JpGU-AGU Joint Meeting 2017

Presentation information

[EE] Poster

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

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

Sat. May 20, 2017 10:45 AM - 12:15 PM Poster Hall (International Exhibition Hall HALL7)

convener:Tomoaki Hori(Graduate school of Science, University of Tokyo), Yoshimasa Tanaka(National Institute of Polar Research), Aoi Nakamizo(Applied Electromagnetic Research Institute, National Institute of Information and Communications Technology), Mitsunori Ozaki(Faculty of Electrical and Computer Engineering, Institute of Science and Engineering, Kanazawa University)

[PEM14-P23] Simultaneous existence of the cusp aurora and polar cap arcs during northward IMF

*Yushin Oda1, Satoshi Taguchi1, Keisuke Hosokawa2 (1.Graduate school of science, Kyoto University, 2.Department of Communication Engineering and Informatics, University of Electro-Communications)

Keywords:cusp aurora, northward IMF, polar cap arcs

The cusp aurora for northward IMF is created by the particle precipitation caused by high-latitude reconnection poleward of the cusp. The aurora generally appears at 75 - 80 MLAT in the daytime sector. In this sector the polar cap arcs are also often seen when IMF is northward. In this research we show the spatial and temporal features of the cusp aurora and polar cap arcs by examining events in which both exist simultaneously. We analyzed the 630 nm auroral image data from a highly sensitive all-sky imager at Longyearbyen, Svalbard in Norway, and the precipitating particle and ion drift data from the DMSP spacecraft. The spacecraft data show that lobe convection exists in the daytime sector, and that the cusp electron precipitation and higher-energy electron precipitation occur at different places simultaneously. It is also clear from the all-sky image data that the former and latter produce the cusp aurora and polar cap arcs, respectively. Detailed examination of the all-sky image data obtained immediately before and after the time when whether the observed auroral structures are the cusp proper or polar cap arcs are undoubtedly determined reveals their spatial and temporal features.