Development and Application of a Hygroscopicity Basis Set for the Analysis of the Mixing State of Nascent Sea Spray Aerosols

Primary aerosol particles, such as those produced from breaking waves in the ocean, are known to display large particle-particle variability in chemical composition, which affects their ability to act as cloud condensation nuclei (CCN). Current measurement techniques typically characterize CCN activation efficiency in terms of the single parameter hygroscopicity coefficient, κ, but these techniques do not account for how the chemical heterogeneity of marine aerosol particles translates to corresponding differences in their hygroscopicity. Here, we describe a methodology for assessing the distribution of super saturated hygroscopicities within the same aerosol population, in terms of a "κ basis set" analysis, and apply that methodology to model aerosol mixtures with prescribed mixing states. Moreover, the generalizability of this new analysis allows for application to hygroscopicity data sets that have been previously collected, as well as those outside of the marine environment. Development and application of the κ basis set analysis will be discussed.