See the Quikscat animation (recording Sept 7, 2007 to Jan 4, 2008 ice movement
Now updated thru Jan 29, 2008. Hopefully this link and updates will stay active. _________________ "It is no measure of health to be deemed sane in an insane society" J. Krishnamurti
Joined: Feb 19, 2007 Posts: 94 Location: British Virgins
Posted: Sat Feb 09, 2008 8:20 pm Post subject: Re: Record ice loss in Arctic
TheDude wrote:
FreddyH wrote:
Come on Dude, the Nat'l Research Council has revisited the hockey stick and deemed it a piece of crap.
June 22, 2006 is "new"?
Here's what they actually said in their press release:
Quote:
The Research Council committee found the Mann team's conclusion that warming in the last few decades of the 20th century was unprecedented over the last thousand years to be plausible, but it had less confidence that the warming was unprecedented prior to 1600; fewer proxies -- in fewer locations -- provide temperatures for periods before then. Because of larger uncertainties in temperature reconstructions for decades and individual years, and because not all proxies record temperatures for such short timescales, even less confidence can be placed in the Mann team's conclusions about the 1990s, and 1998 in particular.
Here is a repost co-authored by the RC staff, including Michael Mann himself, for anyone who's playing along.
Quote:
Finally, it is worth pointing out and emphasising that the report provides absolutely no support for the oft-heard claims that the original hockey stick was the result of 'programming errors', or was 'not reproducible', or there was some scientific misconduct involved. These claims were always spurious and should now finally be laid to rest. Hopefully, we can all start to move forward with the science again.
Hi Dude, if I could chime in. Nobody seriously says these things about the methodology. Mann clearly manipulated the proxies chosen, cherry picking those that dampened the MWP and enahanced the LIA. It was not difficult to uncover his deeds. The hockey stick was a joke and IPCC dropped it from all documents associated with AR4 2007. From the NRC summary:
Quote:
Large-scale surface temperature reconstructions yield a generally consistent picture of temperature trends during the preceding millennium, including relatively warm conditions centered around A.D. 1000 (identified by some as the “Medieval Warm Period”) and a relatively cold period (or “Little Ice Age”) centered around 1700. The existence of a Little Ice Age from roughly 1500 to 1850 is supported by a wide variety of evidence including ice cores, tree rings, borehole temperatures, glacier length records, and historical documents. Evidence for regional warmth during medieval times can be found in a diverse but more limited set of records including ice cores, tree rings, marine sediments, and historical sources from Europe and Asia, but the exact timing and duration of warm periods may have varied from region to region, and the magnitude and geographic extent of the warmth are uncertain.
Thats Danish, not Dutch. Unfortunatly Babblefish isn't much help.
Here is their English home page, but it doesn't include the article you cite above
http://www.dmi.dk/eng/index/forecasts/forecast_for_sea_areas.htm _________________ 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
25 pct. of North Pole melted on a year
Of THIGHS' PIOUS
Offentliggjort 08.02.08 hrs. 22: 31
The ice about North Pole disappears faster, than even the most sceptical forecasts have anticipated.
During the last year about one quarter of the ice mass in the area has disappeared, senior researcher Rasmus Tonboe estimates at Danmark Meteorologiske Institut, DMI.
"We have just analysed new satellite pictures of the ice, which shows that there is about 25 pct. less ice, than it was a year ago. It's completely wild", Rasmus Tonboe ascertains.
The temperature has risen
He explains the dramatic de-melting with two conditions:
"Firstly the temperature has in the area risen, secondly there has been changed current conditions, which have led large quantities of ice away from the arctic regions. There is no doubt that the ice melts, but nobody has dared anticipate that it'd happen so quickly, as that we now see", it sounds from Rasmus Tonboe.
Great consequences
So far the most dramatic predictions have talked about that North Pole may be completely ice-free in summer once between 2040 and 2060. If the present de-melting doesn't appear to be an accidental variation of the climate, but is due to the global heating, it can even go faster.
"Then it want to not go 40 years, before the arctic regions are ice-free. Then it wants to not stop", professor Eigil Kaas from the University of Copenhagen thinks.
Dramatic consequences
Professor Ola Johannessen from Nansen Instituttet in Bergen thinks that it'll get dramatic consequences for the climate on the whole globe, if the arctic ocean stays ice-free.
"That will get great consequences for the weather in Greenland and on the rest of the globe. That will change the entire global climate, if we get a news, ice-free ocean", thinks Ola Johannessen, who is one of the researchers who have followed the developments in the arctic ice most closely.
_________________ 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: Mon Feb 11, 2008 6:53 pm Post subject: Re: Record ice loss in Arctic
Relatively speaking, it appear the winter sea ice has recovered fairly well. Before we get our hopes up, we have to remember that this is all thin ice and will therefore melt quickly. I suspect that this summer will see summer ice extend between the 2005 and 2007 record value.
