On the auroral current-voltage relationship

Journal Article · Fri Mar 01 04:00:00 EST 1991 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/90JA02462· OSTI ID:5268317

Lu, G; Reiff, P H ^[1]; Burch, J L; Winningham, J D ^[2]

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1. Rice Univ., Houston, TX (USA)
2. Southwest Research Inst., San Antonio, TX (USA)

A simple model of collisionless plasma kinetic theory (Knight, 1973) has been used to predict the relationship between the upward parallel current and the parallel potential drop. The DE 1/DE 2 pair offers a unique opportunity to test this relationship because the DE 1 spacecraft can measure the high altitude plasma parameters without contamination from auroral heating. The field-aligned current density from Knight's formula is almost linear in the ratio of j{sub {parallel}}/e{Phi}{sub {parallel}} for values of e{Phi}{sub {parallel}}/kT between 1 and 10. The authors find, using measured values of J{sub {parallel}} (mapped to the surface) and {Phi}{sub {parallel}} (inferred from measurements either at high altitudes or low altitudes), the ratio of J{sub {parallel}}/e{Phi}{sub {parallel}} varies considerably but with a mean value about 0.5{approximately}2.2 {times} 10{sup {minus}9} mho/m{sup 2}. Using either the full Knight's formula or the linear simplification. they can predict the parallel potential drop (given the high-altitude density, temperature, current, and magnetic mirror factor) to test against the measured potential drop, or they can predict the current given the potential drop and the high-altitude plasma parameters. The agreement is generally quite good and the linear simplification is reasonable; however, the Knight current, since it does not include upward ionospheric electrons, is not valid in the downward return current region. They also show that suprathermal electron bursts are observed in the diffuse aurora at the same invariant latitudes, both at high and at low altitudes. Thus they suggest that these bursts are more properly described as a spatial rather than temporal phenomenon.

• OSTI ID: 5268317
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 96:A3; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCELERATION
AURORAE
AURORAL ZONES
COLLISIONLESS PLASMA
CURRENT DENSITY
CURRENTS
DISTRIBUTION FUNCTIONS
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELECTRIC CURRENTS
ELECTRIC POTENTIAL
ELECTRODYNAMICS
ELECTRONS
ELEMENTARY PARTICLES
EXPLORER SATELLITES
FERMIONS
FUNCTIONS
HEATING
IONOSPHERE
LEPTONS
MATHEMATICAL MODELS
OHM LAW
PLANETARY IONOSPHERES
PLASMA
SATELLITES