500 MILES OFF THE NORTH POLE (Reuters) - As polar bears stalked their ship, scientists drilled into the Arctic sea ice this week to try and figure out why it's disappearing so fast.
The disintegrating ice floes – each half the size of a football field – floated among narrow lanes of open water next to the Arctic Sunrise, the Greenpeace ice breaker likely to be the most northerly ship in the world, according to ice pilot Arne Sorensen.
Nearby, in a monochrome landscape between the Norwegian island of Svalbard and the North Pole, a large cub patted and licked a lollipop-shaped part of laser scanner as it passed. Cracks several meters wide appeared in seconds beneath the scientists' feet, prompting a hasty retreat.
Changes in the Arctic are being driven both by manmade greenhouse gases and natural weather patterns. With less ice, less sunlight is reflected back into space, warming the air and melting more ice.
Experts say thinning of ice over recent decades may hasten an ice-free summer as soon as 2020. And, while thickness is more difficult to measure by satellite than area, if anything it is more important.
That has put the onus on better data, through new satellite, plane and submarine observations and a low-tech approach on the ice itself -- drilling holes and poking a tape measure down.
"What the radar of the satellite sees is just the part of the ice that is really above the water and since about nine tenths of the ice is underneath the water there is a huge uncertainty in what the satellite can actually see," said Cambridge University PhD student Till Wagner told Reuters.
"That's what we are here for to get a better handle on how thick the ice actually is," he said, standing on a floe next to the Arctic Sunrise.
WILD CARD
The sea ice area retreats each summer and this year is closing on a record low in 2007. With one week of the melt season to go, it is now less than two-thirds of the area it covered in the early 1970s.
The sea ice, distinct from ice sheets hundreds of meters thick over rock in Greenland, floats on the Arctic Ocean and wildlife including polar bears and walruses depend on it for survival.
Wider "wild card" risks from an ice-free ocean in summer include weather disruption as the difference in temperature between the equator and poles is the engine of the world's weather.
If the Arctic Ocean were open sea in autumn, without an insulating layer of ice, that would allow more warming of the polar air.
One forthcoming study calculated that the total volume of Arctic sea ice fell to a record low in 2010, suggesting that thinning has continued despite a rather steadier ice extent over the past three or four years.
Other scientists are poring over new satellite estimates of thickness from the European Space Agency's CryoSat, which will plug a gap in data between the last US ICESat satellite and the start date for the next around 2016.
"The preliminary map of CryoSat thickness shows reasonable agreement ... with airborne data," said University College London's Seymour Laxon by email. "Some of this data is only now becoming available."
On the ice floe near the North Pole this week, the researchers' coup de grace is a three-dimensional scan which may help scientists understand its shape and strength better.
"Traditionally, you might be doing a section or a plan to understand an area but to fully see this in 3D and combine it with the satellite information we are able to really get a really high resolution understanding of what's going on out here," said Will Trossell, at start-up company Scanlab.
Arctic ice breaks up as polar bears stalk ship
Stepping onto an Arctic ice floe on Monday, an unusually mild, easterly breeze blew at the end of the annual summer melt. The footprints of two polar bears from the night before were disintegrating in a dusting of snow.
At nearly 81 degrees latitude, the air temperature was 2.5 degrees Celsius – normal for a winter's day in Europe but rather mild for the high Arctic, even in late summer. The previous day had been 4 degrees colder.
The monochrome scene was calm after the rolling swell of the Fram Strait between the Norwegian island of Svalbard and Greenland. We were embedded in an ice pack stretching half the area of Brazil, across the North Pole.
The Greenpeace icebreaker Arctic Sunrise nearby shuddered occasionally, nudged by white slabs of ice the size of a small car park, which jostled among threads of open water.
The water temperature was below zero, the ship's log read, and the air was filled by the hum of its generators. The ship's mooring ropes were driven by two giant stakes into ice up to 10 meters thick.
This entire Arctic landscape is forecast to disappear within decades and replaced by open sea each summer, perhaps for the first time in 7,000 years or more. The dramatic retreat signals the scale of humankind's impact on the climate, experts say.
