日本地球惑星科学連合2014年大会

講演情報

ポスター発表

セッション記号 P (宇宙惑星科学) » P-EM 太陽地球系科学・宇宙電磁気学・宇宙環境

[P-EM37_30PO1] 磁気圏構造とダイナミクス

2014年4月30日(水) 18:15 〜 19:30 3階ポスター会場 (3F)

コンビーナ:*三好 由純(名古屋大学太陽地球環境研究所)、長谷川 洋(宇宙航空研究開発機構宇宙科学研究所)

18:15 〜 19:30

[PEM37-P04] JAXA準天頂衛星とMAGDAS地上観測点による沿磁力線電流の同時観測

竹内 勇人1、*河野 英昭2東尾 奈々3松本 晴久3Baishev Dmitry G.4魚住 禎司2阿部 修司2湯元 清文2吉川 顕正2MAGDAS/CPMN group 2 (1.九州大学大学院理学研究院地球惑星科学部門、2.九州大学国際宇宙天気科学・教育センター、3.宇宙航空研究開発機構、4.Yu.G.Shafer Inst. of Cosmophysical Research and Aeronomy, Siberian Branch, Russian Academy of Sci.)

In this paper we conduct a QZS-MAGDAS conjunction study of a field-aligned current (FAC). QZS (Quasi-Zenith Satellite) is operated by JAXA, and MAGDAS is the ground magnetometer network mainly operated by ICSWSE (International Center for Space Weather Science and Education), Kyushu Univ.

There have been only limited number of papers on satellite-ground conjunction studies of FACs, because satellites usually passes overhead at a ground observatory in a short time.
On the other hand, the footpoint of QZS stays near one ground point in Siberia, Russia, because the orbit of QZS is close to that of geosynchronous satellites on the Japanese meridian. Moreover, a few Siberian MAGDAS observatories exist near the QZS footpoint.

Another advantage of QZS is that, unlike geosynchronous satellites, QZS has 41deg inclination and 0.1deg eccentricity which enable QZS to stay for a long time at northern high latitudes in the magnetosphere; this high-latitude feature increases the detectability of FACs, because the FAC magnitude is in general smaller near the equator, i.e., the FAC source region in the magnetosphere. Thus, the pair of QZS and Siberian MAGDAS is expected to have more chances of simultaneously observing the same FAC than past satellite-ground pairs.

We have been searching for events in which, when QZS and a Siberian MAGDAS observatory were located near the same field line (calculated by the Tsyganenko 96 model), QZS and MAGDAS simultaneously observed transient magnetic field perturbations.

In this paper we present such an event observed by QZS and a Siberian MAGDAS observatory CHD (Chokurdakh). We have found that the transient magnetic perturbations of this event can be interpreted to have been generated by the motion of a local current circuit consisting of line FACs and an ionospheric current. More details will be presented at the meeting.