Tracking Ocean Currents

NOAA Global Drifter Program: Drifter Buoy

The task is simple: "Your job is to design and draw a device to track ocean currents."

As we've been studying different aspects of ocean currents — causes, movement, etc. — it's a worthwhile endeavor to think about the instruments used to track ocean currents. A major component of How Science Works includes gathering data, and I think it is important for students to consider the myriad challenges scientists face when tasked to collect a particular type of data, such as ocean currents. I, therefore, ask students to design a device that could track ocean currents and share their design with the class (How Science Works, "publication," "discussion with colleagues," and "feedback and peer review").

The designs are always innovative, creative, thoughtful, and reasonably practical. The best part of this activity is comparing student designs with actual ocean tracking devices used by NOAA and seeing the overlap.

NOAA's Global Drifter Program utilizes drifter buoys to track ocean currents around the world:

"The modern drifter is a high-tech version of the "message in a bottle". It consists of a surface buoy and a subsurface drogue (sea anchor), attached by a long, thin tether. The buoy measures temperature and other properties, and has a transmitter to send the data to passing satellites. The drogue dominates the total area of the instrument and is centered at a depth of 15 meters beneath the sea surface."

Students are delighted to see that many of the ideas they developed in class are actually used in the drifter program. We discuss similarities and differences between their designs and NOAA's drifters to better understand the challenges and limitations involved in measuring ocean currents.

The design activity is followed up with a tracking activity that uses data from NOAA's drifter buoys to track the flow of global ocean currents. Students discover that currents in the Pacific Ocean flow in a giant, clockwise gyre at a fairly slow, but steady rate; in the process, large quantities of heat are redistributed around the planet.

It's easy for a teacher to have students just learn factual information about currents from a textbook, but that's like eating processed junk food—it provides little in the way of long-lasting nutritional value (i.e., shallow learning). US science organizations such as NOAA, NASA, and USGS provide valuable data and information that is perfect for an inquiry-based science classroom. These organizations are the primary sources of science discovery and exploration on planet Earth, and we should be leveraging their expertise in the classroom to engage our students in How Science Really Works.

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A sampling of student designs for ocean tracking devices: