Precipitation Signatures and Lifetime Estimates of Energetic Radiation Belt Electrons Scattered by Magnetospherically Reflecting Whister Waves

In this paper we use a numerical model to estimate the energetic radiation-belt electron lifetimes driven by lightning-generated magnetospherically reflecting (MR) whistler waves. The model consists of several distinct stages: (i) we use an extensive ray tracing and interpolation technique to compute the frequency-time (f-t) signature of an MR whistler wave at 1 degree latitude intervals along a given L-shell in the magnetosphere, (ii) the above information is used as an approximation to the MR whistler wave structure along the particular L-shell, and the equations of motion for a series of test particles are integrated to obtain pitch angle changes. A broad range of resonant electron velocties is considered including harmonic resonances ranging from m=-5 to +5 including the Landau resonance. (iii) The pitch-angle change data obtained in (ii) is convolved with a realistic model for the electron distribution (AE8 with "sinusoidal" loss-cone distribution) to yield precipitated electron flux. (iv) Step (iii) is repeated for a range of L-shells in the range 1.3 to 5.5 to give a global view of the precipitation signature. This global view is then extrapolated in longitude and transformed to geographic coordinates to give an indication of the ionospheric patch sizes affected by the precipitating electrons, as well as the temporal fluence of the affected region. The global view is also used to estimate the lifetimes of energetic electrons driven by MR whistlers, by using crude estimates of lightning occurrence frequency and extent of the affected magnetospheric regions.