On Wednesday, the shrinking sea ice was closing in on the 2007 record low area of 4.1 million square km, according to the U.S.-based National Snow and Ice Data Center. The annual minimum was 7 million square km in the early 1970s.
Environmental group Greenpeace wanted to draw attention to changes in the high Arctic, and ferried Cambridge University researchers from Svalbard to measure the thickness of the ice. Experts say it has been thinning for decades, possibly hastening an entirely ice-free summer as soon as 2020.
The sea ice area is easily read from satellites overhead. Measuring thickness is more difficult, and the most direct approach is to drill a hole and poke a tape measure down.
While doing just that the researchers on Monday were confronted directly with the annual seasonal melt which ends around mid-September each year.
They raced to evacuate the floe when a 3-meter wide crack appeared suddenly, in under a minute. A combination of melting, the swell of the sea and wind broke the floe apart.
The night before, a polar bear and her cub blundered through research equipment left on the ice, adding to the novel dangers of Arctic field experiments.
The polar bear is called "Nanuk", which means the Great Wanderer in the local Arctic Inuit language. But it was clear that there was nothing random about the bears which stalked our ship from floe to floe.
Experts say Arctic wildlife, including bears, depend on hunting from the ice. They are likely to suffer from an ice-free summer, while warmer air and water could shift birds and fish.
Wider, "wild card" consequences could see disrupted global weather patterns, when a warmer, open sea, without its insulating layer of ice, releases more heat into the polar autumn air. The difference in temperature between the poles and equator is the basic engine of world weather.
Meanwhile, some experts say a warmer Arctic could speed up the melt of the Greenland ice sheet, which contains enough water to raise sea levels by 7 meters.
On this research trip, the most dramatic recording was simply our arrival time back in Svalbard, hastened many hours by a sea ice retreat of 8 miles in just three days.
Researchers who go to the Arctic rarely find themselves in the same place twice and it is a privilege to measure such a change so precisely.
"We were basically at the same point where we entered and left the ice, and you could see there was a difference," said Arne Sorensen, Arctic Sunrise ice.
(Reporting by Gerard Wynn; Editing by Karolina Tagaris)
500 MILES OFF THE NORTH POLE (Reuters) - As polar bears stalked their ship, scientists drilled into the Arctic sea ice this week to try and figure out why it's disappearing so fast.
The disintegrating ice floes – each half the size of a football field – floated among narrow lanes of open water next to the Arctic Sunrise, the Greenpeace ice breaker likely to be the most northerly ship in the world, according to ice pilot Arne Sorensen.
Nearby, in a monochrome landscape between the Norwegian island of Svalbard and the North Pole, a large cub patted and licked a lollipop-shaped part of laser scanner as it passed. Cracks several meters wide appeared in seconds beneath the scientists' feet, prompting a hasty retreat.
Changes in the Arctic are being driven both by manmade greenhouse gases and natural weather patterns. With less ice, less sunlight is reflected back into space, warming the air and melting more ice.
Experts say thinning of ice over recent decades may hasten an ice-free summer as soon as 2020. And, while thickness is more difficult to measure by satellite than area, if anything it is more important.
That has put the onus on better data, through new satellite, plane and submarine observations and a low-tech approach on the ice itself -- drilling holes and poking a tape measure down.
"What the radar of the satellite sees is just the part of the ice that is really above the water and since about nine tenths of the ice is underneath the water there is a huge uncertainty in what the satellite can actually see," said Cambridge University PhD student Till Wagner told Reuters.
"That's what we are here for to get a better handle on how thick the ice actually is," he said, standing on a floe next to the Arctic Sunrise.
WILD CARD
The sea ice area retreats each summer and this year is closing on a record low in 2007. With one week of the melt season to go, it is now less than two-thirds of the area it covered in the early 1970s.
The sea ice, distinct from ice sheets hundreds of meters thick over rock in Greenland, floats on the Arctic Ocean and wildlife including polar bears and walruses depend on it for survival.
Wider "wild card" risks from an ice-free ocean in summer include weather disruption as the difference in temperature between the equator and poles is the engine of the world's weather.
If the Arctic Ocean were open sea in autumn, without an insulating layer of ice, that would allow more warming of the polar air.
