摘要
As one of the most devastating tropical cyclones over the western North Pacific Ocean,Super Typhoon Lekima(2019)has caused a wide range of heavy rainfall in China.Based on the CMA Multi-source merged Precipitation Analysis System(CMPAS)-hourly data set,both the temporal and spatial distribution of extreme rainfall is analyzed.It is found that the heavy rainfall associated with Lekima includes three main episodes with peaks at 3,14 and 24 h after landfall,respectively.The first two rainfall episodes are related to the symmetric outburst of the inner rainband and the persistence of outer rainband.The third rainfall episode is caused by the influence of cold,dry air from higher latitudes and the peripheral circulation of the warm moist tropical storm.The averaged rainrate of inner rainbands underwent an obvious outburst within 6 h after landfall.The asymmetric component of the inner rainbands experienced a transport from North(West)quadrant to East(South)quadrant after landfall which was related to the storm motion other than the Vertical Wind Shear(VWS).Meanwhile the outer rainband in the vicinity of three times of the Radius of Maximum Wind(RMW)was active over a 12-h period since the decay of the inner rainband.The asymmetric component of the outer rainband experienced two significant cyclonical migrations in the northern semicircle.
基金
supported by Postdoctoral Science Foundation of China(No.2019M661342).
