"Our work was on the side of: here's where the oil leaked and here's where it went," Mezic said. "We agreed that it would be beautiful if we could put a detailed hydrodynamic model together with a detailed bacterial model."
The resulting computer model has data on the chemical composition of hydrocarbons flowing into the Gulf of Mexico, and is seeded with 52 types of bacteria that consumed the hydrocarbons.
The physical characteristics were based on the U.S. Navy's model of the gulf's ocean currents and on observations of water movements immediately after the spill and for several months after it ended.
The scientists then sought the help of Mezic's former colleagues--engineers at the University of Rijeka in Croatia.
"We needed somebody to build the software," Mezic said. "It was a big task, a mad rush, but they did it.
"The power behind this is a tour de force. A typical study of this kind would take a year, at least. We found a way that led us to answers in three or four months."
The model revealed that one of the key factors in the disappearance of the hydrocarbon plumes was the physical structure of the Gulf of Mexico.
"It's the geography of the gulf," Valentine said. "It's almost like a box canyon. As you go northward, it comes to a head.
"As a result, it's not a river down there; it's more of a bay. And the spill happened in a fairly enclosed area, particularly at the depths where hydrocarbons were dissolving."
When the hydrocarbons were released from the well, bacteria bloomed. In other locations outside the gulf, those blooms would be swept away by prevailing ocean currents.
But in the Gulf of Mexico, they swirled around as if they were in a washing machine, and often circled back over the leaking well, sometimes two or three times.
"What we see is th
|Contact: Cheryl Dybas|
National Science Foundation