Abstract
We utilise Principal Component Analysis to identify and quantify the
primary electric potential morphologies during geomagnetic storms.
Ordering data from the Super Dual Auroral Radar Network (SuperDARN) by
geomagnetic storm phase, we are able to discern changes that occur in
association with the development of the storm phases. We find that the
first 6 eigenvectors provide over ~90% of the
variability, providing us with a robust analysis tool to quantify the
main changes in the morphologies. Studying the first 6 eigenvectors and
their eigenvalues with respect to storm phase shows that the primary
changes in the morphologies with respect to storm phase are the
convection potential enhancing and the dayside throat rotating from
pointing towards the early afternoon sector to being more sunward
aligned during the main phase of the storm. We find that the ionospheric
electric potential increases through the main phase and then decreases
after the end of the main phase is reached. The dayside convection
throat points towards the afternoon sector before the main phase and
then as the potential increases throughout the main phase, the dayside
throat rotates towards magnetic noon.Furthermore, we find that a two
cell convection pattern is dominant throughout and that the dusk cell is
overall stronger than the dawn cell.