@article{oai:nipr.repo.nii.ac.jp:00004235, author = {Obara,Takahiro and Mukai,Toshifumi and Fukui,Katsura}, journal = {Proceedings of the NIPR Symposium on Upper Atmosphere Physics}, month = {Jan}, note = {P(論文), To understand the processes of formation of polar arcs together with patches, an investigation has been made based on the simultaneous observations with an all-sky imager at Qaanaaq in Greenland and Akebono (EXOS-D) satellite. On some occasions, we have identified coexistence of polar arcs with patches. Specifically, polar arcs were replaced by patches or vise versa. These phenomena have been seen in the transient periods of IMF polarity change. Growth and decay of polar arcs with respect to the IMF polarity change has also been investigated with a particular interest in a delay time. The delay time was in a range from 30min to 1 hour. Since a life time of patches seems to be longer than 1hour, the coexistence was noticed by the all-sky imager at Qaanaaq.}, pages = {28--35}, title = {Coexistence of polar arcs with patches ─Results from the simultaneous observations by Akebono satellite and all-sky imager at Qaanaaq─}, volume = {11}, year = {1998} }