日本地球惑星科学連合2022年大会

講演情報

[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-EM10] Dynamics of Magnetosphere and Ionosphere

2022年5月26日(木) 09:00 〜 10:30 303 (幕張メッセ国際会議場)

コンビーナ:佐藤 由佳(日本工業大学)、コンビーナ:家田 章正(名古屋大学 宇宙地球環境研究所)、藤本 晶子(九州工業大学)、コンビーナ:今城 峻(京都大学大学院理学研究科附属地磁気世界資料解析センター)、座長:長谷川 洋(宇宙航空研究開発機構宇宙科学研究所)、西野 真木(宇宙航空研究開発機構宇宙科学研究所)


09:20 〜 09:45

[PEM10-02] An Analysis of Region 2 Field-Aligned Current Bifurcations

★Invited Papers

*Harneet Kaur Sangha1,2、S E Milan1,3、B J Anderson4、H Korth4 (1.Univ. of Leicester, UK、2.Univ. of Alabama in Huntsville, US、3.Birkeland Centre for Space Science, Univ. of Bergen, Norway、4.Johns Hopkins Univ. Applied Physics Laboratory, US)

The Earth’s Field-Aligned Currents (FACs) electrodynamically connect the magnetosphere and the ionosphere, enabling energy and momentum to be transported between the different regions of the solar wind-magnetosphere-ionosphere-thermosphere coupled system. The FACs form two concentric rings in the ionosphere. The higher latitude currents are known as the Region 1 or R1 FACs, and the lower latitude currents are known as the Region 2 or R2 FACs. The R1 currents directly link the ionosphere to the magnetopause at the outer magnetosphere, and the R2 currents link the ionosphere to the ring current in the inner magnetosphere.
Utilizing the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE), we study the FACs and how they vary with time. Using this dataset, we identified a new phenomenon within the R2 FAC system, coined Region 2 Bifurcations (R2Bs) (Sangha et al., 2020). These R2Bs appear as a second ring of R2-like current, further equatorward than the original R2 FACs. The occurrence of R2Bs shows a peak at substorms, and we also suggest a relationship with Sub-Auroral Polarization Streams (SAPS). To study these connections, we conducted some superposed epoch analyses of some solar wind and geomagnetic conditions, which show both R2Bs and SAPS to be substorm-related processes.