A few people have already remarked on some pretty surprising numbers in Arctic sea ice extent this year (the New York Times has also noticed). The minimum extent is usually in early to mid September, but this year, conditions by Aug 9 had already beaten all previous record minima. Given that there is at least a few more weeks of melting to go, it looks like the record set in 2005 will be unequivocally surpassed. It could be interesting to follow especially in light of model predictions discussed previously.
There are a number of places to go to get Arctic sea ice information. Cryosphere Today has good anomaly plots. The Naval Sea ice center has a few different algorithms (different ways of processing the data) that give some sense of the observational uncertainty, and the National Snow and Ice Data Center give monthly updates. All of them show pretty much the same thing.
Just to give a sense of how dramatic the changes have been over the last 28 years, the figures below show the minimum ice extent in September 1979, and the situation today (Aug 9, 2007).
The reduction is around 1.2 million square km of ice, a little bit larger than the size of California and Texas combined.
Update: As noted by Andy Revkin below, some of the discussion is about ice extent and some is about ice area. The Cryosphere Today numbers are for area. The difference is whether you count ‘leads’ (the small amounts of water between ice floes) as being ice or water – for the area calculation they are not included with the ice, for the extent calculation they are.
Update: From the comments: NSIDC will now be tracking this on a weekly basis.
Sphere says
A significant event, such as a major pyroclastic in Alaska, might cause a full recovery in the ice this winter. Given that there hasn’t been a full recovery for three or four years now, absent a major event is it possible for a reasonable recovery to happen this winter from normal variation? In other words, aren’t we pretty sure of starting next year with a deficit? (Major volcanic explosions seem to have approximately 18 months of effect.)
Nigel Williams says
If the fragment of sea surface ice hanging on between the Kara Sea and the East Siberian Sea goes in the next few weeks…
http://arctic.atmos.uiuc.edu/cryosphere/
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.1.html
will that allow the establishment of a surface-water wind-driven gyre between the Atlantic and Pacific carrying the warm water already pushing so hard along that coast?
http://www.emc.ncep.noaa.gov/research/cmb/sst_analysis/images/wkanomv2.png
And if that happens – if increasingly dynamic as well as warmer sea surface conditions establish in the next few weeks will it not significantly reduce the opportunities for re-freezing of the surface waters? I can imagine a lot of fog, and very little freezing going on – like on the Grand Banks off New Foundland.
Would that be a tipping point?
Sphere says
Re #202: “And if that happens – if increasingly dynamic as well as warmer sea surface conditions establish in the next few weeks will it not significantly reduce the opportunities for re-freezing of the surface waters? I can imagine a lot of fog, and very little freezing going on – like on the Grand Banks off New Foundland.
Would that be a tipping point?”
I was just thinking about the shipping and geopolitical implications… Interesting question.
(But I do think that the tipping point has already been reached — barring geological intervention.)
Steele says
With posters talking about climate tipping points, why would my statement about no sunspots and climate cooling be removed? Why is censorship needed when posts are respectful?
[hint: see comment #7 of our comment policy]
Steele says
Chris,
I am a biologist. Here is a link to my field station- http://www.sfsu.edu/~sierra/ I am seeking the truth, but do not buy the CO2 hypothesis. I had hoped that this would be a place for debate but I have had my posts blocked and edited. I would think if the evidence was so strong there would be no need for such tactics.
[again, please see comment #7 of our comment policy]
Steele says
I would think if the evidence was so strong there would be no need for such tactics.
[again, please see comment #7 of our comment policy]
After reading comment #7 it would appear anything that disagrees with the CO2 hypothesis for warming could be labeled specious or misleading. How then does one have a debate or question your CO2 assumptions or omissions without be censored?
J.S. McIntyre says
re 199
Re #186: “While the Ross touches both East and West Antarctica, wouldn’t the result be more impactful to East Antarctica?”
The West Antarctic is considered less stable because more of the ice is below sea level. (I think there is also a slope more conductive to ice flow, but am not sure on that.) It is expected that it will require less climatic change for it to collapse.
