RAPID: Impact of Gulf Oil Surface Films on Atmosphere-Ocean Exchange

Columbia University, New York NY

Investigators

Abstract

The Deepwater Horizon offshore platform well blowout, which occurred on 20 April 2010 off the coast of Louisiana, has released large amounts of crude oil and methane into the Gulf of Mexico. As a result, petroleum-based surface films (accompanied by elevated levels of subsurface methane and other dissolved gases) have spread over an unprecedented large area, raising the possibility that air-sea transfer of momentum, heat and gaseous constituents may be modified sufficiently so as to have significant impacts on regional meteorology and ocean/atmospheric chemistry. Prior research, conducted primarily in laboratory settings, has demonstrated that air-sea fluxes of momentum, energy and gases are sharply reduced by the presence of such surface active agents (termed 'surfactants'). This RAPID-type effort will allow a combination of moored and episodic ship-based transect type measurements of the above-mentioned air-sea fluxes (as well as some subsurface quantities) to be conducted over a month-long period near National Data Buoy Center site #42012 off Mobile Bay, Alabama. This work will be done in conjunction with efforts already being conducted by the Dauphin Island Sea Lab operated by the University of South Alabama, and will make use of their 25' research vessel. Supported research activities will address four themes: (1) in situ characterization of surfactant concentrations associated with the oil spill; (2) measurements of air-sea exchanges of momentum, water vapor, heat, carbon dioxide and methane; (3) quantification of impacts of these fluxes on the surface ocean heat budget and biogeochemistry; and (4) investigation of the spill's impact in reducing thermal coupling between the atmosphere and underlying ocean surface. The Intellectual Merit of this work rests in collection of high-quality flux measurements in conjunction with an oil spill of unprecedented scale, as needed to better assess impacts on ocean/atmosphere chemistry and regional meteorology through potential modification of land-/sea-breeze systems and possibly on the behavior or more intense tropical storms. Broader Impacts of the research will include improved understanding of influences of widespread petroleum spills (or other surfactant sources) on regional meteorology and atmospheric/oceanic chemistry, the dissemination of these findings via conference presentations and formal publication, and enhanced training/career development for a supported postdoctoral research associate.