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Electric and magnetic fields in the high‐latitude magnetosphere
Author(s) -
Fairfield D. H.
Publication year - 1977
Publication title -
reviews of geophysics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 8.087
H-Index - 156
eISSN - 1944-9208
pISSN - 8755-1209
DOI - 10.1029/rg015i003p00285
Subject(s) - magnetosphere , geophysics , physics , noon , polar , magnetopause , field line , electric field , interplanetary magnetic field , plasma sheet , magnetic field , ionosphere , computational physics , atmospheric sciences , solar wind , astronomy , quantum mechanics
The configuration of high‐latitude electric and magnetic fields is reviewed. Various results indicate that high‐latitude magnetic field lines from the outermost regions of the dayside magnetosphere converge toward a point near the noon meridian. This configuration funnels particles toward noon, where they can flow down field lines to form the midday cusp. Plasma convects away from this entry region and is associated with a dawn‐dusk electric field across the polar cap. Plasma flow is enhanced on the side of the polar cap where the components of interplanetary and magnetospheric magnetic fields are in the same direction. The electric fields associated with these flows produce Hall currents on the polar cap which vary with sector structure. Some evidence suggests that polar cap convection may reverse during intervals of strong northward interplanetary field. The flow reversal at the polar cap boundary is probably associated with ‘inverted V’ particle events, auroral arcs, parallel electric fields, and field‐aligned currents. It is concluded that most observations are consistent with an open field magnetosphere model.