In BAESI’s new “Modeling the Formation of Ocean Currents” lesson, students do experiments with models of ocean saltwater, cold seawater, and warm water to help them understand how cold water and salty water are denser than warm and less salty water. This prepares them to understand the important process of the “great conveyor belt” of water and energy through Earth’s interconnected global ocean. The lesson is designed for grade 5-12 students, with a variety of Enrich / Extend activities listed at the end of the lesson to help you meet the needs of all learners. For instance, it is applicable to high school chemistry and physics classes, as well as earth science classes.

Guiding Questions

  • How and why does ocean water move?
  • Why is that process important for life on Earth?
  • How might the process be changing due to human activities?
  • How can we help restore balance to thermohaline circulation patterns on Earth?


  • Students will measure salt accurately to create saline solutions to model seawater of different salinity levels.
  • Students will experiment with different saline solutions and freshwater and demonstrate understanding that increasing salinity increases water density.
  • Students will create models of warm and cold seawater and slowly mix them together, then demonstrate understanding of how decreasing
    water temperature increases its density.
  • Students will form hypotheses to predict the results of their experiments, record their observations, and compare the results with their predictions in writing.

The lesson is aligned to the Next Generation Science Standards (NGSS) & Common Core State Standards, as well as California’s Environmental Principles and Concepts. We hope you and your students enjoy the simulation and other activities and we’d love to hear your feedback!

Click here for more new lessons that help you integrate climate change and other Earth science topics with biology and physical science!


Adapted from “Great Ocean Conveyor Belt.”