AUTHOR=Krall J. , Huba J. D. TITLE=Counterstreaming Cold H+, He+, O+, and N+ Outflows in the Plasmasphere JOURNAL=Frontiers in Astronomy and Space Sciences VOLUME=8 YEAR=2021 URL=https://www.frontiersin.org/journals/astronomy-and-space-sciences/articles/10.3389/fspas.2021.712611 DOI=10.3389/fspas.2021.712611 ISSN=2296-987X ABSTRACT=

The Naval Research Laboratory (NRL) Sami3 is Also a Model of the Ionosphere (SAMI3) ionosphere/plasmasphere code is used to examine H⁺, He⁺, N⁺, and O⁺ thermal outflows during a storm. Here, H⁺ and He⁺ outflows are associated with refilling while O⁺ and N⁺ outflows are associated with ring current heating. An improved model of counterstreaming H⁺ outflows from the two hemispheres is presented, using an implementation of SAMI3 with two fluid species for H⁺. The two-fluid H⁺ model avoids nonphysical high-altitude “top-down refilling” density peaks seen in one-fluid H⁺ simulations. Counterstreaming cold ion populations are found in all cases. In these fully three-dimensional simulations with realistic magnetosphere boundary conditions, nonphysical top-down refilling density peaks were milder than those found in previous single-field-line or single-magnetic-longitude simulations. In the present two-fluid H⁺ case, “bottom-up refilling” density peaks were so mild as to be difficult to detect. For O⁺ and N⁺, the nonphysical high-altitude density peak is a brief (1–2 h) transient that occurs when heating-driven northward and southward flows first meet. In general, He⁺ outflows mimic H⁺ outflows while N⁺ outflows mimic O⁺ outflows.