南半球风暴轴对冬夏季中纬度海温异常的响应特征  

Response Characteristics of Storm Track over the Southern Hemisphere to the Midlatitude SST Anomalies in Winter and Summer

作　　者：徐策 张力[2,3] 甘波澜 XU Ce;ZHANG Li;GAN Bo-Lan(College of Oceanic and Atmospheric Sciences, Ocean University of China, Qingdao 266100,China;Physical Oceanography Laboratory,CIMST,Ocean University of China, Qingdao 266100, China;Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266237,China)

机构地区：[1]中国海洋大学海洋与大气学院,山东青岛266100 [2]中国海洋大学物理海洋教育部重点实验室,山东青岛266100 [3]青岛海洋科学与技术试点国家实验室,山东青岛266237

出　　处：《中国海洋大学学报（自然科学版）》2020年第8期1-8,共8页Periodical of Ocean University of China

基　　金：国家自然科学基金项目(41906015);全国博士后创新人才支持计划科学基金项目(861805033113)资助。

摘　　要：利用HadISST(Hadley Centre Global Sea Ice and Sea Surface Temperature)和20CRv2(Twentieth-Century Reanalysis dataset version 2)数据集,对1951—2000年南半球中纬度海表面温度(Sea Surface Temperature;SST)进行了经验正交函数分解(EOF),结合回归分析方法,分析了南半球风暴轴对冬夏季中纬度海温异常的响应特征。结果表明:南半球夏季SST第一模态表现为三极子型,南大西洋、南印度洋和南太平洋的SST暖异常能够使对流层低层涡动活动增强,体现在850 hPa涡动热量极向热通量增加,其最大值出现在南太平洋西部。南半球冬季SST第一模态表现为在南大西洋、南印度洋分布暖异常,在南太平洋中西部出现弱偶极子型SST异常,分别能够在局地增强和减弱对流层低层涡动活动,体现在增强和减弱,其大值区出现在南印度洋。进一步对大气斜压性和斜压能量转换的诊断结果表明,上述中纬度海温异常的存在能导致对流层低层出现一致性的斜压增强(减弱),进而加强(削弱)大气涡动活动。Response of synoptic-scale(2~8 d)eddy activities in the Southern Hemisphere(SH)lower troposphere to sea surface temperature(SST)variations in the midlatitudein winter and summer is investigated based on regression analysis using reanalysis datasets from 1951 to 2000.Results show that the response is characterized by a pronounced seasonal difference.During the SH summer time,the first modeappears a tripole SST anomalies pattern.That is,warm SST anomalies in the South Atlantic(SA),South Indian Ocean(SIO)and western areas of South Pacific(SP)at midlatitudes could result in a systematic strengthening of the low-level eddy activities,which are represented by the poleward transient eddy heat flux at 850 hPa(〈v′T′〉).During the SH wintertime,the first SST mode exhibits warm SST anomalies in the SA and SIO,a weak dipole pattern in the weastern-middle areas of SP.Such SST anomalies could result in a strengthening(weakening)of the low-level eddy activities over the SA and SIO(western areas of SP).The coherent intensification of the lower tropospheric baroclinicity associated with such midlatitude warm(cold)SST anomalies in winter and summer is presumed to be responsible for the strengthening(weakening)of eddy activities therein.

关 键 词：风暴轴 海温异常 南半球中纬度 大气斜压性 

分 类 号：P731.11[天文地球—海洋科学]