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A new model for substorm onsets: The pre‐breakup and triggering regimes
Author(s) -
Rothwell P. L.,
Block L. P.,
Silevitch M. B.,
Fälthammar C. G.
Publication year - 1988
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl015i011p01279
Subject(s) - breakup , substorm , instability , kinetic energy , plasma , physics , perturbation (astronomy) , mechanics , geophysics , classical mechanics , nuclear physics , magnetosphere , quantum mechanics
This model explains why breakup has been observed as low as L = 5‐6 and predicts that a higher concentration of O + in the plasma sheet will permit breakup at such low L values. The establishment of a coupled current structure within a single arc leads to a quasi‐stable system i.e. the pre‐breakup regime. Perturbation of the pre‐breakup structure leads to an instability criterion. Certain quiescent configurations are inherently unstable. Transitions from a stable to an unstable situation can trigger a rapid poleward expansion of the quiescent arc or substorm breakup. The kinetic energy of injected plasma from the magnetotail supplies the energy for breakup.