Guest commentary from Spencer Weart, science historian
Despite the recent announcement that the discharge from some Antarctic glaciers is accelerating, we often hear people remarking that parts of Antarctica are getting colder, and indeed the ice pack in the Southern Ocean around Antarctica has actually been getting bigger. Doesn’t this contradict the calculations that greenhouse gases are warming the globe? Not at all, because a cold Antarctica is just what calculations predict… and have predicted for the past quarter century.
It’s not just that Antarctica is covered with a gazillion tons of ice, although that certainly helps keep it cold. The ocean also plays a role, which is doubly important because of the way it has delayed the world’s recognition of global warming.
When the first rudimentary models of climate change were developed in the early 1970s, some modelers pointed out that as the increase of greenhouse gases added heat to the atmosphere, much of the energy would be absorbed into the upper layer of the oceans. While the water was warming up, the world’s perception of climate change would be delayed. Up to this point most calculations had started with a doubled CO2 level and figured out how the world’s temperature would look in equilibrium. But in the real world, when the rising level of gas reached that point the system would still be a long way from equilibrium. “We may not be given a warning until the CO2 loading is such that an appreciable climate change is inevitable,” a National Academy of Sciences panel warned in 1979.(1)
Modelers took a closer look and noticed some complications. As greenhouse gases increase, the heat seeps gradually deeper and deeper into the oceans. But when larger volumes of water are brought into play, they bring a larger heat capacity. Thus as the years passed, the atmospheric warming would increasingly lag behind what would happen if there were no oceans. In 1980 a New York University group reported that “the influence of deep sea thermal storage could delay the full value of temperature increment predicted by equilibrium models by 10 to 20 years” just between 1980 and 2000 A.D. (2)
The delay would not be the same everywhere. After all, the Southern Hemisphere is mostly ocean, whereas land occupies a good part of the Northern Hemisphere. A model constructed by Stephen Schneider and Thompson, highly simplified in modern terms but sophisticated for its time, suggested that the Southern Hemisphere would experience delays decades longer than the Northern. Schneider and Thompson warned that if people compared observations with what would be expected from a simple equilibrium model, “we may still be misled… in the decade A.D. 2000-2010.” (3)
The pioneer climate modelers Kirk Bryan and Syukuro Manabe took up the question with a more detailed model that revealed an additional effect. In the Southern Ocean around Antarctica the mixing of water went deeper than in Northern waters, so more volumes of water were brought into play earlier. In their model, around Antarctica “there is no warming at the sea surface, and even a slight cooling over the 50-year duration of the experiment.” (4) In the twenty years since, computer models have improved by orders of magnitude, but they continue to show that Antarctica cannot be expected to warm up very significantly until long after the rest of the world’s climate is radically changed.
Bottom line: A cold Antarctica and Southern Ocean do not contradict our models of global warming. For a long time the models have predicted just that.
(1) National Academy of Sciences, Climate Research Board (1979). Carbon Dioxide and Climate: A Scientific Assessment (Jule Charney, Chair). Washington, DC: National Academy of Sciences.
(2) Martin I. Hoffert, et al. (1980) J. Geophysical Research 85: 6667-6679.
(3) Stephen H. Schneider and S.L. Thompson (1981) J. Geophysical Research 86: 3135-3147.
(4) Kirk Bryan et al. (1988). J. Physical Oceanography 18: 851-67. For the story overall see Syukuro Manabe and Ronald J. Stouffer (2007) Journal of the Meteorological Society of Japan 85B: 385-403.
#396 Cobblyworlds
“The minima is set in the Arctic Basin, not Baffin Sea (which is ice-free in September), so any increase there is not really relevant to trying to figure out what last year means for the future.”
You may be right. But I interpret greater expansion at the edges as meaning more thickness at the center. That doesn’t have to be the case, but I believe that it is most of the time.
gusbob posts:
[[***The energy has travelled a long ways, and we know that the neutrinos emerge much more rapidly than do the photons, etc. This would not be the case for a near-surface source.***
Do we know that from the sun’s observations or from supernova observations?]]
