How Climate Change is Causing Antarctic Sea-ice to Expand

As rising temperatures continue to shrink the extent of Arctic summer sea-ice, there has been much speculation as to why the ice cover on the opposite side of the planet has expanded slightly in recent years. Now British scientists have found the explanation–and it’s related to climate change.

Using data gathered by U.S. military satellite-tracking of the motion of the Frozen Continent’s icepack between 1992 and 2010, the researchers have found a link between Antarctic winds and the growth of sea-ice in the Weddell, Cooperation and Ross seas.

The analysis, “Wind-driven Trends in Antarctic Sea-ice Drift,” was published online yesterday in the science journal Nature Geoscience.

“Sea-ice is constantly on the move; around Antarctica the ice is blown away from the continent by strong northward winds. Since 1992 this ice drift has changed. In some areas the export of ice away from Antarctica has doubled, while in others it has decreased significantly,” said lead author Paul Holland , of the British Antarctic Survey, in a news statement about the research.

“Until now these changes in ice drift were only speculated upon, using computer models of Antarctic winds,” Holland said. “This study of direct satellite observations shows the complexity of climate change. The total Antarctic sea-ice cover is increasing slowly, but individual regions are actually experiencing much larger gains and losses that are almost offsetting each other overall. We now know that these regional changes are caused by changes in the winds, which in turn affect the ice cover through changes in both ice drift and air temperature.”

The changes in ice drift also suggest large changes in the ocean surrounding Antarctica, which is very sensitive to the cold and salty water produced by sea-ice growth, Holland added.


Map of Antarctic sea-ice in 2012 courtesy of NASA Earth Observatory.


The new research also helps explain why observed changes in the amount of sea-ice cover are so different in the two polar regions, BAS said in its statement. “The Arctic has experienced dramatic ice losses in recent decades while the overall ice extent in the Antarctic has increased slightly. However, this small Antarctic increase is actually the result of much larger regional increases and decreases, which are now shown to be caused by wind-driven changes.”

Co-author Ron Kwok, of the Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, said: “The Antarctic sea ice cover interacts with the global climate system very differently than that of the Arctic, and these results highlight the sensitivity of the Antarctic ice coverage to changes in the strength of the winds around the continent.”

There has been contrasting climate change observed across the Antarctic in recent decades, British Antarctic Survey said in its statement. “The Antarctic Peninsula has warmed as much as anywhere in the Southern Hemisphere, while East Antarctica has shown little change or even a small cooling around the coast. The new research improves understanding of present and future climate change. It is important to distinguish between the Antarctic Ice Sheet — glacial ice — which is losing volume, and Antarctic sea ice — frozen seawater — which is expanding.”

The research was funded by the Natural Environment Research Council (NERC) and National Aeronautics and Space Administration (NASA).

12418031_10153900711084116_8462971761216697621_nDavid Braun is director of outreach with the digital and social media team illuminating the National Geographic Society’s explorer, science, and education programs.

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Forty years in U.S., UK, and South African media gives David Braun global perspective and experience across multiple storytelling platforms. His coverage of science, nature, politics, and technology has been published/broadcast by the BBC, CNN, NPR, AP, UPI, National Geographic, TechWeb, De Telegraaf, Travel World, and Argus South African Newspapers. He has published two books and won several journalism awards. He has 120,000 followers on social media. David Braun edits the National Geographic Society blog, hosting a global discussion on issues resonating with the Society's mission and initiatives. He also directs the Society side of the Fulbright-National Geographic Digital Storytelling Fellowship, awarded to Americans seeking the opportunity to spend nine months abroad, engaging local communities and sharing stories from the field with a global audience. Follow David on Facebook  Twitter  LinkedIn
  • klem

    Ok I don’t understand anymore. I thought climate change was bad, that’s why they always talk about fighting climate change. You don’t fight climate change if it is good, you fight it because it’s bad. But expanding Antarctic sea ice is good, so we should not be fighting climate change now, is that what this means?

    I find the climate change thing really confusing.

  • Richard Sympson

    @klem (11:36am)

    You’ll note that none of the authors stated whether or not increasing Antarctic sea ice was “good” or “bad,” so where you get the idea that it’s necessarily “good” is curious. The total change in southern sea ice is also much less with regard to trend and volume when you compare it to sea ice loss in the north.

  • alexia

    wow that is so sad WHAT HAVE WE DONE? STOP POLUTING

  • mememine69

    Exaggeration may not be a crime but 26 years of needless CO2 panic was a pure war crime and history is watching this CO2 madness. They only agree it is real, not that it is a crisis and a crisis that isn’t a crisis is …………….an”exaggeration” and real planet lovers are happy a crisis wasn’t real, for whatever reason.
    If it’s really a CO2 “crisis” of climate (nothing is worse), then “science” needs to be clear about this comet hit of an emergency for the planet, my children and billions of others!
    Scientific Consensus: “We could possibly be at the point of no return potentially from the likelihood of unstoppable warming…….” Not one IPCC warming is without “maybes”.
    The IPCC has never said any crisis would or will happen, only “might” and “could”.
    Help, my house could be on fire maybe?

  • Ty Allen

    Stop perpetuating the hoax of man-made climate change.

    This is pure politics, and now that the facts are showing that global-alarmists like Al Gore and his hordes of hoaxers have been lying to us, now National Geopolitics is force to conjure up some lame excuse as to why we should believe the lie even though we know it’s a lie.

    The Bible had it right 4000 years ago: “While the earth remaineth, seedtime and harvest, and cold and heat, and summer and winter, and day and night shall not cease.” – Genesis 8:22

  • Fred Levitan

    Wow, the breadth of ignorance expressed in the comments on this science-based article is astounding! Ignore the evidence and spout your dogma all you want people, but PLEASE GO BACK TO SCHOOL AND LEARN SOME SCIENCE!

  • Joe

    I am a firm believer in climate change. It happens every day. Why, is usually related to the sun. Look there . . but not directly. Climate are cycles, circles if you will. Everything is a circle, just add time. Most of the cycles are on scale beyond our record. While preparing for Global warming we might as well be blindsided by another snowball earth event. We just don’t know yet. We should not pollute, We should clean up our act. We should fund the sciences. But this is not why.

  • Joe

    We should fund the sciences as they help us clean up our act. Pollution is obviously bad but we are making huge strides in the last 50 years. We should live clean without ‘Crisis’. We are constantly thrown crisis from every direction because we are basically lazy otherwise, We kind of bring the hysteria on ourselves. Crisis works, said the boy who cried “Wolf”.

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