Modeling of coastal currents along the egyptian Mediterranean coast

Abstract

The coastal currents are important in many applications related to pollutant transport, shore processes and coastal management. This paper is an attempt to simulate the current patterns in a limited coastal Mediterranean Egyptian waters up to about 100 km from the coast, in the different seasons, using Princeton Ocean Model (POM). This hydrodynamic model is a three-dimensional, primitive equations, time dependent, sigma coordinates and free surface model.

The simulation domain has dimensions of about 361 km x 113 km, extending from long. 30.00E to long. 33.75 E and from the Egyptian coast to lat. 32.00 N. Horizontal resolution of about one-minute grid interval is used (about 1.6 km in X-direction and 1.85 km in Y-direction) with a number of grid points of about 226 x 61. In the vertical direction 14 sigma levels are chosen between 0.0 and -1.0. The area bathymetry was obtained with high resolution from the Admiralty charts no. 2630 updated by the Egyptian Government Survey Authority and Egyptian Navy. Initial velocities assumed to be zeros. Free radiation condition is used for the normal velocity at the open boundaries while the normal and tangential velocities are set to zero at coastline everywhere.
To simulate the motion due to different factors affecting in the water circulation along the Egyptian Mediterranean coast, four scenarios were chosen; two dimensional mode to simulate the vertically average circulation, wind driven circulation in three-Dimensional mode, the thermo- haline circulation and the total current taking into consideration both thermo-haline and wind driven effects.

The results manifested peculiar eddy systems in-front of the Egyptian Mediterranean coasts which are persistent at different levels extending from sea surface to 50 meters. There are 5 to 8 eddies cyclonic and anti-cyclonic. The eddies in-front of El-Arish (east of the area) are appearing and disapearing during the different seasons. The eddies have important impact on the ecosystem of the south eastern part of the Mediterranean.

click here to see the results of the hydrographic studies.

click here to see the results of the model.

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