A study of ionospheric convection pattern in the vicinity of low latitude auroral precipitation during huge geomagnetic storms

With increasing solar activity, both auroral precipitation region and ionospheric convection of high-latitude proper expand to lower geomagnetic latitudes, leading to difficulties in monitoring the disturbances using the pre-existing observation instruments designed for high-latitude ionospheric dynamics. The Super Dual Auroral Radar Network (SuperDARN) was originally developed for studying high-latitude phenomena, but since the early 2000s, it has expanded toward lower geomagnetic latitudes, enabling the monitoring of sub-auroral and mid-latitude phenomena. The SuperDARN Hokkaido Pair of (HOP) radars, operated by Nagoya University, Japan, are located at the lowest geomagnetic latitude (=36.9 AACGM geomagnetic latitude and are most suitable for monitoring the ionospheric and magnetospheric dynamics during geomagnetic storms including recent huge storms such as the May 2024 storm. In this paper, we report the spatial and temporal evolution of ionospheric convection associated with the auroral precipitation during huge geomagnetic storms using the SuperDARN HOP radars data, together with ground-based camera data and the particle precipitation data at Low-Earth Orbit (LEO) satellites. The majority of low latitude auroral precipitation is accompanied by the sheared zonal ionospheric flows in its vicinity, but detailed flow patterns vary from event to event. Details of the multi-event analysis result will be presented.