The Arctic

What is the Arctic?
The Arctic is the Earth’s northernmost region. Mostly comprised of ocean, the Arctic can be defined in many ways. Among them:
Arctic Circle

An imaginary line around the Earth at 66° 33’ N above which the sun does not completely set on the summer solstice.
Polar Treeline

The northernmost limit above which trees don’t grow.
Temperature

The areas at high latitudes where the average summer temperature does not rise above 10°C (50°F).
Politics

Various geographical boundaries set by the eight nations with territory in the Arctic.

Arctic Meltdown

Arctic ice and snow have been shrinking. And that means our planet’s air conditioning system may be in trouble.  Why?

The light color of snow and ice reflects most of the Sun’s energy back into space, rather than being absorbed by the dark color of land and open water. That is one reason the Arctic’s cold is so extreme—and our planet does not overheat

But with less ice cover, the ocean and the land warm up, causing more ice to melt, further warming the planet.


What’s Melting?

Whether on land or at sea, Arctic ice has been decreasing in recent years.

Sea ice (frozen ocean water) is decreasing both in the area it covers and in its thickness. Photo © RADM Harley D. Nygren/Department of Commerce Icebergs are huge chunks of glaciers that broke off into the ocean. Ninety percent of an iceberg is below the water’s surface. Photo © Peter Hemming Photography Permafrost is permanently frozen soil on land and on the shallow Arctic seafloor. Photo © Galen Rowell/CORBI

Greenland’s immense ice sheet has thinned along the coastlines as melting has increased. Melting ice caps and glaciers can add water to oceans and raise sea levels. Photo courtesy of NASA Most mountain glaciers have been retreating since the 1960s, with the trend speeding up in the 1990s. Photo © Chris Linder Photography

Shrinking Sea Ice

Shrinking sea ice is one of the most worrisome changes in the Arctic.
The loss of sea ice is already affecting the region’s environment, wildlife, and cultures. In addition, shrinking sea ice may be an early sign of increased global temperatures: Sea ice is very sensitive to small changes in the air above it and in the water below it.

How Much Has Sea Ice Declined?

Satellite data show the extent of Arctic summer sea ice has shrunk 15-20% since 1979. Submarine surveys show a loss in thickness of up to 40% in some areas in the past few decades.

Sea Ice: A Hunter’s Friend

To Arctic residents, decreased sea ice is not an abstract theory. It is an everyday reality.

Sea ice that is thinner, arrives later, and breaks up earlier means that Arctic hunters don’t have a safe platform from which to hunt. It also means that seals, walrus, and other marine mammals that depend on sea ice are moving farther north, out of reach of local hunters.

Arctic communities worry that the longtime staples of their diets may become inaccessible.

The Inuit traditionally hunt seals from the ice, but one way to cope with a warming climate is to hunt seals from boats in open water instead of from ice floes. Photos © Bryan and Cherry Alexander Photography

The sea ice shifts around a lot. In recent years, some hunters  have found it too dangerous to step onto the ice. Photo © Bryan and Cherry Alexander Photography

A Global Player

The Ocean Conveyor Belt

Ocean circulation is driven by density differences. (Density is controlled by ocean temperature and saltiness.)  Cold, dense water in the Arctic merges with salty water from the Gulf Stream to create the sinking North Atlantic Deep Water (NADW) in the Norwegian-Greenland Sea. The NADW helps to drive global ocean circulation.

Illustration The M Factory © Smithsonian Institution

Arctic sea ice influences global ocean circulation and, in turn, our climate. How?
When ocean water freezes, it rejects salt. The layer of cold water beneath the sea ice becomes saltier and denser, making it heavy enough to sink. In the Arctic, cold water sinks in the Norwegian-Greenland Sea. As a result, it is replaced by shallow, warm water that moves northeast from the tropics.

But when sea ice—and glaciers—melt, they release freshwater into the ocean. Freshwater, however, is not dense enough to sink and could disrupt ocean circulation and affect the exchange of heat between the poles and the tropics. In turn, global climate could change.


Who’s At Risk?
What do ivory gulls and polar bears have in common?
All of them, and many other species, depend on sea ice—at least for part of the year.  It’s uncertain how Arctic species will fare if sea ice continues to retreat and melts faster.

Polar bears (Ursus maritimus) rely on sea ice as a platform for catching seals—and to travel: a highway when it is solid or a raft when it breaks up and floats. Photo © Chris Linder Photography Ringed seals (Pusa hispida) are tied to sea ice for everything they do—rest, hunt, give birth, and nurse their young. Photo © Brendan P. Kelly Ivory gulls (Pagophila eburnean) are scavengers that depend on leftovers from polar bear kills. Photo © Bryan and Cherry Alexander Photography

Walrus (Odobenus rosmarus) dive from sea ice to the sea bottom where they root out clams and other invertebrates. Photo © Chris Linder Photography Ice algae (Fragillariopsis sp. and Nitschia sp.) are food for many Arctic animals. Photo © Evelyn and Barry Sherr, College of Oceanic and Atmospheric Sciences, Oregon State University

Slip Sliding Away

Melting ice is an enemy for Arctic communities—especially those that hug the coast.
Decreased sea ice and thawing permafrost can increase the risks of coastal erosion. How?  Less sea ice means that ocean waves travel over more open water and gain strength before breaking on shore. The shore, already weakened by thawing permafrost, is more likely to erode.

More at Stake than Land
Melting ice is eroding not just land but a way of life. Coastal erosion is forcing the village of Shishmaref, Alaska, to relocate to the mainland. The price tag could exceed $180 million.

