日本地球惑星科学連合2014年大会

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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-EM36_28PM1] 大気圏・電離圏

2014年4月28日(月) 14:15 〜 16:00 312 (3F)

コンビーナ:*大塚 雄一(名古屋大学太陽地球環境研究所)、津川 卓也(情報通信研究機構)、川村 誠治(独立行政法人 情報通信研究機構)、座長:横山 竜宏(情報通信研究機構)、松村 充(電気通信大学附属宇宙・電磁環境研究センター)

14:15 〜 14:30

[PEM36-15] ロケット及び地上観測による中規模伝搬性電離圏擾乱の研究

*山本 衛1加藤 寬大1石坂 圭吾2横山 竜宏3岩上 直幹3高橋 隆男4田中 真4遠藤 研5熊本 篤志5渡部 重十6山本 真行7阿部 琢美8斎藤 享9津川 卓也3西岡 未知3Bernhardt Paul10Larsen Miguel11 (1.京都大学生存圏研究所、2.富山県立大学、3.情報通信研究機構、4.東海大学情報教育センター、5.東北大学理学研究科、6.北海道大学理学研究科、7.高知工科大学、8.JAXA宇宙科学研究所、9.電子航法研究所、10.NRL、11.クレムソン大学)

キーワード:MSTID, Sounding rocket, Electric field, GPS-TEC, Observation campaign

Medium-scale traveling ionospheric disturbance (MSTID) is an interesting phenomenon in the F-region. The MSTID is frequent in summer nighttime over Japan, showing wave structures with wavelengths of 100-200 km, periodicity of about 1 hour, and propagation toward the southwest. The phenomena are observed by the total electron content (TEC) from GEONET, Japanese dense network of GPS receivers, and 630 nm airglow imagers as horizontal pattern. It was also measured as Spread-F events of ionograms or as field-aligned echoes of the MU radar. MSTID was, in the past, explained by Perkins instability (Perkins, 1973) while its low growth rate was a problem. Recently 3D simulation study by Yokoyama et al (2009) hypothesized a generation mechanism of the MSTID, which stands on electromagnetic E/F-region coupling of the ionosphere. The hypothesis is that the MSTID first grows with polarization electric fields from sporadic-E, then show spatial structures resembling to the Perkins instability. We recently conducted a observation campaign to check this hypothesis. We launched JASA ISAS sounding rockets S-310-42 and S-520-27 at 23:00 JST and 23:57JST on July 20, 2013 while an MSTID event was monitored in real-time by the GPS-TEC from GEONET. We found 1-5mV/m northeastward/eastward electric fields during the flight. Variation of electric fileds were associated with horizontal distribution of plasma density. Wind velocity was measured by the TME and Lithium releases from S-310-42 and S-520-27 rockets, respectively, showing southward wind near the sporadic-E layer heights. These results are consistent to the expected generation mechanism shown above. In the presentation we will discuss electric-field results and its relationship with plasma density variability together with preliminary results from the neutral-wind observations.