Shop Windows to the Universe

Become a nitrogen atom in the nitrogen cycle in our Traveling Nitrogen Classroom Activity Kit/Game. See all our games, activity kits and classroom activities.

Compare Images of Arctic Sea Ice Extent Side-by-side

The images below show sea ice in the Northern Hemisphere. Select images from the popup menus to compare two images side-by-side.

Try this:

  • compare the sea ice in March and September for the same year
  • compare the sea ice in March for two different years
  • compare the sea ice in September for two different years
  • click here if you want to look at sea ice in the southern hemisphere

Select a month:
... and a year:

Select a month:
... and a year:

The images are courtesy of the National Snow and Ice Data Center (NSIDC).

In the Northern Hemisphere (around the North Pole and the Arctic Ocean) the sea ice reaches its maximum extent in early spring, at the end of the long, cold winter. March is usually the month with the most sea ice.

The ice pack melts and breaks up over the summer. September is usually the month with the least sea ice (in the Northern Hemisphere).

The Northern Hemisphere ice pack seems to be shrinking, apparently as a result of global warming. The average rate of decrease in extent of the ice pack in September between 1979 and 2010 was 11.5% (+ or - 2.9%) per decade. Click here to see the predictions that global climate models make about future changes in sea ice extent.

The pink line in the images shows the average (from 1979 to 2000) edge of the ice pack for a particular month.

Click here to view an animation of the annual changes in sea ice extent in the Northern Hemisphere for a seven-year period (2002 through 2008).

Go to the NSIDC web site to:

Last modified October 8, 2010 by Randy Russell.

Shop Windows to the Universe Science Store!

The Summer 2010 issue of The Earth Scientist, available in our online store, includes articles on rivers and snow, classroom planetariums, satellites and oceanography, hands-on astronomy, and global warming.

Windows to the Universe Community

News

Opportunities

You might also be interested in:

Traveling Nitrogen Classroom Activity Kit

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Sea Ice in the Arctic and Antarctic

Sea ice is frozen seawater. It can be several meters thick and it moves over time. Although the salts in the seawater do not freeze, pockets of concentrated salty water become trapped in the sea ice when...more

The Arctic: Earth's North Polar Region

North of the Arctic Circle (at 66.5°N latitude) you will find the Arctic Ocean surrounded by the northernmost parts of the continents of Europe, Asia, and North America. You will find the geographic North...more

Effects of Climate Change Today

The world's surface air temperature increased an average of 0.6° Celsius (1.1°F) during the last century according to the Intergovernmental Panel on Climate Change (IPCC). This may not sound like very...more

Polar Oceans

There are two oceans in Earth’s polar regions: the Arctic Ocean, which occupies most of the north polar region, and the Southern Ocean, which surrounds the continent of Antarctica in the south polar region....more

Polar Games and Activities

Dive into one of our new polar activities or games! Animation showing Annual Variation of Sea Ice Extent in the Arctic Animation showing Annual Variation of Sea Ice Extent in the Antarctic Changing Planet:...more

Climate Change Teacher Resources

Many educators are now finding opportunities to teach about Earth's climate and climate change in their classrooms.  Windows to the Universe provides an interlinked learning ecosystem to a wealth of resources...more

Altocumulus

Altocumulus clouds (weather symbol - Ac), are made primarily of liquid water and have a thickness of 1 km. They are part of the Middle Cloud group (2000-7000m up). They are grayish-white with one part...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part by the National Science Foundation and NASA, our Founding Partners (the American Geophysical Union and American Geosciences Institute) as well as through Institutional, Contributing, and Affiliate Partners, individual memberships and generous donors. Thank you for your support! NASA AGU AGI NSF