Kelvin Wave (Coastal)

A coastal Kelvin wave is a long gravity wave trapped against a coastline by the Coriolis force, its amplitude decaying exponentially offshore over the Rossby radius of deformation (roughly 200 km in shallow coastal seas). In the northern hemisphere it travels with the coast on its right; in the southern hemisphere, on its left. It is non-dispersive, moving alongshore at the shallow-water wave speed sqrt(gh), so its crest keeps its shape. Coastal Kelvin waves carry tidal energy around ocean basins, organize the rotation of the tide about amphidromic points, and propagate storm-surge and sea-level signals far along a coast from the forcing region.