Flow regimes and transient dynamics of two-dimensional stratified flow over an isolated mountain ridge

Abstract

Four regimes are identified for two-dimensional, unstructured, nonrotating, continuously stratified, hydrostatic, uniform Boussinesq flow over an isolated mountain ridge: (I) flow with neither wave breaking aloft nor upstream blocking (F ≥ 1.12, where F = U/Nh; U and N are upstream basic flow speed and Brunt-Väisälä frequency, respectively; and h is the mountain height), (II) flow with wave breaking aloft in the absence of upstream blocking (0.9 < F ≤ 1.12), (III) flow with both wave breaking and upstream blocking, but where wave breaking occurs first (0.6