黑潮延伸体区域50~100 km涡旋分布特征  

Distribution characteristics of eddies with a scale of 50~100 km in the Kuroshio Extension region

作　　者：钱思佳 于方杰[1] 陈戈[1] QIAN Si-jia;YU Fang-jie;CHEN Ge(College of Information Science and Engineering,Ocean University of China,Qingdao 266100,China)

机构地区：[1]中国海洋大学信息科学与工程学院,山东青岛266100

出　　处：《海洋科学》2021年第11期10-19,共10页Marine Sciences

基　　金：国家重点研发计划(2016YFC1400904,2016YFC1402608)。

摘　　要：本文使用基于热成风速度的涡旋识别拓展方法,通过海表面温度数据对黑潮延伸体区域50~100 km涡旋进行研究,发现50~100 km涡旋主要分布在黑潮延伸体流轴两侧,气旋涡和反气旋涡的寿命、半径分布具有一致性。气旋涡多出现在35°N以北,反气旋涡在35°N以南比较集中,与尺度较小的中尺度涡旋分布特征较为相似。冬夏两季涡旋地理分布存在一定差异,主要与不同季节该区域海表温度梯度及风应力旋度的变化有关。35°N以南50~100 km涡旋数量的季节性变化与风速大小的季节性变化存在明显的正相关性。35°N以南50~100 km涡旋三倍半径内风速异常和风应力旋度归一化表明,气旋涡对应风速负异常而反气旋涡对应风速正异常,反气旋涡的产生依赖于风应力负旋度,气旋涡的生成与风应力正旋度有关。This paper utilizes a high-resolution sea surface temperature(SST)and an extended eddy detection algo-rithm based on the thermal-wind velocity to study the characteristics of eddies with a scale of 50~100 km in the Kuroshio Extension region.Results show that eddies with a scale of 50–100 km are mainly distributed on both sides of the Kuroshio Extension region.The lifetime and radius distribution of cyclonic eddies(CEs)and anticyclonic eddies(AEs)are consistent.CEs are mostly distributed in the north of 35°N while AEs are more concentrated in the south of 35°N;this distribution is similar to the distribution characteristic of mesoscale eddies at small scales.There is a slight difference in the eddy distribution characteristics in winter and summer,which is mainly due to the dif-ference in the SST horizontal gradient and wind stress curl in different seasons.The seasonal variation of the num-ber of CEs and AEs in the south of 35°N is positively correlated with the seasonal variation of the wind speed.The normalization of the wind speed anomaly and wind stress curl within three times the radius of eddies with a scale of 50~100 km in the south of 35°N show that AEs correspond to the positive anomaly of the wind speed while CEs correspond to the negative wind speed anomaly.AEs and CEs are generated due to the negative and positive curls of the wind stress,respectively.

关 键 词：黑潮延伸体 50~100 km涡旋 海表面温度 涡旋识别拓展方法 涡旋-风速 

分 类 号：P731.21[天文地球—海洋科学]