Lightning, Electric Field, and Radar Observations of the STEPS 25 June 2000 Multicell Storm
Data from a three-dimensional lightning mapping array and from two soundings by balloon-borne electric field meters were used to analyze the electrical structures of a storm observed on 25 June 2000 during the Severe Thunderstorm Electrification and Precipitation Study (STEPS). This storm had a complex, multicell structure with four sections, each of whose electrical structure differed from that of the others during all or part of the one-hour analyzed period. The number of vertically stacked charge regions in any given section of the storm ranged from two to six. The most complex charge and lightning structures occurred in regions with the highest reflectivity values and the tallest reflectivity cores. Intracloud flashes tended to concentrate in areas with large radar reflectivity values, though some propagated across more than one core into the low-reflectivity anvil. Intracloud lightning flash rates decreased as the vertical extent and maximum value of reflectivity cores decreased. Cloud-to-ground flash rates increased as cores of high reflectivity descended to low altitudes. Most cloud-to-ground flashes were positive. All observed positive ground flashes initiated between the lowest-altitude negative charge region and a positive charge region just above it. The storm’s complexity makes it hard to classify the vertical polarity of its overall charge structure, but most of the storm had a different vertical polarity than what is typically observed outside the Great Plains. Apparently electrical structure can vary considerably from storm to storm, and even within the same storm, as in the present case.
W. David Rust Stephanie A. Weiss Donald R. MacGorman Eric C. Bruning Paul R. Krehbiel
NOAA/OAR National Severe Storms Laboratory, Norman, Oklahoma Cooperative Institute for Mesoscale Met School of Meteorology, Cooperative Institute for Mesoscale Meteorological Studies, The University of New Mexico Institute of Mining and Technology, Socorro, New Mexico
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）