Published: January 2016

Magazine  |  January 2016

See for Yourself: How Arctic Ice Is Disappearing

Since satellites began regularly measuring Arctic sea ice in 1979, it has declined sharply in extent and thickness. Much of the ice that’s there in winter is thin stuff that doesn’t survive the summer. The loss of ice is affecting the entire Arctic ecosystem, from plankton to polar bears. And some scientists think that, by altering the jet stream, it’s affecting weather—and people—around the Northern Hemisphere.

Graphics and maps by Lauren James, Jason Treat, Ryan Williams, Chiqui Esteban, and Chris Combs
Published December 14, 2015

Cycling Toward Oblivion

Every winter almost the entire surface of the Arctic Ocean freezes over. The ice typically reaches its maximum extent in March, then starts to melt, receding to its minimum in September. But the melt season is now three weeks longer than it was just four decades ago. Less ice survives the summer to thicken the following winter. The summer ice is also less concentrated, with more open water between floes. Because open water absorbs more solar heat, more ice melts, creating a positive feedback that amplifies the Baffin warming and melting. The Arctic Bay will continue to freeze in winter—but it could be ice free in summer by 2040.

Summer ice

Average extent in September

 

Concentration, September 2015

Median, 1980-2000

Minimum, 2012

Minimum, 1980

15%

100%

Chukchi

Sea

Alaska

(U.S.)

1980

Russia

Beaufort

Sea

CANADA

2012

2012

North Pole

Baffin

Bay

1980

Longyearbyen

Longyearbyen

greenland

(Denmark)

Barents

Sea

Iceland

FIN.

400 mi

400 km

Norwegian

Sea

norway

SEPTEMBER 2015

At summer’s end Arctic sea ice had shrunk to its fourth smallest extent since satellites began measuring it in 1979. The past nine years were the nine smallest. One reason: the low concentration of ice. Light blue areas are mostly water.

Summer ice

Concentration,

September 2015

Average extent in September

 

Median, 1980-2000

Minimum, 2012

Minimum, 1980

15%

100%

Alaska

(U.S.)

Chukchi

Sea

Beaufort

Sea

2012

North Pole

Baffin

Bay

1980

greenland

(Denmark)

Longyearbyen

Longyearbyen

Barents

Sea

Norwegian

Sea

FIN.

norway

400 mi

400 km

SEPTEMBER 2015

At summer’s end Arctic sea ice had shrunk to its fourth smallest extent since satellites began measuring it in 1979. The past nine years were the nine smallest. One reason: the low concentration of ice. Light blue areas are mostly water.

Russia

Alaska

(U.S.)

Chukchi

Sea

Summer ice

Concentration, September 2015

1980

15%

100%

Average extent in September

 

Beaufort

Sea

Median, 1980-2000

Minimum, 2012

Minimum, 1980

300 mi

2012

300 km

canada

North Pole

2012

1980

Baffin

Bay

Barents

Sea

greenland

(Denmark)

SEPTEMBER 2015

Norwegian

Sea

At summer’s end Arctic sea ice had shrunk to its fourth smallest extent since satellites began measuring it in 1979. The past nine years were the nine smallest. One reason: the low concentration of ice. Light blue areas are mostly water.

Sweden

Iceland

Finland

norway

1979

2.78

Arctic ice, average September extent

in million square miles

2015

1.79

Arctic ice, average

September extent

in million square miles

1979

2.78

2015

1.79

Albedo Effect

Ice and snow reflect some 85 percent of solar radiation; open water is dark and absorbs 93 percent. As the water warms, it melts more ice— a feedback whose effects reach beyond the Arctic.

Ice and snow

Bare ice

Open water

65%

7%

85%

of sunlight

reflected

Snow

Ice

Open

Water

15%

absorbed

35%

93%

Albedo Effect

Ice and snow reflect some 85 percent of solar radiation; open water is dark and absorbs 93 percent. As the water warms, it melts more ice— a feedback whose effects reach beyond the Arctic.

Ice and snow

85%

of sunlight

reflected

Snow

Ice

Open

Water

15%

absorbed

Bare ice

Ice

Open

Water

35%

Open water

Open

Water

93%

Picture of a rubber tire

Why We (Still) Can’t Live Without Rubber

Picture of a resting hiker

This Is Your Brain on Nature

Winter Ice: Younger, Thinner

Maps of the Arctic in March and charts of the ice’s age show a 75 percent decline in the oldest, thickest ice—ice that has survived at least four summers and is into its fifth year or more. Most sea ice now freezes and melts in less than a year.

Age of ice

SWIPE OR MOVE MOUSE

ON THE CHART

0-1 YEARS

1-2 YEARS

2-3 YEARS

3-4 YEARS

4+ YEARS

Age of ice

0-1 YEARS

1-2 YEARS

2-3 YEARS

3-4 YEARS

4+ YEARS

SWIPE OR MOVE MOUSE

ON THE CHART

Warmer Waters

Sea-surface temperatures in the Arctic are increasing. The warmer water makes it harder for sea ice to form and to survive. Seawater freezes at about 28.4 degrees Fahrenheit.

Mean Arctic Ocean surface

temperature, September

 

2007

 

In degrees Fahrenheit

32.3˚F

32˚F

31

30

1985

1995

2005

2015

SOURCES: MARK TSCHUDI, CHARLES FOWLER, AND JAMES MASLANIK, COLORADO CENTER FOR ASTRODYNAMICS RESEARCH, UNIVERSITY OF COLORADO BOULDER; MICHAEL STEELE AND WENDY ERMOLD, POLAR SCIENCE CENTER, UNIVERSITY OF WASHINGTON; JULIENNE STROEVE, NATIONAL SNOW AND ICE DATA CENTER; CLAIRE L. PARKINSON, NASA

 

Warmer Waters

Sea-surface temperatures in the Arctic are increasing. The warmer water makes it harder for sea ice to form and to survive. Seawater freezes at about 28.4 degrees Fahrenheit.

Mean Arctic Ocean surface

temperature, September

In degrees Fahrenheit

2007

 

32.3˚F

32˚F

31

30

1985

2015

SOURCES: MARK TSCHUDI, CHARLES FOWLER, AND JAMES MASLANIK, COLORADO CENTER FOR ASTRODYNAMICS RESEARCH, UNIVERSITY OF COLORADO BOULDER; MICHAEL STEELE AND WENDY ERMOLD, POLAR SCIENCE CENTER, UNIVERSITY OF WASHINGTON; JULIENNE STROEVE, NATIONAL SNOW AND ICE DATA CENTER; CLAIRE L. PARKINSON, NASA

 

Graphic of the polar jet stream
Extreme Weather: The Arctic Connection

When the polar jet stream dips far south, it can deliver blasts of cold and snow to temperate latitudes.


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