Extended Synoptic Analysis Using a Database of Auroral Images

The UVI Online Search Tool (OST) uses a database of image-derived search criteria such as auroral boundaries, integrated power, polar cap area, and auroral morphology. The database spans the entire UVI mission lifetime (approximately 6.5 years) with a 10 minute resolution. This database of image information represents a useful collection of auroral activity that can be used to perform extended (multi-year) studies of auroral variations. Previous studies have performed synoptic surveys of auroral activity, correlated auroral intensity with solar wind conditions, examined dynamics of auroral boundaries, and monitored morphological evolution as a function of IMF. All of these studies, however, have been limited to time periods ranging from a few hours to a few months at most. The OST image parameter database provides the opportunity to extend previous studies to time scales heretofore unavailable. In this paper we use the OST database to study auroral activity during the ascending phase of the current solar cycle (1996-2000) as a function of solar driving conditions and activity indices. Preliminary results indicate that OST has great promise. This paper will report the results of examining the degree to which synoptic auroral behavior varies with solar cycle.