Plain language summary
Plasma in the ionosphere convects across high latitudes in response to electric fields generated by solar wind driving of Earth’s magnetosphere. Magnetic data from the 66-satellite Iridium satellite constellation is routinely analyzed to measure the electric currents flowing between the ionosphere and magnetosphere. In this paper, we combined these observed field-aligned currents with a model of the ionospheric conductance to estimate the corresponding electric field in the ionosphere. We used these electric field estimates to specify the plasma convection in a first-principles ionosphere model, and compared the results against independent data in a moderately disturbed period. The results of our case study indicate that the technique works well, although plasma convection is not the only factor that causes uncertainty into predictions of the high-latitude ionosphere. The data used here can be made available in near-real-time, so it is possible that our technique could be adopted for operational space weather prediction.