Tohoku University Graduate School of Science
Tohoku University Graduate School of Science
Tohoku University Graduate School of Science
Tohoku University Graduate School of Science
出版者
宇宙航空研究開発機構宇宙科学研究本部
出版者(英)
Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA/ISAS)
雑誌名
第37回月・惑星シンポジウム
雑誌名(英)
Proceedings of the 37th ISAS Lunar and Planetary Symposium
ページ
151 - 154
発行年
2004-02
抄録(英)
The Jovian synchrotron radiation (JSR) is a radio wave emitted from the relativistic electrons in the Jovian radiation belt, which has information of dynamics of high-energy particles and electromagnetic disturbances in the Jovian inner magnetosphere. The intensity variation of JSR, however, has been little understood in its timescales and origin. Have been observed JSR for several months a year since 1994 to reveal characteristics of the flux variations especially at the time scales of days to months (short-term) and years (long-term). The regular observations have been made at a frequency of 327 MHz by using parabolic cylinder antennas of the Solar Terrestrial Environment Laboratory (STEL), Nagoya University. The observed JSR flux includes apparent variation due to inevitable system gain variation of the radio receiving system. In order to compensate the system gain variation, has been evaluated system gain using a flux reference radio source that was observed quasi-simultaneously with JSR, and have been made observations of actual galactic back-ground radiation (BG) with the highly stable radio receiving system of Tohoku University. In this paper, reported are the results of the JSR observations for 1994 (around the period of the comet Shoemaker-Levy 9 impacts to Jupiter) when the BG flux levels have not been sufficiently quantified in the previous analysis. The JSR flux became nearly twice as large as the flux before the impacts during the observation period. The observation result suggests that rapid and large number flux variation and/or pitch angle scattering occurred even for relatively low energetic electrons in the inner radiation belt.