One of the most important indicators of our warming climate is the extent and thickness of polar sea ice. Currently satellites measure the extent of polar sea ice but it takes more sophisticated equipment aboard a low-flying plane to actually measure the thickness of sea ice. This lesson will show students how this is done.
How can the ocean be colder than 0 degrees C, the temperature at which water freezes? As it turns out, the concentration of the particles (in this case, the ions from the salt) in ocean water lowers the temperature at which the saltwater will freeze. Students will learn how ocean water freezes at a lower temperature than freshwater by