On calculating ionospheric conductances from the flux and energy of precipitating electrons

Robinson, R. M.; Vondrak, R. R.; Miller, K. L.; Dabbs, Teri M.; Hardy, D. A.

doi:10.1029/ja092ia03p02565

Cited by 441 publications

(585 citation statements)

References 9 publications

Supporting

Mentioning

549

Contrasting

Order By: Relevance

“…With these quantities defined, equation (7) can be solved for the electric field tangential to the poleward arc, E t , and all characteristic parameters of the arc and the ionospheric dissipation can be calculated as outlined in Appendix A. The Cowling conductivity follows from empirical relations with the electron energy flux and mean energy after Robinson et al [1987].…”

Section: Poleward Arc Of the Auroral Bulgementioning

confidence: 99%

See 1 more Smart Citation

Six auroral generators: A review

Haerendel

2011

J. Geophys. Res.

View full text Add to dashboard Cite

[1] The paper reviews generator processes and configurations of six types of auroral arcs: embedded arcs, Alfvénic arcs, onset arcs, poleward arcs during substorms, auroral streamers, and auroral spirals. The arcs and generators are elements in global current systems, which are classified as Types I and II after Boström. The arcs may be dominated by transient processes or be quasi-stationary. The main emphasis of the paper is on the generator forces. They are pressure gradient forces, magnetic normal or shear stresses, or inertial forces. For three cases, the arcs embedded in the oval convection, the poleward arc during substorms, and the auroral streamers, simple expressions are presented of the currents injected into the ionosphere by the generator process, allowing quantitative evaluations. The relations leading from these currents to other key auroral quantities are summarized. The apparent conflict between the widths of Alfvénic arcs and the transverse scales required for energy coupling to the topside ionospheric plasma is solved by assuming current and field filamentation by multiple reflections in the ionospheric Alfvén resonator. The substorm generator is described as a high-beta plasma layer arising from collapse of the tail current sheet. An essential element in this process is the shedding of excess flux tube entropy through energy dumping in the auroral acceleration process and ionospheric dissipation. The dynamics of this process needs further investigation. The physics of the connection between flow bursts in the tail plasma sheet and the flows associated with auroral streamers in the ionosphere is discussed. Regular auroral spirals and the westward traveling surge have in common a concentration of upward field-aligned current which demands strongly enhanced dissipation. They differ by the processes creating the upward current concentration.

show abstract

Section: Poleward Arc Of the Auroral Bulgementioning

confidence: 99%

“…Calculation of the ionospheric electric field and dissipation needs calculation of Pedersen and Hall conductivities. They can be obtained from _ W arc and F k by employing the empirical expressions of Robinson et al [1987].…”

Section: Appendix Amentioning

confidence: 99%

Six auroral generators: A review

Haerendel

2011

J. Geophys. Res.

View full text Add to dashboard Cite

show abstract

“…Brekke et al [1974] suggested that the ratio of heightintegrated Hall conductivity to height-integrated Pedersen conductivity would scale as electron energy, and Robinson et al [1987] provide a prescription for calculating characteristic energy for assumed Maxwellian precipitation as a function of S H /S P .…”

Section: First-stage Conductance Ratio Filteringmentioning

confidence: 99%

Incoherent scatter radar measurements and modeling of high‐latitude solar photoionization

2005

View full text Add to dashboard Cite

[1] A 9-year database of sunlit E region electron density altitude profiles (N e (z)) measured by the Sondrestrom incoherent scatter radar (ISR) has been partitioned over a parameter space of 10.7 cm solar radio flux (F 10.7 ) and solar zenith angle (c) to investigate long-term solar and thermospheric variability and to validate a contemporary EUV photoionization model. A two-stage filter, which rejects N e (z) profiles with large Hall-toPedersen conductance ratio and incorporates an MLT-dependent correction factor for lowenergy precipitation, is used to mitigate auroral contamination. Resultant filtered mean sunlit N e (z) is compared with subauroral N e measured for the same F 10.7 and c conditions at the Millstone Hill ISR in order to confirm adequate high-energy auroral rejection. Mean N e , as expected, increases with solar activity and decreases with large c. Radar model comparison indicates that across all parameter space and for altitudes from 105 to 180 km, the GLOW model estimates are within 5% of the ISR mean with the contribution from photoelectrons accounting for 30 to 50% of equilibrium ion density. Above 180 km, the GLOW model slightly overestimates the height of the F1 layer. Radar model comparison also reveals a low-altitude N e enhancement for high solar activity at altitudes commensurate with 3 to 7 nm XUV and H Lyman-b radiances. The variance of the ISR mean N e is shown to be greatest at low F 10.7 (solar minimum). Simulated N e variance envelopes, given by perturbing the GLOW model neutral atmosphere input by the measured A p , F 10.7 , and T e extrema, are narrower than ISR derived geophysical variance envelopes at solar minimum. We find no evidence for solar cycle control of low-energy precipitation and thus we attribute the observed N e variance at solar minimum to variability in solar EUV flux. In order to address estimation of N e at altitudes where GLOW model photochemical equilibrium assumptions are invalid, we provide an empirical model for Sondrestrom quiet time photoionization N e (z) as a function of F 10.7 and c.Citation: Doe, R. A., J. P. Thayer, and S. C. Solomon (2005), Incoherent scatter radar measurements and modeling of high-latitude solar photoionization,

show abstract

“…The ionospheric dissipation is now modeled using the formulation of Robinson et al [1987]. It would be a …”

Section: Low-dimensional Modelmentioning

confidence: 99%

Dynamical range of the WINDMI model: An exploration of possible magnetospheric plasma states

Smith¹,

Thiffeault²,

Horton³

2000

J. Geophys. Res.

View full text Add to dashboard Cite

Abstract. This paper explores the dynamical range of the WINDMI model (Horton and Doxas, 1998]. Such low-dimensional models provide us with the tools to understand the relationships of simple physical quantities within the magnetosphere (such as energy deposition, macroscopic currents, cross-tail voltage, etc.) without the necessity of coping with the more complete but unwieldy models (MHD or particle codes, for example). The model is highly versatile: certain regions of the parameter space support stable fixed points, while others contain periodic states that exhibit period doubling, and sometimes chaos. States in each of these regimes (stable, periodic, chaotic) are investigated for their ability to accurately describe the observed properties of the magnetosphere-ionosphere system. A brief discussion of applications of this model to current space physics problems is included.

show abstract

On calculating ionospheric conductances from the flux and energy of precipitating electrons

Cited by 441 publications

References 9 publications

Six auroral generators: A review

Six auroral generators: A review

Incoherent scatter radar measurements and modeling of high‐latitude solar photoionization

Dynamical range of the WINDMI model: An exploration of possible magnetospheric plasma states

Contact Info

Product

Resources

About