Title: | Secondary Marine Aerosol Plays a Dominant Role over Primary Sea Spray Aerosol in Cloud Formation |
Author(s): | Mayer KJ; Wang X; Santander MV; Mitts BA; Sauer JS; Sultana CM; Cappa CD; Prather KA; |
Address: | "Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States. Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China. Department of Civil and Environmental Engineering, University of California, Davis, Davis, California 95616, United States. Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92037, United States" |
DOI: | 10.1021/acscentsci.0c00793 |
ISSN/ISBN: | 2374-7943 (Print) 2374-7951 (Electronic) 2374-7943 (Linking) |
Abstract: | "Marine aerosols play a critical role in impacting our climate by seeding clouds over the oceans. Despite decades of research, key questions remain regarding how ocean biological activity changes the composition and cloud-forming ability of marine aerosols. This uncertainty largely stems from an inability to independently determine the cloud-forming potential of primary versus secondary marine aerosols in complex marine environments. Here, we present results from a unique 6-day mesocosm experiment where we isolated and studied the cloud-forming potential of primary and secondary marine aerosols over the course of a phytoplankton bloom. The results from this controlled laboratory approach can finally explain the long-observed changes in the hygroscopic properties of marine aerosols observed in previous field studies. We find that secondary marine aerosols, consisting of sulfate, ammonium, and organic species, correlate with phytoplankton biomass (i.e., chlorophyll-a concentrations), whereas primary sea spray aerosol does not. Importantly, the measured CCN activity (kappa(app) = 0.59 +/- 0.04) of the resulting secondary marine aerosol matches the values observed in previous field studies, suggesting secondary marine aerosols play the dominant role in affecting marine cloud properties. Given these findings, future studies must address the physical, chemical, and biological factors controlling the emissions of volatile organic compounds that form secondary marine aerosol, with the goal of improving model predictions of ocean biology on atmospheric chemistry, clouds, and climate" |
Notes: | "PubMed-not-MEDLINEMayer, Kathryn J Wang, Xiaofei Santander, Mitchell V Mitts, Brock A Sauer, Jonathan S Sultana, Camille M Cappa, Christopher D Prather, Kimberly A eng 2020/12/31 ACS Cent Sci. 2020 Dec 23; 6(12):2259-2266. doi: 10.1021/acscentsci.0c00793. Epub 2020 Nov 25" |