HR: 1330h
AN: SM32B-1156    [PDF]
TI: Seasonal Variation of Auroral Electron Flux
AU: Barth, C A
EM: charles.barth@lasp.colorado.edu
AF: Laboratory for Atmospheric and Space Physics, University of Colorado 1234 Innovation Drive, Boulder, CO 80303 United States
AU: * Bailey, S M
EM: scott.bailey@gi.alaska.edu
AF: Geophysical Institute, University of Alaska 903 Koyukuk Drive, Fairbanks, AK 99775-7320 United States
AU: Baker, D N
EM: dan.baker@lasp.colorado.edu
AF: Laboratory for Atmospheric and Space Physics, University of Colorado 1234 Innovation Drive, Boulder, CO 80303 United States
AB: The deposition of energy by auroral electrons precipitating into the polar lower thermosphere is deduced from observations of nitric oxide at 110 km. Precipitating electrons in the 3-4 keV range deposit their energy in the thermosphere between 100 and 120 km. The interaction of these energetic electrons with the molecules and atoms in the atmosphere produces ionization, auroral emissions, and nitric oxide. We use a thermospheric photochemical model to calculate the nitric oxide density in this altitude range at 60 degrees north and south latitude. This model takes into account all the processes producing nitric oxide including electron precipitation. We compare the model calculations with observations of nitric oxide made with the Student Nitric Oxide Explorer (SNOE) for the two and a half year period from March, 1998 until September, 2000. We iterate the model calculation many times, varying the auroral energy input, in order to achieve a self-consistent determination of the flux of precipitating electrons. The results of this analysis show that the electron flux is larger during the fall/winter season than in the spring/summer season in each hemisphere. These results support the idea of sunlight suppression of auroral activity which leads to a lower flux of precipitating auroral electrons in the illuminated hemisphere.
DE: 0310 Airglow and aurora
DE: 0355 Thermosphere--composition and chemistry
DE: 0358 Thermosphere--energy deposition
DE: 2704 Auroral phenomena (2407)
DE: 2716 Energetic particles, precipitating
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting