Gravity waves generated by the dry convective boundary layer: Two-dimensional scale selection and boundary-layer feedback

Abstract

This study examines the generation of gravity waves by the dry convective boundary layer in two dimensions. In particular, a number of cases are considered which range from zero background-flow conditions to conditions with strong wind shear. These experiments agree with previous studies that identified a distinct horizontal-scale selection of the gravity waves due to changes in wind speed. Detailed linear analysis is completed which attributes the horizontal-scale selection to two processes. The first process is the dissipation of downstream-propagating gravity waves by critical levels, and the second process is the trapping of upstream-propagating waves. The result is a narrow region of th..