Department of Earth and Planetary Science, University of Tokyo
Institute of Industrial Science, University of Tokyo, (present address)Tokyo University of Agriculture
Faculty of Education, Iwate University
登録日
2010-01-04
雑誌名
Advances in polar upper atmosphere research
巻
16
ページ
13 - 35
発行年
2002-01-01
ISSN
1345-1065
Abstract
On the basis of the 1989 Tsyganenko magnetic field model, the field-aligned current (FAC) density distribution in the low-latitude boundary layer (LLBL) is numerically evaluated by assuming the entry of magnetosheath particles into the LLBL. The calculated FAC density/intensity profiles are consistent with observations. This FAC generation arises from the divergence of the magnetic drift current density carried by LLBL particles, and the current intensity is then increased with their kinetic energy density. The FAC generation occurs at the inner edge of the LLBL whenever sheath particles penetrate into the magnetosphere, regardless of the entry process. It is also emphasized that the LLBL FAC production is an inevitable consequence of the formation of the magnetopause, because the magnetopause currents act to shield the magnetic field originating from the currents inside the closed region of the magnetosphere, causing the LLBL inner edge to intersect the magnetic drift paths. This simple situation can be illustrated by calculating the distribution of the flux tube volume in the Tsyganenko model.
Evaluation of the region 1 field-aligned current from the low-latitude boundary layer using the 1989 Tsyganenko model
apuar-v16p13-35.pdf
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