=====================
I understand that. Part of my question focused on the fact the West Antarctic Penninsula, if you look at the map I provided, is apparently less affected by the Ross than it is by the Larsen and a number of smaller shelfs butted up against the penninsula proper.
http://nsidc.org/cgi-bin/atlas_south?zoomdir=0&zoomsize=2&zoom_to=&glossary_term=&layer=south_pole_geographic&imgxy=250.0+250.0&imgext=-3253263.394320+-1735073.810304+1265157.986680+2783347.570696&map=%2FWEB%2FINTERNET%2FMMS%2Fatlas%2Fcryosphere_atlas_south.map&savequery=true&mapext=shapes&layer=land&layer=coastlines&layer=copyright&layer=&layer=glacier_outlines&layer=sea_ice_extent_01&layer=snow_extent_01
http://en.wikipedia.org/wiki/Image:Ant-pen_map.png
The majority of current glacial reduction in the WAP is apparently happening in those areas, and it would seem the Ronne and its status would be more important to the WAP than the Ross Shelf, which, as I pointed out, is a thousand kilometers from the Ronne and the Weddell sea … and a thousand kilometers from the base of the WAP.
Sphere says
Re #206: “The majority of current glacial reduction in the WAP is apparently happening in those areas, and it would seem the Ronne and its status would be more important to the WAP than the Ross Shelf, which, as I pointed out, is a thousand kilometers from the Ronne and the Weddell sea … and a thousand kilometers from the base of the WAP.”
I guess we were talking past each other then. Your analysis of the WAP seems reasonable. The WAP certainly is being effected by the breakup of Larsen B — as well as by general warming. I don’t know how much land ice is contained in the WAP. If it disintegrates is this likely to raise the sea level sufficiently to dislodge the West Antarctic ice?
J.S. McIntyre says
Re #206: “The majority of current glacial reduction in the WAP is apparently happening in those areas, and it would seem the Ronne and its status would be more important to the WAP than the Ross Shelf, which, as I pointed out, is a thousand kilometers from the Ronne and the Weddell sea … and a thousand kilometers from the base of the WAP.”
I guess we were talking past each other then. Your analysis of the WAP seems reasonable. The WAP certainly is being effected by the breakup of Larsen B — as well as by general warming. I don’t know how much land ice is contained in the WAP. If it disintegrates is this likely to raise the sea level sufficiently to dislodge the West Antarctic ice?
======================
Actually, my query was more along the lines of wanting a bit of clarification in relation to what I’ve heard of what is occuring there in relation to the geographic references re the distance of the Ross Shelf from the WAP, as well as its location well within the Antarctic circle as opposed to the WAPs more northerly position (It is the only part of the continent that pokes outside of the Antarctice circle.).
Regarding your closing question, not sure.
Recall reading somewhere – maybe here – that as the sea level rises and the leading edges of glaciers retreat to the shoreline that seawater will likely seap under the glaciers, floating them to some degree and speeding up their flow. I believe this was pertaining to Greenland, though obviously this would apply to Antarctica, as well, speeding up the already increased flow of the glaciers on the WAP from the loss of shelf ice.
The WAP is obviously the most likely to go first, as we’re already seeing:
https://www.realclimate.org/index.php/archives/2006/03/significant-warming-of-the-antarctic-winter-troposphere/
https://www.realclimate.org/index.php/archives/2005/04/retreating-glacier-fronts-on-the-antarctic-peninsula-over-the-past-half-century/
See also:
http://www.giss.nasa.gov/research/news/20041006/
I believe the Ross and Ronne are both a lot more stable than Larsen and the other shelves actually butted up against the actual WAP (of course, this may be more a case of stability by comparison, and not by historical norms.) As for West Antarctica proper, I really do no know. But others have commented that the entire continent is showing increasing evidence of warming, so I do not doubt something more dramatic may be happening there, as well, which was why I was curious about your reference to the Ross.
Relating to the larger, inland sections, there was an interesting, but perhaps outdated at this point, blurb in American Scientist a few years back, discussing the stability of that inland ice sheet in Greenland compared to the coastal regions:
=========
Greenland or Whiteland?
David Schneider
According to most experts, global warming will lead to some worrisome changes in the not-too-distant future. One that is expected to become quite troubling, at least for coastal residents, is rising sea level. The latest assessment of the Intergovernmental Panel on Climate Change, for example, suggests that the world may see anywhere from 11 to 77 centimeters’ rise in sea level before the century runs out. One of the several sources for all this water, the panel’s scientists concluded, will be the partial loss of the Greenland ice sheet. That view seems quite consistent with recent news reports of Greenland’s slushiness, 2002 having been a record year for summer melting there. But a new study suggests that the Greenland ice sheet may, in fact, grow as the climate warms over the next several decades, which would modestly diminish the rate at which the oceans are expected to rise.
http://www.americanscientist.org/template/AssetDetail/assetid/26024
=============
See also more current info here:
https://www.realclimate.org/index.php/archives/2007/07/making-sense-of-greenlands-ice/
Sphere says
Re #209: “I believe the Ross and Ronne are both a lot more stable than Larsen and the other shelves actually butted up against the actual WAP (of course, this may be more a case of stability by comparison, and not by historical norms.) As for West Antarctica proper, I really do no know. But others have commented that the entire continent is showing increasing evidence of warming, so I do not doubt something more dramatic may be happening there, as well, which was why I was curious about your reference to the Ross.”
