Directional Analysis and Potential for Spectral Modelling of Infragravity Waves

In this paper, we interrogated wave data collected by US Army Corps of Engineers at their well-known Field Research Facility, Duck, North Carolina and SHELL Corporation at Lagos, Nigeria. Both measurements were designed to collect wind waves with a conventional wave sampling configuration and not a dedicated infragravity wave sampling regime. Here, we developed a new approach to obtain directional information of and explored the potential to model infragravity waves in the spectral domain. It was found that infragravity wave heights had a strong dynamic relationship with an inverse relative depth parameter and that directional spreadings were moderately correlated with wind wave spreadings and wave energy. Further, infragravity directional spreadings were typically broader compared to their wind wave directional spreading counterparts.