Building a Model of Ocean Currents
In this activity, you will build a model to show the formation of currents in water.

Estimated time to complete: 1 hour
You will need these materials:

2 drinking glasses or small snack bowls
food coloring (2 different colors)
a measuring cup
a clear plastic or glass container, about 6 inches × 10 inches × 2.5 inches deep
water (1 cup hot, 1 cup cold, and enough room temperature water to fill half the container)
Hypothesis and Data Collection

a clear glass bowl with red food coloring swirling on the left and bottom and blue food coloring swirling on the right and top

Fill the plastic container half full with water. Let it sit out until the water is room temperature. Fill one drinking glass with 1 cup of hot tap water. Mix in a few drops of one food coloring. Fill the other drinking glass with 1 cup of cold tap water. Add the other food coloring and mix it well. Move on to part A.

Part A
Make a prediction. What do you think will happen when you add the hot and cold water to the water in the clear container?
Part B
Hold one cup in each hand and gradually pour the hot water into one end of the container and the cold water into the other end. Be sure you pour both at the same time. Watch the water for one minute and record your observations.
Part C
The temperature of the ocean is different at the surface than it is near the deep ocean floor. Why do you think that is the case?
Part D
Based on your results from task 2, do you think that cold ocean water tends to be saltier or less salty than warm ocean water? Explain.
Part E
Sometimes the flow of ocean currents is compared to the movement of a conveyor belt. Does your experiment support this statement?
Part F
The Sun hits the ocean at the equator more directly than at the poles. How does this support the flow of currents in the ocean?