Seminar

Organic Aerosol Formation Downwind from the Deepwater Horizon Oil Spill

DSRC entrance

Joost deGouw, NOAA ESRL CSD

Wednesday, January 19, 2011, 3:30 pm Mountain Time
DSRC 2A305

Abstract

The NOAA WP-3D research aircraft made airborne measurements of the gaseous and aerosol composition of air over the Deepwater Horizon (DWH) oil spill that occurred in April-August of 2010 in the Gulf of Mexico. A narrow plume of hydrocarbons was observed downwind from DWH that was attributed to the evaporation of fresh oil on the sea surface. A much wider plume with high concentrations (>25 mg m-3) of organic aerosol (OA) was attributed to secondary (SOA) formation from unmeasured, less volatile hydrocarbons that were emitted from a wider area around DWH.

These observations have implications for our understanding of organic aerosol in general, as they provide compelling evidence for the importance of SOA formation from less volatile hydrocarbons that are largely unmeasured with current instruments. These species have been suggested as important precursors for SOA formation in polluted air masses and could provide an explanation for the large discrepancy between predicted and measured SOA formation as reported by several groups. Other explanations for this discrepancy, including the enhanced formation of SOA from biogenic VOCs in polluted air, will also be discussed.

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