Whitepaper #115 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: basic research. Additional topics: planetary magnetospheres; planetary ionospheres / upper atmospheres.
In recent years it has become increasingly clear that there are several unexplored aspects of the sub-auroral region that remain elusive in part due to instrumental and observational limitations. This white paper highlights some of the open questions in the sub-auroral region that have arisen since the previous decadal survey and provides recommendations on how science advances can be achieved.