Detailed analysis of substorm observations using SuperDARN, UVI, ground-based magnetometers, and all-sky imagers

A case study of a small-magnitude isolated substorm is presented. The substorm was observed by a variety of instruments including the Super Dual Auroral Radar Network (SuperDARN), the Polar Ultra Violet Imager (UVI), CANOPUS magnetometers, the Alaska chain magnetometers, the Poker Flat meridian-scanning photometer, and the Poker Flat all-sky imager. It was determined that the initial brightening was centered over the combined fields of view of the various instruments. Temporal and spatial relationships among plasma flows, auroral luminosity, and magnetometer perturbations are investigated. It is found that the initial substorm signature was observed in the plasma flows, followed by the auroral brightening, and finally followed by the magnetometer perturbation. Enhanced plasma flows were observed in a spatially confined region near the auroral oval for a period of ∼5 minutes prior to the brightening. After the brightness peaked, the plasma flow velocity decreased back to a preenhancement level.