Spatio-temporal distribution characteristics and causes of STCs'destructive forces in the South China Sea from 1953 to 2022

QIN Mengyun; WANG Ziquan; HUANG Rongyong; YU Kefu

doi:10.19513/j.cnki.hyqxxb.20240107001

Abstract：To understand the spatio-temporal distribution characteristics of the destructive forces of the severe tropical cyclones(STCs;tropical cyclones with intensities equal to or higher than typhoon)to various targets in the South China Sea(SCS;105°-120° E,3°-25°N),the China Meteorological Administration(CMA)Tropical Cyclone Best Track Dataset is used to calculate the power dissipation indices(PDIs)of the tropical cyclones reaching the level of STC.Thereafter,the PDIs are assigned to different spatial locations to analyze the spatio-temporal distribution characteristics of the STCs'destructive forces in the SCS from 1953 to 2022.The results are listed below.(1)The STCs'destructive forces in the SCS exhibit high values in the northeastern part and low values in the southwestern and southern parts.That is,the waters around the Dongsha Islands(116°-120°E,17°-21°N)have the highest PDI,and as it is far away from the Dongsha Islands,the PDI decreases towards the west and the south.(2)The spatial extent of high-destructive-force areas first expands,then narrows,and expands again over the time.(3)The temporal variation of the STCs'destructive forces at different latitudes shows an increasing-decreasing-increasing trend,while the forces in different periods first increase and then decrease from north to south.Moreover,the centroids of the PDIs are generally seen moving southward.Further analysis indicates that the changes in the numbers and duration of the STCs,which are produced in the western Pacific and then enter the SCS,are the most important factor for the spatio-temporal variations of the STCs'destructive forces in the SCS.