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Observation of neutral temperature tidal‐type oscillations in the F 1 region
Author(s) -
Fontanari J.,
Alcayde D.
Publication year - 1974
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1029/rs009i002p00275
Subject(s) - thermosphere , ionosphere , excited state , mode (computer interface) , atmospheric sciences , exosphere , physics , incoherent scatter , computational physics , work (physics) , atomic physics , geophysics , ion , thermodynamics , quantum mechanics , computer science , operating system
Incoherent scatter data gathered at St. Santin yield a determination of the ionic (neutral) temperature in the F 1 region. Although large uncertainties are present in these data, a study of their short‐term variations is possible provided they have been statistically combined in typical periods. It is shown that waves of tidal type are present in the lower thermosphere, with dominant periods of 24 and 12 hr. Seasonal variations are found in good agreement with exospheric temperature observations. Comparisons of experimental results with relevant theoretical works show a rather good general agreement. As concerns the semidiurnal component, Lindzen and Hong's work shows the possible presence of two modes in the thermosphere: a trapped mode generated in situ, and a propagating one generated below 100 km; however, experimental results suggest a rapid damping of the propagating mode above 180 km, while the in‐situ excited mode dominates.