Środowiskowe Seminarium Fizyki Atmosfery

In atmospheric applications, traditional anelastic models apply environmental hydrostatically-balanced pressure profile when formulating moist thermodynamics, and model-derived pressure perturbations are neglected. Such an approach is supported by simple scaling arguments. However, when used in simulations of larger-scale flows (mesoscale, synoptic, etc.), similar arguments show that at least the hydrostatically-balanced component of the pressure perturbation needs to be included. Following this line of thought, we are conducting systematic investigations of various moist atmospheric flows and compare numerical solutions obtained with a fully-compressible acoustic-mode-resolving model and with two versions of the anelastic model, either including or excluding anelastic pressure perturbations in moist thermodynamics. The two versions of the anelastic model are referred to as the generalized and standard anelastic, respectively. So far, numerical solutions for moist thermals rising from rest, mesoscale orographic wave flows, and super-cell simulations were compared. In agreement with the scaling arguments, only negligible differences between anelastic and compressible solutions were simulated. Incorporation of the anelastic pressure perturbations into moist thermodynamics paves the way for ongoing studies where larger-scale moist dynamics are considered.