Department of Geophysics, Faculty of Science, Kyoto University
Institute of Research and Development, Tokai University
Data Analysis Center for Geomagnetism and Space Magnetism, Faculty of Science, Kyoto University
Goddard Space Flight Center
抄録(英)
There is generally high correlation between the orthogonal magnetic and electric field perturbations on the ionospheric field-aligned current region based on observations by polar orbiting satellites. The ratio between the magnetic and electric field perturbations, ⊿B_z/μ_oE_x, has a scale-length dependence : the ratio ⊿B_z/μ_oE_x decreases with decreasing scale length. B. FORGET et al.(J. Geophys. Res., 96,1843,1991) explained this scale-length dependence using a static model. In this paper, we compare the ratio ⊿B_z/μ_oE_x observed by the DE-2 satellite for various spatial scales with the effective Pedersen conductivity Σ_<p, eff> calculated by the method of FORGET et al. The results show that in many cases this model can adequately explain the observed scale-length dependence. However, cases exist in which the difference, ⊿B_z/μ_oE_x-Σ_<p, eff>, decreases at about 0.25-1.0s in temporal scales (2-8km in spatial scales). This behavior is explained as being due to Alfven waves.
雑誌書誌ID
AA10756224
雑誌名
Proceedings of the NIPR Symposium on Upper Atmosphere Physics
Scale-length dependence of the ratio between the magnetic and electric field perturbations in the ionospheric field-aligned current region
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KJ00000036073
(2.03MB)
概要
