Auroral dynamics in the polar cap region

• Main Authors: Kazuo Makita, Masaru Ayukawa, Hisao Yamagishi, Masaki Ejiri, Takeshi Sakanoi
• Format: Report
• Language: Japanese
• Published: Takushoku University/National Institute of Polar Research/National Institute of Polar Research/National Institute of Polar Research/Tohoku University 1995
• Subjects: Greenland
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=4168; http://id.nii.ac.jp/1291/00004168/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=4168&item_no=1&attribute_id=18&file_no=1

The characteristics of extremely high latitude auroras are examined by using Greenland auroral data. In this paper, two different auroras obtained in the dayside and the morning sector are mainly analyzed; (1) polar arc : this aurora is observed during quiet conditions and is related to less than 100eV precipitating electrons, and (2) polar corona : this aurora is observed during disturbed conditions and is related to a few hundred eV electrons. These two auroras may have different sources; the polar arc corresponds to the plasma mantle or low latitude boundary layer and the polar corona corresponds to the low latitude boundary layer or boundary plasma sheet. The relationships of IMF fluctuations are also examined and found that auroral enhancement and/or movement are seen in association with southward turning of the IMF.