大气科学2011，Vol.35Issue(4)：729-738,10.
ENSO事件对云南及临近地区春末初夏降水的影响
Influence of ENSO Event on Rainfall Anomaly over Yunnan Province and Its Neighboring Regions during Late Spring- Early Summer
摘要
Abstract
Using the monthly gridded precipitation data in China, the NOAA extended reconstruction sea surface temperature (SST) data, and the NCEP/NCAR reanalysis data, the authors investigate the impact of the ENSO on the interannual variability of late spring - early summer rainfall in Yunnan Province and the relevant physical mechanism. The analysis of composite and correlation study, reveal a strong negative correlation between the rainfall anom-aly in Yunnan Province and the Nino index. An El Nino (La Nina) event is concurrent with less (more) precipitation during late spring - early summer (April - May) in Yunnan Province. Further analysis of atmospheric circulation demonstrates that an El Nino (La Nina) event is coincident with an anomalous easterly (westerly) over the Arabian Sea and the Bay of Bengal in the lower troposphere, a stronger anomalous anticyclone (cyclone) over the Bay of Bengal, as well as a stronger (weaker) subtropical anticyclone in the northwestern Pacific Ocean. The correlation between height at 200 hPa and rainfall anomaly during late spring-early summer (April - May) in Yunnan Province reveals a relevant Indian Ocean- Asia teleconnection (LA) pattern. The water vapor transport indicates that during an El Nifio (La Nina) event there is a stronger water vapor divergence (convergence) over the region. All above evidences demonstrate that, in comparison with the physical processes in controlling the interannual variation of the summer rainfall in southeastern China and the Yangtze River- Huaihe River valley, the conversion of Indian Ocean - Asia teleconnection pattern from winter to spring is dominant in determination of the rainfall anomaly in Yunnan Province during late spring- early summer, and particularly the increased water vapor transport associated with the intensification of the anomalous cyclone over the Bay of Bengal plays an important role.关键词
ENSO/云南降水/大气环流/遥相关Key words
ENSO, Yunnan late spring-early summer rainfall, atmospheric circulation, Indian Ocean - Asia teleconnection分类
天文与地球科学引用本文复制引用
杨亚力,杜岩,陈海山,张永生..ENSO事件对云南及临近地区春末初夏降水的影响[J].大气科学,2011,35(4):729-738,10.基金项目
国家重点基础研究发展计划项目2010CB950302,中国科学院百人计划项目KZCX2-YW-BR-04,中国科学院知识创新工程项目KZCX2-YW-Q11-02,国家自然科学基金资助项目40876007 （）
