A low-altitude mechanism for mesoscale dynamics, structure, and current filamentation in the discrete aurora

Journal Article · Fri Nov 20 00:00:00 EST 1992 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/92GL02491· OSTI ID:6821475

Keskinen, M J; Chaturvedi, P K ^[1]

---

1. Naval Research Lab., Washington, DC (United States)

The two-dimensional nonlinear evolution of the ionization-driven adiabatic auroral arc instability has been studied for the first time. The authors find: (1) the adiabatic auroral arc instability can fully develop on time scales of tens to hundreds of seconds and on spatial scales of tens to hundreds of kilometers, (2) the evolution of this instability leads to nonlinear hook-shaped' conductivity structures, (3) this instability can lead to parallel current filamentation over a wide range of scale sizes from k[Lambda][sub 0] < 1 to k[Lambda][sub 0] > 1 where ks is the wavenumber and [Lambda][sub 0] is the initial arc width perpendicular to the geomagnetic field, and (4) the k-spectra of the density, electric field, and parallel current develop into inverse power laws in agreement with satellite observations. Comparison with mesoscale auroral phenomenology and current filamentation structures is made. 28 refs., 3 figs.

• OSTI ID: 6821475
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Vol. 19:22; ISSN 0094-8276
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAE
DYNAMICS
SPATIAL DISTRIBUTION
PLASMA INSTABILITY
TWO-DIMENSIONAL CALCULATIONS
DENSITY
ELECTRIC FIELDS
GEOMAGNETIC FIELD
GLOBAL ASPECTS
INSTABILITY
IONIZATION
NONLINEAR PROBLEMS
TIME DEPENDENCE
DISTRIBUTION
MAGNETIC FIELDS
MECHANICS
PHYSICAL PROPERTIES
661320* - Auroral
Ionospheric
&amp; Magnetospheric Phenomena- (1992-)