日本地球惑星科学連合2022年大会

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[E] 口頭発表

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-EM13] Coupling Processes in the Atmosphere-Ionosphere System

2022年5月24日(火) 15:30 〜 17:00 302 (幕張メッセ国際会議場)

コンビーナ:Huixin Liu(九州大学理学研究院地球惑星科学専攻 九州大学宙空環境研究センター)、コンビーナ:大塚 雄一(名古屋大学宇宙地球環境研究所)、Chang Loren(Institute of Space Science, National Central University)、コンビーナ:Deng Yue(University of Texas at Arlington)、座長:大矢 浩代(千葉大学大学院工学研究院)、西岡 未知((独)情報通信研究機構)、斎藤 享(国立研究開発法人海上・港湾・航空技術研究所電子航法研究所)


15:45 〜 16:00

[PEM13-08] 熊本地震前の地表面垂直運動と電離圏

*小山 孝一郎1陳 佳宏2 (1.国際宇宙天気研究・教育センター 九州大学、2.地球科学科、国立成功大学、台湾)

キーワード:地表面垂直運動、電離圏、ダイナモ電場

We studied the role of vertical ground motion as a driving force to excite acoustic gravity wave, which disturbs the ionosphere before Kumamoto earthquake. Data acquired with the slant gages distributed around the epicenter of Kumamoto earthquake which occurred on 14 April 2016 are used. Power spectrum density (PSD) is calculated from the vertical components measured with the slant gages. When the PSD increases, Daytime NmF2 reduces, and night time NmF2 increases, which can be explained by the intensified dynamo electric field. Two conditions to disturb ionosphere by the small ground motion are; the period of ground motion should be shorter than 2 hour, and the ground motion should continuously exist at least for one day, so that wave energy is continuously injected to the atmosphere. The PSD shows the minimum 5 days before, increases 2 days before, and then reduces one day before, following the drastic increase. Large part of the frequency spectrum of the ground motion appears around several 10 minutes to 2 hours.