Influences of Sources and Aqueous Processing on the Molecular Composition of Dissolved Organic Compounds in Cloud Water
Abstract
Organic aerosol formation and transformation occurs within aqueous aerosol and cloud droplets, yet little is known about the composition of high molecular weight organic compounds in cloud water. For this work, cloud water was collected in the summer at the mountain-top observatory at Whiteface Mountain, New York, as well as by airborne sampling above forested northern Michigan. To determine the molecular composition of high molecular weight dissolved organic compounds, cloud water samples were analyzed by electrospray ionization coupled to a high resolution mass spectrometer. In addition, for a comparison of organic aerosol composition prior to cloud activation, atmospheric particles were collected below clouds in northern Michigan and analyzed by nanospray desorption electrospray ionization coupled with high resolution mass spectrometry. The molecular composition of the cloud water and atmospheric particles depends on the influencing sources (biogenic, urban, wildfire). Comparisons of aqueous molecular markers determined by laboratory studies to the observed dissolved organic compounds, as well as comparison between identified organic compounds within the below-cloud particles and cloud water, provides direct evidence of aqueous processing and assists in the determination of important chemical pathways.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFM.A52H..01P
- Keywords:
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- 0317 Chemical kinetic and photochemical properties;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0365 Troposphere: composition and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0368 Troposphere: constituent transport and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 3311 Clouds and aerosols;
- ATMOSPHERIC PROCESSES