Find out the temperature difference between the Gulf Stream and the surrounding water.

  1. Locate the Gulf Stream on the infrared image of the eastern seaboard of the US. Can you find a reference point on land where the Gulf Stream veers off toward Europe?
  2. Using the temperature scale provided below, figure out the temperature range of the slope water (the water closest to shore on the northwest side of the Gulf Stream), the Gulf Stream, and the Sargasso Sea (the water to the east of the Gulf Stream).
  3. There is as much as a 100F difference in the water temperature north and south of Cape Cod, Massachusetts. This extension of land divides two ocean bioregions (separated not by political boundaries, but by the kinds of life that thrive there), effectively barricading warm-water animals from the Gulf of Maine, which begins at the northern tip of Cape Cod.

Can you detect a temperature difference at this location on your satellite image?

  1. Record temperatures on your map of the east coast.
  2. If you have direct readout ground station, use the sensor to determine the temperatures of the water on the computer screen. Place these temperatures in the appropriate locations on your map.

The Gulf Stream influence

Do some library research to find out about the climate of Ireland and England and how the Gulf Stream affects it. Compare their weather and rainfall to that of a location at the same latitude in North America.

Bucking the current

Fill a large tub with water. Use your hands to create a current going in only one direction. Experiment with toy boats or pieces of balsa wood. Using a watch with a second hand or a stop watch, time how long it takes to get from one end of the tub to the other, first going with the current and then against the current.

Now set up a fan so it blows with the current and repeat experiment. Then move fan so it blows against the current. How do the sailing times compare? Discuss how sailors traveling with the Gulf Stream benefited, while sailors fighting the current were slowed as they crossed the Atlantic, even though the winds may have been favorable.


  • satellite image of the Gulf Stream (see temperature range below), map of the eastern United States
reds and oranges 240 to 280 Celsius
yellows and greens 170 to 230 Celsius
light blues 100 to 160 Celsius
dark blues 20 to 90 Celsius

This table describes the different colors which will be seen on the accompanying satellite images, with their corresponding temperatures. Reds and oranges indicate from 24 to 28 degrees Celsius, yellows and greens indicate from 17 to 23 degrees Celsius, light blues from 10 to 16 degrees Celsius, and dark blues from 2 to 9 degrees Celsius.