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 2009)
• 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: February September and a year: 1979 1980 1985 1990 1995 2000 2005 2006 2007 2008 2009	Select a month: February September and a year: 1979 1980 1985 1990 1995 2000 2005 2006 2007 2008 2009
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 2009 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:

• Look at pictures of sea ice extent and make movies.
• Look at more than one picture of sea ice at the same time so you can compare.

Page created March 23, 2007 by Randy Russell. Last modified November 5, 2009 by Randy Russell.
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