摘要
Climate extremes and changes in eastern China are closely related to variations of the East Asian summer monsoon and corresponding atmospheric circulations.The relationship between frequencies of temperature and precipitation extremes in China during the last half century is investigated using Singular Value Decomposition analysis.During 1980-1996,there was a typical pattern with fewer hot days and more precipitation extremes in the northern part of eastern China,and more hot days and fewer precipitation extremes in the southern part.This geographic pattern tended to reverse after 1997,with fewer hot days and more extreme precipitation days south of the Yangtze River and vice versa to the north.Differences in atmospheric circulation between the former and latter periods are presented.We conclude that a mid-level anomalous high/low,upper-level anomalous easterlies/westerlies over the north/south of eastern China,a weakened East Asian summer monsoon and associated upper-tropospheric center of cooling(30°N,110°E) are all favorable for the changes in frequencies of temperature and precipitation extremes.
Climate extremes and changes in eastern China are closely related to variations of the East Asian summer monsoon and corresponding atmospheric circulations. The relationship between frequencies of temperature and precipitation extremes in China during the last half century is investigated using Singular Value Decomposition analysis. During 1980-1996, there was a typical pattern with fewer hot days and more precipitation extremes in the northern part of eastern China, and more hot days and fewer precipitation extremes in the southern part. This geographic pattern tended to reverse after 1997, with fewer hot days and more extreme precipitation days south of the Yangtze River and vice versa to the north. Differences in atmospheric circulation between the former and latter periods are presented. We conclude that a mid-level anomalous high/low, upper-level anomalous easterlies/westerlies over the north/south of eastern China, a weakened East Asian summer monsoon and associated upper-tropospheric center of cooling （30°N, 110°E） are all favorable for the changes in frequencies of temperature and precipitation extremes.
基金
supported by the Key Project of the National Eleventh-Five Year Research Program of China (2007BAC29B06)
China’s National Key Science Program for Global Change Research (2010CB950504)
the National Basic Research Program of China (2009CB42140 and 2012CB956200)
the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA05090100)
