Electrification of the 29 June 2000 Supercell Thunderstorm
Abstract
The 29 June 2000 supercell thunderstorm observed during the Severe Thunderstorm Electrification and Precipitation Study (STEPS) had some rare characteristics compared to other severe thunderstorms. While most thunderstorms are characterized by predominantly negative cloud-to-ground (-CG) lightning, this storm was dominated by positive cloud-to-ground (+CG) discharges. In addition, the electrical structure of the storm was inverted from the usual positive over negative main dipole. Various data sources, including armored T-28 airplane data collected during seven passes through the storm, National Lightning Detection Network data, New Mexico Tech Lightning Mapping Array (LMA) data, CHILL radar data from Colorado State University, and results from previous papers were analyzed to provide insight into these unusual electrical features. These analyses revealed that at mid-levels (-10° C) the strongest updrafts were found on the inflow side of the storm, were not yet glaciated, and had negligible radar reflectivity. At this level, microphysical observations suggest that charge is separated in relatively thin regions surrounding updrafts where ice hydrometeors falling from above encounter significant cloud liquid water concentrations. At mid-levels in this storm, away from the updraft regions, precipitating hydrometeors carried predominately positive charge, much of it probably acquired at higher altitudes.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2011
- Bibcode:
- 2011AGUFMAE12A..04C
- Keywords:
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- 3314 ATMOSPHERIC PROCESSES / Convective processes;
- 3324 ATMOSPHERIC PROCESSES / Lightning