Sea ice is an important part of Arctic and Antarctic ecosystems, providing habitat for primary producers such as algae and plankton. Ships hoping to safely navigate polar waters must also pay close attention to the presence and thickness of sea ice. And sea ice is an important part of Earth's "air conditioning" system, regulating the exchange of heat between the ocean and atmosphere.

To properly understand changes in sea ice over time, scientists need robust data about how long areas of ice have persisted as frozen. In recent years, sea ice has been melting at abnormally high rates. This has created a trend away from older, thicker sea ice (multi-year ice) and toward younger, thinner sea ice (first-year ice) that is more prone to melting during the summer months. 

Satellites have been regularly measuring sea ice in various ways since 1979. Satellite observations of the emissivity of the ice at different wavelengths can help scientists estimate its age. 

NASA’s datasets include measurements of the characteristics, thickness, and concentration of sea ice. These data help scientists better understand polar ecosystems, the effects of climate change, and risks to Arctic shipping.