Papers on Magnetospheric Physics
Anomalous aspects of magnetosheath flow and of the shape and oscillations of the magnetopause during an interval of strongly northward interplanetary magnetic field
Article first published online: 20 SEP 2012
Copyright 1993 by the American Geophysical Union.
Journal of Geophysical Research: Space Physics (1978–2012)
Volume 98, Issue A4, pages 5727–5742, 1 April 1993
How to Cite
1993), Anomalous aspects of magnetosheath flow and of the shape and oscillations of the magnetopause during an interval of strongly northward interplanetary magnetic field, J. Geophys. Res., 98(A4), 5727–5742, doi:10.1029/92JA02263., , , , and (
- Issue published online: 20 SEP 2012
- Article first published online: 20 SEP 2012
- Manuscript Accepted: 15 SEP 1992
- Manuscript Received: 29 MAY 1992
On February 15, 1978, the orientation of the interplanetary magnetic field (IMF) remained steadily northward for more than 12 hours. The ISEE 1 and 2 spacecraft were located near apogee on the dawnside flank of the magnetotail. IMP 8 was almost symmetrically located in the magnetosheath on the dusk flank and IMP 7 was upstream in the solar wind. Using plasma and magnetic field data, we show that (1) the magnetosheath flow speed on the flanks of the magnetotail steadily exceeded the solar wind speed by 20%, (2) surface waves of ∼5-min period and very nonsinusoidal waveform were persistently present on the dawn magnetopause and waves of similar period were present in the dusk magnetosheath, and (3) the magnetotail ceased to flare at an antisunward distance of 15 RE. We propose that the acceleration of the magnetosheath flow is achieved by magnetic tension in the draped field configuration for northward IMF and that the reduction of tail flaring is consistent with a decreased amount of open magnetic flux and a larger standoff distance of the subsolar magnetopause. Results of a three-dimensional magnetohydrodynamic simulation support this phenomenological model.