Resolving the Unique Characteristics of Substorms that Precede Strong Thermal Emission Velocity Enhancement (STEVE) Events using Incoherent Scatter Radar and Spacecraft Observations

Strong Thermal Emission Velocity Enhancement (STEVE) events are bright mauve optical emissions that periodically occur between dusk and midnight in subauroral regions after a substorm onset. However, not every substorm generates a STEVE event. In fact, the number of substorm events that do not have a STEVE associated with them vastly outnumber those that do. The motivation of this work is to determine how the substorms associated with STEVE events are unique compared to other substorms by resolving the conditions of the magnetosphere-ionosphere system prior to STEVE events. Studies of this nature are typically limited due to the rarity of STEVE events, however, a novel and compelling component of this research effort is the incorporation of radar data, in particular Incoherent Scatter Radar (ISR) data. Here, the ionospheric signature of a STEVE event in ISR data is analyzed, and used to enhance our ability to identify undiscovered STEVE events. This presentation will discuss these findings, use them to complement measurements provided by other instruments, such as imagers and spacecraft (in particular, the Swarm spacecraft), and present observations of the preconditioning associated uniquely with substorms that precede STEVE events.