A unified model of cusp spot, High Latitude Dayside aurora (HiLDA)/(Space Hurricane), and 15MLT-PCA

Abstract

A unified model has been proposed to explain the relationship between oval-attached auroral arcs and oval-detached spots in the dayside polar cap.q In general, the processes for generating 15MLT-PCA and HiLDA can coexist.qThe cusp spot, HiLDA (space hurricane), and 15MLT-PCA are useful for tracing the poleward cusp boundary.

A Statistical Study of Space Hurricanes in the Southern Hemisphere

“…Auroras on Earth often occur in two elliptical bands surrounding the north and south poles at ∼67°, which are called “auroral ovals.” The region inside (poleward of) the auroral oval is called the “polar cap,” where a few auroras can be observed as spots or arcs, known as the “polar cap arcs” or “polar cap spots” (Gussenhoven, 1982; Kullen, 2012; Meng, 1981). With the help of the global auroral imagers, many types of polar cap aurora were discovered and named based on their different shapes and locations such as TPA (Transpolar Arcs), 15MLT‐PCA (15 Magnetic Local Time‐Polar Cap Arc), HiLDA (High‐Latitude Dayside Aurora), hot spot, HCA(Horse Collar Aurora) (e.g., Fear & Milan, 2012; Frey, 2007; Frey et al., 2003, 2019; Han et al., 2020, 2023; Hones et al., 1989; Kullen et al., 2015; Milan et al., 2020, 2022; X. Y. Wang et al., 2023; Xing et al., 2018; Y. Zhang et al., 2016; Q.‐H. Zhang et al., 2020).…”