In Shishmaref, Alaska, where food costs are triple those of typical U.S. cities, hunting is an economic necessity. Bearded seals­—the staple of the community’s diet—have become harder to hunt as sea ice has decreased.

Front Row Exposure

On October 3, 1963, Barrow, Alaska, set a new record for severe weather. The most violent storm in memory struck that day.

Both scientists and residents have witnessed more damaging storms in the Arctic since the 1960s—at the same time that most of the region has warmed. Since 1955, Barrow has lost about 15 m (nearly 50 ft) of its shoreline—more in some areas and less in others.

Barrow’s population has tripled since 1963. Now when a storm strikes, more people and more property are in its path.

Will Arctic Storms Change?

It is not clear. But even if storms do not become stronger or more frequent, their impacts could. Increasingly, Arctic coastal communities risk more flooding and erosion when a storm hits. The first line of defense against waves—sea ice and permafrost—has weakened as the Arctic’s climate has warmed.

Some of the greatest decreases in sea ice have occurred in the Beaufort and Chukchi Seas, increasing the impact of coastal storms.

On “Un” Frozen Ground

Thawing ground, or permafrost, is a potential troublemaker throughout the Arctic.

Permafrost is mostly frozen water in which ice crystals help bind it together.  When the ice melts, the ground collapses.

Until recently, permafrost has been solid enough to support houses, highways, pipelines, and airfields. But rising temperatures have melted the frozen soil’s upper portion, compromising its capacity to bear weight.

Caribou: Arctic Lifeline
Caribou are superbly adapted to the Arctic where they are the most common large grazing animal.  As such they sustain the economy and culture of northern people from Alaska, to Greenland, to Russia, to Norway.

Recently, however, polar communities—and scientists—have seen changes in the caribou’s health and numbers. They have also noted warmer weather. They suspect a connection.

Caribou or Reindeer?

They are the same species, Rangifer tarandus, but called caribou in North America and reindeer in Eurasia. Caribou are hunted in the wild. Reindeer are often domesticated and herded.

Sámi Reindeer Herders

A Sámi legend explains: “We are not reapers, we are not field hands. We are reindeer herders. The reindeer are our bread.”

The Sámi, who live in Scandinavia and Russia’s Kola Peninsula, manage reindeer in herds. Reindeer serve the Sámi as a source of wealth, much like savings accounts.

But recently, reindeer herding has become more difficult. Lakes, rivers, and bogs freeze much later in autumn, making it harder to collect the herd from its summer pasture. Migration patterns have also changed, disrupting traditional herding and slaughtering schedules for the Sámi and other herding groups.

Sámi: Pleasing the Reindeer

Reindeer-hide jacket Sámi herders wear a pull-over jacket called a “kolt.” Brightly colored decorative patterns vary from village to village. Photo Donald Hurlbert © Smithsonian Institution

Boots Why a turned up toe?  It’s so the boot can be worn with skis. The toe hooks under a leather strap on the ski. Photo Donald Hurlbert © Smithsonian Institution

The objects here reflect the deep respect the Sámi people show reindeer. They believe they must honor the reindeer with beautifully crafted objects so that the animals will continue to surrender the gift of life.

Innu Caribou Hunters
Caribou antlers hang in a tree, placed there by an Innu hunter. The antlers are a sign of the Innu’s respect to the animal’s spirit. The Innu people live in northern Quebec and Labrador, where caribou have been the mainstay of their lives for thousands of years.

An Innu hunter, Dominique Pokune, butchers a caribou with sharpened stone tools, demonstrating a technique used by his ancestors. Labrador, Canada Photo Stephen Loring © Smithsonian Institution

An Innu elder holds her grandchild at an autumn caribou-hunting camp in Labrador, Canada Photo Stephen Loring © Smithsonian Institution

Since the 1960s, however, the Innu have settled into villages, making it difficult for them to follow and hunt the caribou.  Instead, they have had to rely more and more on other kinds of food.

Innu: Dressed for Respect

Innu hunters wore elaborately decorated coats to honor the spirit master of the caribou. If pleased, the spirit master would release his wards. And then the caribou would “allow” themselves to be killed by Innu hunters.

Caribou skin coat The motifs that decorate this coat were revealed to Innu men in their dreams. The designs represent a symbolic map of the spirit world.

Paint sticks Fork-like sticks were used to paint complicated patterns on clothing. Traditionally, paints were made from a variety of mineral and plant materials. At about the time Turner collected these objects, imported European dyes became available.

Smithsonian scientists have worked with the Innu people of Quebec and Labrador for over 120 years. Some of the Innu artifacts in the Arctic Studies Center were collected by Smithsonian naturalist Lucien M. Turner during the First International Polar Year in 1883.

Predicting Change

For thousands of years, the Gwich’in people of Arctic Canada have observed and hunted the Porcupine Caribou Herd.

But in recent years, they have seen changes: Spring migrations have been off-schedule. And herd size has declined. They have also noted deeper snows and more insects in summer. What might all of this mean for the future of the Porcupine Herd?

Feeling the Heat

Will warmer temperatures threaten caribou populations? It depends on the types of change and how quickly they occur. However, one sub-species of caribou, the Peary, already is at risk of extinction.

Why? Major die-offs are likely related to warmer weather: Deep snow and ice, for example, can make it nearly impossible for caribou to get to food.

The number of Peary caribou on Canada’s Arctic islands plunged from 26,000 in 1961 to 1,000 in 1997. In response, some indigenous communities have voluntarily limited hunting the Peary, but population declines continue.