Estimates of the suprathermal O+ outflow characteristic energy and relative location in the auroral oval

Abstract

We have surveyed one year of northern hemisphere data from the FAST satellite and obtained the first global estimates of the characteristic energy of the energetic oxygen ion outflows and their relative distribution within the auroral oval. Recent results have shown that, above ∼3,000 km, the FAST/TEAMS instrument covers the energy range that includes almost all of the escaping O+. The highest mean characteristic O+ energy is found at the poleward edge of the night-side auroral oval. Our results suggest that the energization and/or transport are operating differently in the noon, dusk, midnight and dawn sectors of the auroral oval. The results presented here also provide required ground truth and boundary conditions for global modeling. Copyright 2005 by the American Geophysical Union.