[P-EM10] Space Weather and Space Climate

[PEM10-26] Ionospheric convection associated with low-latitude auroras

*Nozomu Nishitani¹, Tomoaki Hori¹, Keisuke Hosokawa², Atsuki Shinbori¹, Yuki Obana³, Mariko Teramoto⁴, Kazuo Shiokawa¹, Ryuho Kataoka⁵ (1.Institute for Space-Earth Environmental Research, Nagoya University, 2.Department of Communication Engineering and Informatics, University of Electro-Communications, 3.International Research Center for Space and Planetary Environmental Science, Kyushu University, 4.Kyushu Institute of Technology, 5.National Institute of Polar Research)

Keywords:ionosphere, magnetosphere, low-latitude aurora, SuperDARN

Low-latitude auroras, sometimes reaching up to the latitude of Japanese islands, have been witnessed by an increasing number of people recently, owing to the increasing solar activity and improvement of the sensitivities of handy-type cameras such as smartphones. On the contrary, the physical mechanisms of the low-latitude auroras have not yet been fully understood. Historically the low-latitude auroras were regarded as unstructured emissions, namely stable red auroral (SAR) arcs, due to the overlapping of the plasmasphere and ring current regions. However, recent observations of low-latitude auroras demonstrate that some of these emissions have structured characteristics, suggesting the presence of static electric fields. There have been relatively few observations of electric fields associated with low-latitude auroras, although. Estimating the electric field associated with low-latitude auroras is crucial for space weather studies, e.g., for estimating Joule heating during severe geomagnetic storms, which might affect the orbit change and atmospheric reentry of low earth orbit (LEO) satellites.

The deployment of the SuperDARN radars at mid-latitude in North America and Eastern Asia since 2005 enables us to study the detailed characteristics of the ionospheric electric fields associated with low-latitude auroras. In this paper, we report on the latest results of the relationship between low-latitude auroral precipitation during recent huge storms and ionospheric convection using the SuperDARN radars data (mainly those of the SuperDARN Hokkaido Pair of radars), optical imager data, and auroral particle precipitation data from LEO satellites.