Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 6 3 2006 10.5194/acpd-6-4755-2006 http://www.atmos-chem-phys-discuss.net/6/4755/2006/ http://www.atmos-chem-phys-discuss.net/6/4755/2006/acpd-6-4755-2006.html http://www.atmos-chem-phys-discuss.net/6/4755/2006/acpd-6-4755-2006.pdf 4755 4794 2006-06-14 Some experimental constraints for spectral parameters used in the Warner and McIntyre gravity wave parameterization scheme M. Ern P. Preusse C. D. Warner Institute for Stratospheric Research (ICG-I), Forschungszentrum Juelich, Juelich, Germany Centre for Atmospheric Science, University of Cambridge, Cambridge, UK In order to incorporate the effect of gravity waves (GWs) on the atmospheric circulation most global circulation models (GCMs) employ gravity wave parameterization schemes. To date, GW parameterization schemes in GCMs are used without experimental validation 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 parameters compatible with absolute values of gravity wave momentum flux (GW-MF) derived from CRISTA-1 and CRISTA-2 satellite measurements are deduced for several of the parameters and the limitations of both model and measurements are discussed. The findings presented in this paper show that the initial guess of spectral parameters provided by Warner and McIntyre (2001) are some kind of compromise with respect to agreement of absolute values and agreement of the horizontal structures found in both measurements and model results. Better agreement can be achieved by using a vertical wavenumber launch spectrum with a wider saturated spectral range and reduced spectral power in the unsaturated part. Still, even global features of the measurements remain unmatched, and it is inevitable to provide a globally varying source distribution in future.