Observations of fragmented aurora-like emissions and picket fence on the poleward edge of the auroral oval

115 Astronomy, Space science

This research has been supported by the Japan Society for the Promotion of Science (grant nos. 21H04518, 21KK0059, 22H00173, 22K21345, 23K22554, and 24H00751) and Norwegian Research Council (contract no. 343302). The first author is a JSPS Overseas Research Fellow. The publication of this article was funded by the Swedish Research Council, Forte, Formas, and Vinnova.

The solar wind data from DSCOVR can be downloaded from https://www.ngdc.noaa.gov/dscovr/portal/index. html (last access: 27 January 2026). The Dst index is provided from https://wdc.kugi.kyoto-u.ac.jp/ (last access: 27 January 2026). The magnetometer data at Kilpisjärvi is available at https://space.fmi.fi/image/www/index.php? (last access: 27 January 2026). The images from the all-sky color camera can be downloaded from http://darndeb08.cei.uec.ac.jp/~nanjo/public/skibotn_ imgs/2023_season/20240101/ (last access: 27 January 2026). The Watec ASIs data used in this study are publicly available at http://esr.nipr.ac.jp/www/optical/watec/skb/rawdata2/ (last access: 27 January 2026). The qCMOS camera data are also available at http://gwave.cei.uec.ac.jp/~hosokawa/public/flagments/ (last access: 27 January 2026). The spectral riometer data are available at http://darndeb08.cei.uec.ac.jp/~nanjo/public/riometer (last access: 27 January 2026).

We are grateful to the Skibotn Observatory, UiT The Arctic University of Norway, for providing the site for the observations conducted in this study. We thank the Finnish Meteorological Institute and the IMAGE network for providing the magnetometer data from Kilpisjarvi. We acknowledge the use of the real-time Dst index provided by the World Data Center for Geomagnetism, Kyoto. We also acknowledge the use of data from the Swarm satellites, a mission of the European Space Agency (ESA), and from the DSCOVR satellite, operated by NOAA and NASA