Biomass burning particles are one of the largest aerosol sources worldwide and contribute a significant fraction of the global cloud condensation nuclei (CCN) burden. Chemical aging experiments of sawgrass burning particles took place in a smog chamber by turning on the UV light after HONO or H 2 O 2 injection. The CCN activity and corresponding hygroscopicity of fresh and aged particles were measured. Most of the fresh particles can serve as reasonable CCN, and the average activation diameters at 0.2% supersaturation were 114-125 nm in the experiments. The aging process caused that the mass fraction of organic aerosols decrease and condensed phase nitrate NO 3 increase, and also the average atomic oxygen to carbon (O:C) ratios increase, which were the main reasons that the aged particles were more CCN active and hygroscopic. The average activation diameters decreased by 8-15% at 0.2% supersaturation after aging, and hygroscopic parameter j increased by 30-42%. The chemical aging productions were a little different in experiments, but the CCN property and hygroscopicity change trends were quite similar.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.