Observations of sediment suspension in a high-energy, dissipative Northwest surfrnzone suggest that low-infragravity frequency and episodic (LFE) occurrences of high-energyrninfragravity wave motions are associated with large magnitude sediment suspension events. Thisrnexploratory study investigates the ubiquity and impact on sediment flux of motions withrnfrequencies less than 0.01 Hz and/or of episodic nature. Co-spectral analysis has been used tornestimate the sediment flux related to LFE processes. In three different experiments, therncontribution to the sediment flux from the LFE band in the across-shore direction varies greatlyrnin magnitude, but can be as large as the component due to mean currents. Wavelet analysis of thernfluid and sediment suspension time series support that LFE processes are significant factors inrnthe resuspension and flux of sediment in the surf zone, and therefore are an importantrncontribution presently neglected in sediment transport models.
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