A Process Study of the Tidal Circulation in the

A homogeneous shallow-water model with free surface is used to model the tidal circulation in the Persian Gulf. The numerical finite-difference model includes harmonic diffusion of horizontal momentum and quadratic bottom friction, it has a 9 km mesh size and it is forced by 7 tidal components at its southern boundary. High precision bathymetric data are used to obtain the bottom topography. The numerical model is run for more than a year. The results are the following: 1) The model accurately reproduces the tidal phase and amplitude observed at 42 tidal gauges in the region. This accuracy is attributed to the presence of the 7 components which are able to interact nonlinearly; 2) The amphidromic points are also well positioned by the model due to a proper choice of bathymetry. This was checked also with a simpler geometry of the domain; 3) The tidal currents can be strong in the Straits of Hormuz and in shallow areas; thus they will have an effect of the hydrology of the region. The residual currents are weak so that they will be negligible for the large-scale circulation on long periods; 4) Finally, the sea-surface elevation forecast by the model is in close agreement with in-situ measurements of pressure in the Straits, performed during the GOGP99 experiment.