Characteristics of the association between the interplanetary magnetic field and substorms

Journal Article · Sat Oct 01 04:00:00 EDT 1977 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA082i029p04837· OSTI ID:7287670

Caan, M N; McPherron, R L; Russell, C T

The geomagnetic response to changes in the orientation of the interplanetary magnetic field (IMF) has been investigated for 18 IMF events. These events consisted of clear southward shifts of the IMF when the IMF B/sub z/(GSM) component had been northward for more than 2 hours. It was found that when the IMF thus shifted southward and remained southward for at least 2 hours, a magnetospheric substorm always ensued. Several properties of this subsequent geomagnetic activity were determined to be associated with IMF parameters. The amplitude of auroral negative bays was confirmed to be a function of the southward IMF flux preceding the onsets. Auroral bay activity was also observed to cease abruptly coincident with permanent northward recoveries in the IMF. Finally, it was observed that many of the ground expansion onsets were associated with either IMF northward fluctuations or partial northward recoveries, which we interpret as indicative of the existence of a class of IMF-triggered substorms.

• Research Organization: Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California 90024
• OSTI ID: 7287670
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 82:29; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640107 -- Astrophysics & Cosmology-- Planetary Phenomena
640203* -- Atmospheric Physics-- Magnetospheric Phenomena-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAL ZONES
EXPLORER SATELLITES
FLUCTUATIONS
INTERPLANETARY MAGNETIC FIELDS
MAGNETIC BAYS
MAGNETIC FIELDS
MAGNETOPAUSE
SATELLITES
SOLAR ACTIVITY
SOLAR WIND
VARIATIONS