Transcript Overview of CISM Magnetosphere Research Mary Hudson1, Anthony Chan2, Scot Elkington3, Brian Kress1, William Lotko1, Paul Melanson1, David Murr1, John Lyon1, Hans.

Overview of CISM Magnetosphere Research
Mary Hudson1, Anthony Chan2, Scot Elkington3, Brian Kress1, William Lotko1, Paul Melanson1,
David Murr1, John Lyon1, Hans Mueller1, Jeremy Ouellette1,Barrett Rogers1, Simon Shepherd1,Frank Toffoletto2
1 Dartmouth
Introduction/Motivation
College, 2 Rice University, 3 University of Colorado
3D Radiation Belt Electron Modeling________
MI Coupling – Ionospheric Outflow
Two important extensions of the LFM model with new diagnostic capabilities:
A 3D full-Lorentz test particle code with first invariant conservation and guiding
The magnetosphere responds as a coupled system center switch has been developed using MHD fields calculated with the LFM code, 1.We have developed a multi-fluid version of the LFM code, MF-LFM.
Oxygen outflow, below, appears to have a profound effect on tail reconnection.
to solar wind input provided by MAS-ENLIL or L1
driven by L1 plasma parameters. Pitch angle results, available for the first time with
During single fluid simulations with similar solar wind conditions, the
data. The LFM code provides the single fluid MHD
3D test particle simulations in MHD fields, explain delayed appearance at SAMPEX
reconnection site is always farther down tail by about 10 RE. The earthward
description for the magnetospheric system, coupled altitude (2 months) for drift time scale injection events, strongly peaked at 90 deg.
with the TING/TIEGM ionosphere in the Coupled
motion of the x-line appears to be related to mass addition in the tail;
Magnetosphere-Ionosphere-Thermosphere (CMIT)
momentum balance (amount of mass that has to be accelerated) is more
model. Output from the LFM Model, which has been
favorable if the x-line lies earthward of the single fluid result. See Lyon poster.
fully parallelized to provide greater resolution in the
inner magnetosphere, is being coupled with the Rice
Convection Model to incorporate drift physics. The
complete three-way coupled LTR code will be used
to specify the time dependent fields which affect SEP
and radiation belt particle dynamics. A plasmasphere
boundary can be specified by the RCM or inclusion
of ionospheric dynamics. Mass outflow, which is
important to describing the ionospheric source of
magnetospheric plasma, is being approached with
development of a multi-fluid version of LFM.
Reconnection controls the solar wind coupling, with
plans underway to include a Hall-term in the Ohm’s
Law solved by the global MHD code.
>10 MeV SAMPEX flux
post Halloween 2003
CMIT Study of SEP Access
2. One-fluid LFM simulations using CISM ‘Long Run’(1996) output compare
effects of H+ outflow vs. no outflow on transpolar potential pc, hemispherically
integrated field-aligned current I||, precipitating electron number flux Fe|| and
energy flux Pe||, all at the ionosphere, and the hemispherically averaged
Pedersen conductivity p and energy of precipitating electrons e. See below,
and Lotko poster.
LFM-RCM Coupling: Improved
Region 2 Currents and Tail Pressure
Initial orbit: 605 -- 31 March 1991
Final Orbit: 756 -- 31 May 1991
=10^3.93
LFM-RCM Grid
Comparison
Plots the LFM pressure and field lines
for: (a)
just before
the coupling
RCM isthis
called;
Significant
progress
in LFM-RCM
year with
?
density(b)
floor
in RCM
and increased
interpolation
after
3 hours
with only
the LFM;resolution.
a) Shown
is comparison
Region
1 & 2 the
currents with
(c) the
same timeof
as
(b) with

LFM alone and RCM-coupled (top).
effects
of
the
RCM
included
b) Empirical and model tail pressure (bottom).
See Lyon poster.

Simulated oxygen plume in the magnetosphere, left; closeup of x-line, right.
The CMIT model is used to investigate SEP and GCR
access to the magnetosphere. The SEP-cutoff model
approximates primary SEP fluxes at the Earth using cutoff
rigidities. Reverse particle trajectories originating at the
Earth's surface are computed in static CMIT field
snapshots to locate SEP cutoffs. Cutoff rigidities
calculated in a simulation of the 14 May 1997 storm
shown, with IGRF field embedded. Time-dependent SEP
fluxes are also calculated by isotropically launching a SEP
distribution in the solar wind (see Luhmann poster), and
following forward Lorentz trajectories (Kress et al. 2005;
Hudson et al. 2005), see Kress poster.