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Seasonal and longitudinal dependence of equatorial disturbance vertical plasma drifts
Author(s) -
Fejer Bela G.,
Jensen John W.,
Su ShinYi
Publication year - 2008
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 - 10.1029/2008gl035584
Subject(s) - solstice , equinox , dusk , atmospheric sciences , daytime , disturbance (geology) , local time , dynamo , environmental science , southern hemisphere , noon , thermosphere , climatology , northern hemisphere , ionosphere , geology , physics , latitude , geodesy , geophysics , paleontology , statistics , mathematics , quantum mechanics , astronomy , magnetic field
We used equatorial measurements from the ROCSAT‐1 satellite to determine the seasonal and longitudinal dependent equatorial F region disturbance vertical plasma drifts. Following sudden increases in geomagnetic activity, the prompt penetration vertical drifts are upward during the day and downward at night, and have strong local time dependence at all seasons. The largest prompt penetration drifts near dusk and dawn occur during June solstice. The daytime disturbance dynamo drifts are small at all seasons. They are downward near dusk with largest (smallest) values during equinox (June solstice); the nighttime drifts are upward with the largest magnitudes in the postmidnight sector during December solstice. During equinox, the downward disturbance dynamo drifts near sunset are largest in the eastern hemisphere, while the late night upward drifts are largest in the western hemisphere. The longitudinal dependence of the disturbance dynamo drifts is in good agreement with results from simulation studies.