ESS228
Prof. Jin-Yi Yu
Equatorial
Kelvin Waves
•The equator acts analogously to a topographic boundary
for both the Northern
and Southern Hemispheres, which make the equatorial Kelvin wave to behaves very similar to the coastally-trapped
Kelvin wave.
•Surface equatorial Kelvin waves travel very fast, at
about 200 m per second.
Kelvin waves in the thermocline are however much slower, typically between 0.5 and 3.0 m per second.
•They may be detectable at the surface, as sea-level is
slightly raised above regions
where the thermocline is depressed and slightly depressed above regions where the thermocline is raised.
•The amplitude of the Kelvin wave is several tens of
meters along the thermocline,
and the length of the wave is thousands of kilometres.
• Equatorial Kelvin waves can only travel eastwards.
thermocline
sea level
Kelvin Wave