Numerical simulation of 23 June 2016 Yancheng City EF4 tornadic supercell and analysis of lightning activity  

作　　者：GUO FengXia LI Yang HUANG ZhaoChu WANG ManFei ZENG FanHui LIAN ChunHao MU YiJun 

机构地区：[1]key laboratory of meteorological disaster,ministry of education(klme),joint international research laboratory of climate and environment change(ilcec),collaborative innovation center on forecast and evaluation of meteorological disaster(cic-femd),key laboratory for aerosol-cloud-precipitation of china meteorological administration,nanjing university of information science&technology,Nanjing 210044,China

出　　处：《Science China Earth Sciences》2017年第12期2204-2213,共10页中国科学（地球科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.41275008);the Basic Research Fund of the Chinese Academy of Meteorological Sciences(Grant No.2016Z002);the National Key Basic Research Program of China(Grant No.2014CB441403)

摘　　要：Based on the Weather Research Forecasting(WRF) model that features charging and discharging parameterization,relationships between tornado, hail and lightning were investigated for a tornado-producing(EF4 intensity) supercell thunderstorm over Yancheng City in Jiangsu Province, China, on 23 June 2016. Based on a sounding at 0800, there was a low lifting condensation level, substantial convective available potential energy(CAPE), and strong vertical wind shear near Yancheng City, which promote supercell development. At 1400, observations revealed that hail production and a dramatic increase of positive cloud-to-ground flash rates occurred simultaneously, maximizing five minutes later. The tornado occurred 30 min after the hail production. The time of minimum positive cloud-to-ground flash rates was 15 min later. The simulation indicated that the tornadic supercell moved eastward and that positive cloud-to-ground flash rates increased dramatically at 1400, the same as observed, but their maximum was 5 min later than observed. The simulated updraft volume peaked at 1425 and the simulated downdraft volume maximized5 min later, when the mesocyclone formed. Simulated reflectivities showed no hook echo and horizontal winds for different height at mid-low levels had a different cyclonic shear at 1430, favorable to mesocyclone formation. Based on the simulated results,the region of positively charged graupel ascended resulting from the region of high liquid water content was lifted by the strong updraft, forming a mid-level strong positive charge region. A lower negative charge region formed by the inductive charging mechanism of collisions between graupel and droplets at the bottom of the cloud, conducive to positive cloud-to-ground flashes.Based on the Weather Research Forecasting（WRF） model that features charging and discharging parameterization,relationships between tornado, hail and lightning were investigated for a tornado-producing（EF4 intensity） supercell thunderstorm over Yancheng City in Jiangsu Province, China, on 23 June 2016. Based on a sounding at 0800, there was a low lifting condensation level, substantial convective available potential energy（CAPE）, and strong vertical wind shear near Yancheng City, which promote supercell development. At 1400, observations revealed that hail production and a dramatic increase of positive cloud-to-ground flash rates occurred simultaneously, maximizing five minutes later. The tornado occurred 30 min after the hail production. The time of minimum positive cloud-to-ground flash rates was 15 min later. The simulation indicated that the tornadic supercell moved eastward and that positive cloud-to-ground flash rates increased dramatically at 1400, the same as observed, but their maximum was 5 min later than observed. The simulated updraft volume peaked at 1425 and the simulated downdraft volume maximized5 min later, when the mesocyclone formed. Simulated reflectivities showed no hook echo and horizontal winds for different height at mid-low levels had a different cyclonic shear at 1430, favorable to mesocyclone formation. Based on the simulated results,the region of positively charged graupel ascended resulting from the region of high liquid water content was lifted by the strong updraft, forming a mid-level strong positive charge region. A lower negative charge region formed by the inductive charging mechanism of collisions between graupel and droplets at the bottom of the cloud, conducive to positive cloud-to-ground flashes.

关 键 词：TORNADO SUPERCELL WRF HAIL Positive cloud-to-ground flashes 

分 类 号：P458[天文地球—大气科学及气象学]