Abstract
The fate of Plasmasphere material once it is drained out of the
plasmasphere through a plume is unknown. One of two things may happen to
the vented plasmasphere material. It can be either swept away with the
solar wind, lost to the earth system, or it may be recirculated into the
magnetosphere system, either through the low latitude boundary layer or
over the poles and through the mantle. Recirculating plasmasphere
material could plausibly enter the central plasma sheet and contribute
to the ring current. Using observations to study the fate of the
plasmasphere material is difficult as it is mostly hydrogen and becomes
homogenized with solar wind hydrogen once it passes through the day side
magnetopause. Numerical models, however, can keep the material distinct,
opening the possibility of resolving the question using simulations.
This work seeks to answer the question, does any plasmasphere material
recirculate back into the magnetosphere? This is done by studying
simulations produced by the Space Weather Modeling Framework (SWMF)
configured to couple three models: the Block Adaptive Tree Solar Roe Up
Wind Scheme (BATS-R-US) model, the Dynamic Global Core Plasma Model
(DGCPM) plasmasphere model, and the Ridley Ionosphere Model (RIM). For
this simulation BATS-R-US is configured to use two fluids. The first
fluid represents currently accepted sources of ring current material,
namely the solar wind and high latitude ionospheric outflow. The second
fluid represents the plasmasphere. Within 10 Earth Radii (RE) the
dynamics in BATS-R-US on closed field lines are dictated by coupling
with the DGCPM. DGCPM passes the density of material in the plasmasphere
to BATS-R-US. In addition to this coupling, RIM passes electric field
information to both BATS-R-US and DGPCM while receiving current density
form BATS-R-US. The outputs of the simulation are examined to evaluate
plume recirculation. The fate of the plasmasphere material is then
studied in an idealized.