HR: 1340h
AN: AE33A-0953    [Abstracts]
TI: Gamma Ray Flashes Due to Plasma Processes in the Middle Atmosphere
AU: Gomez, T
EM: tenochg@astro.umd.edu
AF: University of Maryland, College Park, Department of Astronomy, University of Maryland, College Park, MD 20742 United States
AU: * Milikh, G M
EM: milikh@astro.umd.edu
AF: University of Maryland, College Park, Department of Astronomy, University of Maryland, College Park, MD 20742 United States
AU: Guzdar, P N
EM: guzdar@ipr.umd.edu
AF: University of Maryland, College Park, Department of Astronomy, University of Maryland, College Park, MD 20742 United States
AU: Sharma, S A
EM: ssh@astro.umd.edu
AF: University of Maryland, College Park, Department of Astronomy, University of Maryland, College Park, MD 20742 United States
AB: A mechanism for the generation of gamma ray flashes, in the atmosphere, first observed on Compton Gamma Ray Observatory satellite, and recently detected by RHESSI satellite is a runaway discharge mediated by whistler waves. In this model the relativistic electrons produced by a cosmic ray shower during a thunderstorm lead to a runaway discharge, which is maintained by the interaction with whistler waves and the relativistic electrons propagate up in ducts produced by the self-focusing of these waves. Earlier we presented a detailed study of the instability which develops in the lower stratosphere when a beam of hot magnetized electrons interacts with whistler waves [Milikh et al., 2005]. It was shown that the growth rate of such instability depends on the number density of hot electrons, and on their collision rate, and it peaks at about 25 km. The instability develops under the conditions for runaway breakdown similar to those leading to the generation of strong narrow bipolar pulses which indicates a possible correlation between these two phenomena. The whistler wave instability provides the basis for more detailed studies. In the presented paper we continue the development of the model for gamma ray generation by addressing nonlinear processes in the runaway discharge in the presence of the whistler waves. The self-focusing of these waves and the propagation along the ducts are studied by numerically solving a set of nonlinear equations governing the dynamics of the energetic electrons. The conditions for effective production of gamma rays, based on these simulations will be presented. G.M. Milikh, P.N. Guzdar, and A.S. Sharma, J. Geophys. Res. 110, A02308, doi: 10.1029/2004JA010681, 2005.
DE: 3304 Atmospheric electricity
DE: 3324 Lightning
DE: 3367 Theoretical modeling
DE: 4455 Nonlinear waves, shock waves, solitons (0689, 2487, 3280, 3285, 4275, 6934, 7851, SC: Atmospheric and Space Electricity [AE]
MN: Fall Meeting 2005