The Larsen B breakup was caused by summer ice surface melt forming pools which flowed into the sheet and refroze (splitting the sheet). As long as summer temperatures over the Ross and Ronne remain largely below freezing a sudden disintegration like Larsen B isn’t very likely. (Wouldn’t know about other forms of breakup…)
I’ve read somewhere that both Greenland and East Antarctica are largely mountain bound; which is a strong stabilizing influence — but West Antarctica doesn’t have mountains between the major sheet and the sea.
Aside from jutting outside the polar region, I don’t think the WAP has bounding mountains — but rather a mountain spine. The combination would make it particularly unstable.
Alastair McDonald says
NASA have found melting of the Ross Ice sheet. See:
http://www.nasa.gov/vision/earth/lookingatearth/arctic-20070515.html
and
http://alaskareport.com/do77811_antarctica.htm
That is based on conditions over two years ago. It would be interesting to see what happened last year and next.
Sphere says
Re #211: “That is based on conditions over two years ago. It would be interesting to see what happened last year and next.”
A brief excursion into Googleland came up with nothing new…
There’s got to be primary data out there somewhere, but I’ve no idea what the magic incantation would be.
Repeated ice melt along Ross’s inland boundary would be “big news.”
(Of course, no one else would even understand that it was news at all….)
That melt picture from 2005 has me wondering something…why would it melt at the inland boundary before further north?
David B. Benson says
Steele — I respectufully suggest you go to the top of the page and click on
Start Here.
Sphere says
Cryosphere Today is basically reporting “screw you”. There’s no hint of recovery before the normal end of melt — in fact, it looks like leveling may even be late. http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.1.html
Is there any reason to think this is not the butterfly catastrophe? (A butterfly catastrophe is a topological notion — not to be confused with the notion of a butterfly in China effecting weather in New York. Basically, it’s when the equipotential for an event surface curves under and there is no meta-stable state. There is then no choice but to leave the potential surface and fall to the underlying equipotential surface — a catastrophe.)
Alastair McDonald says
Re #212 Sphere,
I am fairly sure that the melting at the base of the Transantarctic Mountains is due to katabatic winds. Normally these are cold winds, but they can be warm as well. See the Bora Wind shown as the last diagram on this web page: http://snrs.unl.edu/amet498/wenzl/katabatic.html
John P. says
Melting is not slowing as it should, in fact, it seems to be speeding. I also have the impression that the melting season will be longer than other years. There’s a lot of heat in that water/air, lots of inertia.
Alastair McDonald says
Re #215 I should have said the melting at the base of the Transantarctic Mountains is probably caused by katabatic Foehn winds. See: http://en.wikipedia.org/wiki/F%C3%B6hn_wind
John L. McCormick says
RE # 216
John P.,
The Chapman graph indicates a melt back of 1.75 million sq. mi since the mid-May high point.
Using the Rothrock estimate of diminished ice thickness from 1958 3.1 m average to 1.8 m average in the 1990s, a very rough calculation is about 8.2 billion tons of ice melt.
Thinning of the Arctic Sea-Ice Cover
D.A. Rothrock, Y. Yu, and G.A. Maykut
University of Washington, Seattle, Washington
http://psc.apl.washington.edu/thinning/Rothrock_Thinn.pdf
Converting ice to liquid at 32 deg F requires 288,000 Btu/ton. Thus, the heat of fusion to change states was about 2.4 trillion Btu since May.
The average thickness continues to decrease as multi-year ice is replaced by new ice each freeze season.
Assuming the heat transported to the Arctic and generated in the Arctic by solar incidence will not diminish considerably during the next twelve months, one could assume next year melt back will be greater than this year because less heat of fusion will be required to melt the new ice and the uncommitted heat will be available to melt more multi-year ice.
