Air Composition over the Russian Arctic: 2–Carbon Dioxide

— We analyze the spatial distribution of carbon dioxide over the seas of the Russian Arctic based on the results of the comprehensive experiment conducted in September 2020. It turned out that during the experiment, the concentration of CO 2 increased from west to east. The minimum of 396 ppm was over the Barents Sea, and the maximum of 4106 ppm was over the Chukchi Sea. The difference between the concentrations at an altitude of 200 m and in the free troposphere attained 156 ppm over the Barents Sea and decreased to 56 ppm over the Laptev Sea. Over the eastern seas, the difference became generally positive, which was associated with the air transfer from Alaska. Above the waters of most seas, the distribution of carbon dioxide was horizontally heterogeneous, which showed the regional features of its assimilation by the ocean and transfer from the continent.