HR: 09:30h
AN: AE31A-05    [PDF]
TI: Positive cloud-to-ground and other horizontally propagating lightning in the convective line and stratiform rain regions of a MCS observed during STEPS
AU: * Lang, T J
EM: tlang@atmos.colostate.edu
AF: Department of Atmospheric Science, Colorado State University, Fort Collins, CO 80523 United States
AU: Rutledge, S A
EM: rutledge@atmos.colostate.edu
AF: Department of Atmospheric Science, Colorado State University, Fort Collins, CO 80523 United States
AU: Wiens, K
EM: kwiens@atmos.colostate.edu
AF: Department of Atmospheric Science, Colorado State University, Fort Collins, CO 80523 United States
AB: We report on an asymmetric mesoscale convective system (MCS) that occurred on 11 June 2000 during the Severe Thunderstorm Electrification and Precipitation Study (STEPS), which took place along the Colorado-Kansas border. This system passed through both dual-Doppler lobes of the CSU-CHILL and S-POL polarimetric radars, and produced a large number of lightning flashes (up to 1 flash per second), which were observed by the New Mexico Tech Lightning Mapping Array (LMA) and the National Lightning Detection Network (NLDN). Many of these were positive cloud-to-ground lightning flashes (+CGs) that came to ground in both the leading convective line and trailing stratiform rain region of the MCS. A significant percentage of these +CGs propagated over large horizontal distances (10s of km) within the stratiform region. However, great variety was observed within this subset, including +CGs that came to ground in the stratiform after initiating in the convective line, +CGs that initiated and came to ground in the convective line but tapped large charge reservoirs in the stratiform, and +CGs that initiated and came to ground within the stratiform region alone. There also were a number of intracloud flashes that propagated over long distances within the stratiform region. Polarimetric and dual-Doppler data from the two radars are used to characterize the kinematic and microphysical structure of the MCS, including the charge reservoirs tapped by these horizontally propagating lightning flashes. Results are compared to present MCS electrification theory.
UR: http://radarmet.atmos.colostate.edu/~tlang/11jun00/
DE: 3304 Atmospheric electricity
DE: 3314 Convective processes
DE: 3324 Lightning
DE: 3329 Mesoscale meteorology
DE: 3354 Precipitation (1854)
SC: Atmospheric and Space Electricity [AE]
MN: 2003 Fall Meeting