EVOLUTION OF INFRAGRAVITY VARIANCE DURING A STORM

Abstract

Data from an alongshore array of bidirectional current meters located in the surf zone were analyzed to provide estimates of the behavior of three bands of wave energy during the passage of a moderate storm. The variance in the incident wave band is found to be saturated, as is expected of depth-limited waves. The infragravity band variance is found to depend most strongly on the offshore wave height. Shear wave variance is found to be correlated with the magnitude of the measured longshore current. During a period of nearly constant high waves, the composition of the low frequency band motions (f< 0.05 Hz) changed dramatically. This change is thought to be related to the directional characteristics of the incident band wind waves.