HR: 0830h
AN: SA21A-09    [Abstracts]
TI: The Relationship Between the Enhanced Aurora and Thin, Dense Ionization Layers
AU: * Johnson, J R
EM: jrj@pppl.gov
AF: Princeton University, Plasma Physics Laboratory, PO Box 451, Princeton, NJ 08543 United States
AU: Okuda, H
EM: okuda@pppl.gov
AF: Princeton University, Plasma Physics Laboratory, PO Box 451, Princeton, NJ 08543 United States
AB: Thin layers of enhanced luminosity are commonly observed during auroral displays. The enhanced luminosity occurs at altitudes where thin, dense, heavy ion layers are often observed in the E-region. Based on the spectral characteristics of the enhanced layers, it is believed that the enhanced emissions result when wave-particle interactions heat ambient electrons to energies at or above the 17 eV ionization energy of N₂. We investigate instabilities that could occur in dense, heavy ion layers in the presence of strong cross-field currents that accompany electron precipitation. We present analytical full-wave solutions and full-particle electrostatic simulations of the nonlinear development of the instability. We also investigate the role of ion-neutral and electron-neutral collisions on the instability. The dense, heavy ion layer increases the growth rate of the instability and heats ambient electrons into a suprathermal tail that could produce enhanced emissions.
UR: http://w3.pppl.gov/~jrj/ionization.html
DE: 2439 Ionospheric irregularities
DE: 2455 Particle precipitation
DE: 2471 Plasma waves and instabilities
DE: 2483 Wave/particle interactions
DE: 2704 Auroral phenomena (2407)
SC: SPA-Aeronomy [SA]
MN: 2005 Joint Assembly