Extended Abstract (112K)10A.3
Aspects of electric field profiles and total lightning in severe thunderstorms in STEPS
W. D. Rust, NOAA/NWS and Univ. of Oklahoma, Norman, OK; and D. R. MacGorman, P. R. Krehbiel, T. Hamlin, J. Harlin, W. Rison, R. Thomas, and E. C. Bruning
We have made soundings of the electric field in coordination with observations from a three-dimensional, total lightning mapping system. The latter has been developed by New Mexico Tech, while the former relies on mobile ballooning techniques developed by NSSL and collaborators. Among those findings to be presented here are profiles of the electric field, E, that are interpreted in context of individual lightning flashes. One preliminary interpretation is that lightning can deposit charge in a region that causes subsequent flashes to avoid that region. Example data support this, but results are tentative. The E profile in strong updrafts, including mesocyclones, indicates an absence of charge in the lower part of the cloud in this region. This evidence is consistent among balloon flights in several years. During the Severe Thunderstorm Electrification and Precipitation Study (STEPS) in the area of Goodland, Kansas, in 2000, the lightning mapping array recorded numerous inverted-polarity intracloud lightning flashes. These inverted-polarity cloud flashes are between midlevel positive charge and upper level negative charge. We report on the search for a correspondence between the inverted-polarity cloud flashes and the charge structure in the storm as inferred from the E profile. The electrical charge structure of a few storms, including severe ones, indicates that there are storms in which the electrical structure is inverted.
Session 10A, Results from the Severe Thunderstorm Electrification and Precipitation Study (STEPS) Experiment
Wednesday, 14 August 2002, 1:30 PM-3:00 PM
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