摘要
利用SODA次表层海温再分析资料和卫星遥感海面高度异常数据,分析了热带太平洋和印度洋温跃层海温之间的联系,提出了太平洋—印度洋温跃层海温异常联合模(PITM)的概念、并定义了该联合模指数.结果表明,联合模指数具有准两年和3~5年的年际变化周期以及2011—2012年的年际变化周期,并具有季节锁相和振幅不对称等特征.联合模的演变过程与温跃层海温异常(TOTA)的发展和传播过程紧密相联:在太平洋,TOTA一般从西太平洋出发沿赤道(5°S—5°N)向东传播,到达东太平洋之后折向北,再沿10°N—14°N纬度带向西传播到达太平洋西岸并向赤道西太平洋扩展,形成一条回路;南太平洋也有类似回路但信号较弱;在印度洋,则主要沿8°S—12°S纬度带向西传播,到达西岸后折向北,然后迅速沿赤道(1.25°S—1.25°N)向东扩展,也形成一条回路.对NCEP/NCAR再分析风场资料的合成分析则表明,联合模的演变过程与大气环流尤其是纬向垂直环流(Walker环流)的变化密切相关,联合模的正位相对应着赤道印度洋区域顺时针的Walker环流以及赤道太平洋区域逆时针的Walker环流;而联合模的负相位则有相反的情况.此外,联合模演变过程中,TOTA的传播发展与850hPa异常纬向风的传播发展有很好的相关.
The Pacific-Indian Ocean Thermocline Temperature Anomaly Mode （PITM） was brought forward and its corresponding index（PITMI） was defined by analyzing the relation of thermocline temperature between Pacific and India Ocean using SODA reanalysis data and sea surface height data from satellite altimeter. The results show that PITMI has quasi-biennial, 4- year periods and interdecadal period of about 11--12 years. Moreover, it also shows seasonal phase-locked and amplitude asymmetric characteristics. Further studies show that the evolution of PITM is closely related with the evolution and spread of Thermocline Ocean TemperatureAnomaly （TOTA）. In the Pacific, TOTA moves eastward from the equatorial western Pacific to the equatorial eastern Pacific along the equator（5°S--5°N）, turning north there, then turning west at 10°N--14°N to the western Pacific and then propagates to the equatorial western Pacific° while in the Indian Ocean, the major path appears as westward propagation along 8°S--12°S and eastward propagation along the equator（1.25°S--1.25°N）. Composite analyses of NCEP/NCAR wind reanalysis data show that the evolution progress of PITM has a tight relationship with atmosphere circulation, especially the zonal circulation （Walker circulation） over the tropical Pacific and Indian Ocean. Positive phase of PITM is corresponding with clockwise Walker circulation over the equatorial India Ocean and anticlockwise Walker circulation over the equatorial Pacific while the negative phase has reverse situation. Moreover, the propagation and evolution of TOTA also has a clear correlation with that of zonal wind anomaly at 850 hPa.
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2013年第10期3270-3284,共15页
Chinese Journal of Geophysics
基金
国家"973"项目(2013CB956203)资助
关键词
温跃层海温异常(TOTA)
太平洋一印度洋TOTA联合模(PITM)
大气环流异常
合成分析
Thermocline ocean temperature anomaly（TOTA） ~ Pacific-Indian Ocean thermoclinetemperature anomaly mode （PITM）~ Atmospheric general circulation anomaly^Composite analysis
