Halil İbrahim Sur

Chapter 16 Satellite-derived flow characteristics of the Caspian Sea

Abstract Mesoscale dynamics of the Caspian Sea are analyzed with satellite data to capture rapid submesoscale motions not sufficiently resolved by in-situ measurements. A combination of Sea-viewing Wide Field-of-view Sensor (SeaWiFS) ocean color data and Advanced Very-High Resolution Radiometer (AVHRR) sea surface temperature (SST) measurements provide a novel evaluation of marine biogeochemical and physical processes and their forcing mechanisms. The main feature of the Caspian Sea is higher pigment concentration with respect to other basins in the Mediterranean region. SeaWiFS detects riverine sediments introduced into the Caspian Sea by the Ural, Terek, Volga, and other rivers, and planktonic flora created in the Caspian Sea by nutrient-rich river runoff. The influence of river flow into the north-northwestern shelf area is especially evident after springtime flooding. Runoff from the Volga River has a major impact on the biomass in the northern Caspian Sea. Eddies and river plumes in coastal waters transport materials and momentum into the Caspians northern and middle basins. In winter, the cyclonic (counterclockwise) circulation leads to much higher SST in the eastern part of the Caspian than in the west. In summer, wind-induced upwelling yields a pronounced decrease in temperature and higher biomass in the upper layer of the eastern Caspian Sea. In spring, cold water is formed over the entire northern Caspian Sea.

The chemical oceanographic consequences of environmental restoration projects in the Golden Horn estuary (Marmara Sea, Turkey)

The input of industrial and domestic waste to the horizontal circulation in the Golden Horn Estuary of Marmara Sea has resulted in one of the most polluted estuaries in the past. Consequently, the dissolved oxygen concentrations in both the surface and bottom waters decreased toward to the estuary head during 1998–2005. In contrast, the total suspended solids content of the surface water decreased toward to the estuary mouth. However, construction of the operational collector system surrounding the estuary during the process of rehabilitation projects, combined with the opening of the middle pontoons of the Valide Sultan Bridge, resulted in gradually improved water quality of the estuary with a concomitant decrease in pollution. However, phytoplankton blooms and eutrophication persist especially in the innermost part of the Golden Horn in 2005. The region from the estuary mouth up to Camialtı has a dynamic structure, and sufficient circulation seemingly occurs in this part of the Golden Horn.