In this work a method to estimate the contribution to tidal residues originated by non-linear interaction between tides and low frequency phenomena is presented. In order to perform the validation, the method is applied on current data series taken from the Strait of Gibraltar which allows us to find a clear relationship between current tidal residues and low frequency fluctuations in the flow, which may be explained in terms of the non-linear interaction between tidal and sub-inertial signals in the current velocity. |