Multiple transpolar auroral arcs reveal insight about coupling processes in the Earth’s magnetotail
Qinghe Zhang, Yongliang Zhang, Chi Wang, M. Lockwood, Hui-Gen Yang, Binbin Tang, Zan‐Yang Xing, Kjellmar Oksavik, L. R. Lyons, Yu‐Zhang Ma, Qiugang Zong, J. Moen, Lidong Xia
Abstract
Significance Colorful and dynamic aurora has attracted human’s attention since the dawn of time. However, mystery remains in understanding a distinct class of aurora, transpolar auroral arc (TPA) (or “theta” aurora) which occurs in extremely high latitude of the Earth polar regions when interplanetary magnetic field (IMF) is northward. Previous theories are unable to explain why multiple TPAs often occur. Our comprehensive observations in the ionosphere and magnetotail as well as a three-dimensional magnetosphere modeling shed insight on how multiple TPAs form. Our study offers clues how solar wind energy and mass transfer into the magnetosphere and ionosphere under a northward IMF that occurs nearly half of the time.