Relationship between the mean periods of wind-generated and infragravity waves: a sensitivity analysis

Abstract

A sensitivity analysis was performed on the mean infragravity wave period by varying five input parameters associated to short-waves. The mean infragravity wave period was estimated from the short-wave directional spectrum using a second-order wave theory. The analysis was based on a sensitivity index and showed that the mean infragravity wave period is more sensitive to both the significant short wave height and the mean short wave period than to the water depth, the directional spreading coefficient and the JONSWAP peak-enhancement factor. The maximum value of the mean infragravity wave period obtained (60 s) indicates that larger mean infragravity wave periods might not be forced by the second-order wave theory, thereby depending on the bottom topography.