Presentation Information
[PEM28-P02]Postnoon aurora spot and poleward-drifting multiple arcs
*Yohei TSUJIMOTO1, Satoshi TAGUCHI1, Keisuke HOSOKAWA2, Yasunobu OGAWA3 (1.Graduate School of Science, Kyoto Univ., 2.Graduate School of Informatics and Engineering, Univ. of Electro-Communications, 3.National Institute of Polar Research)
Keywords:
High-latitude ionosphere,postnoon aurora spot,auroral arc,all-sky imager
To understand when and how the postnoon aurora spot is created, we examined data from the all-sky imager installed in Longyearbyen, Svalbard. From the detailed examination of the data obtained during two winter seasons (2013-2014, and 2014-2015), we have found that the postnoon aurora spot consists of poleward-drifting multiple arcs, which happened at intervals of about 2 min. In some events, each poleward-drifting arc distorts into a folding structure at the final stage of the poleward drift, and becomes even brighter. We report the characteristics of the occurrence and motion of the poleward-drifting arcs, and discuss what is important for the creation of the postnoon aurora spot.