From nuclear physics. Sunlight is “fossil light,” a photon takes something like a million years to get from the core to the surface, being absorbed and reemitted in (nearly but not quite) random directions many times a second. Neutrinos are barely absorbed and zip right out.
#401 Tilo Reber,
Greater expansion at the edges doesn’t necessarily mean more thickening at the centre. The processes of growth of thin ice on open water and additional thickness on perenial ice are not the same. In the reverse process – the gross reduction in ice-volume and extent, Bitz & Roe show that the loss of thick ice is faster than thin, they propose that this is because of the physical properties of the ice. My post 386 reply to M Ward, links to the paper(preprint). Their comments about equilibrium response times apply in this case, thin ice is expected to grow rapidly over the winter, and to re-gain thicker ice will take longer than a winter – to do that the recent years trend in summer extent will need to reverse.
What we’re headed for (on an unknown timescale) is a seasonal ice cap, you won’t see winter ice-free conditions under current levels of greenhouse gasses, as outgoing longwave will cool the Arctic too much. It’s quite feasible that for some time we’ll have an ice sheet that grows each winter and may have the sort of extent we see now (winter cooling is set by OLR and incoming atmosphere/ocean heat fluxes). We could even have a period where some summers you have a remnant ice-sheet, others an almost totally ice-free ocean. But the message of a seasonally ice-free Arctic is that we cannot take comfort in the presence of a winter ice sheet. I’m not a professional but for some months now all of my reading has supported the supposition that ice thickness is a crucial factor in resisting the melt impact of insolation during the melt season.
I’ve previously been using a combination of the PIOMAS model and QuickScat to try to get a picture of the current thickness. I’d been hoping that this cold winter might help add thickness, I found some support for that, but I seriously doubt it’ll be enough. Now that Wayne in post 389 has pointed me to the National Ice Centre, I’ve found that on a snapshot view of a few areas in the Arctic Basin I have been over-estimating thickness. To get a wider view in context of the recent past will take me much more time.
2 corrections:
I should have referred to the Arctic being virtually ice free THIS year, not next. And it is of course Baffin Bay. – Rapid posting in a rushed lunchbreak. Doh! ;)
BPL: From nuclear physics. Sunlight is “fossil light,” a photon takes something like a million years to get from the core to the surface, being absorbed and reemitted in (nearly but not quite) random directions many times a second. Neutrinos are barely absorbed and zip right out.
Thanks but that doesn’t answer the question.
gusbob — okay, what was the question?
“Greater expansion at the edges doesn’t necessarily mean more thickening at the centre.”
I believe that is what I said also. Although if your argument is that it doesn’t mean a thickening the majority of the time, I would have to disagree.
“and to re-gain thicker ice will take longer than a winter”
I wasn’t trying to say that all the thick ice that was lost will be regained this winter. I’m sure that it won’t. I’m only saying that there is a good chance that some that thickness will be regained this winter.
“But the message of a seasonally ice-free Arctic is that we cannot take comfort in the presence of a winter ice sheet.”
I don’t believe that we are headed to a seasonally ice free arctic. We have had the NW passage open in the past. The fact that it opened last year is simply an event that has happened may times before, and is not a guarantee of a trend that will continue. I don’t think that we can make too much out of a 30 year record. And to say that it will continue because of AGW and the level of CO2 is to use a circular argument.
Tilo Reber (406) states And to say that it will continue because of AGW and the level of CO2 is to use a circular argument.
Not so. It is a direct statement of causality.
#406 Tilo Reber,
You say:
“And to say that it will continue because of AGW and the level of CO2 is to use a circular argument”
That is incorrect.
There are good physical reasons to expect CO2 increases to cause higher temperatures. And the water vapour amplification effect applies as much to solar/volcanic, and other factors impacting insolation, as it does to increased greenhouse gasses like CO2 affecting outgoing longwave.
