Sea ice is the central player in a dynamic system that affects the planet’s oceans and climate. Sea ice is also a force to be reckoned with as polar waters open to human activity, such as shipping that is already taking place through the Northern Route along the coast of Russia and is potentially slated for the fabled Northwest Passage along the coast of Canada. Sea-ice motion, revealed in the data available here, is a critical factor in the thinning and melting of Arctic sea ice as it forms, rafts, ridges, and opens into leads and polynyas — and as winds and currents move it through and out of the Arctic.

The sea-ice imagery and data products available through NASA’s Alaska Satellite Facility Distributed Active Archive Center (ASF DAAC) are supported under NASA’s Making Earth Science Data Records for Use in Research Environments (MEaSUREs) program.

Dramatic Changes

Though the extent of sea ice fluctuates, overall it is shrinking and substantially thinner than in past decades, and in spring and summer it is retreating earlier and faster. The melting, along with the absorption of solar energy by newly exposed, darker water, alters the circulations of oceans and the atmosphere, affecting climate and weather globally.

Observable Through Remote Sensing

Remote sensing has been central to observing and researching changes in sea ice. Synthetic aperture radar (SAR), used to create the majority of the imagery available in the ASF archive, is among the power tools of remote sensing and has been used extensively in the science of sea ice. SAR bounces a microwave radar signal off the Earth’s surface, including water and ice, to detect physical properties. Unlike optical technology, SAR can “see” through darkness, clouds, and rain.

Critical for Seafood

Sea ice also plays a substantial role in feeding the world. The ice serves as a farm for tiny organisms that drive the entire ecosystem. Seasonal sea ice in the Bering Sea is an integral part of an international fishery that provides more than half of the U.S. seafood catch. In addition, sea ice provides wildlife nurseries, molting sites, dens, hiding places, feeding grounds, resting platforms, and even transportation for Pacific walruses that migrate by riding on melting ice floes.