Wave Transformation and Swash
This study was motivated by recent observations of energetic infragravity (IG) waves or “sneaker” waves. It is hypothesized that runup predictions from numerical simulations that use 100 frequencies in the input energy spectrum are not the same from those that use 1,000 frequencies because of nonlinearity. Numerical simulations are used to test the effects of frequency resolution on extreme runup events. More than one million waves were simulated from 100 different combinations of wave heights and peak periods and only 5 extreme IG runup events were identified.