大气科学2012，Vol.36Issue(4)：673-685,13.DOI:10.3878/j.issn.1006-9895.2012.11049
亚洲—太平洋夏季风系统的基本模态特征分析
Analysis of the Leading Modes of the Asian-Pacific Summer Monsoon System
摘要
Abstract
The interactions among the Asian-Pacific monsoon subsystems have significant impacts on the climatic regimes in the monsoon region and even the whole world.The Asian-Pacific summer monsoon system is under the control of the huge divergent circulation system which is divergent at the upper level and convergent at the lower level.Three branches of the air flows from the divergent center at the upper level play significant roles in the promotion of the Indian summer monsoon (ISM),the East Asian subtropical summer monsoon (EASM),and the South China Sea summer monsoon (SCSSM),respectively.It is one of the perfect performances of the holistic characteristics of the Asian-Pacific summer monsoon system.The leading modes of a couple of meteorological elements in the Asian-Pacific monsoon region have shown a more consistent characteristics on both the interdecadal and interannual timescales: the decreasing trend emerges in the Asian-Pacific summer monsoonon the interdecadal timescale during recent 55 years; while on the interannual timescale,the subsystems of the Asian-Pacific summer monsoon have synchronous variation with quasi-two-year and quasi-four-year cycles.The quasi-two-year oscillation of the monsoon system gives expression that when the ISM is anomalously strong,the monsoon rainfall belt will be strong and more northward,bringing more precipitation in the northern-central Indian continent.Because of the western Pacific subtropical high (WPSH)'s northward shift and the ISM's anomalously eastward extension in the same year,an anomalous cyclone circulation occurs over the western North Pacific in 10°N-30°N and another anomalous anticyclone circulation in 30°N-50°N.It is indicated that the EASM is anomalously strong,and can push the monsoon belt northward to northern China.That is to say,when one of the Asian-Pacific summer monsoon subsystems is much stronger than normal,the other monsoon subsystem in the same year will be also stronger than normal,but both of them will become weaker than normal in the next year.The tropospheric biennial oscillation (TBO) may be an inherent cycle in the Asian-Pacific summer monsoon system.It reflects the significant holistic characteristics of the Asian-Pacific summer monsoon system on the interannual timescale under the response of the tropical Pacific-Indian Ocean temperature forcing.关键词
亚洲—太平洋夏季风系统/印度夏季风/东亚夏季风/准两年振荡/大气热源Key words
Asian-Pacific summer monsoon, Indian summer monsoon (ISM), East Asian summer monsoon (EASM), tropospheric biennial oscillation (TBO), atmospheric heat source分类
天文与地球科学引用本文复制引用
刘芸芸,丁一汇..亚洲—太平洋夏季风系统的基本模态特征分析[J].大气科学,2012,36(4):673-685,13.基金项目
国家重点基础研究发展计划2010CB950404,国家重大科学研究计划2012CB955203,国家自然科学基金资助项目41005037,国家科技支撑计划 2009BAC51B05 （）
