Premium
Ionospheric symmetry caused by geomagnetic declination over North America
Author(s) -
Zhang ShunRong,
Chen Ziwei,
Coster Anthea J.,
Erickson Philip J.,
Foster John C.
Publication year - 2013
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 - 10.1002/2013gl057933
Subject(s) - empirical orthogonal functions , tec , declination , earth's magnetic field , longitude , ionosphere , magnetic declination , geology , middle latitudes , total electron content , local time , geophysics , climatology , geodesy , latitude , atmospheric sciences , physics , magnetic field , mathematics , astronomy , statistics , quantum mechanics
We describe variations in total electron content (TEC) in the North American sector exhibiting pronounced longitudinal progression and symmetry with respect to zero magnetic declination. Patterns were uncovered by applying an empirical orthogonal function (EOF) decomposition procedure to a 12 year ground‐based American longitude sector GPS TEC data set. The first EOF mode describes overall average TEC, while the strong influence of geomagnetic declination on the midlatitude ionosphere is found in the second EOF mode (or the second most significant component). We find a high degree of correlation between spatial variations in the second EOF mode and vertical drifts driven by thermospheric zonal winds, along with well‐organized temporal variation. Results strongly suggest a causative mechanism involving varying declination with longitude along with varying zonal wind climatology with local time, season, and solar cycle. This study highlights the efficiency and key role played by the geomagnetic field effect in influencing mesoscale ionospheric structures over a broad midlatitude range.