Quite possibly this year, very probably within ten years I think we will see a rapid switch to a seasonally ice-free Arctic. I also think that Lindsay and Zhang were probably correct when they proposed in 2005 that the tipping point had been passed around 1990, “The Thinning of Arctic Sea Ice, 1988–2003: Have We Passed a Tipping Point?” http://psc.apl.washington.edu/lindsay/pdf_files/tipping_point.pdf I don’t think last years loss was predictable, in theory any weather event since 1995ish could have caused that, but the further the thinning went the less notable a weather event it would have taken.
The picture painted by National Ice Centre(NIC) and QuikScat does not look good. It doesn’t suggest significant thickening, but we’ll see within a few months if anything odd will happen this year. Take a look at these from the NIC, zone Hi West Arctic 2:
2003, a typical year.
http://www.natice.noaa.gov/pub/West_Arctic/Hi_West/Hi_West_two/2003/hiw2030310color.jpg
2007 same time last year:
http://www.natice.noaa.gov/pub/West_Arctic/Hi_West/Hi_West_two/2007/hiw2070305color.jpg
and about now:
http://www.natice.noaa.gov/pub/West_Arctic/Hi_West/Hi_West_two/2008/hiw2080310color.pdf
The “Egg Code” is explained here: http://www.natice.noaa.gov/egg_code/index.html
And NIC’s Arctic site is here: http://psc.apl.washington.edu/IDAO/model.html
Expert analysis of ice states including thickness categories.
When was the Northwest Passage last open as it was last year?
And what is your reference?
I do hope you weren’t thinking of Amundsen 1906(2 winters stuck in ice), or that Chinese Navy Circum-navigation (traced to a dubious source). According to Overpeck et al “There is no paleoclimatic evidence for a seasonally ice free Arctic during the last 800 millennia.” http://marine.rutgers.edu/~francis/pres/OverpecketalEOS05.pdf
Another popular report of glacier shrinkage:
http://news.bbc.co.uk/2/hi/in_depth/7299561.stm
with largest losses in Europe.
Bad news for those predicting a rebound in Arctic ice pack:
Similar to comment #410, but has a useful graphic showing loss of old ice:
http://news.bbc.co.uk/2/hi/science/nature/7303385.stm
All the graphics from the NASA presentation are here.
Thanks for the links. I really should have said, “Bad news for us all.”
On this page http://uwnews.washington.edu/ni/article.asp?articleID=36894 there’s a link to a pdf copy of the paper behind that article. Nghiem et al 2007 “Rapid reduction of Arctic perennial sea ice” GRL, VOL. 34, L19504, doi:10.1029/2007GL031138, 2007.
Check out figure 3.
Well if we can’t avoid “interesting times” we can at least endeavour not to come to the attention of those in authority, and to not find that which we seek. ;)
Arctic Pollution Dates to 1800s
http://www.livescience.com/environment/080319-arctic-haze.html
Re the Nghiem et al “Rapid reduction of Arctic perennial sea ice” paper, it only looks at the state of Arctic ice to March 2007. It doesn’t even include last summer’s melt!
Followup to 261:
Re:417 Part of the Wilkins Ice Shelf collapsed today.
http://news.aol.com/story/_a/massive-ice-chunk-collapses-in/20080325150409990001
Yeah the Antarctic is cold, but it’s starting to follow in step with the rest of the world as predicted,
Links to the NSIDC and BAS press releases here. Watch the BAS video. Superb (and sobering) images.
Apparent sudden lead (ice fissure) appearance in High Arctic.
IMHO probably just apparent, not real.
From National Ice Centre:
Hi Arctic West 2, 10-14/3/08: http://www.natice.noaa.gov/pub/West_Arctic/Hi_West/Hi_West_two/2008/hiw2080310bw.pdf
Hi Arctic West 2, 17-21/3/08: http://www.natice.noaa.gov/pub/West_Arctic/Hi_West/Hi_West_two/2008/hiw2080317bw.pdf
Between these 2 analyses about 9 leads suddenly appear. I had previously emailed NIC about the apparent changes and the reply (coincidentally from the same analyst) advises that whilst there is some deformation of the first year ice, the NIC are also providing more detail to document this year’s melt.
