Tide-induced residual current in a coastal lagoon of the Gulf of California

Abstract The non-linear tidal interactions in the narrow, shallow coastal lagoon Yavaros Bay are investigated using a vertically integrated two-dimensional numerical model. The model sea surface elevations and currents are validated by comparison of computed tidal harmonics against those derived from harmonic analysis of the sea surface and current time series. Calculations show that tides become mixed, mainly semidiurnal in the lagoon. MK 3 , MS 4 , and M 4 , generated by advection and non-linear continuity, are the most energetic shallow water constituents. A large, half-basin clockwise eddy was found, whose source of energy is the M 2 tidal energy flux. The size of the shoal where the eddy occurs is almost the same as the maximum tidal excursion length (∼3 km).