Lesson 2: Primary Production and Upwelling in the Ocean
Colorful Convection Currents
Materials / Preparation
Review the instructions and video at Easy Science Experiments: Colorful Convection Currents
Each group of students will need:
Groups of two to four
Easy Science Experiments: Colorful Convection Currents includes a video demonstration. If you have never seen this activity done, you may want to review the video before trying the activity.
This hot and cold water activity can be rather messy. We encourage you to try the activity yourself before doing it in the classroom. Providing students with buckets can help to avoid major water spills during this activity. Make sure that the bottles are only stacked inside the buckets. You may want to do the activity outside. If you feel that your students will not be able to do the activity, you show the online video, but it is more powerful to have students do the experiment themselves.
Keep an ample supply of hot and cold colored water handy.
For most students, it is intuitive that hot and cold water would mix. To see the cold water staying at the bottom may challenge their assumption. This is a good thing! But it’s important that the students first set up the experiment with the hot water at the bottom. Make sure to have a thorough discussion about what is happening. For students who haven’t studied density, you may want to include some basic density concepts at this point.
OPTIONAL: If time permits, as an extension students can also experiment with salt water of various concentrations—this will deepen the students’ understanding of layers in the water column.