Relationships of models of the inner magnetosphere to the Rice Convection Model

Heinemann, Michael; Wolf, R. A.

doi:10.1029/2000ja000389

Cited by 24 publications

(44 citation statements)

References 16 publications

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“…This discrepancy is, in large part, a symptom of the ''pressure balance inconsistency'', i.e., the fact that statistical models indicate that the specific entropy, PV 5/3 (where V = R ds/B is the flux tube volume, and P is the pressure), typically increases strongly and monotonically with distance from Earth [Erickson and Wolf, 1980]. This is inconsistent with adiabatic drift theory, which implies that P s V 5/3 is conserved along a drift path for particles in strong, elastic pitch-angle scattering, if losses are negligible [Heinemann and Wolf, 2001]; here P s is the partial pressure due to particles with isotropic energy invariant l s = W K V 2/3 , and W K = kinetic energy. , convection models therefore compress the plasma to unnaturally high densities and energies during earthward convection.…”

Section: Introductioncontrasting

confidence: 49%

Magnetic storm ring current injection modeled with the Rice Convection Model and a self‐consistent magnetic field

Lemon

Wolf

Hill

et al. 2004

Geophysical Research Letters

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122

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[1] We simulate plasma transport from the plasma sheet to the ring current, for the first time including the feedback effect of the drifting particles on both the electric and magnetic fields. Results suggest that strong, steady adiabatic convection throughout the middle plasma sheet leads to a highly stretched inner plasma sheet, but no ring current particle flux increases. We subsequently impose a substantial reduction of the specific entropy PV 5/3 near midnight outside 10 R E , where P is particle pressure and V = R ds/B is flux tube volume. This produces a strong enhancement of the asymmetric ring current, which becomes symmetric when the pressure depletion and strong convection are quelled. We suggest that a reduction of the specific entropy in a region of the inner plasma sheet, apparently by some process that violates the assumption of adiabatic drift, plays a major role in the injection of a storm-time ring current.

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Section: Introductioncontrasting

confidence: 49%

Magnetic storm ring current injection modeled with the Rice Convection Model and a self‐consistent magnetic field

Lemon

Wolf

Hill

et al. 2004

Geophysical Research Letters

Self Cite

122

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“…A slightly more complicated (but more realistic) way to view the same phenomenon is through the use of a bounce‐averaged drift formalism. If one uses this formalism but also assumes that strong, elastic pitch angle scattering keeps the distribution function isotropic, then the distribution function f (λ, , t ) is constant along a drift path, where is the isotropic energy invariant, and E is the particle's kinetic energy [ Wolf , 1983; Heinemann and Wolf , 2001]. The assumption of isotropy is reasonable in the middle plasma sheet, beyond the “isotropy boundary” [e.g., Sergeev et al , 1993], because chaotic motion in the current sheet keeps the distribution roughly isotropic [ Stiles et al , 1978], but it becomes less realistic close to the Earth.…”

Section: Introductionmentioning

confidence: 99%

Pressure balance inconsistency exhibited in a statistical model of magnetospheric plasma

Garner

2003

J. Geophys. Res.

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[1] While quantitative theories of plasma flow from the magnetotail to the inner magnetosphere typically assume adiabatic convection, it has long been understood that these convection models tend to overestimate the plasma pressure in the inner magnetosphere. This phenomenon is called the pressure crisis or the pressure balance inconsistency. In order to analyze it in a new and more detailed manner we utilize an empirical model of the proton and electron distribution functions in the near-Earth plasma sheet (À50 R E < X < À10 R E ), which uses the Tsyganenko [1989] magnetic field model and a plasma sheet representation based upon several previously published statistical studies. We compare our results to a statistically derived particle distribution function at geosynchronous orbit. In this analysis the particle distribution function is characterized by the isotropic energy invariant l = EV 2/3 , where E is the particle's kinetic energy and V is the magnetic flux tube volume. The energy invariant is conserved in guiding center drift under the assumption of strong, elastic pitch angle scattering. If, in addition, loss is negligible, the phase space density f (l) is also conserved along the same path. The statistical model indicates that f (l,x) is approximately independent of X for X À35 R E but decreases with increasing X for X ! À35 R E . The tailward gradient of f (l,x) might be attributed to gradient/curvature drift for large isotropic energy invariants but not for small invariants. The tailward gradient of the distribution function indicates a violation of the adiabatic drift condition in the plasma sheet. It also confirms the existence of a ''number crisis'' in addition to the pressure crisis. In addition, plasma sheet pressure gradients, when crossed with the gradient of flux tube volume computed from the Tsyganenko [1989] magnetic field model, indicate Region 1 currents on the dawn and dusk sides of the outer plasma sheet.

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“…This procedure effectively amounts to a single fluid reduction. In this paper we show that this implied procedure can be written explicitly as an a priori energy transport equation with a nonzero heat flux as suggested by Heinemann and Wolf [2001]. The chief benefit of this theory is that it provides a computationally more efficient way to tackle the convection problem.…”

Section: Introductionmentioning

confidence: 99%

Heat flux in magnetospheric convection: A calculation based on adiabatic drift theory

Liu

2006

Geophysical Research Letters

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[1] Empiric evidence and theoretical argument indicate that magnetospheric convection is globally sub-adiabatic. Reconciliation of the sub-adiabaticity with the underlying adiabatic particle drifts is a problem that has not been conclusively demonstrated. In this paper, through an ensemble average, we show that the Rice Convection Model contains a heat flux due to thermal inequilibrium between two adjacent flux tubes of equal volume. The averaged theory is based on field variables obeying a set of partial differential equations (Eulerian formulation), instead of conservative variables advecting with fluid elements (Langrangian formulation). We apply the theory to investigate a one-dimensional case of subadiabatic variation of thermodynamic properties in the plasma sheet.

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Relationships of models of the inner magnetosphere to the Rice Convection Model

Cited by 24 publications

References 16 publications

Magnetic storm ring current injection modeled with the Rice Convection Model and a self‐consistent magnetic field

Magnetic storm ring current injection modeled with the Rice Convection Model and a self‐consistent magnetic field

Pressure balance inconsistency exhibited in a statistical model of magnetospheric plasma

Heat flux in magnetospheric convection: A calculation based on adiabatic drift theory

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