How a Polluted Atmosphere Affects Lightning
The National Lightning Detection Network (NLDN) for 18 years and the Houston Lightning Detection and Ranging (LDAR) network for two years, have operated in the highly polluted atmosphere over Houston, Texas. We find on an annual basis relative to the surrounding environment a ground flash density enhancement of a factor of two (3-4 to 7 flashes/km 2 ), a positive flash density increase of a factor of two (0.25 to 0.5 flashs/km 2 ), and the percentage of positive flashes decreasing from 10％ in the surrounding environment to 5％ over Houston. Three summer storms in 2006 with a total of 71 ground flashes have been analyzed. For multiplicities of 1-5, we find a lower flash spatial extent for higher multiplicities and lower mean source heights. Ground flashes with higher peak currents had smaller flash spatial extent. A comparison of the two data sets for 37 isolated, ordinary convective thunderstorms reveals an average time separation in 34 thunderstorms of 3.2 minutes with the first IC preceding the first CG. In the remaining 3 thunderstorms, however, the CG preceded the IC, thus removing hope of a reliable warning signal for the first CG flash.
Richard Orville Larry Carey Brandon Ely Joe Jurecka Chas Hodapp Scott Steiger Nathan Clements Shane Motley
Department of Atmospheric Sciences, Texas A&M University, College Station, Texas 77843-3150
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）