I am not a scientist (as you can tell) but this looks to me like the Artic sea ice entering a tipping point phase.
Fergus Brown says
Since this post went up, the anomaly in the Antarctic on CT has dropped to (nominally) zero, and in the Arctic has dropped to around -2.25M km2. I was wondering if this is a record for the global sea ice anomaly? Anyone know? Also, I can’t find anything on why sea ice seems to have stopped growing in the Antarctic, about three or four weeks ealier than last year…
Regards,
Alastair McDonald says
Re #218 The concept of “tipping point” does not seem to be well understood. It occurs in a dynamical system when the forcings from the positive feedbacks exceed those from the negative feedbacks. Normally a dynamic system will be stable with the negative feedbacks dominating. Think of a ball sitting in a saucer. It does not move, because it will have to rise up the side of the saucer and the negative feedback from gravity keeps it steady.
If we could make the saucer flat, then turn it into a dome, the ball would then run away down the side of the dome. The tipping point is when the change from flat to dome happens, and when gravity changes from being a negative to positive feedback.
The tipping point for the Arctic ice happened many years ago when the ice first started to melt. The ice-albedo effect now dominates the behavior of the ice and that is the positive feedback which has taken over. Before the ice disappears there is also a point of no return, which is reached after the tipping point. It seems that we are now past that event too.
It seems obvious to me that we have already passed teh tipping point for the destrucyion of the Greenland ice sheet, but not neccessarily the point of no return. However, when the Arctic Ice has melted, then by your estimate there will be an additional 2.4 trillion Btu entering the Arctic Ocean each year with no ice to melt. With that additional heat in the Arctic region it seems clear to me that it will not be long before the Greenland Ice sheet also passes it point of no return.
John Wegner says
I just wanted to note that there is more Arctic sea ice out there than is being recorded by the Cryosphere Today or the NSIDC.
Here is a Visible satellite picture of the Beaufort Sea from yesterday from the Terra/Modis satellite. This area is supposed to be ice-free according to the software-generated pictures from the NSIDC and the Cryosphere (I assume you believe your own eyes.)
http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2007233/crefl1_143.A2007233221500-2007233222001.4km.jpg
Here is the same picture in false-color where the ice is coded to be Red (note the orange color is cloud-cover.)
http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2007233/crefl1_367.A2007233221500-2007233222001.4km.jpg
Sphere says
Re #220: “If we could make the saucer flat, then turn it into a dome, the ball would then run away down the side of the dome. The tipping point is when the change from flat to dome happens, and when gravity changes from being a negative to positive feedback.”
People use the term tipping point in different ways, although I tend to use your definition. What he is calling a tipping point would be akin to the point where the ball falls off the plate — what I’d call a catastrophe.
Falling off the plate is in a sense a tipping point — the equipotential surface at the edge of the plate is such that there is no meta-stable surface available and the ball tips off the plate.
Hank Roberts says
John, that image seems to me to match up reasonably well with the map, once I rotate one to match the other. Big gap north of Alaska; ice along the shoreline where Canada extends further north.
“Sea ice extent is particularly low in the East Siberian side of the Arctic (the Chukchi and East Siberian Seas) and the Beaufort Sea north of Alaska. Ice in the Canadian Archipelago is also quite low. Along the Atlantic side of the Arctic Ocean, sea ice extent is not as strikingly low, but is still less than normal.” says the map caption.
Sea ice is defined as including areas of broken floating ice and water. The pixel size on the map is larger than the small floating ice chunks; they talk about that issue at NSDIC.
Ike Solem says
Alastair says: “The tipping point for the Arctic ice happened many years ago when the ice first started to melt. The ice-albedo effect now dominates the behavior of the ice and that is the positive feedback which has taken over.”
Things seem to be far more complicated than that. Take a look at Arctic Sea Ice decline in the 21st Century, Bitz, RC, Jan 2007
“As illustrated in Fig 1, the sea ice retreat accelerates during the 21st century as the ice decays and more sunlight is absorbed by the ocean (the positive ice-albedo feedback). Increasing ocean heat transport under the sea ice adds to the melt back. The retreat appears abrupt when natural variability in the ocean heat transport into the Arctic Ocean is anomalously high. We did not find clear evidence of a threshold, which can be difficult to identify given the variability and complexity of the climate system. Therefore we can neither verify or rule-out the existence of a tipping point. Regardless, the rapid declines seen in our runs are a serious concern.
