Spontaneous generation and propagation of inertia-gravity waves in baroclinic lifecycles(formerly paper JP5.14)

Jets and fronts are known from observations to be important sources of gravity waves. However, the mechanisms responsible for their generation from motions that are predominantly balanced are yet poorly understood. This hinders the development of parameterisations for these sources of gravity waves in General Circulation Models.

Numerical simulations were carried out with the Weather Research and Forecast Model to study the spontaneous generation of inertia-gravity waves (IGW) in several idealized baroclinic lifecycles. IGW appear in several regions of the flow. They can be associated to the upper-level jet, but also to the surface fronts. The horizontal propagation of these waves in the complex background flow in which they appear needs to be considered to understand their characteristics. Implications for gravity wave parameterisations will be discussed.