日本地球惑星科学連合2019年大会

講演情報

[E] 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-EM11] Dynamics of Magnetosphere and Ionosphere

2019年5月29日(水) 13:45 〜 15:15 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:中溝 葵(情報通信研究機構 電磁波研究所)、尾崎 光紀(金沢大学理工研究域電子情報学系)、藤本 晶子(九州工業大学)、堀 智昭(名古屋大学宇宙地球環境研究所)

[PEM11-P06] Transient polar ionospheric convection response to negative dynamic pressure pulse

*Jianjun Liu1 (1.Polar Research Institute of China)

キーワード:Dynamic pressure, Ionospheric convection, Auroral oval

The response of the high latitude ionospheric convection to a sudden decrease in solar wind dynamic pressure provides a unique opportunity to investigate how the solar wind couples to the dayside magnetosphere and ionosphere. Here, the event shows three IMF components do not have prominent changes, but the solar wind plasma went down to near zero magnitude, which leads to very weak solar wind driving during northward IMF. However, ionospheric convection observed by SuperDARN radars showed enhanced plasma flow speed in the central polar cap region just after the negative pressure pulse arrival to the magnetosphere. Simultaneous convection map generated by SuperDARN measurement presents enlarged convection cell with obvious equatorward moving Heppner-Maynard boundary. It is noted that cross polar cap potential enhanced instantly and this enhanced feature continued almost 10 min. The distribution of total electron content (TEC) exhibited typical auroral oval signature especially on dayside ionosphere, TEC density in auroral oval showed a noticeable decrease after the arrival of the negative pressure pulse. Both ionospheric convection and TEC distribution reveal that negative pressure pulse impacts the magnetosphere-ionosphere coupling system directly and dramatically. Moreover, the TIEGCM model also showed an enhanced polar potential pattern.