HR: 1340h
AN: AE23A-0895    [Abstracts]
TI: Electromagnetical, Visual and Meteorological Analyses of two Gigantic Jets Observed Over Missouri, USA
AU: * van der Velde, O A
EM: vdvo@aero.obs-mip.fr
AF: Université Paul Sabatier, 14 Avenue Edouard Belin, Toulouse, 31400, France
AU: Lyons, W A
EM: walyons@frii.com
AF: FMA Research, Inc., 46050 Weld County Road 13, Fort Collins, CO 80524, United States
AU: Cummer, S A
EM: cummer@ee.duke.edu
AF: Electrical and Computer Engineering Department Duke University, P.O. Box 90291, Durham, NC 27708, United States
AU: Cohen, M B
EM: mcohen@stanford.edu
AF: Stanford University, Packard Bldg Rm. 356, 350 Serra Mall, Stanford, CA 94305-9515, United States
AU: Sentman, D D
EM: dsentman@gi.alaska.edu
AF: Geophysical Institute - Space Physics, University of Alaska Fairbanks, 903 Koyukuk Drive, Fairbanks, AK 99775-7320, United States
AU: Jaugey, N
EM: nicolasj@duke.edu
AF: Electrical and Computer Engineering Department Duke University, P.O. Box 90291, Durham, NC 27708, United States
AU: Nelson, T E
EM: tnelson@frii.com
AF: FMA Research, Inc., 46050 Weld County Road 13, Fort Collins, CO 80524, United States
AU: Smedley, R
EM: rsmed@cox.net
AF: Richard Smedley, rsmed@cox.net, Broken Arrow, OK 74011, United States
AB: An amateur astronomer operating a Watec 100N camera in Broken Arrow, Oklahoma discovered 2 gigantic jets (GJ) rising out of a thunderstorm over SW Missouri on 20 August 2007, at 9:24:04 and 9:25:48 UTC. They are the first observed to occur over the continental United States and this far poleward (37.2°N). The azimuths of the GJs corresponded with two different cores of a slow-moving multicell storm, spaced apart by 50 km. At distances of 239 and 204 km from the camera, the GJs reached heights of 94 and 83 km, with bright transition zones between 45-61 and 50-64 km. The jets only became visible to the camera at/near completion of the pathway to the ionosphere, followed by a glow moving upward through the transition zone over 250-300 ms (at 1.6-5 10⁴ m/s). The storm cluster was aged 4 hours by the time of the GJs. The events occurred over separate NEXRAD radar echo tops reaching 15 km, with evidence of new strong updrafts from GOES IR imagery and radar hail signatures. Within 5 minutes before each event, flash rates of positive cloud-to-ground flashes increased and dominated over negative by a factor of 3-4 for a few minutes (but low rates), but without quick rises or lulls. Weak NLDN- detected flashes (intracloud) correlated to both events in time and space. One sprite was observed 50 minutes after the events. Initial inspection of ELF-VLF transients recorded by receivers operated by Duke and Stanford universities indicated signals close to the approximate event times, but multi-site analysis has yet to confirm the geographical origin and the likelihood of any possible association.
DE: 0342 Middle atmosphere: energy deposition (3334)
DE: 2411 Electric fields (2712)
DE: 3304 Atmospheric electricity
DE: 3314 Convective processes
DE: 3324 Lightning
SC: Atmospheric and Space Electricity [AE]
MN: 2007 Fall Meeting