A statistical relationship between the geosynchronous magnetic field and substorm electrojet magnitude

Journal Article · Mon Mar 01 04:00:00 EST 1993 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/92JA01660· OSTI ID:6589537

Lopez, R E ^[1]; Rosenvinge, T von ^[2]

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1. Univ. of Maryland, College Park (United States)
2. Johns Hopkins Univ. Applied Physics Lab., Laurel, Maryland (United States)

In this paper the authors examine the relationship between geosynchronous magnetic field variations during substorms measured by GOES 5 and the auroral electrojet as measured by AE and Poste de la Baleine. As in previous studies, the authors find that the more taillike the field prior to the local onset, the greater the dipolarization of the field during the substorm. They also find that the greater the deviation of the field from a dipolar configuration, the larger the change in AE during the event. This implies that stronger cross-tail currents prior to the substorm are associated with larger substorm-associated westward electrojets and thus more intense substorms. Previous work has shown that in order to produce the observed taillike fields at geosynchronous altitude, the intense cross-tail current that builds up during the growth phase must be localized in the near-Earth ([le] 10 R[sub E]) region. Since the westward electrojet is the ionospheric leg of the substorm current wedge, this result implies that the substorm-associated westward electrojet is drawn from the near-Earth region. In fact, the authors find that most of the current diversion occurs in the near-Earth magnetotail. Furthermore, they estimate that a diversion about half of the near-Earth cross-tail current can account for the current in the northern and southern westward electrojets associated with the substorm current wedge. 25 refs., 9 figs.

• OSTI ID: 6589537
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 98:A3; ISSN JGREA2; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

661320* -- Auroral
Ionospheric
& Magnetospheric Phenomena-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAE
BOLTZMANN STATISTICS
COMPARATIVE EVALUATIONS
CONFIGURATION
CURRENTS
DIPOLE MOMENTS
E REGION
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELECTRIC CURRENTS
ELECTROJETS
EVALUATION
GEOMAGNETIC FIELD
IONOSPHERE
MAGNETIC FIELDS
MAGNETIC STORMS
MAGNETOTAIL
PLANETARY IONOSPHERES
VARIATIONS