Midnight sector observations of auroral omega bands

We present observations of auroral omega bands on 28 September 2009. Although generally associated with the substorm recovery phase and typically observed in the morning sector, the features presented here occurred just after expansion phase onset and were observed in the midnight sector, dawnward of the onset region. An all‐sky imager located in northeastern Iceland revealed that the omega bands were ∼150 × 200 km in size and propagated …