Satellite Image of the Gulf Stream off the East Coast of the United States

This satellite image shows the sea surface temperature field associated with the Gulf Stream and the adjacent Slope Water off the east coast of the United States on April 18, 1989. The temperatures are color coded with the warmer waters shown by yellow hues and cooler waters by blue and magenta. This false-color image reveals the meandering Gulf Stream as it leaves the coast near Cape Hatteras, NC, and flows out into the middle of the Atlantic Ocean. On this day, a large meander near 65W has folded back on itself forming a completely closed loop. This satellite image was supplied by Dr. Peter Cornillon.

Superimposed on this image are in situ measurements taken by several different types of instruments on the same day. These measurements indicate the path of the Gulf Stream below the sea surface and the strength of its flow.

• Contoured Maps of Thermocline Depth. A strong subsurface temperature gradient, called the thermocline, is associated with the Gulf Stream. The thermocline slopes downward from the sea surface to depths of about 1000 meters on the southern side of the Gulf Stream. Measurements of the subsurface temperature field were made by two arrays of inverted echo sounders. One array (the Inlet Array) was located near Cape Hatteras and the other (the Central Array) was centered near 68W. The depth of the 12 degree Centigrade temperature is contoured above using a 50 meter contour interval. The shallowest depths (the upper right corner) are less than 150 meters and the deepest depths (lowere right) are in excess of 850 meters. Click here to bring up larger drawings of the contoured thermocline fields for the Central or Inlet Arrays.
• Current Velocities. Currents at 400 meters depth were measured at 11 sites and are shown by the black lines. The location of each measurement is indicated by a plus symbol. The length of the vector and its orientation indicate the current speed and its direction. This measurements were collected as part of the SYNOP experiment.
• RAFOS Float Tracks. The paths taken by 6 RAFOS floats are shown by the blue lines. Each line segment indicates the location of the float over a 32-hour period, centered April 19th at 1200 UT. Longer tracks indicate that the floats were located in the swifter part of the flow. Although the depth of the neutrally-buoyant floats changed along the path, they were typically located at depths between 200 and 600 meters. The RAFOS float data were supplied by Dr. Tom Rossby.

Dynamics of Ocean Currents Group at URI/GSO:
Maintained by Karen Tracey
Last Updated: September 18, 2000