Dipolarization: A consequence of substorm expansion onset

Journal Article · Tue Jan 01 04:00:00 EST 1991 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/90GL02435· OSTI ID:5222191

Kan, J R ^[1]

---

1. Univ. of Alaska, Fairbanks (United States)

Dipolarization observed in the near-Earth plasma sheet can be initiated by the substorm expansion onset. Field-aligned currents at the substorm expansion onset are enhanced first in the ionosphere in response to an enhanced magnetospheric convection. Closure of substorm field-aligned currents through the plasma sheet can disrupt the cross-tail current to cause dipolarization in the plasma sheet. The electric field induced by the current disruption can launch a fast-mode compression wave to result in the plasma injection event. A new X line can form tailward of the dipolarization region during the substorm expansion phase. A timing sequence of substorm events is inferred from the proposed conceptual model of substorms based on the magnetosphere-ionosphere coupling process on the Alfven bounce time scale.

• OSTI ID: 5222191
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Journal Name: Geophysical Research Letters (American Geophysical Union); (United States) Vol. 18:1; ISSN 0094-8276; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CONVECTION
CURRENT DENSITY
CURRENTS
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELECTRIC CURRENTS
ELECTRIC FIELDS
ENERGY TRANSFER
EXPANSION
HEAT TRANSFER
IONOSPHERE
MAGNETIC BAYS
MASS TRANSFER
MATHEMATICAL MODELS
PLANETARY IONOSPHERES
PLASMA SHEET
POLARIZATION