School of Meteorology Seminar Series presents...
Electrical Properties of an Asymmetric Mesoscale Convective System on 4 June 2003
Rebekah LaBar
School of Meteorology
The University of Oklahoma, Norman, OK
25 March 2009, 2:00 PM
National Weather Center, Room 5600
120 David L. Boren Blvd.
University of Oklahoma
Norman, OK
Directions to the NWC (.pdf, 60 kb)
On 4 June 2003 an asymmetric mesoscale convective system (MCS) in central Oklahoma was surveyed as part of the Thunderstorm Electrification and Lightning Experiment field program. This case study examines three-dimensional lightning mapping data, cloud-to-ground lightning data, balloon-borne vector electric field meter and radiosonde measurements, polarimetric radar observations, and various electrical and microphysical data measured from a T-28 aircraft. Lightning initiation point locations and the three-dimensional structure of the storm’s electric field are explored in relation to the storm structure. The MCS had an average flash rate of 1.6 flashes per minute over the analysis period from 1500 to 1800 UTC. Most of the lightning initiation points were found in the leading convective line from 4 to 8 km mean sea level. The points were generally clustered around the top of the enhanced differential reflectivity column or near a minimum in the correlation coefficient. Five to ten charge regions were inferred within the stratiform region of the storm. Cloud particle images indicate the presence of graupel in some of the negatively charged regions.