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Equatorial disturbance dynamo electric fields
Author(s) -
Fejer B. G.,
Larsen M. F.,
Farley D. T.
Publication year - 1983
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/gl010i007p00537
Subject(s) - dynamo , daytime , disturbance (geology) , geomagnetic storm , geology , storm , ionosphere , electric field , geophysics , latitude , dynamo theory , atmospheric sciences , f region , middle latitudes , thermosphere , earth's magnetic field , climatology , geodesy , physics , magnetic field , geomorphology , oceanography , quantum mechanics
F‐region vertical drift data from Jicamarca, Peru show that equatorial east‐west electric fields are sometimes perturbed 16‐24 hours after the onset of geomagnetic storms. These disturbance dynamo electric fields, which must be caused primarily by the action of neutral winds at low and middle latitudes, decrease and sometimes even reverse the quiet time electric field pattern during both daytime and nighttime. The long delay excludes the possibility that gravity waves are responsible and suggests that the thermospheric circulation is disturbed. The data also show that after some storms there are no such delayed disturbances, a fact which may be due to the longitudinal structure of the disturbances at high latitudes and/or that only very strong storms can produce major thermospheric perturbations that extend to middle and low latitudes.