Using the latest satellite observations, NASA researchers and others report that the Arctic is still on “thin ice” when it comes to the condition of sea ice cover in the region. A colder-than-average winter in some regions of the Arctic this year has yielded an increase in the area of new sea ice, while the older sea ice that lasts for several years has continued to decline.
On March 18 the scientists said they believe that the increased area of sea ice this winter is due to recent weather conditions, while the decline in perennial ice reflects the longer-term warming climate trend and is a result of increased melting during summer and greater movement of the older ice out of the Arctic.
Quote:
Joey Comiso of NASA's Goddard Space Flight Center in Greenbelt, Md., the lead author of a 2007 related study, used data from NASA's passive microwave data set to establish that the perennial ice cover at the summer Arctic ice minimum in 2007 was about 40 percent less than the 28-year average. According to the latest observations from the National Snow and Ice Data Center (an organization partially funded by NASA), perennial sea ice dropped from about 40 percent of the total ice pack last year to 30 percent of total ice this winter. The perennial ice is also growing younger, meaning that it is thinner and will be more vulnerable during the summer melt period.
_________________ "It is no measure of health to be deemed sane in an insane society" J. Krishnamurti
Joined: Sep 17, 2006 Posts: 634 Location: No man's land
Posted: Tue Mar 18, 2008 4:19 pm Post subject: Re: Record ice loss in Arctic
An ecological horror movie unfolding:
Quote:
Some 965,300 square miles (2.5 million sq kms) of perennial ice have been lost -- about one and a half times the area of Alaska -- a 50 percent decrease between February 2007 and February 2008, Meier said.
The oldest "tough as nails" perennial ice has decreased by about 75 percent this year, losing 579,200 square miles (1.5 million sq kms, or about twice the area of Texas, he said.
This doesn't mean the Arctic is open water during the winter, but it does mean that in many areas, the stronger perennial ice is being replaced by younger, frailer new ice that is more easily disturbed by wind and warm sea temperatures.
"It's like looking at a Hollywood set," Meier said of an Arctic largely covered with younger ice. "It may look OK but if you could see behind you'd see ... it's just empty. And what we're seeing with the ice cover is it's becoming more and more empty underneath the ice cover."
Reuters article _________________ "It is no measure of health to be deemed sane in an insane society" J. Krishnamurti
Viewing the Arctic from space via NASA satellites might make you think the Arctic ice cover is on its way back.
But more than 70 percent of that sea ice is new, thin and salty, having formed only since September, Comiso said. The more important ice is perennial sea ice that lasts through the summer, and that ice has hit record low levels.
Compared to the 1980s, the Arctic has lost more than half of its perennial sea ice and three-quarters of its "tough as nails" sea ice that is six years or older, Meier said. The amount of lost old sea ice is twice the area of the state of Texas, he said.
On top of that, a change in Arctic atmospheric pressure this winter is pushing a large amount of the valuable older ice out of the Arctic to melt, Meier said.
That means next summer when temperatures warm, expect lots of melting, the scientists said.
"We're in for a world of hurt this summer," ice center senior scientist Mark Serreze told The Associated Press. Depending on the weather, there could be as much melting this year as last, maybe more, Serreze and Meier said.
_________________ Oxygen: - An intensely habit-forming accumulative toxic substance. As little
as one breath is known to produce a life-long addiction to the gas, which addiction invariably ends in death.--Isaac Asimov
Joined: Sep 17, 2006 Posts: 634 Location: No man's land
Posted: Tue Mar 18, 2008 5:26 pm Post subject: Re: Record ice loss in Arctic
Quote:
Depending on the weather, there could be as much melting this year as last, maybe more, Serreze and Meier said.
We have just been given evidence that the underlying cause of the perennial ice melt during the winter months was warmer ocean temperatures (as we know that cooler air temperatures prevailed throughout most of the Arctic), so I find it hard to believe that weather conditions this summer will make a significant difference. _________________ "It is no measure of health to be deemed sane in an insane society" J. Krishnamurti
Joined: Mar 26, 2005 Posts: 3780 Location: over here
Posted: Tue Mar 18, 2008 5:32 pm Post subject: Re: Record ice loss in Arctic
Quote:
The Arctic is losing its old, thick ice faster than in previous years, according to satellite data.
The loss has continued since the end of the Arctic summer, despite cold weather across the northern hemisphere.
The warm 2007 summer saw the smallest area of ice ever recorded in the region, and scientists say 2008 could follow a similar pattern.
Older floes are thicker and less saline than newly-formed ice, meaning they can survive warm spells better.
Ice more than two years old now makes up about 30% of all the ice in the Arctic, down from 60% two decades ago.
