亚洲夏季风的年际和年代际变化及其未来预测  

Interdecadal and Interannual Variabilities of the Asian Summer Monsoon and Its Projection of Future Change

作　　者：丁一汇[1] 孙颖[1] 刘芸芸[1] 司东[1] 王遵娅[1] 朱玉祥[2] 柳艳菊[1] 宋亚芳[1] 张锦[1] 

机构地区：[1]中国气象局国家气候中心,北京100081 [2]中国气象局气象干部培训学院,北京100081

出　　处：《大气科学》2013年第2期253-280,共28页Chinese Journal of Atmospheric Sciences

基　　金：国家重点基础研究发展计划2010CB950404;2012CB417205;国家自然科学基金重点项目41130960;国家自然科学基金资助项目41005037

摘　　要：本文是对我们近五年在亚洲夏季风年代际与年际变率及其未来预测方面研究的一个综述。主要包括下列三个问题:(1)根据123年中国夏季降水资料和印度学者的分析,检测出亚洲夏季风具有明显的年代际尺度减弱,这种年代际变化使中国东部(包括东亚)和南亚夏季降水的格局在过去60年中发生了明显变化。在东亚,从1970年代后期开始,主要异常雨带有不断南移的趋势,结果造成了南涝北旱的降水分布,这主要受到60～80年年代际振荡的影响。青藏高原前冬和春季积雪的年代际减少与热带中东太平洋海表温度的年代际增加是东亚降水型改变的主要原因,这是通过减弱亚洲地区夏季海陆温差与夏季风强度而实现的。未来亚洲夏季风的预测表明,东亚夏季风和南亚夏季风对气候变暖有十分不同的响应。东亚夏季风在本世纪将增强,雨带北推,尤其在2040年代之后;而南亚夏季风环流将继续减弱。这种不同的变化是由于两者对高低层海陆热力差异的不同响应造成。(2)年际尺度的变率在亚洲夏季风区主要表现为2年与4～7年的振荡。本文着重分析了2年振荡(TBO)形成的过程、机理及其对东亚降水的影响。对TBO—海洋机理进行了具体的改进,说明了东亚夏季风降水深受TBO影响的原因,尤其是阐明了长江型(YRV)TBO和淮河型(HRV)TBO的特征及其形成的循环过程。(3)在总结亚洲夏季风时期遥相关型的基础上,本文提出了季节内和年际尺度的低空遥相关型:即西北太平洋季风的遥相关型与印度"南支"和"北支"遥相关型。它们基本上反映了沿低空夏季风强风速带Rossby波群速度传播的结果。据此可以根据西北太平洋和印度夏季风的变化分别预测中国梅雨和华北雨季来临和降水异常。最后研究还表明,在本世纪亚洲夏季风可能更显著地受到人类活动造成的全球变暖的影响,未来的亚洲夏季风活�The present paper presents a concise summary of our studies on interdecadal and interannual variabilities of the Asian summer monsoon and its projection for recent five years, which can be summarized in the following three aspects： 1） A significant interdecadal weakening of the Asian summer monsoon was identified on the basis of our analysis of a 123-year precipitation dataset in China and studies made by Indian investigators. This variability has caused significant changes in summer precipitation patterns in both East and South Asia. In East Asia, the main monsoon precipitation belt has continuously retreated southward, leading to a precipitation pattern of droughts in North China and floods in South China. The interdecadal change in the preceding winter and spring over the Tibetan Plateau and the sea surface temperature anomaly （SSTA） of the tropical central and eastern Pacific, in addition to the resulting land-sea thermal contrast, are the main drivers for the weakening of the Asian summer monsoon. In the future, the responses of the South and East Asian summer monsoons to a warmer climate will differ, with a continuous weakening in the former and enhanced circulation and precipitation fields in the latter. 2） The interannual variability is mainly characterized by biennial and four-seven-year oscillations. The present paper focuses on formative processes, mechanisms and influences of tropospheric biennial oscillation （TBO） on precipitation in East Asia. The formation and cycle processes of two particular TBO modes, the Yangtze River Valley （YRV） and the Huaihe River Valley （HRV） modes, have been examined. 3） On the basis of previous studies of teleconnection modes in the Asian monsoon region, we suggest the occurrence of low-level teleconnection types propagating along a strong monsoonal airflow belt from South Asia or the western North Pacific to East Asia. Such teleconnection types can exert an important effect on the Meiyu/Baiu season and summer precipitation in North China and N

关 键 词：亚洲夏季风 年代际和年际变率 对流层两年振荡(TBO) 遥相关型 季风预测 

分 类 号：P466[天文地球—大气科学及气象学]