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Equatorial Kelvin wave variability during 1992 and 1993Temperature and ozone data from the Microwave Limb Sounder (MLS) instrument on Upper Atmosphere Research Satellite (UARS) are used to analyze the variability of Kelvin wave activity during the first two years of the UARS mission. The analysis is carried out using the asynoptic mapping technique. Time frequency plots for zonal wavenumbers 1 and 2, at two heights representing the middle stratosphere and the stratopause, respectively, are used to analyze the temporal variability of the waves, and its possible relationship to the equatorial quasi-biennial oscillation (QBO) and semiannual oscillation (SAO). Kelvin wave activity reaches a maximum during the solstice seasons and almost disappears during the equinoxes, in agreement with previous studies. Eastward propagating variance is estimated for wave periods from 4 to 20 days, at all UARS pressure surfaces currently available for MLS. The semiannual modulation of variance is observed to extend down to the lower limits of the height ranges of the temperature and ozone retrievals. Furthermore, a superposed QBO modulation is detected up to the stratopause. Comparison between the variance in eastward propagating waves and the mean zonal wind shows a possible participation of kelvin waves in the forcing of the QBO. At the stratopause the role of Kelvin waves in forcing the SAO appears to be limited, in agreement with previous results. Between the 21-hPa and 4.6-hPa surfaces there appears to be a transition zone where there is no clear relationship between Kelvin wave activity and mean zonal flow acceleration.
Document ID
19950048925
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Canziani, Pablo O.
(University of Washington, Seattle, WA United States)
Holton, James R.
(University of Washington, Seattle, WA United States)
Fishbein, Evan
(Jet Propulsion Laboratory, California Inst. of Tech., Pasadena, CA United States)
Froidevaux, Lucien
(Jet Propulsion Laboratory, California Inst. of Tech., Pasadena, CA United States)
Date Acquired
August 16, 2013
Publication Date
March 20, 1995
Publication Information
Publication: Journal of Geophysical Research
Volume: 100
Issue: D3
ISSN: 0148-0227
Subject Category
Meteorology And Climatology
Accession Number
95A80524
Funding Number(s)
CONTRACT_GRANT: NAS5-26301
Distribution Limits
Public
Copyright
Other

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