Trend and variability of China's summer precipitation during 1955–2008

Abstract

AbstractTrend and variability of China's summer precipitation during 1955–2008 are examined. The results show that (1) summer precipitation has significantly increased in South China and significantly decreased in North China, while there are no significant trends in the West and China overall; (2) interannual variability is greatly intensified all over China with more wet and dry extreme years in the second bin (1977–2008) than in the first bin (1955–1976). Covariability between China's summer precipitation and the Pacific sea surface temperature (SST) is analysed using singular value decomposition (SVD) technique. The first mode of SVD displays an El Niño‐Southern Oscillation (ENSO)‐like SST pattern, the associated precipitation shows negative anomalies in North China; the second mode exhibits SST fluctuations in the western and central Pacific that corresponding to positive anomalies in South China. In addition, cooling over the mid‐lower reaches of Yangtze River basin (i.e. South‐central China) might also contribute to decreased (increased) summer precipitation in North (South) China. The percentages of variance of summer precipitation and SST explained by each mode suggest that the increased variability of the second SVD mode in the second bin is consistent with intensified variability of China's summer precipitation in the same period. © 2013 Royal Meteorological Society