Alaska Satellite Facility
Delivering Remote Sensing Data Since 1991

Dramatic Changes

Sea ice has profound impacts on the rest of the planet and is a telling indicator of climate change. 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 sunlight by newly exposed, darker water, alters the circulations of oceans and the atmosphere, affecting weather globally.

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

Sea Ice 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.

Arctic MEaSUREs See Arctic MEaSUREs

Arctic Ocean imagery and data analysis based on satellite remote sensing.

Images of Polar Regions  See Polar Year 07-08

  • High-definition satellite snapshots of the polar regions during 2007-2008 for gauging past and future environmental changes in the polar ice, ocean, and land. Collected as part of the Global Inter-agency International Polar-Snapshot Year (GIIPSY).
This 1998 RADARSAT-1 image reveals grease ice along a pack-ice front in the Bering Sea. Grease ice forms after frazil (slush-like ice) crystals are pushed against each other. When the fragile "arms" of the crystals break and form a mixture of damaged crystals and crystal remnants, the result is grease ice—an oily-looking "ice soup" on the water surface. Its viscous nature smooths out small ocean waves. © CSA, 1998.This 1998 RADARSAT-1 image reveals grease ice along a pack-ice front in the Bering Sea. Grease ice forms after frazil (slush-like ice) crystals are pushed against each other. When the fragile "arms" of the crystals break and form a mixture of damaged crystals and crystal remnants, the result is grease ice—an oily-looking "ice soup" on the water surface. Its viscous nature smooths out small ocean waves. © CSA, 1998.
Northwest Passage sea ice contrasts with the coast of Baffin Island, Canada, in this ALOS-PALSAR image taken 8 March 2011. © JAXA, METI 2011Northwest Passage sea ice contrasts with the coast of Baffin Island, Canada, in this ALOS-PALSAR image taken 8 March 2011. © JAXA, METI 2011
Dipole eddies swirl in the vicinity of the Bering Sea's Sarichef Strait, between Hall and St. Matthew Islands, in this ERS-1 image acquired on 15 February 1992. The eddies are tidal generated and were observed only when frazil (slush-like ice) and grease ice acted as tracers. © ESA, 1992Dipole eddies swirl in the vicinity of the Bering Sea's Sarichef Strait, between Hall and St. Matthew Islands, in this ERS-1 image acquired on 15 February 1992. The eddies are tidal generated and were observed only when frazil (slush-like ice) and grease ice acted as tracers. © ESA, 1992
Get SAR Data

Get SAR Data

Select and download SAR data online using Vertex.

Use the ASF API for downloading SAR data via a command line.