In our quest to better understand ocean currents, we investigated the effects of temperature on the motion of fluids through water. Students set up and performed a controlled experiment that tested the movement of hot vs. cold potassium permanganate solution (aka, "purple stuff") in columns of room temperature water. Watch as one group of students performs a trial (hot on the left, cold on the right):
Based on the experiment, ponder the following questions:
- How does temperature affect ocean water?
- How does temperature affect the way water moves?
- Which is more dense, hot water or cold water? What evidence from the experiment do you have to support your answer?
- How might uneven solar heating of the Earth (equator vs. poles) cause ocean currents?
- How do you think ocean currents affect global weather and climate?
To better appreciate how and why scientists monitor and study ocean circulation, explore NASA's Aquarius Mission website, which has many excellent animations such as the one below: