NASA: Arctic's thickest ice diminishing faster than thin ice

2012-03-01 23:20:53 GMT+7 (ICT)

GREENBELT, Maryland (BNO NEWS) -- The oldest and thickest Arctic sea ice is disappearing at a faster rate than the younger and thinner ice at the edges of the Arctic Ocean's floating ice cap, according to a new study revealed by NASA on Thursday.

The new research takes a closer look at multi-year Arctic sea ice and reveals that it is diminishing at a rate of 15.1 percent per decade. Scientists define multi-year Arctic sea ice as ice that has made it through at least two summers.

The study has reviewed multi-year ice "extent" - which includes all areas of the Arctic Ocean where multi-year ice covers at least 15 percent of the ocean surface - and how the ice has diminished with each passing winter over the last three decades.

When young ice that has formed over winter quickly melts again during the cyclical summer melt season, the thicker ice, known as multi-year ice, survives through the season.

However, Joey Comiso, senior scientist at NASA's Goddard Space Flight Center and author of the study, which was recently published in Journal of Climate, noted that the rapid disappearance of older ice makes Arctic sea ice even more vulnerable to further decline in the summer.

Researchers also analyzed how the ice cap evolves through other measurements such as multi-year ice "area," which discards areas of open water among ice floes and focuses exclusively on the regions of the Arctic Ocean that are completely covered by multi-year ice.

In the study, Comiso found that multi-year ice area is shrinking even faster than multi-year ice extent by 17.2 percent per decade.

"The average thickness of the Arctic sea ice cover is declining because it is rapidly losing its thick component, the multi-year ice," said Comiso. "At the same time, the surface temperature in the Arctic is going up, which results in a shorter ice-forming season. It would take a persistent cold spell for most multi-year sea ice and other ice types to grow thick enough in the winter to survive the summer melt season and reverse the trend."

In addition, Comiso found that the extent of perennial ice, ice that has survived at least one summer, is shrinking at a rate of 12.2 percent per decade, while its area is declining at a rate of 13.5 percent per decade. These numbers indicate that the thickest ice, multiyear-ice, is declining faster than the other perennial ice that surrounds it.

In the winter of 2008, multi-year sea ice hit its record minimum extent, when it was reduced to about 55 percent of its average extent since the late 1970s, when satellite measurements of the ice cap began.

Multi-year sea ice then recovered slightly in the three following years, ultimately reaching an extent 34 percent larger than in 2008, but it dipped again in winter of 2012, to its second lowest extent ever.

-- © BNO News All rights reserved 2012-03-01

"The Arctic seems to be warming up. Reports from fishermen, seal hunters, and explorers who sail the seas about Spitzbergen and the eastern Arctic, all point to a radical change in climatic conditions, and hitherto unheard-of high temperatures in that part of the earth's surface.

"The oceanographic observations have, howerer, been even more interesting. Ice conditions were exceptional. In fact, so little ice has never before been noted. The expedition all but established a rocord, sailing as far north as 81° 29'. This is the farthest north ever reached with modern oceanographic apparatus." - 10 October 1922. US consul, Bergen, Norway to the State Department.

Nothing new here - just another silly attempt at scaremongering by NASA.

Stories keep coming of arctic and antarctic ice melting at faster-than-replacable rates. Similar stories about glaciers worldwide - melting and receding at alarming rates. However, no amount of scientific data will affect the thinking of die-hard global warming deniers. Even if half of Greenland had rock showing, the deniers would continue to say its a ruse.

Stories keep coming of arctic and antarctic ice melting at faster-than-replacable rates

Well, I suppose it might look like that if all you read are WWF press releases, but if you look at the science that is being carried out, you will find that Antarctic ice extent is close to a record high, and that the Arctic is close to a record low.

You will also discover that these shifts have happened many times before over geological time.

It's a pity that many in the Green/Left community ignore everything that happened before they were born, so that everything to them seems 'unprecedented' and catastrophic.

what nasa is not telling you, its not global warming, but a.. polar shift that is speeding up, it was traveling at 25 miles per year and is now traveling at 40 miles per year, and i would guess at one point just flip..their not telling you the truth.

Stories keep coming of arctic and antarctic ice melting at faster-than-replacable rates. Similar stories about glaciers worldwide - melting and receding at alarming rates. However, no amount of scientific data will affect the thinking of die-hard global warming deniers. Even if half of Greenland had rock showing, the deniers would continue to say its a ruse.

There hasn't been warming for over a decade now. Even the most ardent warmists like Prof Jones admit this when pushed.

NONE of the climate models predicted this, yet we are still supposed to take our lifestyles back in time 200 years because of the forcasts made from these very (inaccurate) models.

I don't think anyone denies that there have been profound climate shifts in Earth's history. The current trend toward general warming, particularly at the poles and high altitudes, may or may not be part of a larger natural cycle. The bigger issue is whether the current warming trend is affected/exacerbated/caused by human activity. If so, to what extent, and what can be done to lessen the human impact.

For my small part, I've planted hundreds of trees (dozens per year), I use internal combustian powered vehicles as little as possible - same with jet travel and air-conditioning and electricity use. Even if global warming was a hoax, using less carbon-based fuels is a better way to go.

what nasa is not telling you, its not global warming, but a.. polar shift that is speeding up, it was traveling at 25 miles per year and is now traveling at 40 miles per year, and i would guess at one point just flip..their not telling you the truth.

I think you're referring to the shift of magnetic north. It's moving across the north of Russia. I doubt it has anything to do with weather.

Does this mean they will have to think about relocating Bangkok a bit faster than first thought.

Having observed glacier retreat in NZ over a 45 year period, I'll accept global warming as a fact.

But as 45 years is insignificant in global time, and an extra volcanic eruption or two makes man's efforts seem puny, I also accept Al Gore as a wanke_r, and given his lifestyle, an even bigger hypocrite.

Meanwhile, every time another hydro-dam is proposed (the most efficient and economic way of using solar energy) the same people who whine about global warming get their knickers in a knot about some fish, frog or subsistence farmer who's lifestyle might be affected.

There's still so much to find out about the polar ice caps & "global warming" -- the most recent research (Liu & Curry, 2012) suggests that a lack of ice at the Arctic may have been partly responsible for the brutally cold European winters of 2009/10 and 2010/11, through cyclic mechanisms called the Arctic Oscillation and the North Atlantic Oscillation.

So the whole situation is much more complex, nuanced and volatile than the High Priests of the Cult of Warm would like everyone to believe.

EDIT: Link corrected.

Having observed glacier retreat in NZ over a 45 year period, I'll accept global warming as a fact.

But as 45 years is insignificant in global time, and an extra volcanic eruption or two makes man's efforts seem puny, I also accept Al Gore as a wanke_r, and given his lifestyle, an even bigger hypocrite.

Meanwhile, every time another hydro-dam is proposed (the most efficient and economic way of using solar energy) the same people who whine about global warming get their knickers in a knot about some fish, frog or subsistence farmer who's lifestyle might be affected.

So, does that mean you approve of every dam that's proposed?

Having observed glacier retreat in NZ over a 45 year period, I'll accept global warming as a fact.

But as 45 years is insignificant in global time, and an extra volcanic eruption or two makes man's efforts seem puny, I also accept Al Gore as a wanke_r, and given his lifestyle, an even bigger hypocrite.

Meanwhile, every time another hydro-dam is proposed (the most efficient and economic way of using solar energy) the same people who whine about global warming get their knickers in a knot about some fish, frog or subsistence farmer who's lifestyle might be affected.

So, does that mean you approve of every dam that's proposed?

No