There’s also the role of the atmosphere in the poleward heat transport, as well as the loss-of-insulation effect, which allows the Arctic Ocean to exchange heat with the atmosphere. In the winter, open leads result in more ocean-to-atmosphere heat transfer, and in the summer the effect is in the same direction. See http://www.sciencemag.org/cgi/content/full/315/5818/1533
Estimates are that most (~98%) of the energy supplied annually to the Arctic system is due to atmospheric poleward heat transport. We could speculate that the warming atmosphere causes the sea ice to thin in the Arctic, resulting in increased heat transfer to the atmosphere from the ocean and a resultant increase in the rate of sea ice melting – a stable feedback loop which is amplified by the ice-albedo feedback effect in the summertime. Thinning sea ice is also more susceptible to being piled up by the wind, exposing more of the ocean to the atmosphere – a global warming-induced amplification of the ‘intrinsic natural variabilty’ in the Arctic.
Oddly enough, Roger Pielke Sr. claims that “Thus, it is regional warming, not “global warming” that appears to be the reason for this melting (Indeed, if it were global warming, we should see a similar reduction in Antarctic sea ice coverage, which, however, is not occurring).” (Aug 10 2007 post)
Anyone see any flaws in Dr. Pielke’s reasoning?
Nigel Williams says
Yikes!
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.jpg
When you run along the annual minima on this chart, we see we have another hockey-stick happening right before our eyes!
wayne davidson says
#220 Alastair, I agree with the tipping point scenario, but I don’t think it will happen as easily as within a laboratory experiment. The entire meteorological dynamics have changed since there is a present “colder sector” over the Arctic Ocean remaining ice, contrasted to when not long ago the ice was spread more evenly around the North Pole. This affects what we were use to weatherwise. So far I am seeing a more persistent low over Hudson Bay, and of course everyone has heard about the rain. There is a North Pole centered wobble in met systems rather than a Pole centered merry go round of planetary waves. That ultimately garrantees a summer time cooler wetter zone (Eastern North America, Western Europe) as opposed to a dryer hotter zone (the rest of the Northern Hemisphere). I still would like to see some models show what might happen, longer term with this ice assymetry at the North Pole. Moisture gained ultimately affects global temperatures (seasonal short term), so the run away effect may be not transpire exactly as expected, as such contrarians will still be fooled or try to fool the lay in believing that GW is bunk, despite the overwelming message given by the missing ice at the Pole.
wayne davidson says
223 Hank, Looking at single sat pics of ice often misleads, clouds and contrast settings fool many experts, its wiser to look at the Cryosphere today animation:
http://arctic.atmos.uiuc.edu/cryosphere/sea.ice.movie.2007.mov
Perhaps Mr Wegner and Nigel will apppreciate that the ice moves constantly, even during the dark winter, especially more during summer. The melt down in June was something really rare (“never seen anything like this” is an understatement) I would like to thank the Cryosphere Today guys for their excellent work as well.
horrified observer says
A new update is posted at NSIDC. http://nsidc.org/news/press/2007_seaiceminimum/20070810_index.html
There is a wonderful animation showing icemovement and seasonal depositions. Apperently wind and drift is a heavy influence, ice transported south melts quicker. Packed ice is more resisting.
How is the wheater pattern of the arctic changing by the now open sea? I read that this summer has seen unusual high preassure sunny skies. Is this just wheater or is it influenced by reduced ice? Will drift increase when the caps extent is reduced?
Timothy Chase says
NSIDC wrote:
If the 22 Aug 2007 had been the minimum sea ice extent for the year, relative to 2005, we could “expect” there to be sea ice throughout the summer up to 2031. But if we kept losing it at the same rate until the end of September, relative to 2005, with the minima for the year being 4.6 km^2 relative to the 2005 figure of 5.32, the same rough calculation would tell us 2018.
Sphere says
Re #229: “If the 22 Aug 2007 had been the minimum sea ice extent for the year, relative to 2005, we could “expect” there to be sea ice throughout the summer up to 2031. But if we kept losing it at the same rate until the end of September, relative to 2005, with the minima for the year being 4.6 km^2 relative to the 2005 figure of 5.32, the same rough calculation would tell us 2018.”
And if all the multi-year ice is flushed out through the Greenland Sea this winter then what?
Steve Bloom says
Re #228: As Wayne Davidson noted, this is an unusual year. Since the present behavior hasn’t been modeled, I don’t think the experts will hazard a serious guess until they see what happens over the next couple of years. Of course, at this point a complete summer collapse over a very short time cannot be ruled out.
