WASHINGTON — Oil pulsing from the April 20 BP spill in the Gulf of Mexico could slip into the Gulf Stream's loop current and begin to shoot up the Atlantic coastline by the end of the month — just as thousands of tourists are flocking to beaches along North and South Carolina.
A scientific computer modeling study released Thursday shows that once the slick joins the loop current, it could move northward at up to 100 miles a day. It would flow up to Cape Hatteras and then turn northeast out into the Atlantic, according to the models, which were produced by the National Center for Atmospheric Research, which is funded by the National Science Foundation and produces climate science for universities.
The six different models are simulations — not forecasts — meaning they don't say exactly how the oil could flow. The oil slick would be affected by local weather conditions and the ever-shifting pattern of the loop current.
The spill now is in a relatively stagnant area of the Gulf, held there in part by a temporary eddy. There have been reports of only small amounts of oil in the loop current so far.
The models vary in how the oil would behave in the loop current, with models showing that the oil could take up to three months to join the Gulf Stream. They don't show how much oil, if any, would wash ashore the coastlines of Southeastern states, or how the slick might be affected by a tropical storm.
But those who produced the models said the oil is likely to have a widespread effect.
"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," said Synte Peacock, an oceanographer with the National Center for Atmospheric Research.
"We can ask: Are there any scenarios where the oil stays in the Gulf? The answer seems to be no," Peacock said. "We can ask, is there any possibility it's going to stay (within the Gulf) for six months? And the answer seems to be no to that, too."
It's unclear how dense the oil would be in the loop current, or whether it would float on the surface or be submerged below. Scientists at NCAR said the models provide an "envelope" of how the oil could act in four months following the BP blast.
The models assumed liquid dye tracer being released at the spill site. Scientists then tracked the rate of dispersal in the top 65 feet of the water and at four additional depths, with the lowest being just above the seabed.
The models assume the oil continues to flow through June 20, but make various assumptions about how the loop current could act in the coming weeks. All, though, show oil eventually riding the loop current thousands of miles up the coastline to Hatteras.
"The loop current is a pathway out of the Gulf," Peacock said. "Once (oil) is in the loop current in significant amounts, it's a matter of days or weeks before it's going to get into the Atlantic."
Several other models, including one by the University of South Florida, also have indicated that the oil would flow into the Gulf Stream.
Researchers at the National Oceanic and Atmospheric Association in Washington cautioned against making too much of the new scientific models from NCAR.
NOAA officials pointed out that the dye presumed in the model doesn't have the same density as oil and wouldn't evaporate or break down at the same rate.
"It represents a 'big picture' look at how the oil will enter the Gulf Stream," said NOAA spokesman Chris Vaccaro. "As oil weathers, it changes characteristics and no longer behaves like a fluid, making it harder to do long-term forecasts."
Ben Fox, spokesman for S.C. Gov. Mark Sanford, said the state is paying attention to NOAA forecasts.
"NOAA and other scientists are telling us that there is a potential, but uncertain possibility, that the oil spill in the Gulf of Mexico might affect the South Carolina coastline, but with minor impact at most," Fox said in a statement.
The Coast Guard on Thursday reported that it found an oil sheen near Duck Key, Fla., as well as tar balls and one oiled vessel there. The material was sent for testing to determine whether it was oil from the gusher that resulted from the sinking of the Deepwater Horizon rig. There have been 37 other reports of tar balls in the Florida Keys recently, but none of the samples have been from the BP oil spill.
Nonetheless, the spill has been heading toward Florida. The Coast Guard said that protective booms were being set up to protect the Dolphin Research Center and dolphins at Hawk's Key Resort.
Doug Radar, chief ocean scientist for the Environmental Defense Fund, said that at some point the eddy will fade, the loop current will reorganize and the oil will continue its travels.
"That'll happen. And it'll happen sooner rather than later," Radar said. "This is only a short-term blessing."
(Renee Schoof of the McClatchy Washington Bureau contributed.)
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