摘要
利用1958—2014年印度热带气象研究所的全印度降水量、欧洲中期天气预报中心(ECMWF)、日本气象厅(JRA-55)及美国环境预报中心与国家大气预报中心(NCEP/NCAR)的再分析资料,研究了索马里急流(SoMali Jet,SMJ)与印度夏季降水的相关关系。结果表明:1983年之前,SMJ与印度夏季降水有显著的正相关关系,这跟以往的认识一致,但在1983年之后两者的正相关关系显著减弱。研究进一步发现,在1983年之前,南印度洋及索马里沿岸有越赤道气流正异常,阿拉伯海、印度西北地区存在西南风正异常,异常强的SMJ对应着异常强的阿拉伯海西南季风,从而增加印度夏季的水汽输送,进而加强季风降水,且SMJ与南亚高压联系密切;但在1983年后,阿拉伯海北部及印度西北地区的西南风正异常减弱了,特别是在印度西海岸的西南风正异常显著减弱了,而且其与南亚高压的关系也显著减弱了,从而导致SMJ与印度夏季降水的正相关关系显著减弱。另外,在印度夏季降水与ENSO、SMJ相关关系减弱的同时,初步显示它与东亚/太平洋遥相关型(EAP)的相关关系却有所加强。
The whole India summer rainfall data set from the Indian Institute of Tropical Meteorology,monthly Reanalysis data set from European Center for Medium-Range Weather Forecasts(ECMWF),Japan Meteorological Agency/Japan(JRA-55)and National Center for Environment Prediction/National Center for Atmospheric Research(NCEP/NCAR)during 1958—2014 are used to study the relations between Somali jet and Indian summer rainfall.It is found that before 1983,SMJ had significant positive correlation with the Indian summer rainfall,which accorded with our past understanding.But after 1983,the positive correlation has significantly weakened.Further study indicated that before 1983,there was a positive anomaly of the Somali equatorial airflow in the South India ocean and the Somali coast and there was a positive anomalous southwest wind in the Arabia sea and the northwest of India,which increased the summer water vapor transport to India and further strengthened Indian summer precipitation.SMJ was closely related to the South Asia high.However,after 1983,the south-west wind positive anomaly in the north of the Arabia sea and the northwest of India has weakened,particularly in the west coast of India.The correlation between SMJ and the South Asia high has also weakened,which results in the weakening correlation between SMJ and Indian summer rainfall.In addition,while the relations between Indian summer rainfall and ENSO,SMJ are weakening,it is preliminarily shown that the correlation between Indian summer rainfall and East Asia/Pacific Teleconnection(EAP)is significantly strengthening.
作者
郭品文
吴冰菁
GUO Pinwen;WU Bingjing(Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science&Technology,Nanjing 210044,China)
出处
《大气科学学报》
CSCD
北大核心
2020年第5期880-887,共8页
Transactions of Atmospheric Sciences
基金
国家自然科学基金资助项目(41975063)。
作者简介
联系人:郭品文,E-mail:guo@nuist.edu.cn。
