Polar/TIMAS statistical results on the outflow of molecular ions from earth at solar minimum Original Research Article

Ion composition data from the first 22 months of operation of the Polar/TIMAS instrument, covering the 15-eV/e to 33-keV/e energy range, have been surveyed to determine the typical abundance, at solar minimum, of N2+, NO+ and O2+ ions in the auroral ion outflow, as compared to that of the better known O+ ions. The results indicate that molecular ions have roughly the same energy distribution as the O+ ions, with maximum differential flux occurring below 400 eV, but are far less abundant, by two orders of magnitude. The molecular ions also differ from the O+ ions in that they seem more specifically associated with enhanced geomagnetic activity.