SIMULATION OF THE SEA WATER CIRCULATION AND COASTAL CURRENTS IN THE CASPIAN SEA

The Caspian Sea is the largest enclosed water body in the world. It is located in the west Asia and surrounded by the five countries of Russia, Kazakhstan, Turkmenistan, Iran and Azerbaijan. It is about 1300 km long and its width varies between 200 and 450 km in different regions. The bathymetry of the Caspian basin shows that the basin can be divided into the flat northern part, the middle bowl shape, and southern Caspian containing a depression reaching a maximum depth of 1025 meters, with an abrupt western slope and a gentler eastern slope (Figure 1). The physical oceanographic characteristics of this basin are of the great importance, particularly for Iran which has more than 800 km coastline and significant natural resources at the sea. The simulation of flow patterns in the Caspian Sea was the subject of different studies during recent decades. Primarily, numerical investigations did not result in reliable findings, mainly due to numerical model weaknesses as well as inadequate initial and boundary conditions. Later on, more sophisticated numerical models such as three-dimensional models were employed to simulate circulation in the Caspian Sea (e.g. [1-3]). These studies revealed that there are relatively strong coastal currents along the southwestern coasts of the Caspian Sea. None of the previous studies on the Caspian Sea flow regimes focused on local currents along the Iranian coastal areas. Therefore, the Iranian Port and Maritime Organization (PMO) initiated a project, led by Pouya Tarh Pars Consulting Engineers to examine the physical processes along the Iranian sector of the Caspian Sea through the use of field measurements and numerical modeling. In this paper the results of these studies with regard to coastal currents are presented.