STEVE as an Extreme Ionospheric Plasma Environment

Much is still unknown about the auroral region. STEVE (Strong Thermal Emissions Velocity Enhancement), a mauve-white sub-auroral emission that gained scientific recognition in 2015, is one such case. High electron temperatures (over 6000 K) and fast ion drift speeds (over 10 km/s) have been reported within STEVE by the European Space Agency's Swarm satellites. If true, STEVE is embedded in an extreme plasma environment compared with typical high-latitude ionospheric conditions. The goal of this study is to investigate the extent that these reported environments can be corroborated. We report 28 new STEVE event conjunctions between Swarm satellites and ground-based observations previously not reported in the literature. One STEVE event found demonstrated ion drift speeds above 15 km/s, well outside of the instrument's functional range. By using the new reported STEVE values, thermal ion imaging (TII) Monte Carlo simulations for Swarm's electric field instrument detectors are used to substantiate or refute the most extreme STEVE events. These results are compared to the new Swarm TRACIS (TII Raw And Corrected Imagery/Spectra) dataset, demonstrating raw particle energy data to validate these reported ionospheric conditions. This project's results provide greater insight into STEVE as an extreme ionospheric plasma environment and inform future satellite measurement techniques aiming to study aurora.