Modeling of gravity-wave tail spectra in the middle atmosphere via numerical and Doppler-spread methods

Hines, C. O., Childress, L. I., Kinney, J. B., Sulzer, M. P. (July 2004) Modeling of gravity-wave tail spectra in the middle atmosphere via numerical and Doppler-spread methods. Journal of Atmospheric and Solar-Terrestrial Physics, 66 (11). pp. 933-948. ISSN 1364-6826

Abstract

Wind fluctuations in the middle atmosphere exhibit an Eulerian spectral tail approximating to the form m−3 at large vertical wavenumbers m. The tail is taken here to result from a characteristically Eulerian nonlinearity in the governing fluid dynamic equations, a nonlinearity that is absent from a Lagrangian description. It is modeled here via a previously described analytic transformation from assumed model Lagrangian input spectra. The present work gives numerical expression to the earlier analytic results for the intensity of the tail. The resultant tail spectra are found to represent well the relevant data at reasonable values of Richardson number. Under an assumption of constant Richardson number, they exhibit saturation as height increases, as do the observations. Previously obtained approximate results, including those of the Doppler-spread theory of saturation, are found to represent well the new numerical results. Implications for that theory and for the associated Doppler-spread parameterization are discussed in a companion paper.

Item Type: Paper
Subjects: physics
CSHL Authors:
Communities: CSHL labs > Kinney lab
Depositing User: Matt Covey
Date: July 2004
Date Deposited: 30 Apr 2015 19:47
Last Modified: 30 Apr 2015 19:47
URI: https://repository.cshl.edu/id/eprint/31369

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