On the Removal of Gravitational Noise in Numerical Forecasts (gtSpecial IssueltData Assimilation in Meteology and Oceanography: Theory and Practice)

[摘要] There are several successful techniques for removing relatively high-frequency "noise" due to propagating inertial-gravitational waves in model forecasts. Not all behavior that is sometimes considered noise is necessarily spurious, however, including that due to tidal forcing. Published evidence of the natural existence of high-frequency behavior within numerical weather prediction and general circulation models is briefly reviewed and some additional evidence with yet another model is introduced. In this new model, the existence of local diabatic balances is also examined. Imposing balances or filters at scales /here high-frequency oscillations are naturally and realistically occurring causes errors which may become more significant as we demand more accurate models and atmospheric analyses. The intention of this paper is to stimulate further research into the naturally occuring high-frequency behavior in numerical models, as well as in the atmosphere, for the purpose of improving both models and atmospheric analyses.

[学科分类] 大气科学