The parameterization of IGW spectral characteristics at the middle atmosphere altitudes.

The suggested spectral gravity wave parameterization scheme describes gravity wave upward spectral evolution in the one-dimensional background wind field and neglecting, nonhydrostatic effects and downward back-reflection. The scheme is based on the empirical joint (k, m, phi) -spectra of horizontal wind fluctuations whose saturated portions of the spectral shape incorporate a vertical wave number m spectrum with an m(-3) slope. Other more complicated wave-breaking models are not used. The linear parts of these spectra are dominated by invariant aspects of gravity wave propagation and by spectral characteristics of tropospheric gravity wave sources, The special emphasis was placed on the problem of the critical level filtering.