HR: 0830h
AN: SA21B-0069    [PDF]
TI: Energy Distribution of Precipitating Electrons Estimated From Optical and Cosmic Noise Absorption Measurements
AU: Mori, H
EM: mori@crl.go.jp
AF: Communications Research Laboratory, 4-2-1 Nukui-Kitamachi, Koganei, Tokyo, 184-8795 Japan
AU: * Ishii, M
AF: Communications Research Laboratory, 4-2-1 Nukui-Kitamachi, Koganei, Tokyo, 184-8795 Japan
AU: Murayama, Y
AF: Communications Research Laboratory, 4-2-1 Nukui-Kitamachi, Koganei, Tokyo, 184-8795 Japan
AU: Kubota, M
AF: Communications Research Laboratory, 4-2-1 Nukui-Kitamachi, Koganei, Tokyo, 184-8795 Japan
AU: Sakanoi, K
AF: Communications Research Laboratory, 4-2-1 Nukui-Kitamachi, Koganei, Tokyo, 184-8795 Japan
AU: Yamamoto, M
AF: Kochi University of Technology, 185 Miyanokuchi, Tosayamada, Kochi, 782-8502 Japan
AU: Monzen, Y
AF: University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo, 182-8585 Japan
AU: Lummerzheim, D
AF: Geophysical Institute, University of Alaska Fairbanks, 903 Koyukuk Drive, Fairbanks, AK 99775-7320 United States
AU: Watkins, B J
AF: Geophysical Institute, University of Alaska Fairbanks, 903 Koyukuk Drive, Fairbanks, AK 99775-7320 United States
AB: This study is a statistical analysis on energy distribution of precipitating electrons, based on CNA (cosmic noise absorption) data obtained from the 256-element imaging riometer in Poker Flat, Alaska, and optical data measured with an meridian scanning photometer over 79 days during the winter periods from 1996 to 1998. On the assumption that energy distributions of precipitating electrons represent Maxwellian distributions, CNA is estimated based on the observation data of auroral 427.8-nm and 630.0-nm emissions as well as the average atmospheric model, and compared with the actual observation data. Although the obsevation data have a broad distribution, they show systematically larger CNA than the model estimate. CNA determination using kappa or double Maxwellian distributions, instead of Maxwellian distributions, better explains the distribution of observed CNA data. Kappa distributions represent a typical energy distribution of electrons in the plasma sheet of the magnetosphere, the source region of precipitating electrons. This result suggests that the energy distribution of precipitating electrons reflects the energy distribution of electrons in the plasma sheet.
DE: 2407 Auroral ionosphere (2704)
DE: 2455 Particle precipitation
DE: 2716 Energetic particles, precipitating
SC: SPA - Aeronomy [SA]
MN: 2003 Fall Meeting