Predicting Method for Transformation of Infragravity Waves with Interferometric Green's Functions

Abstract

The propagation of infragravity waves in intermediate water depths near and in a port is investigated with field observations. A Green function method which is used for seismic interferometry is applied to estimate wave profiles of infragravity waves. The equations used in the method include Boussinesq equations with external forcing terms by fluctuating components of short gravity waves, atmospheric pressure and surface wind stresses. It is shown that when external forces are uncorrelated noise source, Green functions between two points can be retrieved by taking cross-correlation of records. The wave profiles of infragravity waves are estimated with the Green function and compared with the measured data. The agreement between them shows fairly good.