大气科学学报2017，Vol.40Issue(6)：737-748,12.DOI:10.13878/j.cnki.dqkxxb.20160118001
夏半年热带太平洋中部型海温异常与热带印度洋海盆模对同期中国东部降水的共同影响
Combined influences of tropical central Pacific SSTA and tropical Indian Ocean Basin Mode on precipitation in eastern China during summer half-year
摘要
Abstract
Based on the NCEP/NCAR reanalysis data and the HadISST monthly mean sea surface temperature(SST) data from 1961 to 2013,this paper investigates the characteristics of tropical central Pacific SST anomaly(SSTA) and tropical Indian Ocean Basin Mode(IOBM),and their combined influences on climate in eastern China during summer half-year.Results demonstrate that the tropical central Pacific SSTA pattern index(CPI) and IOBM index (IOBMI) are almost independent of each other in sense of statistics.When the CPI and IOBMI have same signs (referred to PPNN cases) and opposite signs(referred to PNNP cases),the tri-pole and dipole SSTA patterns are observed in tropical India Ocean and Pacific Ocean,respectively.Mechanisms behind different anomalous rainfall patterns in eastern China are different in PPNN and PNNP cases.In PPNN cases,moisture can be transported from Maritime Continent(MC) to the Yangtze-Huaihe River basin.The anomalous circulations in eastern China are generated and maintained due to Gill response of atmosphere to the tropical SSTA.The anomalous vertical circulation cells over region from MC northward to the Yangtze-Huaihe River show some connections between anomalous thermal forcing over MC and rainfall anomalies over the Yangtze-Huaihe River basin.However,in PNNP cases,no moisture is transported into the Yangtze River.Due to the significant westward shift of location of SSTA center in Pacific,the corresponding anomalous circulations also shift westward as a Gill response of atmosphere to central Pacific SSTA pattern.Meanwhile,Rossby wave energy can propagate into region south of the Yangtze River from MC,facilitating the maintenance of anomalous anti-cyclonic circulation over region south of the Yangtze River.These results are beneficial to us for better understanding the causes of rainfall anomalies and the role of SSTA patterns over Indo-Pacific region in inducing precipitation anomalies in eastern China.关键词
热带印度洋海盆模/太平洋中部型海温异常/中国东部降水/夏半年Key words
tropical Indian Ocean Basin Mode/central Pacific SSTA/precipitation in eastern China/summer half-year引用本文复制引用
王旭栋,管兆勇,周游..夏半年热带太平洋中部型海温异常与热带印度洋海盆模对同期中国东部降水的共同影响[J].大气科学学报,2017,40(6):737-748,12.基金项目
国家自然科学基金资助项目(41330425) （41330425）
公益性行业(气象)科研专项(GYHY201406024) （气象）
灾害天气国家重点实验室开放课题(2015LASW-A03) （2015LASW-A03）
