Premium
Magnetospheric sash dependence on IMF direction
Author(s) -
Siscoe G. L.,
Erickson G. M.,
Ö Sonnerup B. U.,
Maynard N. C.,
Siebert K. D.,
Weimer D. R.,
White W. W.
Publication year - 2001
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 - 10.1029/2000gl003784
Subject(s) - magnetopause , interplanetary magnetic field , solar wind , physics , geophysics , field line , earth's magnetic field , magnetic field , perpendicular , geodesy , geology , geometry , mathematics , quantum mechanics
The magnetospheric sash is a ribbon of weak field shaped like a horseshoe with its open ends adjacent to the north and south dayside, magnetopause cusps and its closed end forming the cross‐tail current sheet. The clock angle of the sash in the dawn‐dusk meridian plane (as seen from the sun) rotates from 0° to 90° as the clock angle of the interplanetary magnetic field (IMF) rotates from 0° to 180°. We use a global MHD simulation to obtain the sash clock angles for IMF clock angles of 45°, 90°, and 135°. Remarkably, the results are very close to the clock angle of the magnetic null points obtained by superposing a uniform field representing the IMF on a dipole field representing the earth. Contours of magnetic field strength on cross sections perpendicular to the solar wind flow direction show how the sash evolves tailward from the dayside cusps.