sea ice

NASA image: Rossby Waves of the JetstreamA series of major extreme weather events in the Northern hemisphere including the heatwave in the United States in 2011, the Russian heatwave of 2010, the Pakistani floods of 2010 have now been attributed to a common physical cause. The scientists suggest in a new scientific study that man-made climate change repeatedly disturbs the patterns of atmospheric flow - the atmospheric Rossby waves of the jet stream - around the globe's Northern hemisphere through a subtle resonance mechanism.

"An important part of the global air motion in the mid-latitudes of the Earth normally takes the form of waves wandering around the planet, oscillating between the tropical and the Arctic regions. So when they swing up, these waves suck warm air from the tropics to Europe, Russia, or the US, and when they swing down, they do the same thing with cold air from the Arctic," explains lead author Vladimir Petoukhov.

The diminishing Arctic sea-ice extent is resulting in changes in how greenhouse gases interact between the land, ocean and atmosphere according to a new study.

"Changes in the balance of greenhouse gases can have major consequences because, globally, plants and the oceans absorb around half of the carbon dioxide that humans release into the air through the use of fossil fuels. If the Arctic component of this buffer changes, so will the amount of greenhouse gases in the atmosphere", says Dr Frans-Jan Parmentier, a researcher at Lund University, Sweden, and lead author of the study.

While the Arctic sea-ice has experienced a dramatic reduction, Antarctic sea ice continues to increase in extent hitting a new record in October this year. So what's going on?

The trend of a slight gradual increase in Sea ice around Antarctica has puzzled scientists. Firstly, the gradual increase in Antarctic sea ice is far less than the amount of sea ice vanishing in the Arctic Sea. Global sea ice trend still shows a marked retreat.

But in Antarctica working out why the sea ice trend has seen a one percent increase per decade since the 1970s has bamboozled climate modelling for Antarctica. The scientists put it down to changes in atmospheric circulation caused by the ozone hole and the growing strength of the westerly circumpolar winds. A new study based upon 18 years of detailed satellite ice motion measurements has put forward that it is primarily local winds pushing ice mainly north creating polyanas in the ice flows where more ice can easily form.

Arctic summer sea ice is at a new record low level since satellite measurements began recording data in 1979. The summer minimum is down to about 1.32 million square miles (3.41 million square kilometers), half the average summer ice between 1979 and 2000. The minimum record was last set in 2007 with this year's sea-ice extent being about 18% lower than 2007. Some scientists predict we may see summer sea ice vanish by 2015-16, well ahead of International Panel on Climate Change (IPCC) 2007 Report predictions.

"The polar meltdown shows we're teetering on the brink of climate-change catastrophe," said Shaye Wolf, climate science director at the Center for Biological Diversity's Climate Law Institute. "Arctic sea ice plays a critical role in regulating the planet's climate. As man-made global warming shrinks the ice, our risk of droughts and other extreme weather goes up. We can't wait any longer to cut carbon pollution."

See also: Classic climate feedback: Arctic Sea Ice Extent lowest on record and still shrinking | Arctic warming at more than double the global warming average | Sea ice volume: Multi-year arctic sea ice reducing dramatically

On August 26 it was announced that arctic sea ice extent this summer has dropped to it's lowest level ever recorded, surpassing the previous record in 2007. And summer sea ice melt still has further to go this season with ice extent usually reaching a minimum area in mid September.

"This is a profound — and profoundly depressing — moment in the history of our planet," said Shaye Wolf, climate science director at the Center for Biological Diversity’s Climate Law Institute. "The sea-ice death spiral, coming during one of the warmest summers in American history, is just one more clear sign of the deepening climate crisis that we ignore at our own peril."

Related: Sea ice volume: Multi-year arctic sea ice reducing dramatically | Climate Code Red Blog: Big call: Cambridge prof. predicts Arctic summer sea ice "all gone by 2015"

Arctic air temperatures are warming faster than anywhere else on Earth. Although the level of precipitation is remaining unchanged, there is reduced snowfall in summer which is being replaced by increasing rain. The loss of summer snow and increase in rain is resulting in a positive feedback mechanism increasing warming and melting of the Arctic ice.