Confirm breakpoint-forcing mechanisms beyond group-resolving models

Establish whether the finite-source interference and directional Doppler mechanisms identified for breakpoint-forced infragravity-wave generation remain valid outside the group-resolving modelling framework, using phase-resolving simulations, laboratory experiments, or in situ observations.

Background

The paper derives and tests two mechanisms governing breakpoint-forced infragravity waves: destructive interference across a finite breaking region, which attenuates higher frequencies, and source-centroid migration, which compresses shoreward arrivals and stretches seaward arrivals. These mechanisms are evaluated using a one-dimensional group-resolving model coupled with a variable-depth Green-function calculation.

The authors explicitly qualify the generality of these findings because the numerical experiments use a single breaking closure and offshore sea state and because the mechanisms have not yet been independently tested with phase-resolving simulations, laboratory measurements, or field observations. Confirmation through those approaches would determine whether the proposed mechanisms describe physical nearshore wave generation beyond the modelling framework used in the paper.