Heterogeneous Reactivity of Nitric Acid with Nascent Sea Spray Aerosol: Large Differences Observed between and within Individual Particles.

Current climate and atm. chem. models assume that all sea spray particles react as if they are pure NaCl. However, recent studies of sea spray aerosol particles have shown that distinct particle types exist (including sea salt, org. C, and biol. particles) as well as mixts. of these and, within each particle type, there is a range of single-particle chem. compns. Because of these differences, individual particles should display a range of reactivities with trace atm. gases. We studied the compn. of individual sea spray aerosol particles after heterogeneous reaction with nitric acid. As expected, a replacement reaction of chloride with nitrate is obsd.; however, there is a large range of reactivities spanning from no reaction to complete reaction between and within individual sea spray aerosol particles. These data clearly support the need for lab. studies of individual, environmentally relevant particles to improve our fundamental understanding as to the properties that det. reactivity. [on SciFinder(R)]