Acidity across the interface from the ocean surface to sea spray aerosol
| Autor: | Vicki H. Grassian, Jon S. Sauer, Lauren A. Garofalo, Christopher T. Lee, Christopher D. Cappa, Victor W. Or, Todd R. Martz, Matson A. Pothier, Daniel R. Crocker, Kyle J. Angle, Mahum Farhan, Kathryn J. Mayer, Timothy H. Bertram, Sudarshan Srinivasan, Rebecca M. C. Simpson, Stephanie L. Mora Garcia, Delphine K. Farmer, Alexia N. Moore, Kimberly A. Prather |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Oceans and Seas
Environment complex mixtures Atmosphere Human health chemistry.chemical_compound Earth Atmospheric and Planetary Sciences Humans Seawater sea spray acidity Aerosols Marine biology Multidisciplinary Air Hydrogen-Ion Concentration respiratory system Sea spray Aerosol chemistry Environmental chemistry Atmospheric chemistry Phytoplankton Physical Sciences Carbon dioxide Environmental science aerosols |
| Zdroj: | Proceedings of the National Academy of Sciences of the United States of America, vol 118, iss 2 Proceedings of the National Academy of Sciences of the United States of America |
| ISSN: | 1091-6490 0027-8424 |
| Popis: | Significance Sea spray aerosol, produced through breaking waves, is one of the largest sources of environmental particles. Once in the atmosphere, sea spray aerosol influences cloud formation, serves as microenvironments for multiphase atmospheric chemical reactions, and impacts human health. All of these impacts are affected by aerosol acidity. Here we show that freshly emitted sea spray aerosol particles become highly acidic within minutes as they are transferred across the ocean−air interface. These results have important implications for atmospheric chemistry and climate, including aerosol/gas partitioning, heterogeneous reactions, and chemical speciation at the surface and within sea spray aerosol. Aerosols impact climate, human health, and the chemistry of the atmosphere, and aerosol pH plays a major role in the physicochemical properties of the aerosol. However, there remains uncertainty as to whether aerosols are acidic, neutral, or basic. In this research, we show that the pH of freshly emitted (nascent) sea spray aerosols is significantly lower than that of sea water (approximately four pH units, with pH being a log scale value) and that smaller aerosol particles below 1 μm in diameter have pH values that are even lower. These measurements of nascent sea spray aerosol pH, performed in a unique ocean−atmosphere facility, provide convincing data to show that acidification occurs “across the interface” within minutes, when aerosols formed from ocean surface waters become airborne. We also show there is a correlation between aerosol acidity and dissolved carbon dioxide but no correlation with marine biology within the seawater. We discuss the mechanisms and contributing factors to this acidity and its implications on atmospheric chemistry. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|