Abstract
Omega bands are mesoscale auroral structures emerging as eastward moving
sinusoidal undulations well within the closed field line region of the
auroral oval. While associated with geomagnetic activity, neither
specific conditions of their appearance nor their causes are well
understood. We perform a superposed epoch analysis of OMNI and SuperMAG
measurements taken during 28 omega band events recorded by auroral
all-sky imager (ASI) observations from 2006-2013 to identify their solar
wind drivers. We find local enhancements in the solar wind flow speed,
magnetic field, pressure, and proton density at the onset of the omega
band observation. In the magnetosphere-ionosphere, we see enhancements
in the ring current, partial ring current, and auroral electrojets.
These features are consistent with geomagnetic activity caused by stream
interaction regions (SIRs). 19 of our events overlap with SIRs from
published event catalogs. Our findings suggest that omega bands are
driven by SIR-like events.