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Observational evidence of ionospheric migrating tide modification during the 2009 stratospheric sudden warming
Author(s) -
Lin J. T.,
Lin C. H.,
Chang L. C.,
Huang H. H.,
Liu J. Y.,
Chen A. B.,
Chen C. H.,
Liu C. H.
Publication year - 2012
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 - 10.1029/2011gl050248
Subject(s) - ionosphere , atmospheric sciences , geology , subsidence , radio occultation , atmospheric tide , sudden stratospheric warming , thermosphere , cosmic cancer database , middle latitudes , latitude , environmental science , climatology , stratosphere , geodesy , geophysics , physics , astronomy , paleontology , structural basin , polar vortex
In this paper, modifications of the ionospheric tidal signatures during the 2009 stratospheric sudden warming (SSW) event are studied by applying atmospheric tidal analysis to ionospheric electron densities observed using radio occultation soundings of FORMOSAT‐3/COSMIC. The tidal analysis indicates that the zonal mean and major migrating tidal components (DW1, SW2 and TW3) decrease around the time of the SSW, with 1.5–4 hour time shifts in the daily time of maximum around EIA and middle latitudes. The typical ionospheric SSW signature: a semi‐diurnal variation of the ionospheric electron density, featuring an earlier commencement and subsidence of EIA, can be reproduced by differencing the migrating tides before and during the SSW period. Our results also indicate that the migrating tides represent ∼80% of the ionospheric tidal components at specific longitudes, suggesting that modifications of the migrating tides may be the major driver for producing ionospheric changes observed during SSW events, accounting for greater variability than the nonmigrating tides that have been the focus of previous studies.