Joined: Apr 28, 2005 Posts: 3658 Location: West shore Lake Eire, MI, USA
Posted: Mon Feb 11, 2008 8:50 pm Post subject: Re: Record ice loss in Arctic
Dan1195 wrote:
Relatively speaking, it appear the winter sea ice has recovered fairly well. Before we get our hopes up, we have to remember that this is all thin ice and will therefore melt quickly. I suspect that this summer will see summer ice extend between the 2005 and 2007 record value.
As you say ice AREA has recovered very well while ice VOLUME has continued to fall over the course of the winter as older ice is flushed through the Flam Strait.
Time will tell, I just wish I could peak at the last chapter now (sep 2008) and set aside worrying for the next seven months. _________________ 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: 639 Location: No man's land
Posted: Wed Feb 13, 2008 1:10 pm Post subject: Re: Record ice loss in Arctic
I'll be surprised if the Arctic sea ice survives two more summers.
Quote:
ANCHORAGE, Alaska - Arctic sea ice next summer may shrink below the record low last year, according to a University of Washington climatologist. Ignatius Rigor spoke Monday at the Alaska Forum on the Environment and said global warming combined with natural cyclical changes likely will continue to push ice into the North Atlantic Ocean.
The last remnants of thick, old sea ice are dispersing and the unusual weather cycles that contributed to sea ice loss last year are continuing, he said.
"The buoys are streaming out," Rigor said, referring to the markers used to monitor the flushing of ice into the North Atlantic.
A similar pattern preceded sea ice loss last summer was not expected to continue so strongly.
Scientists are watching Arctic sea ice closely, trying to sort out the effects of global warming and natural cyclical changes.
Formal projections of sea ice loss will be made for another month or so but all indications are that ice loss will equal or exceed last year's "unless the winds turn around," Rigor said.
New ice now covering the polar seas is not like older, thicker sea ice that once covered the region in winter, Rigor said. In 1989, 80 percent of the ice in the Arctic was at least 10 years old, he said. Today, only about 3 percent of the ice is that old.
Anchorage Daily News _________________ "It is no measure of health to be deemed sane in an insane society" J. Krishnamurti
Posted: Wed Feb 13, 2008 3:47 pm Post subject: Re: Record ice loss in Arctic
billg wrote:
I'll be surprised if the Arctic sea ice survives two more summers.
Quote:
ANCHORAGE, Alaska - Arctic sea ice next summer may shrink below the record low last year, according to a University of Washington climatologist. Ignatius Rigor spoke Monday at the Alaska Forum on the Environment and said global warming combined with natural cyclical changes likely will continue to push ice into the North Atlantic Ocean.
The last remnants of thick, old sea ice are dispersing and the unusual weather cycles that contributed to sea ice loss last year are continuing, he said.
"The buoys are streaming out," Rigor said, referring to the markers used to monitor the flushing of ice into the North Atlantic.
A similar pattern preceded sea ice loss last summer was not expected to continue so strongly.
Scientists are watching Arctic sea ice closely, trying to sort out the effects of global warming and natural cyclical changes.
Formal projections of sea ice loss will be made for another month or so but all indications are that ice loss will equal or exceed last year's "unless the winds turn around," Rigor said.
New ice now covering the polar seas is not like older, thicker sea ice that once covered the region in winter, Rigor said. In 1989, 80 percent of the ice in the Arctic was at least 10 years old, he said. Today, only about 3 percent of the ice is that old.
Seriously balls. I have been watching cryosphere regularly and seeing the ice get to near average at the moment. I was begining to really believe last year was largely a freak of the high pressure over Siberia, and that we had dodged a bullet for about a decade or so.
Posted: Wed Feb 13, 2008 4:19 pm Post subject: Re: Record ice loss in Arctic
looking at the latest time lapse of sea ice extent over at Cryosphere today it has actually ecclipsed last years winter extent. But if its thin, then as soon as the sun starts baking the north pole....yea bad news. Looks great from up above. I will be watching the melt season intensely and comparing it to previous years. I think we could be watching history here.
Posted: Wed Feb 13, 2008 8:43 pm Post subject: Re: Record ice loss in Arctic
That's the real story, the thickness of the ice. The wintertime extension is doing a good job insulating the sea surface from radiating heat. But once the summer arrives this thin ice crust will disappear quickly.
Joined: Sep 17, 2006 Posts: 639 Location: No man's land
Posted: Fri Feb 15, 2008 12:14 pm Post subject: Re: Record ice loss in Arctic
Cabrone wrote:
Yes, and how much 24 hr sunshine heat will the collapse of millions of square km of ice put into the system? Scary stuff indeed.
