Assimilation of radio sounding measurements — Global Navigation Satellite System (GNSS) data, ionosondes, beacon satellites, and more — of the ionosphere has been ongoing for over a decade, and has enabled ionospheric plasma mapping at global scales and at unprecedented resolution. Data assimilative technology has allowed us to sense and map the redistribution of plasma in response to stormtime forcing, in the form of storm-enhanced densities (SED), plumes of plasma feeding into the plasmasphere, bubbles, depletions and troughs. However, the drivers behind these formations have had to be measured in situ or indirectly, and with greater sparsity than measurements such as total electron content (TEC) from GNSS.