The atmosphere contains primary organic aerosols (POA) and secondary organic aerosols (SOA). Primary aerosols are compounds that are directly emitted into the atmosphere while secondary organic aerosols are formed from reactions with other volatile organic compounds. SOAs are produced from both biogenic and anthropogenic sources and have implications for public health, the climate, cloud formation, air quality, visibility. Aerosols can affect global radiation patterns directly by absorbing and scattering radiation and indirectly by acting as cloud condensation nuclei (CCN). The CCN properties of inorganic particles in aerosols are well understood as CCN behavior can be predicted by chemical composition, solubility, surface tension, and size of dry particles. However, less is known about the ability of different organic aerosol concentrations and the impacts that those aerosols have on CCN particles which could impact cloud microphysics, formation and lifetime.<sup> </sup>To better understand the effect that different organics have on the CCN activity of salts, deliquescence and efflorescence relative humidity (DRH and ERH) was measured using a quartz crystal microbalance (QCM) that was equipped with a humidity chamber to measure phase changes by measuring the difference in oscillation frequency between the solid and liquid phases. DRH values of inorganic salts with a variety of soluble organic compounds will be presented. Ammonium sulfate shows a decrease in deliquescence relative humidity in the presence of organics and this trend appears to be concentration dependent.

Deliquescence relative humidity of inorganic aerosols in the presence of soluble organics

255th National Meeting (2018)

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