First High-speed Camera Observations of Lightning in South Brazil
We report preliminary results of cloud-to-ground lightning observations in the South region of Brazil (specifically the Rio Grande do Sul State) in the summer of 2005/06. A total of 33 cloud-to-ground flashes from three thunderstorms were recorded with a Redlake MotionScope 8000S digital high-speed camera (1,000 frames/s) synchronized with GPS. The Brazilian Lightning Location System (BrazilDat) was already covering this Brazilian State at the time of the observations. We could find some preliminary statistics about the cloud-to-ground lightning parameters: stroke multiplicity, continuing current duration, total flash duration, interstroke interval and number of strike points. An interesting parameter found was the high percentage of positive flashes. Based on reprocessed network solutions, we found that 61％ of the observed flashes were positive, while a 19-month average was ~34％. This is the first time an accurate-stroke-count methodology is applied over the south of Brazil, where the thunderstorms were already found to be particular by some authors in terms of very high flash rate, very high flash density and frequent occurrence of Mesoscale Convective Systems.
Maurício G. Ballarotti Marcelo M. F. Saba Osmar Pinto Jr. Vandoir Bourscheidt Kleber P. Naccarato
National Institute for Space Research, Space Geophysics Division, S. José dos Campos – SP, Brazil
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）