論文

査読有り
2017年6月

Global simulation study for the time sequence of events leading to the substorm onset

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
  • T. Tanaka
  • ,
  • Y. Ebihara
  • ,
  • M. Watanabe
  • ,
  • M. Den
  • ,
  • S. Fujita
  • ,
  • T. Kikuchi
  • ,
  • K. K. Hashimoto
  • ,
  • R. Kataoka

122
6
開始ページ
6210
終了ページ
6239
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1002/2017JA024102
出版者・発行元
AMER GEOPHYSICAL UNION

We have developed a global simulation code which gives numerical solutions having an extremely high resolution. The substorm solution obtained from this simulation code reproduces the precise features of the substorm onset in the ionosphere. It can reproduce the onset that starts from the equatorward side of the quiet arc, two step development of the onset, and the westward traveling surge (WTS) that starts 2 min after the initial brightening. Then, we investigated the counter structures in the magnetosphere that correspond to each event in the ionosphere. The structure in the magnetosphere promoting the onset is the near-Earth dynamo in the inner magnetospheric region away from the equatorial plane. The near-Earth dynamo is driven by the field-aligned pressure increase due to the parallel flow associated with the squeezing, combined with equatorward field-perpendicular flow induced by the near-Earth neutral line (NENL). The dipolarization front is launched from the NENL associated with the convection transient from the growth phase to the expansion phase, but neither the launch nor the arrival of the dipolarization front coincides with the onset timing. The arrival of flow to the equatorial plane of the inner magnetosphere occurs 2 min after the onset, when the WTS starts to develop toward the west. The expansion phase is further developed by this flow. Looking at the present result that the onset sequence induced by the near-Earth dynamo reproduces the details of observation quite well, we cannot avoid to conclude that the current wedge is a misleading concept.

Web of Science ® 被引用回数 : 13

リンク情報
DOI
https://doi.org/10.1002/2017JA024102
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000405534800022&DestApp=WOS_CPL

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