Środowiskowe Seminarium Fizyki Atmosfery

High-resolution simulation of moist global flows for numerical weather prediction and climate research requires convection-permitting nonhydrostatic flow solvers valid across the entire range of spatialscales, from small-scale dynamics to planetary-scale flows. Flowsolvers based on compressible dynamics meet such a requirement, butthey need special treatments of acoustic modes to make themcomputationally efficient. Soundproof (e.g., anelastic) flow solversfilter out acoustic modes, but their application to the large-scaledynamics has been questioned in the past. In addition, mesoscaleand large-scale hydrostatic pressure perturbations are typicallyexcluded from moist thermodynamics in the standard anelastic model.This presentation will review these issues and will report applicationof the compressible and anelastic versions of the EULAG model tothe idealized baroclinic instability problem and to the Held-Suarezclimate benchmark. Systematic differences between compressible andanelastic solutions are present in the baroclinic test case inagreement with fundamental differences in the vorticity dynamicsin the two systems. In contrast, the climate benchmark shows thatthe compressible and anelastic model versions simulate similarzonally averaged fields, and that the meridional transports ofentropy, momentum and moisture agree well between the two modelversions.