Vital Signs

As the frozen interface between the ocean and atmosphere, sea ice plays a key role in the Earth’s climate and polar ecosystems.

Arctic SST is an essential indicator of the role of the ice-albedo feedback cycle in any given summer sea ice melt season.

Primary production by single-celled phytoplankton and sea ice algae forms the foundation of the Arctic Ocean’s unique ecosystems and the fisheries they support.

The biological, physical and climatic conditions of Arctic tundra ecosystems are changing profoundly, as vegetation and underlying permafrost soils are strongly influenced by warming air temperatures and the rapid decline of sea ice on the nearby Arctic Ocean.

Surface air temperatures (SAT) represent one of the strongest indicators of Arctic change over the last 50 years.

Snow covers the Arctic land surface (land areas north of 60° N) for up to 9 months each year, and influences the surface energy budget, ground thermal regime, and freshwater budget of the Arctic.

The Greenland ice sheet sits atop the world’s largest island and holds the equivalent of 7.4 m of potential sea level rise. Following a period of relative stability from the 1970s to early 1990s, the ice sheet began losing ice at an accelerating rate and has now experienced annual net ice loss every year since 1998.

Arctic sea ice is an important part of the climate system.

Summer sea surface temperatures (SST) in the Arctic Ocean are driven mainly by the amount of incoming solar radiation absorbed by the sea surface.

Autotrophic single-celled algae living in sea ice (ice algae) and water column (phytoplankton) are the main primary producers in the Arctic Ocean.