a, Map indicating the location of Svalbard (white star symbol; 78.5° N, 11.8° E) and surrounding chlorophyll-a concentration from the MODIS-Aqua sensor in June 2017. b–c, Temporal variations in elemental (b) and biomolecular (c) compositions of Arctic aerosols derived from 15 T FT-ICR MS analysis during the observation period. d, aerosol size distributions within the range of 10–400 nm in diameter estimated from SMPS during the observation period. CHO: compounds containing carbon, hydrogen, and oxygen; CHON: compounds containing carbon, hydrogen, oxygen, and nitrogen; CHOS: compounds containing carbon, hydrogen, oxygen, and sulfur; CHONS; compounds containing carbon, hydrogen, oxygen, nitrogen, and sulfur.