A global magnetosphere-ionosphere coupling model of substorms

Journal Article · Fri Oct 01 04:00:00 EDT 1993 · Journal of Geophysical Research

DOI:https://doi.org/10.1029/93JA01168· OSTI ID:75619

Kan, J R ^[1]

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

A global model of substorms is proposed on the basis of observational synthesis and theoretical modeling. Since the theoretical basis of the present model is the magnetosphere-ionosphere coupling (MIC) process, it will be called the MIC model of substorms. Substorms can occur in the MIC model without a new X line formed in the near-Earth plasma sheet, in contrast to the highly popular near-Earth neutral line (NENL) model of substorms. Following enhanced dayside reconnection, the ionosphere overloads both the solar wind on open field lines and the plasma sheet on closed field lines. The solar wind responds to the overload by providing more driven energy from the dynamo action on open field lines. The plasma sheet responds to the overload by collapsing itself, i.e., dipolarizing its field configuration to form the substorm current wedge. The explosive intensification during the expansion phase is powered by releasing the magnetic energy stored on closed field lines in the plasma sheet. The stored energy is released by the unloading instability driven by a positive feedback in the substorm current wedge. 68 refs., 6 figs., 1 tab.

• Sponsoring Organization: USDOE
• OSTI ID: 75619
• Journal Information: Journal of Geophysical Research, Journal Name: Journal of Geophysical Research Journal Issue: A10 Vol. 98; ISSN JGREA2; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
COUPLING
EARTH MAGNETOSPHERE
IONOSPHERE
MAGNETIC STORMS
MATHEMATICAL MODELS
SOLAR WIND