QuikScat doesn’t have the resolution needed to confirm the presence of these leads that were not reported prior to 17/3/08. I’ve tried inverting the colours and playing with contrast, but even that doesn’t reveal such fine structure. It’s possible that someone with polar orbiting satellite IR images may be able to say more, as the images from Environment Canada do show such detail.
http://www.weatheroffice.gc.ca/satellite/index_e.html
But I think I’ve noticed such leads on earlier Env-Canada source Polar IR images. So I am assuming that the appearance of these leads is due to increased reporting detail from the NIC.
If anyone can show that these leads have appeared suddenly, feel free to shake me from my complacency. :)
Re #398: Hear hear Nick. I think it’s fair to say we can actually ‘see’ inside the Sun, for one, widely accepted as reasonable, notion of ‘seeing’:
http://en.wikipedia.org/wiki/Helioseismology
Is this the beginning of the beginning? While the Bering Sea is only showing the slightest sign of the warm water thrust that seemed to presage last years melt
http://lwf.ncdc.noaa.gov/oa/climate/research/sst/ani-weekly.html
the SST warming south and west of Greenland nudging towards Baffin / Newfoundland Bay seems to have led to the loss of 250,000sqkm of ice extent quite rapidly over the last couple of weeks.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.4.html
Re #422
The present rate of decrease appears to be faster than last year, with the substantial reduction in perennial ice over the winter, this summer could be interesting.
#422 Nigel, Ya the melt started sometimes last week, the really big unknown story
is Arctic clear air, still prevailing later than usual. Is this because of the new ice which allowed the bromides to escape steadily instead of a sudden burst? Time will confirm shortly,
meantime, UK extreme sport fans should be proud of Hannah (no longer there) and Ben Saunders, as he gives a direct view of the big blue Arctic Ocean sky, a direct account is always helpful in understanding remote sensing. Thanks and Good luck Ben!
http://north.bensaunders.com/journal/entry/windchill-31-03-2008-18-30-39/
From the original commentary above:
“Bottom line: A cold Antarctica and Southern Ocean do not contradict our models of global warming. For a long time the models have predicted just that.”
Now we have:
“A chunk of ice the size of the Isle of Man has started to break away from Antarctica in what scientists say is further evidence of a warming climate.”
So… which is it? The models can’t predict both a cold Antarctica and a warm Antarctica at the same time, unless they are worthless. Is this contradiction that hard to see?
#425 Bill,
The models don’t predict substantial warming in the continent of Antarctica at this stage, but the Antarctic Peninsular is not continental, its a peninsular, which by definition sticks out into a body of water (the Southern Ocean). And the models show warming of the sea.
i.e. there is no contradiction, the models are not worthless.
#422 – 424. Nigel/Phil/Wayne.
From area/extent alone I see nothing remarkable at present. From Cryosphere Today:
Okhotsk – down.
Bering – up.
Baffin/Newfoundland – down (small jump up recently).
Greenland – level.
Barents – up (small drop down recently).
And in the key area for the Summer minima, the Arctic Basin – no change as yet (which I maintain is to be expected).
Could you point to specifics if you see anything unusual in extent/area?
NASA are starting an intensive study of pollution haze in the Arctic spring: http://www.nasa-usa.de/home/hqnews/2008/apr/HQ_08091_ARCTAS.html
Watch the NASA press release page because in the March media teleconference they said more detail about ice-thickness would follow in early April.
Bill, There is no contradiction. Try reading the article. It clearly states that the issue is in how the ocean responds to the increased energy input. Over time, the entire Earth, including Antarctica, will warm. That’s what the models predict. Over time, you will have fluctuations–that’s weather. But the trends are clear.
