Sea Ice is mainly found in the Arctic and Antarctic regions, and is a key part of polar ecosystems. Channels within sea ice can fill with salt water and provide habitats for primary producers like algae and plankton, forming the basis of a local ecosystem. Sea ice is also a major fact in sea level rise and salinity distributions, and presents a major obstacle for ships navigating far northern or southern waters. 

NASA's Gravity Recovery and Climate Experiment (GRACE) and GRACE-FO use minute variations in Earth’s gravitational field to measure the planet’s distribution of mass, and this can be used to identify sea ice. Missions like Landsat can also provide direct observations of sea ice.

Over time, these data help researchers track changes in polar environments, and provide a valuable gauge of global climate change. They’re also vital for accurate predictions of sea-level rise, and modeling long-term circulation patterns in the ocean.