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Semidiurnal variations in the time scale of irregularities near the Antarctic summer mesopause
Author(s) -
Fraser G. J.,
Khan Usman
Publication year - 1990
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/rs025i005p00997
Subject(s) - mesopause , atmospheric sciences , geology , advection , turbulence , atmospheric tide , climatology , mesosphere , thermosphere , meteorology , geodesy , environmental science , stratosphere , geophysics , ionosphere , physics , thermodynamics
Measurements from the MF spaced antenna mode radar at Scott Base (78°S, 167°E) include an estimate of the autocorrelation time scale ( T 0.5 ) of the scatterers, corrected for advection by the mean wind. Summer observations (December 1983) show a semidiurnal variation of T 0.5 . At heights of 87–95 km the minimum values of T 0.5 occur when the zonal component of the semidiurnal tide is at its westward maximum. If it is assumed that decreasing values of T 0.5 are associated with increasing turbulence, then these results are consistent with those of Balsley et al. (1983), who proposed that enhanced turbulence is generated in summer by low‐frequency gravity waves and tidal components above the polar mesopause.