Waves in planetary atmospheres are interesting in their own right, but their importance lies mostly in the effects they have on the background atmosphere. Gravity waves may transport momentum, heat, and minor constituents through wave fluxes and may mix the atmosphere through the turbulence they induce when they break down (Lindzen, 1981; Fritts, 1984; Garcia and Solomon, 1985; Walterscheid, 1981, 1995, 2001; Walterscheid and Schubert, 1989). Planetary waves transport heat, momentum, and constituents (e.g. ozone) latitudinally and play a significant role in the heat, momentum, and ozone budgets (Holton and Wehrbein, 1980; O'Sullivan and Salby, 1990; Fusco and Salby, 1999).

Atmospheric waves

Planetary atmospheres admit a rich variety of waves. These waves involve to varying degrees the rotational, compressional, and buoyant properties of a fluid in motion. Many wave disturbances arise in instabilities, including those that give rise to weather systems. Other motions arise as free waves or waves forced by agents external to the atmosphere (e.g. planetary topography and s olar heating). These comprise two broad classes of waves in planetary atmospheres: Rossby waves and gravity waves. Rossby waves are the comparatively low-frequency waves that dominate the ultra-long wave field in the lower atmosphere. Rossby waves are rotational waves where latitudinal displacements are opposed by the latitudinal gradient of planetary rotation. Gravity waves, in contrast, are comparatively high-frequency divergence waves where vertical displacements are opposed by pressure forces induced by gravity.