Some experimental constraints for spectral parameters used in the Warner and McIntyre gravity wave parameterization scheme

[摘要] In order to incorporate the effect of gravity waves (GWs) on the atmosphericcirculationmost global circulation models (GCMs) employ gravity wave parameterizationschemes.To date, GW parameterization schemes in GCMs are used without experimentalvalidation of the set of global parameters assumed for the GW launch spectrum.This paper focuses on the Warner and McIntyre GW parameterization scheme.Ranges of parameterscompatible with absolute values of gravity wave momentum flux (GW-MF)derived from CRISTA-1 and CRISTA-2 satellite measurementsare deduced for several of the parameters and the limitations of bothmodel and measurements are discussed.The findings presented in this paper show that the initial guessof spectral parameters provided by by Warner and McIntyre (2001) are some kind of compromise with respect to agreement ofabsolute values and agreement of the horizontal structures found in bothmeasurements and model results.Better agreement can be achieved by using a vertical wavenumberlaunch spectrum with a wider saturated spectral range and reducedspectral power in the unsaturated part.However, even with this optimized set of global launch parameters not allfeatures of the measurements are matched. This indicates that for furtherimprovement spatial and seasonal variations of the launch parameters shouldbe included in GW parameterization schemes.

[学科分类] 大气科学