Systematic analysis of flow-orography interactionin idealized numerical simulations

Current generation climate and global numerical weather prediction models still must parameterize
the effects of subrgid-scale orography, which they cannot explicitly resolve. One of the effects are
the orography gravity waves that affect the dynamics and transport throughout the atmosphere due
to flux convergences during their dissipation. Complicating the problem further is the interplay with
the turbulence parameterization schemes, which influence the dynamics and mixing near the
surface and then aloft in unstable regions in the free atmosphere.
In this work, we study the life cycle of orography gravity waves numerically under background
conditions and set-ups ranging from idealistic to realistic. A hierarchy of idealized three-
dimensional simulations of mountain–flow interaction is developed for various orographic shapes,
atmospheric conditions and model settings (with turbulence parameterizations or in large-eddy
resolving mode) to address the coupling between orographic gravity waves and turbulence. The
ultimate goal of the study is to provide constraints for parameterized mixing in climate models and
establish foundations for coupling the turbulence and gravity wave parameterizations.