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Thermospheric poleward wind surge at midlatitudes during great storm intervals
Author(s) -
Zhang ShunRong,
Erickson Philip J.,
Foster John C.,
Holt John M.,
Coster Anthea J.,
Makela Jonathan J.,
Noto John,
Meriwether John W.,
Harding Brian J.,
Riccobono Juanita,
Kerr Robert B.
Publication year - 2015
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 - 10.1002/2015gl064836
Subject(s) - millstone hill , middle latitudes , surge , geomagnetic storm , atmospheric sciences , geology , dynamo , storm , climatology , ionosphere , geophysics , incoherent scatter , environmental science , earth's magnetic field , physics , magnetic field , oceanography , quantum mechanics , geomorphology
We report a significant poleward surge in thermospheric winds at subauroral and midlatitudes following the 17–18 March 2015 great geomagnetic storm. This premidnight surge is preceded by strong westward winds. These disturbances were observed over three sites with geodetic latitudes 35–42°N in the American sector by Fabry‐Perot interferometers at 630 nm wavelength. Prior to the wind disturbances, subauroral polarization streams (SAPS) were measured by the Millstone Hill incoherent scatter radar between 20 and 02 UT. We identify the observed neutral wind variations as driven by SAPS, through a scenario where strong ion flows cause a westward neutral wind, subsequently establishing a poleward wind surge due to the poleward Coriolis force on that westward wind. These regional disturbances appear to have prevented the well‐known storm time equatorward wind surge from propagating into low latitudes, with the consequence that the classic disturbance dynamo mechanism failed to occur.