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

The pictures below show sea ice around the South Pole. Click on the popup menus above the pictures to choose which pictures to look at. You can look at two pictures at once and compare them.

Try this:

  • compare the sea ice in February and September for the same year (like February 2000 and September 2000)
  • compare the sea ice in February for two different years (like February 1979 and February 2010)
  • compare the sea ice in September for two different years
  • click here if you want to look at sea ice in the northern 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).

Sea ice builds up during the winter when it is cold. When is there the most sea ice? There is usually a lot of sea ice in early spring, right after winter ends, around September. Remember, in the southern hemisphere, summer and winter happen at the opposite times of year from the northern hemisphere!

Over the summer, when it is warm, the sea ice melts. When is there the least sea ice? Since a lot of ice melts in the summer, there is usually much less sea ice in early fall around February, right after the end of summer.

The pink line in the pictures shows where the edge of the sea ice is, on average, in that month. Compare the edge of the ice in 1979 to the pink line. Now compare the edge of the ice in 2010 to the pink line. Do you see any difference?

Click here to see a movie of changes in sea ice over seven years (2002 to 2008). Watch how the ice melts in the summer and freezes and grows in the winter.

If you want to see more pictures of sea ice, go to the NSIDC web site to:

Last modified October 8, 2010 by Randy Russell.

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The Spring 2010 issue of The Earth Scientist, focuses on the ocean, including articles on polar research, coral reefs, ocean acidification, and climate. Includes a gorgeous full color poster!

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