Japan Geoscience Union Meeting 2018

Presentation information

[EE] Evening Poster

P (Space and Planetary Sciences) » P-EM Solar-Terrestrial Sciences, Space Electromagnetism & Space Environment

[P-EM13] Study of coupling processes in solar-terrestrial system

Sun. May 20, 2018 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall7, Makuhari Messe)

convener:Mamoru Yamamoto(Research Institute for Sustainable Humanosphere, Kyoto University), Yasunobu Ogawa(National Institute of Polar Research), Satonori Nozawa(名古屋大学宇宙地球環境研究所, 共同), Akimasa Yoshikawa(Department of Earth and Planetary Sciences, Kyushu University)

[PEM13-P10] Conjugate observations of the evolution of polar cap arcs in both hemispheres

*Zan-Yang Xing1, Qing-He Zhang1, De-Sheng Han2,6, Yong-Liang Zhang3, Natsuo Sato4, Shunrong Zhang5, Ze-Jun Hu2, Yong WANG1, Yu-Zhang Ma1 (1.Institute of Space Sciences, Shandong University at Weihai, 2.Polar Research Institute of China, 3.Applied Physics Laboratory, The Johns Hopkins University, 4.National Institute of Polar Research, 5.MIT Haystack Observatory, 6.Tongji University)

Keywords:Polar cap arc, Conjugacy, Interplanetary magnetic field

We report results from the analysis of a case of conjugate polar cap arcs (PCAs) observed on February 5, 2006 in the northern hemisphere by the ground based Yellow River Station all-sky imager (Svalbard) and in both hemispheres by the space based DMSP/SSUSI and TIMED/GUVI instruments. The PCAs motion in dawn-dusk direction shows a clear dependence on the interplanetary magnetic field (IMF) By component and presents a clear asymmetry between southern and northern hemispheres, i.e., formed on the duskside and moving from dusk to dawn in the northern hemisphere and vice versa in the other hemisphere. The already existing PCAs’ motion is influenced by the changes in the IMF By with a time delay of ~70 minutes. We also observed strong flow shears/reversals around the PCAs in both hemispheres. The precipitating particles observed in the ionosphere associated with PCAs showed properties of boundary layers plasma. Based on these observations, we might reasonably expect that the topological changes in the magnetotail can produce a strip of closed field lines and local processes would be set up conditions for the formation and evolution of PCAs.