The shrinking of Arctic ice has global implications, as its white surface reflects solar energy back into space whereas the open ocean absorbs it.
Long March
March is the month when the Arctic ice usually reaches its largest extent, as the dark winter nears its end.
Nasa's data shows the area covered by ice is roughly the same as it was last year; but this masks a significant change.
"Although this March the area is slightly larger than last March, the area of [thick] perennial ice has reached an all time low," said Seelye Martin, manager of the Cryospheric Sciences Program at Nasa headquarters in Washington DC.
The loss of old, thick ice has continued through the winter months, despite the unusually cold weather deriving from La Nina conditions (the other extreme of the El Nino Southern Oscillation) in the Pacific.
read on @ BBC news _________________ "The best thing about the future is that it comes only one day at a time."
Joined: Sep 17, 2006 Posts: 634 Location: No man's land
Posted: Tue Mar 18, 2008 6:04 pm Post subject: Re: Record ice loss in Arctic
Yet, on this glorious day when we have been told by our most prestigious scientific organizations that the Arctic ice cap is experiencing a catastrophic collapse, the stock market SOARS...
Quote:
The Dow Jones industrial average (INDU) rose 420 points, its biggest one-day point gain since July 2002, for a gain of 3.5%. The broader Standard & Poor's 500 (SPX) index added over 54 points, its biggest one-day point gain since Jan. 2001, for a gain of 4.2%.
The tech-fueled Nasdaq composite (COMP) advanced over 91 points, its biggest one-day point gain since May 2002, for a gain of around 4.2%.
_________________ "It is no measure of health to be deemed sane in an insane society" J. Krishnamurti
Posted: Tue Mar 18, 2008 9:54 pm Post subject: Re: Record ice loss in Arctic
The environment still hasn't whacked Wall Street with a spiked two-by-four across the back of the head yet. So it will merrily pretend it is not there or does not matter. But the pain will arrive, sooner rather than later.
The age of ice graphic is impressive, the summer ice loss this year will be a record. The quoted articles are still harping about atmospheric conditions as if they were all important. The change in the ocean circulation is not only bringing in warm water but flushing out the old ice even in winter. The claim is made that it is the "natural cycle" of the Arctic Oscillation, but this claim is a load of BS. There would have been similar perennial ice transport events in the past if it was business as usual. The AO is an atmospheric phenomenon and not an ocean circulation feature, so once again all the thinking is fixated on the atmosphere.
Joined: Apr 28, 2005 Posts: 3655 Location: West shore Lake Eire, MI, USA
Posted: Tue Mar 18, 2008 10:32 pm Post subject: Re: Record ice loss in Arctic
IMO for whatever its worth the heat capacity of the Arctic ocean is the key. This last fall you had gulf stream water intruding ON THE SURFACE to 80 degrees north latitude! Couple that with extream shifts in the albedo of the surface due to the seasonal ice all melting and you are going to end up with a huge latent heat level in the Arctic.
If this pattern persists for a few years the top 150 meters of the Arctic will reach latent heat capacity/saturation, at which point it will become very resistant to ice formation during the Sep-Mar period of polar night.
If you lose the winter ice cover several things happen. For one thing winter evaporation adds a lot of moisture to the climate system. For another when the sun comes back up the following March there is no sea ice to absorb energy, the solar flux will go directly into the heat balance of the top 150 meters of the sea. If and/or when that happens you get the last step in the feedback loop, the warm saline gulf waters will stay warm because the surface waters will be warm themselves. This in turn will cause them to stay on the surface and become even more saline, until even as warm water their salinity density is enough to cause them to sink. In the Med Sea this happens at a salinity of between 38 and 39, depending on where inthe Med basin you are talking about. The Arctic bottom water ranges from 37.25 to 37.49 today. The descending warm highly saline water would therefor displace the cold bottom water now in the deep Arctic basins and set up an extended ocean conveyor, with the Gulf Stream extending as far as the geographic north pole before descending and leaving the Arctic over the 600 meter sill in the Fram straight. _________________ Oxygen: - An intensely habit-forming accumulative toxic substance. As little
as one breath is known to produce a life-long addiction to the gas, which addiction invariably ends in death.--Isaac Asimov
Joined: Oct 28, 2006 Posts: 150 Location: Southern California
Posted: Wed Mar 19, 2008 12:44 am Post subject: Re: Record ice loss in Arctic
Tanada wrote:
If you lose the winter ice cover several things happen. For one thing winter evaporation adds a lot of moisture to the climate system. For another when the sun comes back up the following March there is no sea ice to absorb energy, the solar flux will go directly into the heat balance of the top 150 meters of the sea. If and/or when that happens you get the last step in the feedback loop, the warm saline gulf waters will stay warm because the surface waters will be warm themselves. This in turn will cause them to stay on the surface and become even more saline, until even as warm water their salinity density is enough to cause them to sink. In the Med Sea this happens at a salinity of between 38 and 39, depending on where inthe Med basin you are talking about. The Arctic bottom water ranges from 37.25 to 37.49 today. The descending warm highly saline water would therefor displace the cold bottom water now in the deep Arctic basins and set up an extended ocean conveyor, with the Gulf Stream extending as far as the geographic north pole before descending and leaving the Arctic over the 600 meter sill in the Fram straight.
