Atmospheric Waves and Dynamics
R. A. Vincent
Physics, University of Adelaide, Adelaide, SA 5005, Australia
Atmospheric waves have periods ranging from a few minutes to tens of days. This talk will focus on atmospheric gravity (buoyancy) waves, tides and large-scale planetary waves. These waves play important roles in the middle and upper atmosphere because they efficiently couple energy and momentum from their source regions to regions where they dissipate. The resulting body forces drive large-scale circulations that profoundly affect the state of the atmosphere.
The theory of wave-mean flow interactions will be outlined and the importance of waves and wave effects in equatorial regions discussed. Phenomena such as the quasi-biennial oscillation (QBO) and the semiannual oscillations at the stratopause and mesopause are primarily wave driven, although the relative importance of different wave types has yet to be established. Transient wave events, such as the quasi-2-day wave and 5-7 day wave, also appear to play important roles in changing the state of the equatorial MLT.