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Impact of midnight thermosphere dynamics on the equatorial ionospheric vertical drifts
Author(s) -
Fang T.W.,
Akmaev R. A.,
Stoneback R. A.,
FullerRowell T.,
Wang H.,
Wu F.
Publication year - 2016
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1002/2015ja022282
Subject(s) - thermosphere , ionosphere , plasmasphere , equator , zonal and meridional , atmospheric sciences , f region , midnight , atmosphere (unit) , environmental science , physics , geology , geophysics , meteorology , geodesy , plasma , latitude , magnetosphere , quantum mechanics , astronomy
Recent satellite and ground‐based observations have revealed the existence of upward drifts in the postmidnight equatorial ionosphere (~0–3 LT). The phenomenon has not been explained by theoretical models. Simulations using the Whole Atmosphere Model coupled with the Global Ionosphere Plasmasphere model have successfully reproduced the unusual nighttime upward drifts. The simulations and observations by the Ion Velocity Meter onboard the Communications/Navigation Outage Forecasting System also reveal substantial longitudinal dependence of the drifts. Our analysis indicates that the upward drifts are driven by thermosphere dynamics associated with the midnight temperature maximum (MTM). The MTM locally reverses the typical large‐scale zonal and meridional wind pattern, in turn affecting the nighttime F layer electrodynamics. In addition, the longitudinal variation of the drifts in different seasons depends on the magnitude and position of the MTM peak relative to the magnetic equator.