SA31D-2370
Ionospheric convection associated with low-latitude aurora observed at Rikubetsu, Hokkaido, Japan during the 2015 St. Patrick’s Day storm
Wednesday, 16 December 2015
Poster Hall (Moscone South)
Nozomu Nishitani1, Tomoaki Hori1, Ryuho Kataoka2, Yusuke Ebihara3, Kazuo Shiokawa4, Yuichi Otsuka5 and Hidehiko Suzuki6, (1)Nagoya University, Solar-Terrestrial Environment Laboratory, Nagoya, Japan, (2)National Institute of Polar Research, Tachikawa, Japan, (3)Kyoto University, Kyoto, Japan, (4)Nagoya University, Nagoya, Japan, (5)Nagoya University, Solar terrestrial Environment Laboratory, Nagoya, Japan, (6)Meiji University, Kawasaki, Japan
Abstract:
The 2015 March storm (St. Patrick’s day storm), which occurred during 17-21 March 2015, is the largest one during Solar Cycle 24 for now. During the main phase of the storm, optical instruments installed at Rikubetsu, Hokkaido, Japan (geomagnetic altitude: 36.5 degs), such as all-sky CCD camera, wide field of view digital camera and meridian scanning photometer, registered auroral emissions during 15 to 19 UT (corresponding to 00 to 04 LT) on March 17. In addition, both the SuperDARN Hokkaido East and West radars succeeded in obtaining unprecedented set of high-time-resolution ionospheric convection data associated with the low latitude aurora up to below 50 degs geomagnetic latitude. It is found that the initial stage of the low latitude aurora appearance (before 1630 UT) was associated with equatorward convective flow, and later there was sheared flow structure, consisting of westward flow (about 500 m/s) equatorward of eastward flow (1000 m/s), with the equatorward boundary of auroral emission embedded in the westward flow region. Details of the observation and the data interpretation will be presented.
