ESS228
Prof. Jin-Yi Yu
Internal Gravity (Buoyancy) Waves
qIn a
fluid, such as the ocean, which is bounded both above and below, gravity waves
propagate primarily in the horizontal plane since
vertically traveling waves are reflected from the boundaries to form
standing waves.
q In a fluid that has no upper boundary, such
as the atmosphere, gravity waves may propagate vertically as
well as horizontally. In vertically propagating waves the phase is a function
of height. Such waves are referred to as internal
waves.
q Although internal gravity
waves are not generally of great importance for synoptic-scale weather forecasting
(and indeed are nonexistent in the filtered quasi-geostrophic models), they
can be important in mesoscale motions.
qFor
example, they are responsible for the occurrence of mountain lee
waves. They also are believed to be an important mechanism
for transporting energy and momentum into the middle atmosphere, and are
often associated with the formation of clear air turbulence (CAT).
