Lightning activity and precipitation structure of hailstorms
By using the cloud-to-ground (CG) lightning location data from the lightning detection network of Henan Province, surface Doppler radar data and standard orbit data of PR, TMI and LIS on TRMM satellite, the spatial and temporal characteristics of CG lightning flashes in 10 severe hailstorms are analyzed. The results show that the percentage of +CG lightning in these hailstorms is high with an average value of 45.5%. There is a distinct increase in CG flash rate during the rapid development stage of hailstorms. The hailstone falling corresponds to an active positive flash period, and the increase of +CG flash rate is generally accompanied with a decrease of –CG flash rate. The flash rate declines rapidly during the dissipating stage of hailstorms. The precipitation structure and lightning activity in two typical hailstorms are studied in detail. It is found that strong convective cells with reflectivity greater than 30dBZ mainly are situated in the front region of hailstorms, whereas the trailing stratiform region is in the rear part of the hailstorms. The maximum heights of echo top are higher than 14 km. Convective rain contributes much more rainfall of the total than stratiform rain, about 85% and 97% of the total in the two cases, respectively. Total lightning in the hailstorms is very active with the flash rate up to 183 fl/min and 55 fl/min, respectively. The results also indicate that most lightning flashes occurred in the echo region greater than 30dBZ and its immediate periphery. The probability of lightning occurrence is 20 times higher in convective region than in stratiform region. The result suggests that the lightning information is helpful to the identification of convective rain region. The linear relationship between flash rate and ice water content is preliminarily disclosed.
Guili Feng Xiushu Qie Tie Yuan Shuzhen Niu
Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences,L The Meteorological Observatory of Henan Province, Zhengzhou 450003, China
国际会议
第13届国际大气电学会议(The 13th International Conference on Atmospheric Electricity)
北京
英文
2007-08-13(万方平台首次上网日期,不代表论文的发表时间)