南太平洋6-8月SST异常的主要模态及其与ENSO和SAM的联系  

PRINCIPAL MODES OF JJA SST ANOMALIES OF THE SOUTH PACIFIC AND THEIR RELATIONS WITH ENSO AND SAM

作　　者：孙密娜[1,2] 管兆勇[1] 张蓬勃[1,3] 

机构地区：[1]南京信息工程大学,气象灾害省部级共建教育部重点实验室,江苏南京210044 [2]天津市气象局,天津300074 [3]南京市气象局,江苏南京210008

出　　处：《热带气象学报》2010年第2期174-180,共7页Journal of Tropical Meteorology

基　　金：国家重点基础研究发展计划(2006CB403602)资助

摘　　要：利用1951—2006年NCEP/NCAR再分析资料,采用EOF分析方法提取了南太平洋6—8月SST异常变化的两个主要模态,结果表明:EOF1主要反映了ENSO信息,EOF2与南半球环状模(SAM)存在关联。EOF1以年际时间尺度变化为主,EOF2的周期接近于年代变化。EOF1的时间序列与同期Ni?o3指数存在显著相关,EOF2的时间序列与3—5月SAM指数存在显著相关。分析EOF1、EOF2与我国夏季降水的相关场,得出6—8月南太平洋SST出现西低东高型分布的年份我国华北地区夏季降水偏少,出现西高东低型分布的年份则降水偏多。3—5月出现中纬度和赤道东太平洋SST异常偏低,而赤道中太平洋SST异常偏高分布型的年份,我国江南地区夏季降水偏多;出现相反的分布型则降水偏少。The NCEP/NCAR reanalysis data have been employed to diagnose variations of the SST anomalies in the South Pacific. Two leading EOF modes are found to dominate the spatial and temporal changes of the SST anomalies in JJA. The EOF1 mode shows the distribution of SST anomalies with higher variance in tropical regions, whereas the EOF2 mode shows the distribution Of SST anomalies with higher variance in the South Polar Region. The EOF1 and EOF2 respectively have interannual and decadal periodicities of variation. Significant correlations have been found between EOF1 and ENSO in JJA, and lag correlations between EOF2 and SAM in MAM and JJA. Significant correlations have been found between the two modes and summer precipitation of China. When the SST anomalies display a pattern of being low in the west and high in the east, the precipitation in North China tends to be below normal in JJA. When the SST anomalies display a pattern of being negative in the central and eastern tropics, the precipitation in the middle and south of China tends to be above normal in August.

关 键 词：SST异常 ENSO SAM 南太平洋 北半球夏季 

分 类 号：P461.2[天文地球—大气科学及气象学]