Evaluation of Carbon Dioxide Partial Pressure and Air-Sea Fluxes in the Sea of Marmara

The increasing impact of global warming has made it crucial to monitor greenhouse gases (GHG). Carbon dioxide (CO2) is especially important due to its significant increase. Oceans and seas play a vital role in absorbing excess CO2 from the atmosphere, but they are facing challenges such as ocean acidification and damage to coral reefs. Therefore, it's essential to thoroughly understand climate change and its human-caused effects and to take necessary precautions or improve existing measures. In this direction, in seawater, determining alkalinity is crucial for monitoring CO2, along with other physical and chemical parameters, in order to help set carbon budgets and reduce environmental pressures. For this purpose, in this study in the Sea of Marmara, alkalinity and CO2 measurements were conducted for the first time at stations CG2, CG3, MD26, and MD24. The CO2 partial pressure (pCO2) values ranged from 95 to 165 µatm at the surface of all stations, and total alkalinity values ranged from 1.075 to 1.46 mmol kg-1 at specified depths. Based on these measurements, flux values were calculated between −1.10 and −5.39 mmol m2 day-1, indicating that the Sea of Marmara acted as a net CO2 sink.