This project extends previous work to understand the detailed surface chemistry of sea salt aerosols. In particular the role of magnesium chloride in influencing the nature of the surface will be studied as a function of relative humidity. The goal will be to develop quantitative understanding of the mechanisms and kinetics of reactions involving sea salt particles under conditions relevant to the atmosphere in order that such processes can be accurately incorporated into numerical models of atmospheric chemical processes. A number of analytical tools will be used including the combination of diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and mass spectrometry, which will allow measurement of gas and condensed phase products simultaneously. In addition, aerosols will be generated in a reaction chamber with observations made using long path Fourier transform spectroscopy (LP-FTIR), differential optical absorption spectroscopy (DOAS) in the ultraviolet spectral region, and atmospheric pressure ionization mass spectrometry (API-MS).
Broader impacts of these activities include improved quantification of processes to be incorporated into numerical models of atmospheric chemistry in the marine boundary layer; education and training opportunities for undergraduate and graduate students (including those from underrepresented groups) and early career scientists; as well as outreach activities to K-12 students and to the public. This project is supported jointly by the Atmospheric Chemistry and Analytical and Surface Chemistry Programs.
