Abstract
Infragravity waves are low-frequency surface waves that can impact a
variety of nearshore and oceanic processes. Recent measurements in the
North Sea showed that significant bursts of infragravity energy occurred
during storm events. Using a spectral wave model, we show that a
substantial part of this energy was radiated from distant shorelines
where it was generated by the incident sea-swell waves. These radiated
infragravity waves can cross the sea basin and reach distant shorelines
where they add to locally generated infragravity waves that are trapped
by refraction. During storms, the shoreward directed component of the
infragravity waves can reach up to O(0.5) m in height along the
coastline, suggesting that they can potentially impact the coastal
environment of the North Sea.