夏季西北太平洋大气环流异常及其与热带印度洋-太平洋海温变化的关系  

Circulation variation over western North Pacific and its association with tropical SSTA over Indian Ocean and the Pacific

作　　者：晏红明[1] 李清泉[2] 袁媛[2] 李崇银[3,4] 

机构地区：[1]云南省气候中心,昆明650034 [2]国家气候中心,北京100081 [3]解放军理工大学气象学院,南京211101 [4]中国科学院大气物理研究所LASG国家重点实验室,北京100029

出　　处：《地球物理学报》2013年第8期2542-2557,共16页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(41065004,41005038);国家自然科学基金委-云南联合基金项目(U0833602)联合资助

摘　　要：本文分析了夏季西北太平洋大气环流异常特征及其与海温变化的关系,发现夏季西北太平洋异常反气旋/气旋(WNPAC/WNPC)是西北太平洋地区对流层中低层存在的重要大气环流异常现象,与东亚—西北太平洋低纬度至高纬度的经向PJ波列及欧亚中高纬度东西纬向波列的变化有关,通过与中高纬度环流变化的联系,对东亚及欧亚中高纬度气候有重要影响.夏季WNPAC/WNPC与热带海温变化的关系存在明显的不对称性,显著的WNPAC一般出现在El Nio衰减年夏季,与前期El Nio成熟年冬季的赤道东太平洋暖海温异常和El Nio衰减年春夏季印度洋海盆尺度的暖海温异常有明显的正相关关系,进一步表明了WNPAC在El Nio事件影响夏季气候中的重要桥梁作用;而夏季显著的WNPC与前期和同期热带海温变化的关系存在明显的不确定性,主要与夏季热带印度洋和赤道中东太平洋之间东暖西冷的热力差异异常引起的孟加拉湾—赤道西太平洋西风异常有关.进一步分析WNPAC/WNPC与海温变化关系不对称的可能原因,发现El Nio和La Nia衰减年夏季热带印度洋和太平洋海温变化所引起的印—太之间海温(热力)差异的一致性特征可能是导致WNPAC/WNPC与海温变化关系不对称的主要原因.The circulation variation over western North Pacific and the relationship between circulation and tropical Sea Surface Temperature Anomalies （SSTA） were investigated in this paper. The results showed that western North Pacific anticyclone （WNPAC）/ cyclone （WNPC）is two significantly anomalous phenomena at mid-low troposphere over western North Pacific, and their variation is related to PJ wave line and zonal wave line at mid-high latitude region of Eurasia. Owing to this interrelation, WNPAC/WNPC can influence the climate over East Asian and Eurasia. The result showed also that the relationship between WNPAC/WNPC in summer and SSTA is obviously asymmetrical. Generally, evident WNPAC occur in summer of feeble E1 Nino years, and are related with warm SSTA in winter of mature El Nino years over equatorial East Pacific and warm SSTA in spring and summer of weakening E1 Nifio years over Indian Ocean, which further display the important bridge role of WNPAC in E1 Nino event influence on summer climate over East Asian. But the relationship between obvious WNPC and SSTA in Indian Ocean is not steady. The formation and maintenance of WNPAC are mainly related to anomalous westerlies resulting from thermal contrast between SSTA over Indian Ocean and SSTA over the Pacific. The possible cause of asymmetry is further investigated. The results showed that the thermal contrasts between Indo-Pacinc in E1 Nino and La Nina summer are accordant, which possibly result in asymmetry relationship between WNPAC/WNPC and SSTA.

关 键 词：西北太平洋大气异常反气旋(WNPAC) 气旋(WNPC) 印度洋海盆模(IOBM) ELNINO LaNina事件 WALKER环流 印—太海温热力差异 

分 类 号：P732[天文地球—海洋科学]