Gravity Waves | Gravity Waves Excited by Jets and Fronts

Jets and fronts are known to be significant sources of gravity waves. This has been shown by numerous studies with real-data observations and/or numerical models. Case studies have highlighted the jet exit region as particularly favorable to low-frequency gravity waves. They have also identified wave ducting as a key maintenance mechanism for waves propagating over long distances near the ground. In idealized frameworks exhibiting gravity wave generation within the life cycle of baroclinic disturbances, the key generation mechanism has been related to geostrophic adjustment. As it can be understood as the adjustment of an imbalance that is continuously forced by the evolution of the balanced flow, the term “spontaneous balance adjustment” generalizes this notion. The three-dimensional flow in which the waves are excited strongly influences their characteristics. In more realistic flows, moist processes and topography also contribute strongly to the generation, resulting in more complex gravity wave fields that can not simply be understood as a superposition.