Case studies of the storm time variation of the polar cusp

Journal Article · Sat Jan 01 00:00:00 EST 1983 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA088iA01p00137· OSTI ID:6034499

Meng, C

The latitudinal variations of the polar cusp region were examined during three intense geomagnetic storms. The variations were compared with the intensity of storm time ring current inferred from the Dst index, with the magnitude of the north-south component B/sub z/ of the interplanetary magnetic field and with substorm activity. The common feature is that the rapid equatorward shift occurred during the increase of the ring current growth and during the southward turning of the interplanetary magnetic field orientation. The equatorwardmost latitude of the cusp was reached before the peak of the ring current intensity, by a few to several hours, coinciding with the occurrence of the largest magnitude of the southward interplanetary magnetic field component. However, details of the polar cusp latitudinal movement differ from storm to storm. During the three storms studied, the poleward recovery commenced at the peak magnitude of the negative IMF B/sub z/ component, but the recovery proceeded without a clear relation to variations of the interplanetary B/sub z/ component, to the ring current intensity, or to the substorm activity. The lowest cusp latitude observed was at approx.61.7/sup 0/, and the magnitude of this shift seems to be related to the magnitudes of -B/sub z/. It is further observed that the approximate rates of the cusp macroscopic equatorward and poleward movements are about 3/sup 0/ and 1.5/sup 0/ per hour, respectively.

• Research Organization: Applied Physics Laboratory, The Johns Hopkins University, Laurel, Maryland 20707
• OSTI ID: 6034499
• Journal Information: J. Geophys. Res.; (United States), Vol. 88:A1
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
POLAR CUSP
LATITUDE EFFECT
MAGNETIC STORMS
INTERPLANETARY MAGNETIC FIELDS
MAGNETIC BAYS
MAGNETOPAUSE
MAGNETOSPHERE
RING CURRENTS
CURRENTS
EARTH ATMOSPHERE
ELECTRIC CURRENTS
GEOGRAPHICAL VARIATIONS
MAGNETIC FIELDS
VARIATIONS
640203* - Atmospheric Physics- Magnetospheric Phenomena- (-1987)