Results of Studying Physicochemical Characteristics of Atmospheric Aerosol in the 71st Cruise of RV Akademik Mstislav Keldysh

In summer 2018 along the route of the 71st cruise of RV Akademik Mstislav Keldysh in the North Atlantic we carried out the measurements of such atmospheric aerosol characteristics as aerosol optical depth, near-surface aerosol and black carbon concentrations, content of chemical elements in aerosol samples, and organic and elemental carbon, as well as the isotopic composition of black carbon. It is shown that the average values of most characteristics decrease severalfold during passage from the Baltic Sea to the North Atlantic (57°–60° N), and then to the Norwegian Sea. For instance, the average black carbon concentration decreased from 83 to 29 ng/m3. Episodic impact of continental aerosol was noted even in remote regions of ocean. Outflow of smokes from forest fires in the north of Canada to the region of measurements (southward of Greenland) had the strongest effect on aerosol characteristics. The average concentrations of chemical elements in aerosol composition over the North Atlantic were several times larger than in the Arctic region, and smaller than in the background region of Siberia.