The topic of balanced flow and its breakdown is of fundamental importance to geophysical fluid dynamics and weather prediction, yet the dynamics associated with it remain largely unknown. The objective of this project is to investigate the nature of balance in upper-tropospheric jets and fronts, the conditions for it to breakdown and the generation of inertia-gravity waves, and the physical mechanisms responsible for it. The approach is to start with a simple two-layer primitive equation for the examination of the fundamental dynamics and then extended to frameworks with increasing complexity, such as including the stratosphere. Numerical simulations using these models will examine the life cycles of baroclinic waves in which frontal systems develop and inertia-gravity waves are generated. Based on the results from the numerical studies, an idealized analytic model will be developed to describe the essential dynamic behavior of the generation of inertia-gravity waves.
This project will enhance the understanding of the inertia-gravity waves that are important to weather forecasting. The importance of this work extends beyond the pedagogical applications to include potential benefits to aviation and weather forecasting. If an analytical approach for forecasting significant gravity wave activity generated by some kind of flow imbalance can be formulated, then it will have direct applications to forecasts of clear-air turbulence associated with upper-level jet streams, and to the generation of severe weather resulting from gravity wave forcing. Results from the project can demonstrate the roles that breaking waves from frontal systems may play in the atmospheric general circulation.
