Changes in Tropical Cyclone Rainfall in China

摘要

 The torrential-rainfall-associated tropical cyclone (TC) activity often causes flood disasters in China. Moreover, studies suggest that TC-related rainfall rates are likely to increase in a warmer climate. Using daily precipitation observations at 514 meteorological stations during 1965-2009, this study investigates the primary features of TC rainfall in China, with a particular focus on the contribution of TC rainfall to the changes in the precipitation climate and the average rainfall per TC. TC rainfall mainly affected eastern and southeastern China, accounting for more than 10% of the summer rainfall in South and Southeast China. TC rainfall trended upward in the lower reach of the Yangtze River and Southeast China, contributing to the “wetting in the south and drying in the north” pattern by enhancing the rainfall in Southeast China. This study suggests that the average rainfall per TC has significantly increased in Southeast China during 1965-2009. In the peak season (July-September), all significant changes are upward trends that occur south of the Yangtze River east of 110°E. This study finds that the increasing rainfall per TC was not accompanied with the enhanced TC intensity. In addition, no significant trend can be found in the translation speed of TCs that affected China during 1965-2009, suggesting that the increasing TC rainfall per TC in China was not due to the slowdown of TC movement.