Auroral and Electrodynamic Measurement Needs for 21st Century Models

Models of the ionosphere and thermosphere have gained in complexity over the past 30 years. Many of these models are pushing to higher resolution in order to capture the smaller-scale dynamics that can occur within the system. While this allows the models to more accurately simulate standing and traveling disturbances, they are limited by the drivers, which include auroral precipitation and electric potentials (or field-aligned currents) at high-latitudes, and upward propagating tides and gravity waves from the lower atmosphere. At high latitudes, specification of drivers has been relatively low resolution spherical harmonic expansions of the potential and grid-based models of the auroral precipitation. In addition, electric potential and auroral models have been developed in isolation, such that their features are not correlated properly with each other. This leads to the energy inputs, across many scales, being incorrect within the models. In order to specify the energy inputs properly into IT models that simulate the high latitudes, it is important to capture the larger-scale structure as well as the statistical variability and correlations of that structure across a variety of scales. This presentation will highlight these topics, discuss some of the recent progress in empirical modeling, and will suggest measurement techniques, such as constellations of small satellites and ground-based measurements that can greatly improve the state of the auroral and electrodynamic driving within high-resolution IT models.