Calendar Event Details
AEROCENTER: Greg Drozd
Affiliation: UMBC
Event Date: Monday, January 30, 2017
Location: G133
Time: 1:00 PM
Using Detailed Chemical Composition of Surfaced Oil to Inform History and Predict Aerosol Formation During the DWH Oil Spill: Insights on Subsurface Oil Transport, Aerosol Yields, and Satellite Observ
Releases of hydrocarbons from oil spills can have large environmental impacts in both the ocean and atmosphere. While evaporation of oil following a spill is mainly modeled simply as a mass loss mechanism, the resulting production of atmospheric pollutants can also be a major concern, particularly for continental releases, such as pipeline leaks. Following on observations of significant secondary organic aerosol (SOA) production from the Deepwater Horizon (DWH) spill, we modeled oil evaporation and the resulting potential SOA formation. Composition of surfaced oil indicates multiple transport pathways after release, and comparison of modeled SOA to observations of SOA during the DWH spill suggest high and rapid yields of SOA from intermediate volatility organic compounds (IVOC). Oil-spill conditions (e.g. sea-surface vs. sea-floor release) also affect the rate of evaporation and composition of oil-spill vapor plumes and pollutant formation.
Novel bottom-up modeling of oil evaporation is based on unprecedented characterization of oil composition from the Deepwater Horizon (DWH) oil spill using GC×GC-VUV-HRTOFMS. Such detailed and comprehensive characterization of the DWH oil allows for bottom-up estimates of the relationship between oil volatility and composition. We developed an evaporative model, based solely on our composition measurements and thermodynamic properties, rather than common boiling point parameterizations, which is in excellent agreement with published mass evaporation rates.
With modeled evaporation, we model potential (maximal) SOA production as a function of wind speed, temperature, and oil composition. Yields of SOA are estimated to be 6% after 1-2 days of evaporation. Predicted composition of surface slicks suggests significant amounts of oil surfaced up to 100km away from the DWH site. Comparisons and synergies with satellite observations, particularly slick thickness, will also be discussed.
Posted or updated: Wednesday, January 18, 2017
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