This hands-on experiment demonstrates how the density of water is affected by temperature and salinity, then addresses how climate change impacts the Global Ocean Conveyor.
Students will observe how temperature and salinity impact the density of water in two containers and then discuss how increases in precipitation, ice melt, and global temperatures affect ocean currents that transport heat and nutrients around the world.
The questions for discussion following the activity help illustrate the components of a good experiment.
The activity requires a few materials that teachers may already have.
Students should know the terms density and salinity, and have a basic understanding of global warming.
Students should understand that the oceans are saltwater and that rain and ice are freshwater.
There is some background information for the teacher about the Global Ocean Conveyor, but the teacher will need to explain this concept to students before doing the activity.
Have students make predictions for what will happen when the ice melts and support their predictions with evidence from what they already know.
The answer to the last question can lead naturally to a discussion or lesson about positive feedback loops contributing to climate change.
After discussing that warmer oceans melt sea ice, students can learn about rising sea levels or glacial melt.
Students can read the linked articles about density and salinity in their reading period to build background before doing the experiment.
This resource is from the CLEAN collection. “The CLEAN collection is hand-picked and rigorously reviewed for scientific accuracy and classroom effectiveness.”
Next Generation Science Standards (NGSS)
ESS2: Earth's Systems
MS-ESS2-4 Develop a model to describe the cycling of water through Earth's systems driven by energy from the sun and the force of gravity.
MS-ESS2-6 Develop and use a model to describe how unequal heating and rotation of the Earth cause patterns of atmospheric and oceanic circulation that determine regional climates.
5-ESS2-1 Develop a model using an example to describe ways the geosphere, biosphere, hydrosphere, and/or atmosphere interact.
ESS3: Earth and Human Activity
MS-ESS3-1 Construct a scientific explanation based on evidence for how the uneven distributions of Earth's mineral, energy, and groundwater resources are the result of past and current geoscience processes.
ETS1: Engineering Design
3-5-ETS1-3 Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved.
Common Core English Language Arts Standards (CCSS.ELA)