A generalized Kraichnan like model for simulating stratified flows

A generalization to the Kraichnan gaussian, white noise in time model of turbulent velocity field is proposed. The generalization is designed to mimic the effects of stratification in the atmospheric boundary layer by introducing different scaling exponents for horizontal and vertical velocity components, resulting in strong vertical anisotropy. The inevitable compressibility of the model leads one to take into account also the density statistics of the fluid, which will immediately lead to a boundary layer like structure in the flow statistics and non zero time correlations. Possible applications for passive scalar, tracer and inertial particle statistics and their anomalous scaling behavior will be discussed.