Fig. 2.

a–b, The total number (a) and total intensity (b) of the Arctic aerosols during the spring and summer. c, The relative intensity of assigned element classes (i.e., CHO, CHON, CHOS, CHONS, and remainder) and molecular compositions (i.e., lignins, tannins, carbohydrates, proteins, lipids, condensed aromatics, and unsaturated hydrocarbon-like compounds) of the Arctic aerosols during the spring and summer. The error bar represents one standard deviation from the mean value. 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.