CHARACTERISTICS OF TROPICAL CYCLONE EXTREME PRECIPITATION AND ITS PRELIMINARY CAUSES OVER MAINLAND OF THE SOUTH CHINA

XIA Hou-jie; ZHU Wei-jun; REN Fu-min

doi:10.16032/j.issn.1004-4965.2017.04.008

Abstract：Based on 184 meteorological-station daily precipitation data during 1960-2014 over mainland of the South China(Guangdong and Guangxi),Tropical Cyclone(TC) Best Track Dataset,ERA-interim Reanalysis Dataset and ERA-40 Reanalysis Dataset,and applying the Objective Synoptic Analysis Technique(OSAT),tropical cyclone track similarity area index(TSAI) and the dynamic composite analysis,analyses were carried out on characteristics of TC extreme precipitation and its preliminary causes from a perspective of TC maximum daily precipitation (TMP).Results display that,during the past 50 years,regional-mean frequencies of TMPs above 50 mm,100 mm and 250 mm show-0.66 times/(10 y) and-0.44 times/(10 y) decreasing trends and 0.16 times/(10 y) increasing trend with obvious interannual variations,respectively.Frequencies and intensities of different level TMPs present a similar distribution pattern of large values distributing mainly along the coastal regions and decreasing quickly from coastal regions to inland regions.In addition,large values concentrate in three subregions:the eastern coast of Guangdong (the eastern subregion),the western coast of the Pearl River Delta (the middle subregion) and the coast from the Leizhou Peninsula to coast of Guangxi (the western subregion),with the western subregion being the one with largest values of intensity and frequency.Comparison analysis reveals that,the TCs,which cause extreme precipitation in the western subregion,have tracks of the strongest regularity with mainly westward movement and landfall locations concentrating within the area.Meanwhile,causes analysis preliminarily reveals that TC's slow movement and reinforcement of the South China Sea Summer Monsoon are in favor of producing extreme precipitation.