摘要
Based on cloud-ground lightning data and Doppler weather radar echo products, both thecharacteristics and the relations of lightning and radar echoes for strong convective rainstorms over Yunnanare analyzed during the flood season of 2007. The results show that most rainstorms are convective in whichlightning is mostly negative and the negative lightning number accounts for more than 90% of the total.Although the correlation between precipitation and the lightning number is small on the rainstorm day, thelarge day-lightning frequency usually produces heavy precipitation. Hourly evolution of precipitation andlightning frequency shows peak-style characteristics. And their evolution is very coherent in strongrainstorm, but lightning often occurs before precipitation, whose peaks are in phase with or 1-to-2-hourlagged behind that of lightning frequency. Meanwhile the peaks of positive frequency are in phase with orfall behind that of precipitation. When the wind field is heterogeneous in radial velocity, it is conducive toboth the development of convection echoes and occurrence of lightning. Strong lightning-producingconvective rainstorms correspond to strong echo fields and usually result in reflectivity above 30 dBZ andecho top ET of more than 9 km, respectively.
Based on cloud-ground lightning data and Doppler weather radar echo products, both thecharacteristics and the relations of lightning and radar echoes for strong convective rainstorms over Yunnanare analyzed during the flood season of 2007. The results show that most rainstorms are convective in whichlightning is mostly negative and the negative lightning number accounts for more than 90% of the total.Although the correlation between precipitation and the lightning number is small on the rainstorm day, thelarge day-lightning frequency usually produces heavy precipitation. Hourly evolution of precipitation andlightning frequency shows peak-style characteristics. And their evolution is very coherent in strongrainstorm, but lightning often occurs before precipitation, whose peaks are in phase with or 1-to-2-hourlagged behind that of lightning frequency. Meanwhile the peaks of positive frequency are in phase with orfall behind that of precipitation. When the wind field is heterogeneous in radial velocity, it is conducive toboth the development of convection echoes and occurrence of lightning. Strong lightning-producingconvective rainstorms correspond to strong echo fields and usually result in reflectivity above 30 dBZ andecho top ET of more than 9 km, respectively.
基金
Technological and Planning Project of Yunnan Province(2009CA014)
National Natural Science Foundation of China(41265001)
