两类La Niña季节演变过程的海气耦合特征对比  

Contrasting air-sea features associated with two types of La Nia during the seasonal evolution

作　　者：王磊[1] 张文君[1] 祁莉[1] 何金海[1] 

机构地区：[1]南京信息工程大学大气科学学院气象灾害教育部重点实验室,江苏南京210044

出　　处：《海洋学报》2014年第1期72-85,共14页

基　　金：国家重点基础研究发展计划(973计划)项目(2012CB417403,2010CB950400);国家自然科学基金项目(41005049);长江学者和创新团队发展计划资助(PCSIRT);江苏高校优势学科建设工程资助项目(PAPD)

摘　　要：利用1951—2010年逐月的HadISST海表温度资料、SODA次表层海温资料和NCEP/NCAR再分析资料等,对比分析了东太平洋(EP型)La Nia和中太平洋(CP型)La Nia的海气耦合特征在季节演变过程中的差异。EP La Nia海表温度异常中心在发展年夏季出现于南美沿岸,随后向西移动,盛期最大海表温度异常中心位于赤道东太平洋,而CP La Nia海温异常中心少动,基本维持在160°W附近,其强度更强,持续时间更长。受海温分布形态影响,热带大气对两类La Nia的响应非常不同,成熟期间CP型在中太平洋偏旱的强度和范围比EP型大,且略偏西。发展年夏、秋季,北半球位势高度响应较弱;冬季,负PNA位相易伴随两类La Nia出现,但异常活动中心的位置和强度不同,在北大西洋其大气响应几乎相反,这些差异会引起显著不同的区域气候异常。The air-sea coupled features are investigated associated with Eastern Pacific （EP）La Nia and Cen-tral Pacific （CP）La Nia during seasonal evolution,by using the monthly sea surface temperature from HadISST,subsurface sea temperature from SODA,and reanalysis data from NCEP/NCAR. For EP La Nia,the sea surface temperature anomalies （SSTA）occur over South American coast in developing summer and then are displaced westward. The negative SSTA center covers the eastern equatorial Pacific during the mature phase. Nevertheless,no significant propagation of SSTA is observed for the CP La Nia and its SSTA center maintains at around 1 6 0°W. The CP La Nia-SSTA are more intensive and persist longer compared to the EP La Nia. Tropical atmosphere responses are different for two types of La Nia. The CP La Nia is fea-tured by a stronger intensity,a larger extent,and a slightly westward displacement in moist divergence com-pared to the EP La Nia. As a response to the two types of La Nia,height anomalies are both weak in devel-oping summer and autumn. A negative Pacific-North America （PNA）pattern tends to be dominant during La Nia winters. However,their intensity and location differ from each other. Almost opposing North Atlantic Oscillation （NAO）-like atmospheric anomalies occur during the EP and CP La Nia winters,which may cause very different regional climate anomalies.

关 键 词：EP La Niña CP La Niña 海气耦合特征 遥响应 

分 类 号：P732.6[天文地球—海洋科学]