Surface Drifter Observations

Satellite-tracked drifting buoys, or "drifters", follow the ocean at the depth of their drogue (a sea anchor suspended below the surface float). Many are deployed by NOAA as part of the Global Drifter Program (GDP). These are drogued at a depth of 15 m. For more information about these drifters, click here.

Why are they helpful?

Satellite-tracked drifting buoys travel with ocean surface currents. These instruments provide scientists with a direct measure of upper-ocean circulation.

The GDP arranged for 36 drifters to be deployed in the Gulf of Mexico in 2010. The data from these drifters were transmitted on the Global Telecommunication System for real-time distribution, and are available in ASCII format via ftp. These drifters were deployed in pairs, so that their relative spreading rates can be quantified. The subsequent trajectories of these drifters mapped the ocean features in the Gulf, like the warm ring and the Loop Current, and helped understand and forecast where these features would carry the oil.

On June 7-9 2010, 6 drifter pairs were deployed from the R/V Walton Smith (chief scientist Michelle Wood) between the Deepwater Horizon site and the Dry Tortugas. The final two pairs were deployed close together in a convergence region where personnel aboard the Walton Smith observed oil being carried southward in a frontal jet.

In July 2010, 12 drifter pairs were deployed from the R/V Nancy Foster (chief scientist Ryan Smith). These deployments were concentrated in the Loop Current and the large eddies north and northwest of the current.

For more deployment information please visit our Deployment Log page. Additional drifters, drogued at 0.75 m, have been deployed by USF and by NOAA's Northeast Fisheries Science Center. USF also has a map which includes the trajectories of drifters deployed by the U.S. Coast Guard.

Current GDP Observations

Colored lines: GDP SVP-type drifters, drogued at 15 m depth, deployed to monitor ocean currents in the Gulf of Mexico in support of NOAA's response to the Deepwater Horizon oil spill. Stars show beginning locations, circles the current location, and shading indicates sea surface temperature (°C, color scale at bottom). All other drifters in the area are shown with black tracks; most of these are CODE-style drifters drogued at 0.75 m. The most recent 15 days of each drifter's trajectory is shown.

Data source: Drifter Data Assembly Center (DAC), and Global Telecommunication System (GTS)

The map below shows the subsequent paths taken by all GDP drifters that have ever passed through the white box in the northern Gulf of Mexico. The color is the number of days since passing closest to the center of the box. Any time longer than two years is dark red.

Drifter paths

Data source: Drifter Data Assembly Center (DAC)