Despite decades of research, comprehensive understanding of auroral electrodynamics remains elusive. This is especially true at mesoscales (~100x kilometers) where the details of current closure depend on conductivity gradients, localized field-aligned currents and convection flows, which are equally difficult to measure and model. Because of this, puzzling questions remain regarding the spatiotemporal structure of the substorm auroral electrojet, as well as the dayside convection throat and cusp current systems. These questions can now be addressed due to the emergence of heterogeneous multivariate datasets (e.g., radars, ground magnetometers, in situ satellite constellations, remote sensing and imaging platforms), sophisticated global and regional models with increasingly complex physics, and assimilation techniques putting them all together. We solicit contributions utilizing any and all of the above approaches. The session is particularly timely in view of current, nascent and future NASA and other agencies’ space missions, such as EZIE, TRACERS, CINEMA, and SMILE.

• SA - SPA-Aeronomy