Bill writes:
[[So… which is it? The models can’t predict both a cold Antarctica and a warm Antarctica at the same time, unless they are worthless. Is this contradiction that hard to see?]]
Your contradiction depends on a fallacy of equivocation. The evidence is that Antarctica is slowly warming. That’s not the same as saying it’s warm.
Bill (425) — The ‘chunk of ice’ is on the Antarctic Peninsula, much further north than the mainland. The cold portion of Antarctica, and staying that way, is the interior of the mainland.
Re Bill’s question in 425:
It’s not a contradiction to observe that Antarctica is cold but warming. Apparently the system is so sensitive to temperature changes that even a little warming can cause the WAIS to disintegrate.
What everyone doesn’t seem to realise is that we stop burning oil, and the worlds ecconomy goes down the pan. If the worlds ecconomy goes down the pan, then all you climate scientists will be out of a job, because there will be nothing to fund you, and your job, and mine, will be survival farming. There are loads of real problems for you to solve. The most pressing is how do we stop the worlds population growing and growing – 10 bilion very soon? Now if we could get the Pope to say, ‘Ok condoms aren’t such a bad idea’ then thered be a lot less demand on the worlds rescources and you’d get your drop off in CO2. The you can all concentrate on global cooling, and do your science on that. Lets get down to around just 1 billion on the world over the next 50 years or so, because if we don’t, nature usually finds a way doesn’t it chaps?
Oh yes, and despite what ou may think that we will stop burning oil because its ‘dangerous’ tothe environment. We won’t. Was talking to some people on the oil industry last October. There are more and more drill sites being drilled, esp in Russia at the moment. We are an oil based ecconmony, get over it. Until the Energy return over investment drops to 1, we will continue to do our utmost to squeeze every last drop of it from the planet. And when thats done, we will then dig up every last nugget of Uranium out as well, until the EROI on that drops to 1 as well. All you climate fear artists forget one thing. Politicians are business for 5-10 years only. They tell people what the want to hear to get u the ladder. Then when they finally learn the truth, they can’t back track for fear of looking thick. Sorry 2 things actually, I was forgetting pschology. Dont we just LOVE politicians lying to us, it makes us FEEL GGOD..
#425 Warm and cold in the contexts you have supplied are somewhat relative and in Antarctica, you also have to be careful about where you mean. I think this article (and especially the figure) give a very good picture of what is currently going on down there.
http://www.nature.com/ngeo/journal/v1/n2/full/ngeo102.html
#431/432 Pete,
“climate fear artists”
I don’t know what that’s supposed to mean, but I for one agree in general that we’ll continue our fossil fuel dependency until either we run out, or the consequences of climate change hit us so hard that they act as a limiting factor.
Of course we might crack fusion, in which case we should be able to mature and leave the nest properly. But lets leave that aside until it’s at least able to produce more power than it consumes for prolonged periods in a lab test.
At a tangent:
If all life is going to be carbon based (due to the chemical nature of carbon this seems very likely). Then intelligent (as in technologically advanced) life evolves after a long period of deposition of organic carbon in fossil form. So all intelligent life has access to large reserves of fossil fuels, and upon reaching technological maturity proceeds to use these fuels. Then the CO2 emissions caused create substantial and rapid climate change thus impeding further technological development, until the fossil fuels run out. At that point the technologically advanced lifeforms revert to a lower level of technology having no easy cheap energy source.
Thus the Fermi Paradox is answered… ;)
pete writes:
[[What everyone doesn’t seem to realise is that we stop burning oil, and the worlds ecconomy goes down the pan.]]
Nobody is proposing we suddenly stop using oil. We’re just proposing replacing oil (and coal, and natural gas) with other energy sources as fast as possible, and trying to make our economies a little more energy-efficient.
