Does Ring-Current Heating Generate the Cold O+ Shell?

Abstract:

The Naval Research Laboratory (NRL) Sami3 is Also a Model of the Ionosphere (SAMI3) ionosphere/plasmasphere code is used to examine the effect of ring current heating during a storm. With a ring current heating function added to SAMI3, a cold thermal (< 1 eV) oxygen ion outflow is produced, with O⁺ density and location similar to observations of the so-called "oxygen torus." The ring current heating function is based on a Comprehensive Inner Magnetosphere-Ionosphere (CIMI) model simulation of the 2015 October 7 storm. We find that the ring current can heat plasmasphere electrons, subsequently heating plasmasphere H⁺, and ionosphere O⁺. The resulting O⁺ outflows resemble observed O⁺ enhancements in the inner magnetosphere. Further efforts to couple the SAMI3 and CIMI codes will also be discussed.

Research supported by NRL base funds and NASA.