Boundary-layer dynamics in the description of magnetospheric substorms

Technical Report · Fri Jan 01 04:00:00 EST 1988

OSTI ID:5557986

Eastman, T E; Rostoker, G; Frank, L A; Huang, C Y; Mitchell, D G

Magnetospheric substorm activity has been previously explained primarily as the effects of the episodic unloading of energy stored in the Earth's magnetotail. The physics of the unloading process has been associated with magnetic field-line reconnection. The near-Earth neutral line model seeks to explain plasma and field characteristics observed in the magnetotail by the development and ultimate disappearance downtail of a plasmoid involving the population of the plasma sheet anti-earthward of the near-Earth neutral line. This reprint presents a study of a significant number of substorm expansive phase events where the phenomenology at ionospheric levels is clearly defined in terms of onset time and locale of the substorm disturbed region. Through the detailed presentation of a subset of these events is demonstrated that the magnetotail particle and field observations associated with a substorm expansive phase can equally well be explained through the spatial movement of the boundary layers and central plasma sheet in the magnetotail. The sweeping of these regions past the satellite, even in the absence of temporal variations within the various regions, can lead to a set of plasma flow observations typical of what is observed in the magnetotail during substorm activity. Filamentary currents in the plasma-sheet boundary layer can produce the magnetic field signatures presently attributed to retreating plasmoids in the magnetotail. The major strength of this emphasis on boundary-layer dynamics is that it provides a framework which naturally encompasses both the driven system and loading-unloading system which are recognized to be operative simultaneously during magnetospheric substorm activity.

• Research Organization: Iowa Univ., Iowa City, IA (USA). Dept. of Physics and Astronomy
• OSTI ID: 5557986
• Report Number(s): AD-A-209803/6/XAB
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580201* -- Geophysics-- Seismology & Tectonics-- (1980-1989)
BOUNDARY LAYERS
CURRENTS
DISTRIBUTION
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELECTRIC CURRENTS
FILAMENTS
IONOSPHERE
LAYERS
MAGNETIC FIELDS
MAGNETIC STORMS
MAGNETOTAIL
NEUTRAL PARTICLES
PARTICLES
PHYSICS
PLANETARY IONOSPHERES
PLASMA SHEET
PLASMOIDS
SHEETS
SPATIAL DISTRIBUTION