Pete, You speak as if petroleum were the only energy source we could exploit. It is not. You speak as if the current configuration of the economy were they only configuration that could be thriving. This too is false. You presume that a decrease in population will solve all of our problems. It would not. Google “deflation” and read up on the threats of a decreasing population to the economy. All in all, you are pretty seriously misinformed. An economy based on alternative energy sources is not only possible, it could be more prosperous than our current economy. Yes, there are technical issues that must be overcome. However, I have never known of a concerted effort to overcome technical obstacles that has not also born fruit in unanticipated areas. This is a site that concerns itself with science. Science does not tell us what we want to hear, but rather what we need to hear–the truth. And the truth is that climate change is probably the greatest threat to human civilization we will confront in the next century. The way to predict the future is to create the future. The challenge for us now is to create a future that is sustainable–in terms of the evnironment, the economy and the social system. If we fail in that, we won’t have a future worth speaking of.
“Could you point to specifics if you see anything unusual in extent/area?”
Nothing in particular yet, however the Quikscat movie shows so much flow of perennial ice out of the Fram strait and the breakup of the perennial ice in the Beaufort sea this winter leads me to think that a new record low is quite possible.
#420 Re my post.
I was wrong, those leads were real.
There is an interesting fissure on the Arctic coast of the Canadian Archipelago. Given it’s location and the time it could be an area to watch for this summer.
From QuikScat(1) day 95 there’s an opening along the edge of the ice pack off Banks Island. By day 101 it’s between Prince Patrick Island and McKenzie King Island. It’s been visible on Environment Canada’s IR composite(2) for longer than that, but QSkat seems to show when things are substantial. Viewing a slideshow indicates it’s growing and spreading off the coast of Ellesmere island.
1) http://manati.orbit.nesdis.noaa.gov/cgi-bin/qscat_ice.pl Arctic
2) http://www.weatheroffice.gc.ca/satellite/index_e.html HRPT (NOAA polar orbiting), Canadian Arctic Composite, 10.7um IR.
Re #439
Yes I’ve been watching that area with interest, all the fragmentation and leads could make for interesting developments. NSIDC has started a page on Arctic sea ice analysis (see below), in particular the graph of perennial ice freeboard is very
interesting.
http://www.nsidc.org/arcticseaicenews/index.html
This article in the Chronicle Herald describes more ice shelf woes:
#439-#440 Cobbly and Phil
These big Canadian archipelago leads usually occurred in May, one month ahead of time, they will be bigger with the coming full moon. Temperatures UP Here have been extremely warm, Yellowknife was +11 C about 17 degrees above average. A vaster area of snow melt has just happened as well especially in Western Canada. High Arctic likewise, from unrelenting sunshine
unprecedented in my memory, have warmed the Arctic surface dramatically, since after all ,
the Canadian Arctic was the coldest spot in the world, a mere month ago, the changeover has been dramatic. The pattern is clear, literally and figuratively;
Great Arctic Ocean ice melt of 2007 (few clouds), a rapid refreeze of the Arctic Ocean during the long night of 07-08 (few clouds), and a very warm spring (yes, again from fewer clouds). The dye is set it seems, a great re-melt has started.
Wayne, thanks for the feedback, why do you expect bigger leads with the full moon, tidal effects?
#443- Phil, correct, Tidal effects although apparently small, have had huge impacts during the full or new moon. Documented especially by Arctic Ocean ice dwellers, and by those who made it a habit to watch Polar orbiting HRPT’s for years. On the ice, those extreme sport adventurers, those ascending the Arctic Everest, the North Pole, know it well, its when there are huge compression leads formed, or , sudden forming ridge deformations appear from nowhere, for no other reasons than its the full or new moon.
At about the next full moon watch for yourself, find the tidal wave which creates new leads in this animation sequence, tell me about it when you see it…
http://www.weatheroffice.gc.ca/satellite/animateweb_e.html?imagetype=satellite&imagen
Re #444
Thanks Wayne, I wasn’t sure what the magnitude of tides would be up there.
I couldn’t get anything from your link, I’d be watching around the full moon.
The periodic opening and closing of leads can be seen across the basin, I’ve noticed it from slideshows of the last few years from QuickScat(QS).
