JpGU-AGU Joint Meeting 2017

講演情報

[EE] 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-EM14] [EE] Dynamics in magnetosphere and ionosphere

2017年5月20日(土) 10:45 〜 12:15 ポスター会場 (国際展示場 7ホール)

コンビーナ:堀 智昭(東京大学大学院理学系研究科)、田中 良昌(国立極地研究所)、中溝 葵(情報通信研究機構 電磁波計測研究所)、尾崎 光紀(金沢大学理工研究域電子情報学系)

[PEM14-P22] Comparison of substorm onsets between all-sky images and Pi2 magnetic pulsations.

*三浦 翼1家田 章正1川嶋 貴大1 (1.名古屋大学宇宙地球環境研究所)

キーワード:All-Sky Images (ASIs), auroral breakup

Substorms are explosive disturbance in the earth’s magnetosphere and ionosphere. Substorm onset are traditionally identified using sudden auroral brightenings or magnetic Pi2 pulsations. These auroral brightenings and Pi2s are believed to occur typically within 1 minutes. On the other hand substorm onset has originally been defined to have two-stage development, i.e., two brightenings. Thus, it is unclear whether the Pi2s correspond to the first or the second brightening. To clarify this association, we compared all-sky images and Pi2 pulsations in Canada, using the data from THEMIS project. As a result, a Pi2 pulsation was observed at 04:36 UT on 29 February 2008. About the same time, an auroral initial brightening (04:33:30 UT) and the poleward expansion (i.e., the second brightening, 04:39:18 UT) were observed in Fort Smith. This result suggests that the Pi2 pulsation can be delayed by a few minutes from the substorm onset, which is originally defined by the auroral initial brightening.