Spatiotemporal distribution of auroral brightening in the cusp

Satoshi TAGUCHI; Keisuke HOSOKAWA; Yasunobu OGAWA

Presentation information

Oral

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

[P-EM28_29PM2] Magnetosphere-Ionosphere Coupling

Tue. Apr 29, 2014 4:15 PM - 6:00 PM 413 (4F)

Convener:*Shin'ya Nakano(The Institute of Statistical Mathematics), Yoshimasa Tanaka(National Institute of Polar Research), Tomoaki Hori(Nagoya University Solar Terrestrial Environment Laboratory Geospace Research Center), Chair:Shin'ya Nakano(The Institute of Statistical Mathematics), Yoshimasa Tanaka(National Institute of Polar Research), Tomoaki Hori(Nagoya University Solar Terrestrial Environment Laboratory Geospace Research Center)

4:30 PM - 4:45 PM

[PEM28-15] Spatiotemporal distribution of auroral brightening in the cusp

*Satoshi TAGUCHI¹, Keisuke HOSOKAWA¹, Yasunobu OGAWA² (1.University of Electro-Communications, 2.National Institute of Polar Research)

Keywords:aurora, cusp, particle precipitation, magnetic reconnection, all-sky imager

Previous studies have shown that mesoscale auroral forms occur near the equatorward edge of the background, stable cusp aurora, and that they move in a direction that is consistent with the motion of the magnetic field line after reconnection on the dayside magnetopause. In this study we pay attention to its initial brightening using data from a high-sensitivity all-sky imager at Longyearbyen, Svalbard. The imager has a field-of-view that spans more than 4 hours in MLT, and can observe auroral brightenings that are widely separated in MLT. We determined the position of dayside auroral brightening using the 630-nm auroral images, and examined how these positions are distributed in the cusp, focusing on intervals when IMF was extremely stable. Results of analyses show that brightening occurs over a wide dayside MLT range. We show detailed spatiotemporal patterns for successive brightening events, and discuss the patterns in terms of the formation of intermittent reconnection on the dayside magnetopause.