Kelvin wave

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A Kelvin wave is a low-frequency gravity wave whose motion is concentrated near a vertical boundary (e.g., a shore) or the equator. It occurs in the ocean and the atmosphere, as well as in large lakes. Waves along a coast are called coastal Kelvin waves; those along the equator are equatorial Kelvin waves. In a coastal Kelvin wave, a pressure gradient across the flow balances the Earth's Coriolis force, while the fluid moves along the boundary. Kelvin wave retains its shape as it moves (being, in the shallow water model, non-dispersive), and therefore does not curl over. The direction of the wave is fixed: the coastal wave moves towards the equator along the western coasts, towards the poles along the eastern coasts (like California). Around a closed basin, coastal Kelvin waves travel counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. Equatorial Kelvin waves always travel eastward. Kelvin waves are regular events. Both equatorial and coastal waves are...

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