An examination of the impact of Strong Thermal Emission Velocity Enhancement (STEVE) on mid-latitude ionosphere

Strong Thermal Emission Velocity Enhancement (STEVE) refers to a latitudinally narrow (a few tens of km) optical feature that is observed in the sub-auroral ionoshere. Previous studies have shown that STEVEs primarily occur during the recovery phase of a substorm and unlike regular aurora, they are not associated with any significant particle precipitation. STEVEs were reported to be collocated with extremely strong Sub-Auroral Ion Drifts (SAIDs) where velocities exceeded a few km/s. In this study, we analyze the impact of STEVE on the mid-latitude ionosphere by analyzing observations from multiple Super Dual Auroral Radar Network (SuperDARN) radars spread across continental United States, during STEVE events observed by All-Sky Imagers. In particular, we will examine multiple parameters such as signal-to-noise ratio and Doppler velocities before, during, and after STEVE events to understand the changes in ionospheric electrodynamics associated with STEVE. By investigating multiple STEVE events, we aim to identify recurring patterns and variations in their ionospheric signatures. Using a superposed epoch analysis, we will statistically examine how key parameters evolve relative to the onset of STEVE, revealing consistent patterns and variations. This approach allows us to better characterize the ionospheric response to STEVE and understand the processes influencing these optical and electrodynamic phenomena.