The atmospheric boundary layer over flat terrain has been extensively studied, and many of the results can be applied in a local sense to less idealized conditions. But undulating terrain introduces unique effects which generate internal waves in the overlaying fluid, which will be reabsorbed at levels where the wind reverses. Thus, the wind experiences wave-induced drag, turbulence, and horizontal eddying. Current middle-atmosphere studies address such problems, and it should prove advantageous to both fields to address the boundary layer in a similar fashion. This research also investigates a new type of atmospheric wave mode which requires a "lid" to prevent the wave energy from leaking off into the upper atmosphere. The lid for this new mode occurs at the height where its intrinsic frequency matches the local inertial frequency. One consequence of this is that the duct properties change with latitude; in the tropical troposphere wave momentum can be funneled towards a destructive terminator in the subtropics. Such wave-associated transports influence the distribution of zonal angular momentum.