In'eresting. So what's the probable consequence of this outcome, a plankton boom in the Arctic? ...and then?
Joined: Sep 17, 2006 Posts: 634 Location: No man's land
Posted: Wed Mar 19, 2008 1:31 am Post subject: Re: Record ice loss in Arctic
Quote:
Officials said the loss of long-lasting ice was less the result of warming of the atmosphere than of a long-term rise in ocean temperatures and the effects of the "Arctic oscillation," a variable wind pattern that can either keep icebergs in the Arctic (when the wind pattern is "negative") or push them south (when it is "positive"). Climate experts believe that both the rising water temperature and increasingly frequent "positive" oscillations are a function of global warming.
Josefino Comiso of NASA's Goddard Space Flight Center, the lead author of a related 2007 study, said Arctic Ocean temperatures appear to be rising quickly because less of the water is covered by ice, which reflects sunlight and keeps water temperatures lower. After last summer's very warm weather, the amount of ice cover shrank dramatically, and the water became warmer.
He said climate experts have concluded that the Arctic oscillation, which is a natural climate phenomenon, is also being modified by global warming. The dynamics are not yet understood, but it appears that higher temperatures in the tropics and elsewhere make it more likely that the oscillation will push icebergs down past Greenland and into the Atlantic.
Washington Post _________________ "It is no measure of health to be deemed sane in an insane society" J. Krishnamurti
Joined: Apr 28, 2005 Posts: 3655 Location: West shore Lake Eire, MI, USA
Posted: Wed Mar 19, 2008 5:25 am Post subject: Re: Record ice loss in Arctic
grink1tt3n wrote:
Tanada wrote:
If you lose the winter ice cover several things happen. For one thing winter evaporation adds a lot of moisture to the climate system. For another when the sun comes back up the following March there is no sea ice to absorb energy, the solar flux will go directly into the heat balance of the top 150 meters of the sea. If and/or when that happens you get the last step in the feedback loop, the warm saline gulf waters will stay warm because the surface waters will be warm themselves. This in turn will cause them to stay on the surface and become even more saline, until even as warm water their salinity density is enough to cause them to sink. In the Med Sea this happens at a salinity of between 38 and 39, depending on where inthe Med basin you are talking about. The Arctic bottom water ranges from 37.25 to 37.49 today. The descending warm highly saline water would therefor displace the cold bottom water now in the deep Arctic basins and set up an extended ocean conveyor, with the Gulf Stream extending as far as the geographic north pole before descending and leaving the Arctic over the 600 meter sill in the Fram straight.
In'eresting. So what's the probable consequence of this outcome, a plankton boom in the Arctic? ...and then?
Open water in the Arctic summer always get plankton blooms, the constant sunlight and nutrient rich water are perfect for it. After that the fish flourish, and the predatory species etc etc etc...
It has been calculated that because the Arctic had so much newly exposed surface water last year that it was a significant carbon sink for the first time in about a thousand years.
Like all feedback system in the climate the Arctic has many competing effects, less ice means less direct cooling through Albedo and melting effects. On the other hand it means an increase in carbon dioxide absorbtion and sequestration. If the surrounding land mass and islands flip from Continental Tundra to Boreal Forrest biome as they were 4 million years ago that adds another significant carbon sink to the climate.
Which factors win out in the end is a really interesting question. GHG forcing is, for the first time in human history, tipping us over into different feedback loops. The gulf stream induced ice age of the last 3.1 million years appears to be shifting back to a warm age climate where the Arctic will cease to be ice covered year around. If the climate actually makes that flip Greenland will melt and there is little we could do short term that would not have unforseen consequences. _________________ Oxygen: - An intensely habit-forming accumulative toxic substance. As little
as one breath is known to produce a life-long addiction to the gas, which addiction invariably ends in death.--Isaac Asimov
Posted: Wed Mar 19, 2008 8:51 am Post subject: Re: Record ice loss in Arctic
I read the comments on the article, in the last link. I am always impressed by the fact that the USA get the most Nobel prices in science, yet seems to have the general public that are the most ignorant of science, compared to other Western nations.
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