Throat Aurora and 15MLT-PCA

Throat aurora: The solar wind interacts with the magnetosphere to generate auroras. Auroras primarily occur in a ring-shaped region centered on the geomagnetic poles, known as the auroral oval. Throat aurora is a particular auroral form frequently observed in the dayside ionospheric convection throat region. The throat auroras have been confirmed to be correspondent to magnetopause crack. Based on the observational facts of throat aurora, we suggest that throat aurora should be correspondent to a particular magnetopause reconnection that is radially developed toward the Earth at a rather local region.

15MLT-PCA: The area enclosed by the auroral oval is called the polar cap region. Auroras often occur within the polar cap region as well, including two main types: arcs and patches. This report focuses on the auroral phenomena occurring on the dayside within the polar cap region. These phenomena have been given various names in past research, such as Cusp spot, HiLDA, 15MLT-PCA, and space typhoon. Although these phenomena have distinct observational characteristics, they also share many similarities. In the past, scholars often argued over what to call specific dayside polar cap auroral events, and there has been no clear discussion on the intrinsic connections between these phenomena. Recently, by integrating previous research, we proposed a unified model for these phenomena. In simple terms, it is believed that these phenomena represent different manifestations of tail reconnection on the aurora under different clock angle conditions. This report will briefly introduce the model and discuss its implications for understanding certain issues such as the dawn-dusk asymmetry of space processes and inter-hemispheric asymmetry.