Magnetically Self-Consistent Simulations of Ring Current with Implications for Diffuse Aurora and PIXIE Data Interpretation. Margaret W. Chen 1 and Michael Schulz 2 1 The Aerospace Corporation, Los Angeles, CA 2 Lockheed Martin Advanced Technology Center, Palo Alto, CA.
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Margaret W. Chen1 and Michael Schulz2
1The Aerospace Corporation, Los Angeles, CA
2Lockheed Martin Advanced Technology Center, Palo Alto, CA
2007 The Aerospace Corporation
Previously we have simulated diffuse aurora by using a static axisymmetric B-field model with no ring current.We have studied effects of convective transport and variations in plasmasheet distributions for various scattering models.
Fig 12 of Chen et al. [JGR, 110, A03210, 15 March 2005]
3 static axisymmetric
19 October 1998 Storm (min static axisymmetric Dst ~ –110 nT)
Solar-wind dynamic pressure was very low during the main phase of this storm.
We use AMIE model results (courtesy of G. Lu) to specify total potential drop DV across the polar cap.
from Fig 1 of Chen et al. [JGR, 110, A03210, 15 March 2005]
Ring Current Particle Dynamics static axisymmetric
Hamiltonian:H = MBm + qVE(L,;t)
M = first adiabatic invariant, Bm = mirror-point field, q = particle charge, and VE = electrostatic scalar potential
Euler Potentials: = E/La ; =
Geomagnetic Dipole Moment:mE = 0.305G-RE3
Drift Equations:d/dt = H/; d/dt = +H/
from Figs 2 & 3 of static axisymmetric Chen et al. [JGR, 111, A11S15, 23 Nov 2006]
from Figs 2 & 4 of static axisymmetric Chen et al. [JGR, 111, A11S15, 23 Nov 2006]
Kinetic Energy: static axisymmetric
E = [2/(g + 1)]MBm
p2 = 2m0MBm
Particles gain energy less efficiently from inward radial transport when the magnetic field produced by the ring current itself is taken into account.
Fig 7 of Chen et al. [JGR, 111, A11S15, 23 Nov 2006]
from Figs 2 & 6 of static axisymmetric Chen et al. [JGR, 111, A11S15, 23 Nov 2006]
Magnetic perturbation static axisymmetric DB(0)at “center of Earth”
DB(0) from self-consistent model is about 75% of DB(0) from non-self-consistent model during main phase of 19 Oct 1998 storm.
Fig 9 of Chen et al. [JGR, 111, A11S15, 23 Nov 2006]
Comparison of Simulated and Observed Proton Energy Flux static axisymmetric
At ring current energies the simulated energy flux agrees better (especially so at E = 57 keV) with measured (Polar/CAMMICE) energy flux when model is magnetically self-consistent.
Fig 10 of Chen et al. [JGR, 111, A11S15, 23 Nov 2006]
Application to plasmasheet electron transport (previously based on static axisymmetric B-field model with no ring current) for comparison with UVI and PIXIE data
Fig 12 of Chen et al. [ JGR, 110, A03210, 15 March 2005]
Plasmasheet Electron Dynamics based on static axisymmetric
Fourth Adiabatic Invariant: p3
Flux-Tube Volume: (1/B) ds
H = [(/)2/3c2+ m02c4]1/2m0c2 + qVE(L, ; t)
Strong-Diffusion Lifetime: = 2Bh (1 – )(m/p)
where Bh is the magnetic intensity at altitude h = 128 km, (= 0.25) is a backscatter coefficient, and p/m is the particles’ common speed.
14 based on static axisymmetric
15 based on static axisymmetric
16 based on static axisymmetric
17 based on static axisymmetric
based on static axisymmetric =
Fig 1 of based on static axisymmetric Chen et al. [JGR, 111, A11S15, 23 Nov 2006]
20 based on static axisymmetric
Schulz & Chen [ based on static axisymmetric JASTP, in press, 2007]
22 based on static axisymmetric
23 based on static axisymmetric
Model [based on based on static axisymmetric Søraas and Davis, NASA Report GSFC X-612-68-328, 1968] of equatorial magnetic-field perturbation produced by ring current
Fig 1 of Schulz [JGR, 102, 14149–14154, 1997]
Asymptotic radius of tail lobe, scaled radius of equatorial neutral line, and angular radius of boundary between closed and open mag-netic field lines on Earth’s surface as func-
tions of B01 = (2/3)Dst.
Fig 3 of Schulz [JGR, 102, 14149–14154, 1997]