Breaking wave

At this point, simple physical models that describe wave dynamics often become invalid, particularly those that assume linear behaviour.

Breaking of water surface waves may occur anywhere that the amplitude is sufficient, including in mid-ocean.

However, it is particularly common on beaches because wave heights are amplified in the region of shallower water (because the group velocity is lower there).

A plunging wave occurs when the ocean floor is steep or has sudden depth changes, such as from a reef or sandbar.

A plunging wave that is parallel to the beach can break along its whole length at once, rendering it unrideable and dangerous.

During breaking, a deformation (usually a bulge) forms at the wave crest, either leading side of which is known as the "toe".

It has been found that high-frequency detail present in a breaking wave plays a part in crest deformation and destabilization.

After the tip of the wave overturns and the jet collapses, it creates a very coherent and defined horizontal vortex.

Small horizontal random eddies that form on the sides of the wave suggest that, perhaps, prior to breaking, the water's velocity is more or less two dimensional.

Advection and molecular diffusion play a part in stretching the vortex and redistributing the vorticity, as well as the formation turbulence cascades.

Experiments have been conducted to deduce the evolution of turbulence after break, both in deep water and on a beach.