Citation

Bowen AJ. Journal of Geophysical Research: Oceans 1969; 74(23): 5467-5478.

Copyright

(Copyright © 1969, William Byrd Press for John Hopkins Press)

DOI

10.1029/JC074i023p05467

PMID

unavailable

Abstract

The nearshore circulation of water on a plane beach produced by a wave train, normally incident on the beach, which has a longshore variation in wave height is investigated theoretically. The radiation stress arising from the excess flux of momentum due to the presence of the waves (M. S. Longuet-Higgins and R. W. Stewart, 1964) is found to provide driving terms for a steady flow pattern only inside the surf zone. A circulation pattern is thus produced by a longshore variation in the radiation stress in the surf zone. In shallow water, the radiation stress is proportional to the square of the wave height. The nearshore circulation is therefore directly related to longshore variation in breaker height, currents flowing seaward where the breaker height is low. When the inertial terms are included in the vorticity equation, an increase in the effective Reynolds number produces a narrowing, and consequently a strengthening, of the Seaward flow, which suggests an explanation for the existence of the strong, narrow currents known as rip currents.

Language: en