Analysis Of Tropical Cyclone Precipitation Change In China In July-september During1965-2010

The tropical cyclone precipitation is partitioned from the station observations in China using the Objective Synoptic Analysis Technique (OSAT). With daily station precipitation and tropical cyclone track datasets and so on, the trend of July-September tropical cyclone precipitation in China during1965-2010, the climate characteristics of tropical cyclone precipitation and the associated mechanisms are examined in this study. Results indicate that OSAT is capable of distinguishing simultaneous tropical cyclone precipitation. Tropical cyclone rainfall mainly affected the eastern and southeastern half of China during July-September, it gradually decreases from southeast coastal regions to northwest regions. An increasing trend in tropical cyclone precipitation is found in east China and southeast coastal areas, with a decreasing trend in south China coastal areas, Hainan Island and southwest China over the period1965-2010. The strengthening and westward extension of the Western Northern Pacific subtropical high makes strong moisture convergence in east China, and the change of large-scale steering flows causes shifts in prevailing typhoon tracks from the South China Sea to East Asian coast, leading to changes in the summer tropical cyclone precipitation in China since1965. The long-term trend of tropical cyclone precipitation may be associated with the undergoing global warming.