HR: 0830h
AN: AE21A-1098    [PDF]
TI: The Runaway Electron Avalanche as a Radio Emitter in Thunderstorms
AU: * Tierney, H E
EM: htierney@lanl.gov
AF: Los Alamos National Laboratory, PO Box 1663, MS F665, Los Alamos, NM 87544 United States
AU: Roussel-Dupre, R A
EM: rroussel-dupre@lanl.gov
AF: Los Alamos National Laboratory, PO Box 1663, MS F665, Los Alamos, NM 87544 United States
AU: Symbalisty, E M
EM: esymbalistycfl.rr.com@aftac.gov
AF: AFTAC TTAD, 1030 S. Highway A1A, Patrick AFB, FL 32925-3002 United States
AU: Beasley, W H
EM: whb@ou.edu
AF: School of Meteorology, University of Oklahoma, Norman, OK 73019 United States
AB: Previous simulations of runaway electron avalanches in the atmosphere, which solve the modified relativistic Boltzmann equation for various values of ambient electric field, have yielded the equilibrium ionization rates and energy distribution functions for the runaway electrons. The mean runaway electron energies and associated rates are employed here in two macroscopic treatments in order to set bounds on the expected radio emissions from runaway electron avalanches occuring in thunderstorms. The ambient electric field is that calculated from two disks of charge with sinusoidally varying charge density in altitude and peak charge density of $\pm$ 10 nC/$m^{3}$. An analytic expression for the radiatied electric field from a point-charge avalanche, including high-energy and low-energy electrons is shown to be highly dependent upon the ambient electric field strength and profile. For comparison, a one-dimensional numerical model of a runaway electron avalanche and the resulting radio emissions are presented. For the numerical case the runaway avalanche is dominated by production of high and low-energy electrons, relaxation, electron attachment, and high-energy electron loss. The radius of the 1-D electron avalanche is treated as an independent parameter and the resulting rise in the channel conductivity can limit the amplitude of the radio emissions, even in strong ambient electric fields. The peak electric-field amplitude and HF and VHF spectral amplitudes are compared with narrow bipolar pulse observations.
DE: 3304 Atmospheric electricity
DE: 3324 Lightning
SC: Atmospheric and Space Electricity [AE]
MN: 2003 Fall Meeting