Roles of marine biota in the formation of atmospheric bioaerosols, cloud condensation nuclei, and ice-nucleating particles over the North Pacific Ocean, Bering Sea, and Arctic Ocean

We investigated the association of marine biological indicators (polysaccharides, protein-like gel particles, and chl a ) with the formation of fluorescent aerosol particles, cloud condensation nuclei (CCNs), and ice-nucleating particles (INPs) over the North Pacific Ocean, Bering Sea, and Arctic Ocean during September-November 2019. The abundance of bioindicators was high in the North Pacific Ocean and the Bering Sea (e.g., up to 1.3 mg m - 3 of chl a ), suggesting high biological activity due to a phytoplankton bloom. In the North Pacific Ocean, particles were characterized by high mass fractions of organics and sulfate with a predominance of terrestrial air masses. Conversely, in the Bering Sea and the Arctic Ocean, particles were characterized by high mass fractions of sea salt and sulfate with a predominance of maritime air masses. The averaged range/value of the CCN concentration at 0.4 % supersaturation were 99-151, 43-139, and 36 cm - 3 over the North Pacific Ocean with terrestrial influences, over the Bering Sea with marine biogenic influences, and over the Arctic Ocean with marine influences, respectively, and the corresponding range/value of the hygroscopicity parameter kappa were 0.17-0.59, 0.42-0.68, and 0.66, respectively. The averaged INP concentration ( N INP ) measured at temperatures of - 18 and - 24 circle C with marine sources in the North Pacific and Bering Sea was 0.01-0.09 and 0.1-2.5 L - 1 , respectively, and that over the Arctic Ocean was 0.001-0.016 and 0.012-0.27 L - 1 , respectively. When marine sources were dominant, fluorescent bioaerosols in the fine mode were strongly correlated with all bioindicator types ( R : 0.81-0.88) when the effect of wind-induced uplift from the sea surface to the atmosphere was considered. Correlations between N INP measured at - 18 and - 24 circle C and all bioindicator types ( R : 0.58-0.95 and 0.79-0.93, respectively) were positive, even when the extreme outlier point was omitted, as were those between N INP and fluorescent bioaerosols ( R : 0.50 and 0.60, respectively), suggesting that marine bioindicators contributed substantially as sources of bioaerosols and to cloud formation.