Simulation of tides, residual flow and energy budget in the Gulf of California

Abstract

With the application of a two-dimensional nonlinear hydrodynamical-numerical semi-implicit model, the principal tides M 2, S 2, K 2, N 2, K 1, P 1 and O 1 were studied. Energy budgets of the semi-diurnal M 2 and S 2 were calculated separately. The linear sum of these budgets was compared with the tidal energy budget obtained when these two tidal constituents interact. Since a quadratic form for the bottom friction was used, remarkable differences were found. The results show that in the area of the Colorado River delta, the dissipation of tidal energy is very strong. Intense tidal currents were observed in the same region and over the Salsipuedes Sill. Energy budgets calculated for forcing waves of different periods, but of the same amplitude, were used to estimate the principal periods of resonance. Although the topography of the Gulf is very complex, the model reproduced observed sea-surface elevation and current patterns. To study spring tide conditions, the above seven tidal constituents were simulated. Estimates of residual currents reveal the presence of several intense cyclonic and anticyclonic gyres. Over the Salsipuedes Sill, residual currents of the M 2 tide reach values of more than 15 cm s −1. Horizontal distributions of dissipation rates of tidal energy and of kinetic energy were also obtained.