What is Rossby wave breaking?
Rossby wave breaking is an essential mechanism by which waves (eddies) induce mixing of potential vorticity and alter the mean flow irreversibly. At small amplitudes, a large fraction of wave activity enters the Southern Hemisphere in the southward moving packets and accumulates near the turning latitude.
Why do Rossby waves break?
Rossby waves depend upon a nonzero background potential vorticity (PV) gradient for their restoring mechanism. When the background latitudinal PV gra- dient is small, large-amplitude Rossby waves may break, resulting in the mixing of PV over a longitudi- nally confined region, the wave-breaking region.
Where do Rossby waves occur?
Rossby waves, also known as planetary waves, are a type of inertial wave naturally occurring in rotating fluids. They were first identified by Sweden-born American meteorologist Carl-Gustaf Arvid Rossby. They are observed in the atmospheres and oceans of planets owing to the rotation of the planet.
What are Rossby waves in the atmosphere?
Rossby wave, in meteorology, large horizontal atmospheric undulation that is associated with the polar-front jet stream and separates cold polar air from warm tropical air. These waves are named for Carl-Gustaf Arvid Rossby, who first identified them and explained their movement.
What causes planetary?
Rossby waves, also known as planetary waves, naturally occur in rotating fluids. Within the Earth’s ocean and atmosphere, these waves form as a result of the rotation of the planet. Oceanic and atmospheric Rossby waves — also known as planetary waves — naturally occur largely due to the Earth’s rotation.
What is Rossby and Kelvin waves?
Rossby Wave: Wavy motions results from the conservation of potential vorticity. • Kelvin wave: It is a wave in the ocean or atmosphere that balances the Coriolis force against a topographic boundary such as a coastline, or a waveguide such as the equator. Kelvin wave is non-dispersive.
What causes a Kelvin wave?
Internal coastal Kelvin waves can be generated by wind-induced, time-dependent coastal upwelling. Coastal upwelling (downwelling) is caused by an Ekman mass flux transported offshore (onshore) and forced by longshore winds. The disturbances can then propagate along the coast as boundary-trapped internal Kelvin waves.
Are Kelvin waves dispersive?
Kelvin wave: It is a wave in the ocean or atmosphere that balances the Coriolis force against a topographic boundary such as a coastline, or a waveguide such as the equator. Kelvin wave is non-dispersive.
How fast are Kelvin waves?
These waves are called coastal Kelvin waves, and have propagation speeds of approximately 2 m/s in the ocean.
Where do Kelvin waves occur?
Kelvin wave, in oceanography, an extremely long ocean wave that propagates eastward toward the coast of South America, where it causes the upper ocean layer of relatively warm water to thicken and sea level to rise.
Why do Kelvin waves move east?
The condition of eastward propagation due to equatorial trapping requires that the vertical wavenumber be negative. Hence, an eastward- and downward-propagating equatorial Kelvin wave has constant phase lines that tilt eastward with height (Figure 3).