The Gulf Disaster: "Computers See Oil Spreading Far And Fast"

"Computers See Oil Spreading Far And Fast"
by John D. Cox

"It would indeed be a tragedy if the history of the human race proved to be nothing
more than the story of an ape playing with a box of matches on a petrol dump."
- David Ormsby Gore

"As early as this summer, oil spewing from the floor of the Gulf of Mexico is likely to get caught up in the Gulf Loop Current and flow thousands of miles around Florida and up the East Coast, scientists warned Thursday. The warning came from investigators at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado who put their powerful computer models to the task of simulating how a liquid released from the Deepwater Horizon spill site at different depths is likely to disperse over the next weeks and months.

This animation shows one scenario of how oil released at the location of the Deepwater Horizon disaster on April 20 in the Gulf of Mexico may move in the upper 65 feet of the ocean. This is not a forecast, but rather, it illustrates a likely dispersal pathway of the oil for roughly four months following the spill. It assumes oil spilling continuously from April 20 to June 20. The colors represent a dilution factor ranging from red (most concentrated) to beige (most diluted). The dilution factor does not attempt to estimate the actual barrels of oil at any spot; rather, it depicts how much of the total oil from the source that will be carried elsewhere by ocean currents. For example, areas showing a dilution factor of 0.01 would have one-hundredth the concentration of oil present at the spill site.

The animation is based on a computer model simulation, using a virtual dye, that assumes weather and current conditions similar to those that occur in a typical year. It is one of a set of six scenarios released today that simulate possible pathways the oil might take under a variety of oceanic conditions. Each of the six scenarios shows the same overall movement of oil through the Gulf to the Atlantic and up the East Coast. However, the timing and fine-scale details differ, depending on the details of the ocean currents in the Gulf. The full set of six simulations can be found here. (Visualization by Tim Scheitlin and Mary Haley, NCAR; based on model simulations.)

Last week, Adminstrator Jane Lubchenko of the National Oceanic and Atmospheric Administration observed that the first oil that became entrained in the current that loops around the Gulf before flowing out to the Atlantic as part of the Gulf Stream had become part of an eddy that cut off from the current and remains in the Gulf. However, Synte Peacock, a member of the NCAR research team, said the six simulations by the sophisticated computer models suggested that the potential for trouble from oil in the upper 65 feet of water could be far-flung - and fast. "Actually," she said in a statement released by NCAR, "our best knowledge says the scope of this environmental disaster is likely to reach far beyond Florida, with impacts that have yet to be understood." (The simulation above shows that once oil reaches the fast-flowing Loop Current, it could reach the Atlantic Coast of Florida in a matter of weeks and travel with the Gulf Stream as far north as Cape Hatteras, North Carolina, before turning east.)

NCAR emphasized that the simulations are not forecasts "because it is impossible to accurately predict the precise location of the oil weeks or months from now." Weather and ocean conditions that govern dispersal patterns - including the Loop Current - are too variable.

What happens to the oil in the Atlantic is the subject of more modeling work. German researcher Martin Visbeck, a member of the study team, noted that scientists have been asked about the potential impact along the coasts of Europe. "Our assumption is that the enormous lateral mixing in the ocean together with the biological disintegration of the oil should reduce the pollution to levels below harmful concentrations," he said. "But we would like to have this backed up by numbers from some of the best ocean models."

- http://news.discovery.com/earth/computers-see-oil-spreading-far-and-fast.html
National Oceanic and Atmospheric Administration: http://www.noaa.gov/

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