Modelling of climate change impacts on the Mediterranean current system and analysis of the current energy potential within continental shelf of Turkey

The increasing use of fossil fuels since the Industrial Revolution has caused the Earth's surface temperature to rise by an average of 1.5ºC. The changes in terrestrial and aquatic ecosystems associated with the rise in temperature have negative effects on the vital activities of living organisms. The Mediterranean region, which is the subject of this thesis, is one of the places most affected by climate change. In recent years, one of the main efforts to reduce these negative effects has been to increase investments in renewable energy sources. The interaction between ocean circulation, Coriolis, salinity, temperature, density difference, etc. creates ocean currents. Ocean current energy is one of the renewable energy sources and is expected to provide a significant part of the energy demands of many countries in the future. Copernicus Marine Service satellite data, obtained by remote sensing methods and calibrated with in-situ measurement data, were used in the study. The data set included the study period 1987-2021, 4 x 4 km spatial resolution, hourly data set, depths of 1-20 meters and 20-50 meters. In addition, the study calculated the potential energy production from the current energy by considering an underwater turbine system as an example. As part of the modeling study, the period 2022-2100 was linearly modeled and the current velocity differences between the periods were determined. As a result of the study, the maximum current speed at 1-20 meters depth was determined to reach 3,4 m/s in December-January-February season and the maximum current speed at 20-50 meters depth was determined to reach 3,6 m/s in December- January-February season. In some areas within the Turkish continental shelf, points with current velocities of 2,6 m/s for 1-20 m depth and 2,2 m/s for 20-50 m depth were determined. Within the scope of this thesis, it was determined that the energy recovery potential in the identified areas of the Turkish continental shelf varies between 960-1200 GWh/yr for 1-20m depth and 800-1000 GWh/yr for 20-50m depth. In the modeling, the maximum current velocity difference between 2030-2050 and 2080-2100 for 1-20 meters depth was determined to reach 1,2 m/s. For 20-50 meters depth, the maximum current velocity difference for 2030-2050 and 2080-2100 was determined to reach 1,3 m/s. During the modeling period (2022-2100), the maximum current velocity difference between depths was determined to reach 0,7 m/s. In addition, between 2030-2050 and 2080-2100, the maximum current velocity difference between depths was determined to reach 0,3 m/s and 0,7 m/s, respectively. As a result of the modeling study, it was determined that the current between 1-20 m depth is generally stronger than the current between 20-50 m depth in the eastern Mediterranean coast of Turkey. It was also found that the velocity of the current tends to increase in the longitudinal direction and reaches about 2,6 m/s within the study period.