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(University of Colorado at Boulder) The blanket of sea ice that floats on the Arctic Ocean appears to have reached its lowest extent for 2011, the second lowest recorded since satellites began measuring it in 1979, according to the University of Colorado Boulder’s National Snow and Ice Data Center.

(University of Copenhagen) For the last 10,000 years, summer sea ice in the Arctic Ocean has been far from constant. For several thousand years, there was much less sea ice in The Arctic Ocean — probably less than half of current amounts. This is indicated by new findings by the Danish National Research Foundation for Geogenetics at the University of Copenhagen. The results of the study will be published in the journal Science.

(University of Copenhagen) For the last 10,000 years, summer sea ice in the Arctic Ocean has been far from constant. For several thousand years, there was much less sea ice in The Arctic Ocean — probably less than half of current amounts. This is indicated by new findings by the Danish National Research Foundation for Geogenetics at the University of Copenhagen. The results of the study will be published in the journal Science.

(Helmholtz Association of German Research Centres) On Wednesday, June 15, the research vessel Polarstern of the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association will set off on its 26th arctic expedition. Over 130 scientists from research institutions in six countries will take part in three legs of the voyage.

It ain’t so good to be king right now, at least not for that monarch of the Arctic, the polar bear. His kingdom is melting into the ocean.

Polar bear on an ice flow. © Jan Martin Will/Shutterstock.com

Polar bears don’t subscribe to the Marie Antoinette school of rulership, instead harkening back to the minimalism of the Spartans: despite their supremacy, they require merely ice and a steady supply of blubber to stay happy. But even these polar bare necessities are in increasingly short supply as the frozen ramparts of their pack-ice palaces melt more rapidly each summer and reform more weakly each winter.

Their plight has made them a flagship species for the movement to raise awareness of the effects of global warming but in the meantime polar bears must adapt to the disappearance of their frozen fundament and the consequent difficulty this presents in capturing seals, which they prefer to snag when the unsuspecting pinnipeds surface at holes in the ice.

Ursus maritimus is certainly adaptable. It’s even happy eating human trash, a habit that has made it a dangerous nuisance near human settlements. The species’ inland migration has, in addition to bringing it into conflict with humans, also increased its contact with its cousin, the grizzly bear (Ursus arctos), from which it is descended. At least some of these meetings have had friendly outcomes; an increase in polar bear-grizzly hybrids has been noted where their ranges overlap.

Below, take a look at some photos of this magnificent species in its icy element.

A polar bear crossing pack ice, Hudson Bay, Manitoba, Canada. © Dan Guravich/Corbis

Polar bears, Manitoba, Canada. Credit: Taxi/Getty Images

A polar bear leaping between ice floes in the Arctic Ocean. Greenpeace—EPA/Corbis

Mother polar bear nursing her cubs (Ursus maritimus). Credit: age fotostock/SuperStock

The South pole

Why?
Both poles are cold mainly because they get less sunlight than other latitudes. Both receive 6 months continuous darkness, and the sun only rises to a small angle from the horizon, and have to travel through more atmosphere (which reduces the intensity of the sun’s rays); additionally, due to the low angle and white ice most of the rays are reflected off the surface back into space.

The difference between the two is that the South pole is located on a thick sheet of ice (miles thick), which itself is on a land mass (higher elevation). In contrast, the North pole is located at sea level in the Arctic Ocean, and the body of water helps to mediate temperatures (the water basically acts as a heat reservoir).

You can find more information at:
Scientific American:
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