Practice and application of automatic recognition of a hail echo
In this paper,radar mosaic grid point data and automatic recognition software were used to identify and test the characteristics of hail echo on March 14,2022 based on image recognition technology and methods.Results show that:(1)hail occurs in 200 hPa high-altitude outflow area,500 hPa southern trough and wind shear,850 hPa low vortex and shear line,ground convergence line,and southwest trough weather pattern,as well as in environmental conditions such as high CAPE value,strong inversion layer,"dry above and wet below",and low 0 ℃ layer in Nanchang.(2)Hail is mainly reflected by micro supercell echoes,sometimes isolated,and sometimes within echo groups and bands.The echo intensity is equal to and above 60 dBZ,with a minimum strong echo area of ≥18 km2(micro supercell)and a maximum of ≥180 km2(classic supercell).The strong echo gradient is ≤6 km,and it has a clear cloud anvil echo structure.(3)The algorithm for automatically identifying strong echo edges adopts a combination of DBSCAN Clustering Algorithm and Scatter Contour Algorithm.Multiple strong echoes can be identified simultaneously every 10 minutes,up to a maximum of 19.(4)Classic supercell cases all appear in echo nuclei with ≥65 dBZ,with the strongest being 73 dBZ.The minimum gradient of strong echo is 1 km and the maximum is 5.66 km,with most cloud anvil echoes ranging from 1∶1 to 1∶3.(5)Through the identification and practical testing of four other hail echoes,the identification method has shown good results.
spring hailsupercellecho characteristicsautomatic recognition
万方数据
维普
