Friday, June 27, 2008
Ice-free North Pole likely this summer : Mail Today Exclusive
By Dinesh C Sharma, Onboard CCGS Amundsen in the Arctic Ocean
We are very close to witnessing one of the most dramatic impacts of climate change so far – an ice-free North Pole at the end of this summer.
This means there would be no ice by the end of September in the North Pole. It will be just open sea. The North Pole would then depend on seasonal formation of ice during winter – the ice which usually melts down again in summer – instead of perennial multi-year ice. However, it is some more years before the rest of the Arctic also witnesses ice-free summers.
The North Pole – which is made up of ice accumulating over years - does not melt even during summer time. But this multi-year ice is melting fast due to rising temperature in the Arctic. Latest satellite imagery shows that the current ice cover in the North Pole is made of mostly thin ice.
The prediction is based on field observational data in the Canadian Arctic as well as imageries of ice cover from different satellites. If an ice-free North Pole becomes a reality this summer, it would be way ahead of projections made by the Inter-governmental Panel on Climate Change (IPCC) and other climate models.
"We are not talking models, but field data. We are actually predicting that the North Pole may be free of ice this year for the first time. There will be no multi-year ice left there. It is happening extremely quickly" – this is the categorical statement from Prof David Barber, leading Arctic expert who heads the multi-country Circumpolar Flaw Lead (CFL) Study Project in the Canadian Arctic. "Existing models project Arctic ice to be totally gone sometime between 2013 and 2030. Clearly, all models are underestimating than what observational data tells us".
Since the Arctic plays critical role in the global conveyor belt of oceanic currents which contributes to different weather conditions globally, its sooner-and-faster-than-expected meltdown would have wide ranging climatic effect all over the world. Scientists believe that there is a 'tele-connection' between the Northern polar region and the intensity of the Indian monsoon, though its exact mechanism is not fully understood.
The sea ice cover in the Arctic Ocean comes to a minimum in September and starts to grow out again after this, getting to its maximum extent in March and then shrinking back towards the North Pole. This is the natural cycle of sea ice witnessed for at least a million years. Now this cycle is rapidly changing.
At the end of the summer melt season in September 2007, the Arctic ice cover had reached its lowest since satellite records are kept – 4.3 million square kilometers or 39 percent below the long-term average from 1979 to 2000. The September rate of sea ice decline since 1979 is now about 10 percent per decade, or 72,000 square kilometers per year. During May 2008, the daily ice extent continued to be below the long-term average and was close to low levels seen in May 2007, as per data from the US National Snow and Ice Data Center. Some members of an independent group called "Study of Environmental Arctic Change" estimate the ice extent in September 2008 to be as low as 3.1million sq km.
"The extent of ice cover was very high in February 2008 and there was hope that the ice would recover. But this ice was very thin as it did not form until much later in the year and as a consequence, it has broken up already. We should have had ice till the end of July. We don't have it in June," pointed out Barber while talking to Mail Today in the fast ice region of Franklin Bay. "Right now we are predicting that the minimum value of ice cover in September 2008 is going to be somewhat near that of last September if not lower than that."
The CFL project was launched just at the end of the dramatic meltdown – in October 2007 – and has been tracking the ice in the Arctic since then. The icebreaker, CCGS Amundsen, being used for data collection for the project had to change its path as it could not find suitable locations for holding ice camps for scientific studies.
When the icebreaker entered into floating ice on the Northern side Banks Islands in November last, scientists found the multi-year ice to be highly decayed. Thaw holes were common and the average thickness of the ice was only about 2.8 meters. The ice was thinner than in previous years due to the late formation of sea ice in the Southern Beaufort Sea and Amundsen Gulf. The open strips of water resulting from early melting absorb more energy from the sun and become warm. This large heat storage drew cyclones over the open waters of the Amundsen Gulf in the fall of 2007. These cyclones, in turn, kept the ocean surface rough resulting in delayed onset of freeze-up.
Another sign of vanishing ice was that the ice bridge which forms every year connecting Cape Perry to Cape Lambton never got formed this year. Also, the multi-year ice was much more mobile compared to previous years, as per information beamed back by 24 GPS-fitted ice beacons released as part of the project.
Rising temperature is clearly one of the main reasons for thin ice and its faster melt down. "The global average temperature has gone up by 0.7 degrees. This increase gets amplified in the polar region because of the relationship between sea ice, the ocean and the radiation feedback system. It is getting warmer here faster than the rest of the planet. If the global average temperature rise is 1 degree, the rise in the polar regions would be 3.5 degrees," pointed out Barber.
Reduction in sea ice thickness and extent is being witnessed in the Norwegian Arctic region as well. Dr Haakon Hop, research scientist at the Norwegian Polar Institute said, "We have seen some drastic changes in the ice cover in the marginal ice zones in North and West of Svalbard in the Arctic where we work. The last three winters have been ice-free in the Kongsfjorden…. There is data to show that 50 to 70 percent ice in the Arctic ocean is first year ice, which would be all gone by the end the summer. So there might be very drastic changes happening right now."
Posted by Dinesh C Sharma at 12:41 AM