We're so screwed it's become comical. If you didn't laugh you'd go mad.
Interestingly, whether or not by divine plan, most of humanity has been lulled into believing that the melting of Arctic ice cap isn't that big of a deal. Even as it has melted substantially over the couple decades and now the melt accelerates, sea levels have remained relatively constant and surface temperatures have not increased more than 1 degree C in the temperate and tropical latitudes.
But of course, there is a big difference between a partial meltdown and complete meltdown. After we lose the Arctic ice, we will need to rely on Greenland and Antarctica to help cool the system down and we all know what that means. _________________ "It is no measure of health to be deemed sane in an insane society" J. Krishnamurti
Posted: Fri Feb 15, 2008 5:17 pm Post subject: Re: Record ice loss in Arctic
Hey Tanada,
Back on page 36 of this thread I asked about the possibility of the land mass of Greenland rising as its ice overburden started to melt. I found this on page 6 of the new report Climate Code Red
"Another indication of Greenland’s shrinking ice cap is evidence that its landmass is rising up to 4 cm per year, a buoyancy produced by carrying less weight of ice (Brahic, 2007d)."
(Brahic, C. (2007d) “Shrinking ice means Greenland is rising fast”, New Scientist, 2 November 2007)
So it's already happening, and while 4cm per year doesn't sound like a lot, it's not nothin'. In ten short years, that adds up to nearly half a meter!
A drop of water will stay in place on an level surface, but tip the surface just a little, and suddenly that drop is in motion.
Multiply that drop by...a whole lot, add in ice for slipperiness and sediment for ball-bearing-like lubrication, and you get another positive feedback on the Greenland-icepack-slipping-into-the-sea front.
Joined: Apr 28, 2005 Posts: 3658 Location: West shore Lake Eire, MI, USA
Posted: Fri Feb 15, 2008 6:27 pm Post subject: Re: Record ice loss in Arctic
dohboi wrote:
Hey Tanada,
Back on page 36 of this thread I asked about the possibility of the land mass of Greenland rising as its ice overburden started to melt. I found this on page 6 of the new report Climate Code Red
"Another indication of Greenland’s shrinking ice cap is evidence that its landmass is rising up to 4 cm per year, a buoyancy produced by carrying less weight of ice (Brahic, 2007d)."
(Brahic, C. (2007d) “Shrinking ice means Greenland is rising fast”, New Scientist, 2 November 2007)
So it's already happening, and while 4cm per year doesn't sound like a lot, it's not nothin'. In ten short years, that adds up to nearly half a meter!
A drop of water will stay in place on an level surface, but tip the surface just a little, and suddenly that drop is in motion.
Multiply that drop by...a whole lot, add in ice for slipperiness and sediment for ball-bearing-like lubrication, and you get another positive feedback on the Greenland-icepack-slipping-into-the-sea front.
Thoughts?
If your greenland ice sheet were sitting on a flat table top style topography then you would be correct, a 4 cm rise might spell trouble in the long run. HOWEVER the center of the island that is Greenland has been depressed 300 METERS into the mantle below sea level by the weight of the 3 km thick ice sheet sitting on it. At 4 cm per years it would/will take 7500 YEARS for the center of the island to rise back up to sea level.
Another factor which is often forgotten, when an ice sheet melts the part below sea level floats away, but the depth of water in the bowl as it were still keeps some weight on the bedrock and slows the rebound. From the same page of the report some area's of the ice sheet are falling 10 meters per year from rapid melting, while at the same time they rise 4 cm from the lower weight of the ice. Ultimately central Greenland topographicallu now looks like a gravy boat from a dinner table with the spout facing roughly soth east into the Atlantic. When the weight of the ice sheet gets low enough sea water will flow into the bowl and float the sheet off the bedrock, after that it is estimated the remainder will break up and flow out of the spout as ice bergs of huge dimensions. If things keep speeding up I might even live long enough to see that happen, but I doubt it as of right now.
Another thing to keep in mind, think of the crustal bedrock under the ice sheet as being a sheet of plywood with a solid frame one foot in from the edge. Now pile ice on the plywood and what happens? Around the edge where the solid frame is the plywood can not go down, instead all of the weight moves towards the center as it sags downward. Around the edge the solid frame actually deforms the surface upward slightly because of the streangth of the plywood bending under the weight in the center. The crust under an ice sheet does the same thing, the mountains around the coast of Greenland were actually bent upward as the center bent downward from the weight of the ice. As a result when a lot of ice melts the center rises and the edge falls.
Eventually if the island stays ice free for about 30,000 years, maybe longer, the center and edges will resume their pre ice sheet altitudes and the island will look like it did before the first ice age some 2.5 million years ago.
I don't think I will be around in 30,000 years to see what a 'normal' Greenland looks like _________________ 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
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