OVER THE GULF OF MEXICO — With a loud whoosh, the probe dropped through a chute in the plane’s belly and fell 5,500 feet to the Gulf of Mexico below.
When it hit the water, the probe broke into two parts: a transmitter bobbing on the surface, while a connecting wire and an instrument to measure water temperature and current spooled into the depths.
On impact, the probe began transmitting data to instruments on board the National Oceanic and Atmospheric Administration plane nicknamed “Kermit the Frog.”
The four-engine plane, a WP-3D Orion crammed with scientific equipment, and famous for flying through hurricanes, was taking the pulse of the Loop Current and a giant eddy that so far has helped steer oil away from Southwest Florida beaches.
The marathon 8 1/2-hour flight Friday, during which 68 probes were dropped, was the sixth that University of Miami professor Nick Shay has made aboard a NOAA aircraft, trying to learn more about the behavior of the Loop Current and the warm water eddy, which turns in a clockwise direction and measures about 200 miles across.
The more scientists know about the eddy and the current, and when they might separate, and perhaps reattach again, the better. That knowledge would be important in understanding where oil from the Deepwater Horizon spill may be headed.
Should the eddy break away, there is a cone of uncertainty about its ultimate destination. A move to the north could mean added concern for the Florida Keys. A move to the west could heighten concerns in Texas and Mexico, Shay said.
Lt. Cmdr. Mark Sweeney, a NOAA pilot who was flight commander, called the Orion’s track Friday a “mowing-the-grass pattern,” covering 1,939-miles.
The crew took off from MacDill Air Force Base at about 8:52 a.m. and flew southwest to a point west of the Dry Tortugas and then flew due west, dropping probes at predetermined grid coordinates.
Starting point was 280 miles south of the Deepwater Horizon. This was the southern-most part of the grid over the eddy.
After reaching the western edge of the grid, the Orion turned north for a short distance, and then tracked back east again. Eventually Kermit would make six east and west flights over the eddy, each precisely calculated and each one a little more to the north than the last one.
Two kinds of probes were being used. One measured the temperature of water at 1,000 feet. The other measured temperature and current at depths up to 4,800 feet, a metric mile.
“This is our sixth flight. We’ve being doing them every week to measure the changes,” said Shay, a scientist for the University of Miami’s Rosenstiel School of Marine and Atmospheric Science.
The flight Friday came as close as 45 nautical miles to the Deepwater Horizon site. At that close distance, occasional patches of oil could be seen floating on the surface.
Going into Friday’s flight, crews had previously seen sheen as far away as 280 miles from Deepwater Horizon, Shay said.
Soon after Kermit the Frog dropped its first probe, shortly after 10 a.m., several crew members pointed out patches of orange-brown material floating 280 miles from Deepwater Horizon.
“Stuff on the surface,” Shay said, frowning.
Later, Sweeney said it might have been oil, or it could have been an algae bloom. Not everything that color is oil, he said.
As each new probe hit the water, crew members like Steven Paul and Carlos Quiles watched high-tech displays of data streaming in giving depth and temperature. And, in a time-honored low-tech way, they marked each probe dropped on a grid coordinate with pencil and paper.
“Knowing where these deepwater features are is a good idea,” Shay said.
The Loop Current and the giant eddy can dictate where oil will move on the surface and underwater in plumes.
Shay has been paying particular attention to a location southwest of the Deepwater Horizon where probes have measured an area of constant warm temperatures.
It is a counter-clockwise warm water eddy that has moved 60 miles south in the past week.
Researchers found this area of uncharacteristic temperatures May 8, and have watched it grow ever since.
“It’s not going away, “ Shay said.
Was it oil?
Or could have been some kind of anomaly?
Whatever, it is now 120 nautical miles from the spill site. It starts 300 feet under the surface, and goes down about 450 feet, suggestive of a possible underwater plume.
Attachment and separation
The big eddy to the south, the primary focus of Friday’s mission, is getting ready to separate from the Loop Current, Shay said. That event could have implications for where oil goes, and also for hurricane season.
The Loop Current and eddys in the Gulf are historically “fuel injectors” for hurricanes.
Katrina, Isidore and other hurricanes went to Category 5 with warm-water energy pulled from the Loop Current.
Warm eddys have been known to turn a Category 1 storm into a Category 4 hurricane in 14 hours.
“The idea is to understand the eddy’s behavior. That’s why we are trying to do the deepwater profiling,” Shay said.
Oil that goes into the eddy will probably go to the west, away from Florida, he said.
“My bigger concern is for the people in the Keys,” he said. If the eddy tracks more to the north, that would be bad news for the Keys. If it moves to the west, that would be bad news for Texas and Mexico.
“There are no winners in this,” Shay said.
There are only two more of these tracking flights planned, but there may be talks to extend the operation, given the many unanswered questions about the spill and its consequences.
Jack Parrish, NOAA flight director, said so many flights so early in hurricane season, has ramped up training.
“Normally, this would be a quiet time for us,” Parrish said of the start of hurricane season.
With the oil spill, NOAA and the country are facing a new kind of disaster. “It’s the real thing,” Parrish said.