Hydrocarbons at the Water-Atmosphere Border in the Barents and Kara Sea

The concentrations and composition of hydrocarbons (HCs), aliphatic (AHCs), and polycyclic aromatic hydrocarbons (PAHs) in the Barents and Kara seas were determined in the surface microlayer (SML, about 300 & mu;m thick), melting ice, and surface waters. Field material was collected on cruises 80 and 83 of the R/V Akademik Mstislav Keldysh in August 2020 and June 2021, respectively. In the SML, HCs occur primarily in suspension. In the Barents Sea, the AHC content in suspension was lower (31-96, 68 & mu;g/L on average) compared to the Kara Sea (187-1051, 693 & mu;g/L on average), where research was carried out in early summer. In the Kara Sea, the AHC concentrations in the SML were 3.6 times higher than in dissolved form (89-270, 158 & mu;g/L on average), while compared to the suspension of surface waters, they were almost 15 times higher. Organic compounds also accumulate in ice, but to a lesser extent than in the SML. From the alkane composition, the influence of autochthonous processes on HC generation in melting ice is insignificant. The PAH contents in suspension were also 4.8 times higher on average than in dissolved form. The influence of the combustion products of ship fuel on the PAH composition was traced by markers, which showed that, in addition to phenanthrene, fluoranthene and pyrene dominated in all samples.