Abstract
The energy deposition from ring current ions into the high density
‘cold’ plasma of the ionosphere and plasmasphere is analyzed, based on a
Comprehensive Inner Magnetosphere-Ionosphere (CIMI) simulation of the
2015 October 7 storm. In addition, the Naval Research Laboratory (NRL)
Sami3 is Also a Model of the Ionosphere (SAMI3) ionosphere/plasmasphere
code is used to simulate the effect of ring current heating on the
ionosphere and plasmasphere. We find that, during stormtime peaks in the
Dst index, energy is deposited at altitudes as low as 100 km. Heating
along the entirety of any given field line, both in the ionosphere and
plasmasphere, contributes to increased temperatures in the topside
ionosphere and inner magnetosphere and to subsequent cold O$^+$
outflows. However, relative to the heating of the plasmasphere, the
direct heating of the ionosphere by ring current ions produces only
small effects. Model-data agreement in the N$^+$/O$^+$ density
ratio shows that these O$^+$ outflows are driven by thermal
forcing.