Methane in the surface waters of the Kara Sea

During the scientific expedition of the Institute of Oceanology of the Russian Academy of Sciences, a scanning of thesurface waters of the Kara Sea was carried out in order to map the distribution of the concentration of dissolved methane in asignificant part of the Kara Sea and in adjacent bays. Scanning was carried out in a continuous mode throughout the expeditionby continuous sampling of water from the surface layers of the sea. The selection was carried out using the Protoka hydrotechnical system of the Institute of Oceanology, Russian Academy of Sciences, which made it possible to withdraw water while the vessel was moving. The outboard was analyzed in-situ using a Mets methane sensor. Scanning results showed that in the main part of the Kara Sea, the concentration of dissolved methane is approximately 3-4 nmol/l, which corresponds to the equilibrium concentration of dissolved methane at the contact of the water surface with the Earth's atmosphere. Significantly higher concentrations, about 100 nmol/l, were recorded at the mouth of the Yenisei River, where the waters are saturated with organic material. Data processing revealed a relationship between the concentration of methane and the concentration of dissolved organic matter (DOM), as well as a relationship between the concentration of methane in water and salinity.