Sea Ice Factories
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- Written by:
- Kayvon Sharghi
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- Scientific consulting by:
- Sinead Farrell
- View full credits
Strong winds rush down the sides of the steep Antarctic ice sheet in winter, blowing frigid air against the sprawling sea ice pack that surrounds the continent. Heavy gusts send ice floes—geometric blocks of floating ice—drifting out to sea, exposing patches of dark-blue ocean between coastal sea ice and frozen land. Beneath the surface of these nascent pools, called polynyas, tiny ice crystals grow. The action of wind and waves push budding crystals together, creating thin films of ice on the ocean surface that increase in thickness over time. Parts of the sea ice pack will encounter warm ocean waters where they melt. By late summer, most of Antarctica's sea ice will have disappeared. The process is part of a natural cycle that scientists monitor closely to better understand its role in the global climate system. Since 1979, the total aerial extent of Antarctic sea ice has increased by less than one percent per decade, though measurement differences of 20 percent or more above or below the average extent have been observed from year-to-year. In the visualization below, watch how sea ice cover in the Antarctic changes from May 2009 through July 2010.
Credits
Please give credit for this item to:
NASA's Goddard Space Flight Center
Sea ice photographs courtesy of Sinead Farrell, NASA's Goddard Space Flight Center
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Animators
- Cindy Starr (Global Science and Technology, Inc.)
- Lori Perkins (NASA/GSFC)
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Writer
- Kayvon Sharghi (USRA) [Lead]
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Video editor
- Kayvon Sharghi (USRA)
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Scientist
- Sinead Farrell (University of Maryland) [Lead]
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Producer
- Kayvon Sharghi (USRA)
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Videographer
- Rob Andreoli (Advocates in Manpower Management, Inc.)
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ID: 3862 Visualization
Seasonal Antarctic Sea Ice
Read moreAntarctica is a land mass surrounded by an ocean which allows the sea ice here to move more freely than it does in the Northern Hemisphere. Because there are no surrounding continents to limit its movement, the sea ice is free to float northward into warmer waters where it eventually melts. As a result, almost all of the sea ice that forms during the Antarctic winter melts during the summer. During the winter, up to 18 million square kilometers (6.9 million square miles) of ocean is covered by sea ice, but by the end of summer, only about 3 million square kilometers (1.1 million square miles) of sea ice remain. Antarctic sea ice extent are characterized by fairly large variations from year to year. The monthly average extent can vary by as much as 1 million square kilometers (386,102 square miles) from the year-to-year monthly average. The AMSR-E instrument on the Aqua satellite acquires high resolution measurements of the 89 GHz brightness temperature near the poles. Because this is a passive microwave sensor which is not so sensitive to atmospheric effects, this sensor is able to observe the entire polar region every day, even through clouds and snowfall. The false color in this animation of sea ice surrounding the South Pole is derived from the daily AMSR-E 6.25 km 89 GHz brightness temperature while the sea ice extent is derived from the daily AMSR-E 12.5 km sea ice concentration. The sea ice extent shown is generated using a three day moving average where the daily sea ice concentration is at least 15%. This animation portrays the changes in the sea ice from May 26, 2009 through July 29, 2010. ||
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