Investigating Ionospheric Signatures and Magnetosphere-Ionosphere Coupling During STEVE and STEVE-like Events

Strong Thermal Emission Velocity Enhancement (STEVE) events are bright mauve optical emissions that periodically occur around magnetic midnight in sub-auroral regions often after a substorm onset. Substorms are known to generate STEVE events but the vast majority of substorms are not associated with STEVE emissions. In this study we will discuss:

1) For STEVE events, what is the temporal response of the ionosphere (electron density, ion and electron temperature, ion velocity) and the spectral response after substorm onset?

2) What are the conditions of the magnetosphere-ionosphere system prior to a STEVE event; can preconditioning be identified?

3) How are the mesoscale flow patterns associated with STEVE events different from those associated with substorm events in general?

A novel and compelling component of this research is the incorporation of Incoherent Scatter Radar (ISR) data using the Poker Flat ISR (PFISR), all-sky imager data (namely from THEMIS), as well as citizen science lists of STEVE sightings. We aim to characterize the plasma signatures of STEVE and STEVE-like events (where there is no detectable optical signature but plasma characteristics are consistent with STEVE observations).

Using PFISR data collected from 2010-2025, in combination with spacecraft and magnetometer data, we aim to evaluate the Magnetosphere-Ionosphere coupling properties associated with STEVE events and STEVE-like events. This presentation will discuss these findings. In addition, we will present preliminary findings of amplitude and phase power spectra during STEVE events using high rate GNSS receivers at various locations in the Canadian Arctic.