STUDY OF CURRENT BEHAVIOR ON THE SOUTHERN SHELF OF THE CASPIAN SEA BASE ON FIELD MEASUREMENTS

The Caspian Sea (CS) is the largest internal drainage body of water on earth. The southern coast of the CS has a subtropical climate characterized by warm humid summers and mild, wet winters [9]. The CS surface circulation consists of cyclonic (counter clockwise) eddies in the southern, middle, and northern regions [7]. The mesoscale eddy features have a seasonal evolution [8]. The middle and southern CS has northerly northwesterly winds during summer, with easterly southeasterly winds in winter [2]. Two groups classified atmospheric circulation patterns which determine the wind field over the CS, the first one includes those patterns that are characterized by strong northerly winds [1]. The second group comprises atmospheric circulation patterns with strong southerly wind [6]. Currents on the northern shallow shelf are especially influenced by wind [3]. Along the western coast of the middle CS, the prevailing currents are southeastward and southward. Other types of currents, such as baroclinic currents and seiches, also play an important role in local circulation patterns [2]. It has been suggested that low-frequency motions are responsible for the large-scale sedimentary features of natural beaches [4]. Field investigations of low-frequency motions in the surf zone have dealt primarily with their physical properties, e.g., alongshore and cross-shore structure, secondary circulation patterns, runup and potential forcing [5]. In this study, comprehensive field measurements, 2D modeling and data analysis have been used. We tried to shed some light on the flow pattern and Its correlation with the wind and waves. A series of comprehensive field measurements were carried out by Iranian Ports & Maritime Organization (IRPMO) in south coast of CS. Wind data is extracted from the simulation of wind fields using WRF model by IRPMO.