Convectively-coupled gravity waves in the tropics

Observations are presented showing evidence for a strong, two-way coupling between tropical convection and zonally-propagating gravity wave disturbances with periods < 2 days and zonal scales < 1000 km. To address the question of why westward-moving waves are seemingly preferred over eastward-moving, we describe results from explicit three-dimensional simulations of convection on an equatorial beta-plane, both with and without vertical shear of the background zonal flow.