Modeled surf‐zone eddies on a laboratory scale barred beach with varying wave conditions

We find that mean breaking crest length decreases, while crest end density (number of crest ends in a given area) increases, with increasing directional spread. In contrast, vorticity forcing, offshore low‐frequency rotational motion, and cross‐shore exchange peak at intermediate directional spreads . Distributions of the strength of vorticity forcing per crest and across the surf zone suggest that the peak in vorticity forcing at intermediate spreads results from a combination of a larger total breaking area and relatively long crests with large forcing, despite a lower total number of crests.

However, low‐frequency rotational motion within the surf zone does not peak at mid‐directional spread, instead plateauing at directional spreads greater than . Results suggest that eddy‐eddy interaction, the transformation of vorticity across the surf zone, and influence of bathymetry are fruitful topics for future work.