Oil Transport

Spier C, Stringfellow WT, Hazen TC, Conrad M. 2013. Distribution of hydrocarbons released during the 2010 MC252 oil spill in deep offshore waters. Environmental Pollution 173:224-230. Find it Online*
Majority of the underwater plume was headed in a southwestern direction.  Less water soluble compounds were found in the upper region of the water column, and further away from the dispersant.  Deepwater dispersants increased the oil remaining in the deeper layers and decreased the oil rising to the surface (i.e., may all be due to slower water velocity).  Temporarily persistent subsurface plumes were found at 25, 265, 865, and 1175 meters (i.e., largest and most consistent plume).

Perring AE, Schwarz JP, Spackman JR, Bahreini R, De Gouw JA, Gao RS, Holloway JS, Lack DA, Langridge JM, Peischl J et al. . 2011. Characteristics of Black Carbon Aerosol from a Surface Oil Burn During the Deepwater Horizon Oil Spill. Geophysical Research Letters 38:L17809. Find it Online*
After the BP oil spill, one of the remediation efforts for the surficial oil plumes was in situ mass burnings.  Over a 9 week period of active burnings, there were 410 separate burns that produced black carbon (e.g., soot) aerosols directly injected into the atmosphere.  These aerosols were mainly composed of carbon monoxide and carbon dioxide.  During this time period, the active burnings were equivalent to the total black carbon emissions of all the maritime shipping in the Gulf region over the same duration.  These emissions were noticeably higher than the typical background air.  This air pollution may lead to atmospheric and climate impacts.

Paris CB, Henaff ML, Aman ZM, Subramaniam A, Helgers J, Wang DP, Kourafalou VH, Srinivasan A. 2012. Evolution of the macondo well blowout: simulating the effects of the circulation and synthetic dispersants on the subsea oil transport. Environmental Science & Technology 46(24):13293-302. Find it Online*
The methane gas, which initially caused the underwater explosion of the wellhead, may have helped transport additional oil to the surface.  The Deepwater Horizon explosion caused several plumes that were all dependent on the discharge velocity and water densities.  The main deepwater plumes were located southwest and northeast of the blown well; they were transported by the slow to fast deepwater currents/eddies (a few cm/s to 10 cm/s, respectively). 

Carmichael CA, Arey JS, Graham WM, Linn LJ, Lemkau KL, Nelson RK, Reddy CM. 2012. Floating oil-covered debris from Deepwater Horizon: identification and application. Environmental Research Letters 7(1):015301. Find it Online*
Pieces of the riser pipe buoyancy module, from the Deepwater Horizon drilling rig, have been found along the coast.  These pieces have floated or been transported faster than the projected oil slick.  The physical properties of the pipe have enabled a faster transport on the sea surface compared to floating oil.  Results indicate that weathering (i.e., natural or physical processes) have decreased hydrocarbons (e.g., oil) on the pipe pieces by 25%.  There has been no evidence of oil degradation, but there has been evidence of a reduction in the lighter weight polycyclic aromatic hydrocarbons (PAHs).  This indicates distribution on PAHs within the water column (i.e., oil contamination).  Floating oil debris should be a forewarning sign of oil trajectory to proximal coastlines. 

Falcini F, Jerolmack DJ, Buongiorno Nardelli B. 2012. Mississippi River and Sea Surface Height Effects on Oil Slick Migration. PLoS ONE 7(4):e36037. Find it Online*
The Mississippi River plume exerts a strong influence on circulation patterns within the northern Gulf of Mexico.  It is freshwater, so the difference in density helps create a movement that may have impacted the oil plume from the BP incident (along with magnitude of river discharge, wind stress and the effects of eddy currents).  Lower riverine discharge rates helped induce a freshwater mound near the mouth of the river.  This mound can act as a natural barrier for oil spreading further north into some of the Gulf of Mexico estuaries.  Earlier models of oil trajectory did not account for pressure-driven flows; physical and biological processes are needed in consideration for projection of these oil plumes.

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