Re #229: IMHO that rate is much too conservative. Since we’re losing about .06 million km^2/day just now, in no more than another week we’ll probably be waving bye-bye to 4.6 million km^2 through the rear-view mirror. I’ll be bold and guess that we’ll hit about 4.0 this year. I base that on seeing how much ice loss there was in 2005 after the slope of the extent graph had a similar appearance to the present one, and assuming that the melt season won’t go much later this year. But of course this is anybody’s guess. Also note that the extent metric (basically the area within the intact pack ice perimeter) will go off the rails when there ceases to be enough intact ice to define a perimeter.
Re #230: There’s not much multi-year ice left now. AIUI a lot of that will probably persist in place since it’s caught up by the Canadian islands and Greenland.
Steve Bloom says
Beware the Dark Side, Luke!Er, I mean, don’t let RP Sr. confuse you, Ike. If you read down that thread a bit you’ll notice that RC co-author William Connolley made a correction that RP Sr. was forced to accept. William’s day job is as a sea ice modeler for the British Antarctic Survey, meaning that he’s rather more qualified than RP Sr. in this subject area. But in any case RP Sr.’s reasoning is semantic nonsense since there’s no such thing as a global forcing that has even effects across two or more regions. He has a bad habit of trying to shoehorn his memes into facts that won’t fit them.Steve Bloom says
Re #224: Just to add that since RP Sr. was unable to accept William’s correction with any grace, he added this little snark: “The increase in sea ice areal coverage in Antarctica is not predicted.” It’s true as far as it goes, but of course RP Sr. knows that the trend is sufficiently slight that it isn’t statistically significant, i.e. it doesn’t mean anything. The problem is that since RP Sr. is a senior climate scientist with a more-or-less respected lifetime of work behind him, the uninformed reader will tend to be taken in by assertions of that sort. There’s a very strange pathology going on over there, and RP Sr.’s embrace of the “audit” crowd is of a piece with it.
Nigel Williams says
Its incredible watching the spread of 60 percent ice (red) on the UIUC images heading for the pole.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/arctic.jpg
It even looks like the pole itself is now at 80 percent, not 100 percent ice concentration, so even there we are looking at melting ice blocks floating in a warming sea, not a nice solid reassuring sheet of ice with a comforting layer of cold air sitting on top.
Hello New York! Is anybody standing outside the UN every lunch time with hand-outs of these pix and charts?
Steve Bloom says
This AMS presentation from last year by Wieslaw Maslowski (the U.S. Navy’s sea ice modeler) is worth a look. On page six he notes “If this trend persists for another 10 years (and it has through 2005) the Arctic Ocean could be icefree in summer!” While no other sea ice expert has been willing to stick their neck out quite this far, my understanding is that many of them thought Maslowski could be right even before this summer’s abrupt change.
horrified observer says
re 232. The spread of broken ice is more clear at this site http://iup.physik.uni-bremen.de:8084/amsr/arctic_AMSRE_nic.png.
Flyers outside UN would be good. I am horrified by this development and shocked that it is not front page news. Albedo flip right now and a clear message that IPCC and politicians are way off. Do we still have 1000 days?
Jon Kessler says
Would be interesting to see a stat on the reduction of multi year ice since 1979.
Clearly the one year ice does not have he resilience of the multi-year, and it appears we are loosing the multi-year rather rapidly.
I think #231 is probably correct, would help to have rate of multi-year ice reduction data to project when the ice cap will be gone in summer.
Keep up the great work.
John P. says
Re:232
It hasn’t been solid for a while. You can even swim there:
swiming at north pole
Sphere says
Re 232: “It even looks like the pole itself is now at 80 percent, not 100 percent ice concentration, so even there we are looking at melting ice blocks floating in a warming sea, not a nice solid reassuring sheet of ice with a comforting layer of cold air sitting on top.”
Speaking of a warming sea: http://sharaku.eorc.jaxa.jp/cgi-bin/amsr/polar_sst/polar_sst.cgi?lang=e
It’s going to take some time this Fall to dissipate 5 extra degrees.
Vince says
I wonder how the disappearance of Artic Sea Ice will effect the Greenland Icecap, logically one would assume that the open ocean water will absorb a great deal more heat than the artic ice did, that this would lead to a relatively warm sea surrounding Greenland which would accelerate it’s the loss of land ice.
