Characterization of Combustion Aerosols for Haze and Cloud Formation

Abstract

Aerosols resulting from the combustion of acetylene, wood, and JP-4 aviation fuels have been characterized in both the laboratory and the larger field scales by activity as cloud condensation nuclei (CCN), the total particle or condensation nuclei (CN) count, ion chromatography (IC) on filter samples, and morphology by scanning electron microscopy. The CCN / CN ratio for a given aerosol sample is a quantitative indicator of the ability of a combustion aerosol to become involved in atmospheric removal by nucleation scavenging. On both the laboratory and the field scales, this ratio was in the range 0.2–1.0 for the wood combustion aerosol, 0.2–0.5 for the acetylene case, and only 0.01–0.03 for JP-4. The CCN / CN ratios are identical for both the field and laboratory studies, implying that laboratory studies of CCN activities can be justifiably extrapolated to field studies. Aging and size-classified nucleation studies are also reported.