The Antarctica now holds more sea ice than it did before global warming kicked in

Sep 19, 2013 01:26 GMT  ·  By
Researcher says stronger polar winds are to blame for the increase in sea ice coverage in Antarctica
   Researcher says stronger polar winds are to blame for the increase in sea ice coverage in Antarctica

Recent measurements have shown that the Antarctica now holds more sea ice than it did back in the 1970s, before climate change and global warming kicked in. According to researcher Jinlun Zhang at the University of Washington, this unprecedented sea ice increase is due to stronger winds in the area.

In a paper set to be published in the Journal of Climate, Jinlun Zhang explains that, although some might argue that the increase in the Antarctica's sea ice coverage disproves global warming, this is by no means the case.

The researcher argues that, as satellite records show, the polar vortex that has been swirling over the South Pole for many decades now has been getting stronger over the past few years.

Besides, it has more convergence, which means that it causes thin layers of ice that form at the water's surface to come together and build thicker layers.

It is this phenomenon that has caused sea ice in the Antarctica to reach record highs, a computer model pieced together by Jinlun Zhang and his colleagues indicates.

As the researcher explains in the Abstract to his paper, “Driven by the intensifying winds, the model simulates an increase in sea ice speed, convergence, and shear deformation rate, which produces an increase in ridge ice production in the Southern Ocean.”

Furthermore, “The increase in ridging production contributes to an increase in the volume of thick ice in the Southern Ocean, while the volumes of thin ice and medium thick ice remain unchanged over the period 1979-2010.”

The researcher argues that, according to his investigations, the areas first and foremost affected by these changes in winds at the South Pole are the Weddell, Bellingshausen, Amundsen and Ross Seas.

For the time being, scientists are unable to explain why southern winds are now considerably stronger than they used to be. Some say global warming might be to blame, others point the finger at the ozone hole in the Southern Hemisphere.

The possibility that these winds naturally change every once in a while is also being investigated.