The Gulf Stream

Gulf Stream
	Drawing by Ben Franklin

The Gulf Stream system begins on the eastern side of the Gulf of Mexico, flows through the Florida Straits, and then along the southeastern coast of the United States to Cape Hatteras, North Carolina. From Cape Hatteras, the Stream flows eastward away from the coast, into deeper water as it proceeds toward Europe. Although its path is lengthy and has many segments, the Gulf Stream is considered to be a single current system.

The Gulf Stream is typically 80 to 150 kilometers wide and extends to a depth of about 800 to 1200 meters. The fastest current in the Gulf Stream is near the surface and the speed decreases with depth.

Plotting the course and strength of the stream involves both art and science. Jenifer Clark, the recognized expert on the Stream, produces real-time Gulf Stream charts for sailboat racing, boat deliveries, ocean cruising, and offshore fishing. I used these charts on our trip to Bermuda and found then to be quite helpful. The U. S. Navy produces charts which are available on their website (nlmoc) and through Bermuda Radio Weather.

These charts are based on infrared imagery, satellite altimetry data, and surface isotherm data. The following sites provide some of this information.

Sea Surface Temperature

Infrared Satellite Images: High resolution, real time false color NOAA polar orbiting infrared satellite images covering the entire East Coast and Gulf of Mexico.

Sea Surface Height

Warm eddies are lighter and therefore have higher sea heights (10-50 centimeters). Cold eddies are heavier than the surrounding water and have depressed (10-55 centimeters) sea surfaces.
Delft Institute for Earth-Oriented Space Research (DEOS) Analysis: Gulf Stream velocity derived from near real-time radar altimeter data of the European Remote Sensing Satellite ERS-2 .
Colorado Center for Astrodynamics Research (CCAR) Gulf Stream Near Real-Time Altimeter Data Viewer. This site allows you to view maps of the sea surface height or height anomaly for any region of the Gulf Stream (277°E to 320°E longitude and 30°N to 45°N latitude.

Other

Buoy Drifts: Tracks drifting buoys. You can determine drifter velocities by computing distance divided by time.
Cloud Cover: One of the tricks of figuring out the Gulfstream is to be able to see it. This site will help tell you when the Stream will be under cover.
Bermuda Satellite Image: Real time images but hard to interpret.