Closing the Gap on Missing Sources of Organic Aerosol in the Atmosphere
Event details
| Date | 21.07.2011 |
| Hour | 11:15 |
| Speaker | Christopher Hennigan |
| Location | |
| Category | Conferences - Seminars |
Aerosols or particulate matter are ubiquitous components of the atmosphere that exert important impacts on human health and global climate though our understanding of these effects is far from clear. A better characterization of aerosol physical and chemical properties including their sources and fate is vital in obtaining a more accurate assessment of their contribution to climate change and in devising mitigation strategies with public health in mind. Extensive ambient measurements have demonstrated that organic compounds comprise a significant fraction of aerosol mass in many locations globally. Our knowledge of this organic aerosol (OA) however is incomplete as evidenced by the systematic underprediction of OA concentrations by state-of-the-art computer models. Recent research efforts have intensified to identify this “missing” source of OA with many hypotheses emerging. Measurements conducted in Atlanta Georgia point to liquid water associated with aerosols as an important OA source that has not been considered previously. This mechanism involves the dissolution and subsequent reaction of soluble organic gases in the aerosol aqueous phase. It is likely different from processes occurring in cloud and fog water due to extreme concentration differences. Previous studies have ignored this possibility due to the relatively small amount of water associated with fine particles; however our results provide strong evidence that this pathway contributes significantly to ambient OA concentrations. This mechanism is likely to be important in other locations as well and may represent the dominant source of OA missing from current models.
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Practical information
- General public
- Free
Contact
- Christina Treier