A disturbing image of the Gulf of Mexico on May 2, 2010 released by RoFFS showed an eddy in the loop current coming close to the BP oil spill.
Today, May 11, an image from the AQUA satellite shows a silvery swirl that may be entrained dispersed oil in the loop current.
Chemical dispersants have been keeping the size of the of the bright silvery oil slick from growing despite the daily additions of large volumes of oil. Dispersants may be hiding the real size of the oil spill. Dispersed oil does not form slicks but it contains toxins hazardous to marine life. It is difficult to see dispersed oil from the air or from satellite photographs, but it continues to be a threat to marine life.
The AQUA image from May 9, 2010 shows a bright silvery J shaped oil slick in the Gulf's Mississippi canyon region.
By May 9, birds had already been oiled and tar balls had already shown up on Gulf coast beaches but the oil slick appears to still be offshore on the satellite photo.
That's because most of the oil is below the surface.
A standard spill results in black oil floating on the water's surface, the kind of slick that mechanical skimmers and controlled burns and chemical dispersants can easily attack, said Ed Overton, a professor emeritus of environmental sciences at the university who is analyzing spill samples for the federal government.
"But there is nothing typical here. There is no slick on the water, no big black tide," he said. "The oil is out there as brownish and orangey-brown and tannish-brown patches of sticky gunk that are being moved about by the winds and waves and currents."
"That makes it more difficult to skim, more difficult to burn, and more difficult to disperse," he said. "There isn't a single black tide of oil. It's this messy gunk that floats on the surface and is also down in the water."
Many of the most toxic compounds in crude oil are volatile. When exposed on the surface they evaporate. The spill becomes less toxic to marine live over time because they have evaporated. However, when they are dispersed below the surface, slower bacterial degradation processes are the main means of removal of toxic compounds. Moreover, surface booms are unable to stop dispersed oil from contaminating the water column and bottom sediments that harbor many forms of marine life.
BP admitted on Monday that it will take 75 days or more to get the spill under control.
By conservative estimates twice as much oil will be released in 75 days as the Exxon Valdez disaster. If oil dispersed at depth has not been accounted for this disaster could be far worse than twice as much oil.
With a quick solution ominously uncertain, the oil spill in the Gulf of Mexico is on track to become an unprecedented economic and environmental disaster with millions of gallons of oil destroying an ecosystem as well as a way of life.
BP America said Monday that it would take another 75 days to finish one of two relief wells it's drilling to shut down the flow. By then, if the spill doesn't worsen and the relief well stops the leak, some 20 million gallons of oil will be swirling in the Gulf, nearly double the Exxon Valdez spill in 1989.
"It's going to be unbelievably bad," said Jeremy Jackson, a professor of oceanography at the Scripps Institution of Oceanography in La Jolla, Calif. "This is a problem that won't go away for a decade."
If today's AQUA satellite imagery is showing what I think it is, dispersed oil has already been entrained into the Loop current and is heading for the Florida Keys. Interpretation of the imagery is difficult and needs verification by collection of water samples. Clouds above and sediment in the water can change the appearance of the sea glint, making interpretation difficult. However, irregular turbulent looking features in the glint appear to show processes in the ocean, and are not normal seal glint or cloud caused features.
Caveats given, there is a sliver grey swirl in the sun glint due west of Florida bay and the the Florida Keys.
I have reviewed the imagery at the highest level of imagery, one level higher than shown here, and the swirl does not appear to be caused by clouds or normal sediments. Red pigments from the oxidation of crude oil are a likely cause of the swirl, in my opinion. It appears that oxidized oil is being transported by the Loop current towards the Florida Keys.