Abstract: The effect of model bias on the equatorward propagation of extratropical waves in a GCM simulation is assessed within the context of simple wave-guiding principles. The modes representing these waves are identified through ...

Abstract: The impact of negative dissipation on posttime analysis and forecast correction techniques is examined in a simplified context. The experiments are conducted using a three-level quasigeostrophic model (with a nonsingular ...

Abstract: In this paper it is argued that ensemble prediction systems can be devised in such a way that physical parameterizations of subgrid-scale motions are utilized in a stochastic manner, rather than in a deterministic way as ...

Abstract: Computational models based on discrete dynamical equations are a successful way of approaching the problem of predicting or forecasting the future evolution of dynamical systems. For linear and mildly nonlinear models, the ...

Abstract: The ability of an atmospheric general circulation model to simulate the observed primary modes of intraseasonal variability in the Northern Hemisphere upper-tropospheric winds during boreal winter is examined. The model ...

Abstract: The sensitivity of the atmospheric general circulation model of the Navy Operational Global Atmospheric Prediction System to a parameterization of convective triggering by atmospheric boundary layer thermals is investigated. ...

Abstract: Two versions of the Navy Operational Global Atmospheric Prediction System (NOGAPS) global ensemble, with and without a stochastic convection scheme, are compared regarding their performance in predicting the development ...

Abstract: Singular vector (SV) sensitivity, calculated using the adjoint model of the U.S. Navy Operation Global Atmosphere Prediction System (NOGAPS), is used to study the dynamics associated with tropical cyclone evolution. For ...

Abstract: The rate at which the leading singular vectors converge toward a single pattern for increasing optimization times is examined within the context of a T21 L3 quasigeostrophic model. As expected, the final-time backward ...

Abstract: A suite of high-resolution two-dimensional ensemble simulations are used to investigate the predictability of mountain waves, wave breaking, and downslope windstorms. For relatively low hills and mountains, perturbation ...