SIMULATION OF TIDES, RESIDUAL FLOW AND ENERGY BUDGET IN THE GULF-OF-CALIFORNIA

With the application of a two-dimensional nonlinear hydrodynamical-num erical 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 an d S-2 were calculated separately. The linear sum of these budgets was compared with the tidal energy budget obtained when these two tidal co nstituents interact. Since a quadratic form for the bottom friction wa s used, remarkable differences were found. The results show that in th e 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 w aves of different periods, but of the same amplitude, were used to est imate the principal periods of resonance. Although the topography of t he Gulf is very complex, the model reproduced observed sea-surface ele vation and current patterns. To study spring tide conditions, the abov e seven tidal constituents were simulated. Estimates of residual curre nts reveal the presence of several intense cyclonic and anticyclonic g yres. Over the Salsipuedes Sill, residual currents of the M-2 tide rea ch values of more than 15 cm s(-1). Horizontal distributions of dissip ation rates of tidal energy and of kinetic energy were also obtained. (C) Elsevier, Paris.