Characteristics of Radar Echo Parameters and Microphysical Structure Simulation of a Short-Time Heavy Precipitation Supercell  

作　　者：ZHAO Gui-xiang WANG Yi-jie LIAN Zhi-luan 赵桂香;王一颉;连志鸾(Shanxi Meteorological Observatory,Taiyuan 030006 China;Hebei Meteorological Observatory,Shijiazhuang 050021 China)

机构地区：[1]Shanxi Meteorological Observatory,Taiyuan 030006 China [2]Hebei Meteorological Observatory,Shijiazhuang 050021 China

出　　处：《Journal of Tropical Meteorology》2022年第4期388-404,共17页热带气象学报（英文版）

基　　金：National Natural Science Foundation of China(41475050)。

摘　　要：By using the conventional observations, radar data, NCEP/NCAR FNL 1°×1° reanalysis data and numerical simulation data and with the construction and calculation of radar echo parameters, this paper presents the structural characteristics and physical processes of a short-time heavy precipitation supercell that occurred in the squall line process in Shanxi Province on 24 June 2020. The results show that this squall line event occurred in front of a surface cold front,combined with infiltration of low-level cold air and continuous increase of near-surface humidity in the afternoon. The surface mesoscale convergence line and mesoscale dew point front contributed to the development and systemization of the squall line by a large degree. The short-time extremely heavy precipitation in Pingshun County was caused by the development of a supercell from thunderstorm cells on the front side of the squall line. The characteristics of sharp increase in vertical integral liquid water content, persistent increase in reflectivity factor and continuous rise in the echo top height appeared about 23 min earlier than the severe precipitation, which has qualitative indicating significance for the nowcasting of short-time heavy precipitation. A quantitative analysis of the radar echo parameters suggests that the“sudden drop”of FV40was a precursor signal of cells’ coalescence and rapid development to the mature stage. The areal change of the echo core at the 6 km height was highly subject to the merging and developing of cells, the rapid change of hydrometeor particles in clouds and the precipitation intensity. Changes in the cross-sectional area of convective cells at different heights can indirectly reflect the changes of liquid particles and ice particles in clouds, which is indicatively meaningful for predicting the coalescing and developing-to-maturing of cells and heavy precipitation 30-45 min earlier.A comprehensive echo parameter prediction model constructed by the random forest principle can predict the magnitude of s

关 键 词：SUPERCELL short-time heavy rainfall radar echo parameters microphysical structure 

分 类 号：P458.2[天文地球—大气科学及气象学]