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10. Measuring Surface Circulation
Try Again!

Expedition Menu

1. Introduction
2. Ocean Temperature
3. Circulation
4. Atmospheric Heat
5. Heat and Pressure
6. Atmospheric Pressure
7. Air Pressure and Wind
8. Wind Directions
9. Global Wind Patterns
10. Measuring Circulation

Remember the previous map of the global wind patterns?

The directions of the winds form big circular loops with the major circular loop in the northern hemisphere rotating in a clockwise direction and in the southern hemisphere, in a counterclockwise direction.

We can trace the direction of surface currents below these winds in many ways, for example with current meters or with floats that are carried with the currents.

 

Extremely simplified diagram of ocean surface circulation, we will see in our next expedition that is it is not so simple - -- how are these current directions measured?

Very Briefly Visit (45 seconds or less) each of the sites, listed below, to learn about opportunistic, "low-tech" methods of determining ocean current motions

(Remember to Look for Site in second window of your and return to the window containing the course WWW site when completed)

Very Briefly!!!!!!! (use only 30-45 seconds each)

• Nike Tennis Shoes - Notice the directions of currents in the North Pacific Ocean  (SeaWIFS at NASA)

• Just like Nike Tennis Shores have been used, so have Rubber Duckies

Here are "high tech" methods to determine the current direction 

• Tracking Drifters with Satellites - Gulf of Maine Aquarium
  

• Measuring Currents From Fixed Instruments Moorings - Gulf of Maine Aquarium

• Listen to an Ocean Report on the Tracking Currents with the Drifters in Quicktime

Graphics from Gulf of Maine Aquarium

Using sea surface temperature as a means of tracing the flow of water, try to guess the location and direction of the major circular ocean currents, called gyres. You will find one in each hemisphere (northern and southern) of the major ocean basins.

Image Provided by SSEC, University of  Wisconsin-Madisonfont>

Listen to the Ocean Report from Seaweb in Quicktime
Tracking Ocean Currents with Nuclear Fallout

How can we trace the direction of ocean currents?

a) With current meters
b) With floats
c) With sea surface temperature
d) All of the above
e) Only a and b