Unique solar wind and magnetospheric drivers of omega band substorm activity

Omega bands are mesoscale auroral structures that appear as eastward-moving poleward protrusions in the auroral oval. They typically appear in the post-midnight sector during periods of enhanced geomagnetic activity. Omega bands have been associated with Ps6 pulsations and rapidly time-varying magnetic fields on the ground, making them highly relevant to space weather forecasting. However, while the solar wind and magnetospheric drivers of omega bands have been previously studied, the characteristic signatures of omega band substorm events have not been identified.

In this work, we compare solar wind, magnetospheric, and geomagnetic parameters measured during general substorm activity to the same parameters measured during 205 omega band events from 1997 to 2007 identified using the MIRACLE network. Non-omega substorm events are identified using spline fitting techniques to locate positive bays in the SuperMAG lower auroral electrojet index, and filtered to match the omega band substorm events in intensity. We use OMNI data to determine the solar wind drivers of these events and data from GOES and SuperMAG to identify magnetospheric and geomagnetic signatures of these events. This analysis will allow us to identify the unique solar wind drivers and magnetospheric configurations associated with omega band formation and improve our understanding of magnetosphere-ionosphere coupling dynamics during periods of enhanced geomagnetic activity.