Coastal Upwelling along the Southwest Coast of Caspian Sea Based on Satellite Observations and Numerical Modeling

Coastal upwelling systems are major economic sources, which contribute to 20% of the global fish production from less than 3% of the world oceans surface (Benazzouz et al.,2014). If the wind direction in the northern hemisphere is located on the left side of the beach, wind stress and the Coriolis force will cause the Ekman Transport along thebeach and toward the sea. In this case, water the Ekman layer will replace the water surface from the coast during the vertical water transfer process. In this way, coastalupwelling will take place. Water that rises to the surface as a result of upwelling is typically more nutrient and colder. These nutrients fertilize water surface i.e. these watersurfaces often have high biological productivity. Therefore, perfect fishing spots are typically found where upwelling is common. Upwelling phenomenon along the southernboundaries of Caspian Sea (CS) has received greater attention in the recent years due to its environmental and economic significance. The CS coasts can be divided intoregions with the quite sustainable wind direction regimes. In this regard, there is a legal system so that in most times of the year the north winds (northwest, and northeast) andsoutheast winds are considered as the dominant winds of CS. In average, the frequency of northward winds is 41 percent, and their probability in summer is higher thanother seasons (48.7 percent).The mean of eastern winds’ annual blow is 35.9 percent (Mamedov and Khoshravan, 2012). The water surface of CS in the shallow coastal areasduring summer is often warmer, reaching 30 degrees Celsius in some areas. The upwelling phenomenon in the warm seasons is almost constant in the CS. The extent of the upwelling lasted 5-20 kilometers from the coastline and tens of kilometers along the coast (Kosarev,1990)). Also the upwelling in warm seasons has been confirmed inatmospheric observations (Kosarev and Yablonskaya, 1994), and satellites Observations (Sur et al., 1998). In July, the prevailing wind in the middle of CS is mainlyfrom the north, which has resulted in upwelling along the eastern coast (Knysh et al., 2008). The wind in the middle and the southern parts of CS draws water surface from theeast coast to the west coast, causing an increase in water on the west coast, causing an upwelling on the eastern coast (Ibrayev et al., 2010). In this context, the available satellite data on sea surface winds, sea surface temperature (SST) between March and September 2013 are analyzed to identify the coastal upwelling pattern in the southern coastof CS. Also the three-dimensional hydrodynamic is used for modeling the CS circulation properties.