New Record Extent of Sea Ice in Antarctica

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The polar regions of the Earth, the Arctic Ocean and Antarctica, are of particular concern to scientists and researchers. In one sense, these areas act much like an air conditioner for the planet because of their cold, icy environments and the fact that like they reflect a high degree of solar energy. The poles are also extremely sensitive to climate change, and, consequently, they display the biggest effects of global warming.

This year’s measurements of sea ice show a new record extent around the continent of Antarctica. This means that the ice is at its largest coverage of the southern oceans since scientists began using a long-term satellite record to map sea ice in the late 1970s. Every year since then, the Antarctic has gained an average of 7,300 square miles (18,900 square kilometers), and on September 19, 2014, the Antarctic sea ice extent was more than 7.72 million square miles (20 million square kilometers). According to the National Snow and Ice Data Center, the single-day maximum extent for 2014 was on September 20 with the year’s five-day average maximum reached two days later.

On Sept. 19, 2014, the five-day average of Antarctic sea ice extent exceeded 20 million square kilometers for the first time since 1979, according to the National Snow and Ice Data Center. The red line shows the average maximum extent from 1979-2014. Image Credit: NASA's Scientific Visualization Studio/Cindy Starr

On Sept. 19, 2014, the five-day average of Antarctic sea ice extent exceeded 20 million square kilometers for the first time since 1979, according to the National Snow and Ice Data Center. The red line shows the average maximum extent from 1979-2014.
Image Credit: NASA’s Scientific Visualization Studio/Cindy Starr

Scientists and researchers are unsure about what exactly has caused this record ice extent in Antarctica. It may be that changing weather patterns have simply brought cooler air to some areas. Still, researchers assert that this new record extent could be due to more frequent low-pressure systems centered in the Amundsen Sea. These systems typically change wind patterns, circulating warm air over the Antarctic Peninsula, the finger of land that juts up towards South America, while bringing cold air up over the Ross Sea.

The wind could also play a significant role in extending sea ice out around Antarctica. If winds get stronger in a northward direction, they push the ice out further. There other possibilities, however. Water circulation patterns could be bringing colder waters up to the surface which helps to grow the ice. Moreover, melting ice on the edges of the continent could be also contributing with water that is easier to freeze. Another possibility could be snowfall. Snow piling up on the ice can push thin ice below the water. This allows the ocean water to flood the snow and, once frozen, adds to the overall thickness of the ice.

Whatever the cause, conditions were favorable this year for a larger extent of ice in Antarctica beyond anything scientists have seen before, and this phenomenon is currently bucking the overall trend of a decrease in sea ice. Researchers are quick to point out that not every location on the planet will display a downward trend in sea ice. Antarctica is an extremely complex environment and sea ice as a whole is still decreasing.

In reality, the upward trend in sea ice found in Antarctica is only about a third of the magnitude of the rapid loss of sea ice occurring at the opposite end of the planet. The situation in the Arctic Ocean continues to alarm scientists. This year’s Arctic sea ice minimums are in the top ten of the lowest they have seen in the last three and a half decades. Temperatures in the Arctic have increased by about two to three times the global average in the last decade which leads to more ice melt.

References:

Ramsayer, Kate. “Antarctic Sea Ice Reaches New Record Maximum.” NASA. NASA, 7 Oct. 2014. Web. 16 Oct. 2014. <https://www.nasa.gov/content/goddard/antarctic-sea-ice-reaches-new-record-maximum/index.html#.VDxC6xZuW9x>.