Dual boundary coordinates in polar magnetosphere-ionosphere studies

The high latitude ionosphere, which coincides with the Arctic and Antarctic regions, is a complex region that is strongly coupled with the magnetosphere, neutral atmosphere, and the solar wind. The high latitude ionosphere may be divided into two regions based on the portion of the magnetosphere to which the ionosphere is connected. The most poleward region, the polar cap, is the area characterized by open magnetic field lines that connect directly to the interplanetary magnetic field (IMF) instead of closing in the opposite hemisphere. Within the polar cap, ionospheric plasma moves anti-sunward and HF propagation paths between a transmitter and receiver may occur through reflection in either the E region or F region of the ionosphere. Just equatorward of the polar cap is the auroral oval, a region that experiences high amounts of particle precipitation and energy transfer between the magnetosphere and ionosphere along closed magnetic field lines. The equatorward edge the auroral oval marks the beginning of the mid-latitudes. Defining high latitude coordinates relative to these physically significant boundaries has implications for statistical studies, modeling applications, and research combining magnetospheric and ionospheric data. This study explores the impact of using single or multiple boundaries on such high latitude research efforts, and presents a tool to aid this research.