A study associated with critical Level Resonance in 2-D Flow over Isolated Ridges

A linear hydrostatic model of a stably stratified upwind profile for backward linear shear with a critical level (the wind speed $U=0$) over a two-dimensional orographic barrier having two infinitely long ridges is considered. Analytical expressions for the mountain wave drag, energy flux and surface pressure perturbation are obtained. The results are illustrated by graphs of the mountain drag and the surface pressure for the flow with the Richardson number $R_i=1$ and $R_i\gg1$.