Large-scale vorticity generation by breakers in shallow and deep water

Water wave breaking is of considerable importance in the transfer of moment um, and in other transfers, between the atmosphere and oceans. Typically br eaking occurs on deep water as events that have finite duration and finite spatial extent. Near shore lines most of the water motions are dominated by breaking waves. Recent work on the generation of vorticity by breaking wav es and bores in the surf zone on beaches is considered and typical vortical structures are briefly discussed. Consideration of deep water breaking lea ds to the proposal that the end result of a breaking event in deep water ma y be a coherent structure within the resulting current field. Such a struct ure is topologically equivalent to half a vortex ring. (C) Elsevier, Paris.