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Polar cap convection for B z northward
Author(s) -
Crowley G.,
Can P. S.,
Dozois C. G.,
Reinisch B. W.,
Buchau J.
Publication year - 1992
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 - 10.1029/92gl00395
Subject(s) - polar cap , convection , polar , geology , ionosphere , geophysics , variation (astronomy) , geodesy , atmospheric sciences , physics , meteorology , astrophysics , astronomy
The Digisonde at Qanaq, Greenland (87°Λ) measures the ionospheric convection velocity in the central polar cap. The average local time variation of the velocity for B z northward under various B y conditions is presented. The nightside drifts for B z northward tend to be antisunward, and resemble those which occur for southward IMF, as pointed out by Heppner and Maynard (1987). However, it is difficult to reconcile the observed diurnal drift variation with the Heppner‐Maynard distorted two‐cell model. Modified forms of the Potemra et al. (1984) four cell model offer a more plausible framework in which to understand the Qanaq data. The polar cap cells are relatively small, and are displaced towards the dayside.