In this activity, students learn about sea ice extent in both polar regions (Arctic and Antarctic). They start out by forming a hypothesis on the variability of sea ice, testing the hypothesis by graphing real data from a recent 3-year period to learn about seasonal variations and over a 25-year period to learn about longer-term trends, and finish with a discussion of their results and predictions.

This video introduces phytoplankton - the base of the marine food web, the source of half of the oxygen on Earth, and an important remover of CO2 from the atmosphere. The video also explains how satellites are used to monitor phytoplankton and how warming waters and acidification negatively affect phytoplankton.

This NASA animation depicts thermohaline circulation in the ocean and how it relates to salinity and water density. It illustrates the sinking of water in the cold, dense ocean near Iceland and Greenland. The surface of the ocean then fades away and the animation pulls back to show the global thermohaline circulation system.

This video describes how the normal thousands-of-years-long balance of new ice creation and melting due to ocean currents has been disrupted recently by warmer ocean currents. As a result, glacier tongues that overhang the interface between ice and ocean are breaking off and falling into the ocean.

This Earth Exploration Toolbook chapter is a detailed computer-based exploration in which students learn how various climatic conditions impact the formations of sediment layers on the ocean floor. They analyze sediment core data from the Ross Ice Shelf in Antarctica for evidence of climate changes over time. In addition, they interact with various tools and animations throughout the activity, in particular the Paleontological Stratigraphic Interval Construction and Analysis Tool (PSICAT) that is used to construct a climate change model of a sediment core from core images.

This is a short experiment to demonstrate the concept of thermal expansion of water when heated, as an analogy to thermal expansion of oceans due to global warming.

In this role-playing activity, learners are presented with a scenario in which they determine whether the Gulf Stream is responsible for keeping northern Europe warm. They must also address the potential future of the Gulf Stream if polar ice were to continue melting. The students work in small groups to identify the issue, discuss the problem, and develop a problem statement. They are then asked what they need to know to solve the problem.

This Changing Planet video documents scientists' concerns regarding how melting Arctic sea ice will increase the amount of fresh water in the Beaufort Gyre, which could spill out into the Atlantic and cause major climate shifts in North America and Western Europe. The video includes interviews with scientists and a look at the basics of how scientists measure salinity in the ocean and how ocean circulation works in the Arctic.

The purpose of this activity is to identify global patterns and connections in environmental data contained in the GLOBE Earth Systems Poster, to connect observations made within the Earth Systems Poster to data and information at the National Snow and Ice Data Center, and to understand the connections between solar energy and changes at the poles, including feedback related to albedo.