One forthcoming study calculated that the total volume of Arctic sea ice fell to a record low in 2010, suggesting that thinning has continued despite a rather steadier ice extent over the past three or four years.
Other scientists are poring over new satellite estimates of thickness from the European Space Agency's CryoSat, which will plug a gap in data between the last US ICESat satellite and the start date for the next around 2016.
"The preliminary map of CryoSat thickness shows reasonable agreement ... with airborne data," said University College London's Seymour Laxon by email. "Some of this data is only now becoming available."
On the ice floe near the North Pole this week, the researchers' coup de grace is a three-dimensional scan which may help scientists understand its shape and strength better.
"Traditionally, you might be doing a section or a plan to understand an area but to fully see this in 3D and combine it with the satellite information we are able to really get a really high resolution understanding of what's going on out here," said Will Trossell, at start-up company Scanlab.
Arctic ice breaks up as polar bears stalk ship
Stepping onto an Arctic ice floe on Monday, an unusually mild, easterly breeze blew at the end of the annual summer melt. The footprints of two polar bears from the night before were disintegrating in a dusting of snow.
At nearly 81 degrees latitude, the air temperature was 2.5 degrees Celsius – normal for a winter's day in Europe but rather mild for the high Arctic, even in late summer. The previous day had been 4 degrees colder.
The monochrome scene was calm after the rolling swell of the Fram Strait between the Norwegian island of Svalbard and Greenland. We were embedded in an ice pack stretching half the area of Brazil, across the North Pole.
The Greenpeace icebreaker Arctic Sunrise nearby shuddered occasionally, nudged by white slabs of ice the size of a small car park, which jostled among threads of open water.
The water temperature was below zero, the ship's log read, and the air was filled by the hum of its generators. The ship's mooring ropes were driven by two giant stakes into ice up to 10 meters thick.
This entire Arctic landscape is forecast to disappear within decades and replaced by open sea each summer, perhaps for the first time in 7,000 years or more. The dramatic retreat signals the scale of humankind's impact on the climate, experts say.
On Wednesday, the shrinking sea ice was closing in on the 2007 record low area of 4.1 million square km, according to the U.S.-based National Snow and Ice Data Center. The annual minimum was 7 million square km in the early 1970s.
Environmental group Greenpeace wanted to draw attention to changes in the high Arctic, and ferried Cambridge University researchers from Svalbard to measure the thickness of the ice. Experts say it has been thinning for decades, possibly hastening an entirely ice-free summer as soon as 2020.
The sea ice area is easily read from satellites overhead. Measuring thickness is more difficult, and the most direct approach is to drill a hole and poke a tape measure down.
While doing just that the researchers on Monday were confronted directly with the annual seasonal melt which ends around mid-September each year.
They raced to evacuate the floe when a 3-meter wide crack appeared suddenly, in under a minute. A combination of melting, the swell of the sea and wind broke the floe apart.
The night before, a polar bear and her cub blundered through research equipment left on the ice, adding to the novel dangers of Arctic field experiments.
The polar bear is called "Nanuk", which means the Great Wanderer in the local Arctic Inuit language. But it was clear that there was nothing random about the bears which stalked our ship from floe to floe.
Experts say Arctic wildlife, including bears, depend on hunting from the ice. They are likely to suffer from an ice-free summer, while warmer air and water could shift birds and fish.
Wider, "wild card" consequences could see disrupted global weather patterns, when a warmer, open sea, without its insulating layer of ice, releases more heat into the polar autumn air. The difference in temperature between the poles and equator is the basic engine of world weather.
Meanwhile, some experts say a warmer Arctic could speed up the melt of the Greenland ice sheet, which contains enough water to raise sea levels by 7 meters.
On this research trip, the most dramatic recording was simply our arrival time back in Svalbard, hastened many hours by a sea ice retreat of 8 miles in just three days.
Researchers who go to the Arctic rarely find themselves in the same place twice and it is a privilege to measure such a change so precisely.
"We were basically at the same point where we entered and left the ice, and you could see there was a difference," said Arne Sorensen, Arctic Sunrise ice.
(Reporting by Gerard Wynn; Editing by Karolina Tagaris)