However I’ve not seen anything as extensive as what is happening now.
See QS and it’s apparent that there’s a fissure between the remaining ice pack and the Canadian Archipelago.
Day 104 (today)
http://manati.orbit.nesdis.noaa.gov/ice_image21/D08104.NHEIMSK.GIF
Yet for example day 204 2007, not the same length of fissure:
http://manati.orbit.nesdis.noaa.gov/ice_image21/2007/D07204.NHEIMSK.GIF
(There are already increasing areas of ice free water in the Archipelago as seen from QS)
The fissure is better seen on the Env Canada NOAA images, but I lack an archive of those so can’t check back. (As the 3 people I’ve emailed aren’t overly concerned about it, I’ll post fully what I’ve been seeing). This fissure (lead) runs from Banks Island right the way to the North of Greenland where heavily broken ice is being rafted into the Fram Strait. This can be best be seen from the NOAA images from Environment Canada, although as they’re patchy you may have to keep checking.
10.7um
: http://www.weatheroffice.gc.ca/data/satellite/hrpt_dfo_ir_100.jpg
Visible: http://www.weatheroffice.gc.ca/data/satellite/hrpt_dfo_nir_100.jpg
3um: http://www.weatheroffice.gc.ca/data/satellite/hrpt_dfo_03_100.jpg
I have been keeping images and will try to post a link to 2 excellent overviews shortly (only just got fully back on the ‘net yesterday).
This fissure opened up last week too early to appear on the National Ice Service analyses. It initially followed the boundary of zones D and X (thick sea and landfast ice respectively) on this analysis: http://www.natice.noaa.gov/pub/West_Arctic/Canadian_Arctic_West/2008/canw080407color.pdf
Areas B and C, to the left of the D/X boundary show the very start of it’s opening.
I’d been hoping it would prove to be transitory, but it’s sticking around for much longer than I like given the regional warming described by Wayne and the onset of spring. The Transpolar drift should pin the ice to the North of Greenland/Baffin area of the Archipelago. But I have visions now of the entire mass collapsing into the Arctic Ocean come the summer.
Last year the “kick” ahead of schedule occurred in June, look what that caused. Now we seem to be seeing it ahead of the normal melt season on top of the damage caused last year. I know that NSIDC caution that a similar event to 2007 seemed on the cards in 2006 due to weather – but didn’t happen. However in the face of the current state of the ice-cap that doesn’t reassure me.
Cobbly and Phil, check my website, top news article, and get a treat, and see what a lunar under the ice tidal wave
looks like….
The Quikscat images continue to strengthen my feeling that there will be a further reduction in arctic sea ice this summer. The fragmentation in the Beaufort sea appears to be proceeding apace with the fragmented perennial ice moving rapidly in the gyre. Also attenuation of perennial ice to the north of Greenland via the Fram Strait appears to be continuing.
I’ve attached today’s (day 119) image and day 90 to show what’s happened over the last month, and an image from last year, day 100 for comparison.
http://manati.orbit.nesdis.noaa.gov/ice_image21/D08119.NHEAVEH.GIF
http://manati.orbit.nesdis.noaa.gov/ice_image21/D08090.NHEAVEH.GIF
http://manati.orbit.nesdis.noaa.gov/ice_image21/2007/D07100.NHEAVEH.GIF
It’s quite easy to see a possible absence of sea ice by next summer!
From http://blogs.nature.com/climatefeedback/2008/12/agu_2008_evidence_that_antarct.html
New research presented at the AGU today suggests that the entire Antarctic continent may have warmed significantly over the past 50 years. The study, led by Eric Steig of the University of Washington in Seattle and soon to be published in Nature, calls into question existing lines of evidence that show the region has mostly cooled over the past half-century.
??
[Response: That paper is in press, and I’m not allowed to comment on it per agreement with Nature until it is published. The claim that our result “calls into question existing lines of evidence that show the region has mostly cooled over the past half-century” is wrong though. Wait until the paper is published and I’ll say more.–eric]