Fig. 3: ·OH concentration and organosulfates (OSs) formation pathway.

a ·OH production measured as the intensity of 2-hydroxyterephthalic acid (TAOH) in bulk water samples, droplets, and sea spray aerosol (SSA) particles. Terephthalic acid (TA) was added as an ·OH scavenger; no alcohol or dimethyl sulfide (DMS) was added in ASW. Error bars represent the standard deviation (SD). BDL means “below detection limit”. b Reaction mechanism for the formation of OSs initiated by surface OH radicals.