Evidence of Aqueous Secondary Organic Aerosol Formation from Biogenic Emissions in the North American Sonoran Desert
Abstract
This study examines the role of aqueous secondary organic aerosol (SOA) formation in the North American Sonoran Desert as a result of intense solar radiation, enhanced moisture, and biogenic volatile organic compounds (BVOCs). The ratio of water-soluble organic carbon (WSOC) to organic carbon (OC) nearly doubles during the monsoon season relative to other seasons of the year. When normalized by mixing height, the WSOC enhancement during monsoon months relative to preceding dry months (May - June) exceeds that of sulfate by nearly a factor of ten. WSOC:OC and WSOC are most strongly correlated with moisture parameters, temperature, and concentrations of ozone and BVOCs. No positive relationship was identified between WSOC or WSOC:OC and anthropogenic tracers such as carbon monoxide over a full year. These results are especially of significance as recent modeling studies suggest that aqueous SOA formation is geographically concentrated in the eastern United States and likely unimportant in other areas such as the Southwest.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFM.A54G..07S
- Keywords:
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- 0305 ATMOSPHERIC COMPOSITION AND STRUCTURE Aerosols and particles;
- 0345 ATMOSPHERIC COMPOSITION AND STRUCTURE Pollution: urban and regional;
- 0320 ATMOSPHERIC COMPOSITION AND STRUCTURE Cloud physics and chemistry;
- 3311 ATMOSPHERIC PROCESSES Clouds and aerosols