涡对台风的响应不仅受风应力旋度的作用,还受海洋背景环境条件的调制,存在着需要深入研究的过程和机制。Based on multi-platform observed data,an unexpected response of a warm mesoscale eddy to bypassed typhoon Megi in the South China Sea in 2010 was observed and investigated.During the passage of typhoon Megi,the SLA maximum of the warm eddy increased from 30 to 36 cm,the radius increased from 78 to 116 km,the eddy kinetic energy increased from 166 to 303 m^(2)s^(2),and the amplitude increased from 3 to 9 cm.On the right side of the typhoon,the thermocline water at Argo station on the edge of the warm eddy sank by 20 to 40 m.Diagnosis of the wind stress curl alone indicates that the warm eddy should be weaken and the thermocline should be raised,which are inconsistent with the observation results.Diagnosis based on the reanalysis sea surface velocity indicates that during the passage of typhoon Megi,the water diverges below the typhoon path,while the water converges on the right side of the path in the warm eddy region,and the SLA maximum as well as the amplitude of warm eddy are positively correlated with the convergence intensity.Estimation based on the reanalysis sea surface velocity also indicates that the water at Argo station will sink 29 m.Both the warm eddy characteristics and the thermocline depression are consistent with the observation.The case study shows that the response of mesoscale eddy on the edge of typhoon influence to typhoon is constrained not only by wind stress curl but also by the oceanic background conditions,and further attentions are required to explore the corresponding response and mechanism of upper ocean to typhoon.

关 键 词：台风 暖涡 增强 风应力 辐聚 

分 类 号：P732[天文地球—海洋科学]