Also, when tipping points are discussed, isn’t there also the issue of methane that’s been trapped in Artic Tundra now being released as that Tundra thaws. Seems like this will also increase warming.
Larry says
I have been watching the temperatures in places like Alert (most northern weather station) at 82 north. It 7 Celsius above. The sun is getting very low this time of year, and it should be around -4 to -5. All August it only dropped one degree below freezing for several hours a couple of times.
Looking at the cryosphere, I keep expecting the ice lost graph to start levelling out, but it remains in deep decline. The north pole may melt out or reduce to loose (1/10 – 3/10) pack ice yet before the end of the melt season.
Sphere says
Re #240: “I wonder how the disappearance of Arctic Sea Ice will effect the Greenland Icecap, logically one would assume that the open ocean water will absorb a great deal more heat than the artic ice did, that this would lead to a relatively warm sea surrounding Greenland which would accelerate it’s the loss of land ice.”
It’s a little more complicated because the Greenland plateau rises well above sea level. The warm water will cause warm air carrying more water vapor; which will fall as snow in the highlands of Greenland. Short-term it’s anybody’s guess whether the combination will result in more water sequestered in the Greenland ice cap or less. Of course, with continued warming the water will fall as rain rather than as snow — bye bye ice.
“Also, when tipping points are discussed, isn’t there also the issue of methane that’s been trapped in Arctic Tundra now being released as that Tundra thaws. Seems like this will also increase warming.”
Google isn’t finding much new on the subject. This is from 2005: http://www.iarc.uaf.edu/highlights/methane/index.php
Sphere says
The only “normal” Arctic sea ice area is the Greenland sea. At first I thought it was because this sea is leeward of Greenland, but more and more I think it’s because the Arctic Basin is draining into it as fast as it can. It’s a bit hard to interpret the surface windfields ( http://www.cdc.noaa.gov/map/images/fnl/sfcwnd_30b.fnl.html ), but it looks like they’ve been blowing that way fairly consistently. Anyone know a good picture of near-real-time Arctic currents? (Something like this one for the Gulf Stream: http://rads.tudelft.nl/gulfstream/ )
Pekka Kostamo says
Re 239: Interesting SST imagery. While we were watching the Atlantic, the Pacific performed these tricks.
Nigel Williams says
It looks like that the only reason that tongue of sea ice is lingering towards Siberia is because a current or wind flow is heaping it up against the Severnaya Zemlya islands.
http://en.wikipedia.org/wiki/Severnaya_Zemlya
I imagine that as soon as that blows through the Siberian sea route will be open, and it will be hard to close.
It looks like we have at least another month to go before any serious freezing will take hold,
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.365.jpg
so there is plenty of time for mother nature to shake us off her apron, eh!
I take it that all this thaw is now well outside any models, and so all we can do is watch as the flip flops. With every crack in the ice, the wetted surface area increases, and as the warmer water pushes against the pack the melting runs faster… exponentially, I guess.
http://iridl.ldeo.columbia.edu/SOURCES/.NOAA/.NCEP/.EMC/.CMB/.GLOBAL/.Reyn_SmithOIv2/.weekly/T/2454328/VALUE/X/20/380/RANGEEDGES/.ssta/
I note that the north pole webcams havent broadcast any images for the last 3 weeks.
http://www.arctic.noaa.gov/gallery_np.html
Presumably they are now sitting with that plaque the Russians placed at the pole – 4000m deep. Not a good look.
Darryl says
Lets face the facts. Since the last ice age 10,000 years ago the ice has been melting. Sure lets face it
burning fossel fuels does not help. If you look at the ice melts from 10,000 years ago to now.
I can see why there is such a large ice melt in 2007 and so on in the years to come, there is no ice compared to 10,000 years ago. Maybe when all the ice melts there will be an astroid strike and put the world into another big ice age, just a thought!
Philippe Chantreau says
Darryl, are you aware of the fact that everything we know about glaciation/deglaciation cycles indicate that we should be cooling by now?
Hank Roberts says
But Darryl, what you believe about the time sequence is not the fact commonly understood to be true.
You claim to be facing facts —- you should point to them so others can tell which direction you’re looking.
What source do you believe, that you trust for what you consider this fact?
The peak temperature was — typical of the pattern — right after the ice age ended, some ten thousand years ago.
The best facts we have are from the scientific work, and those show there has been the typical slow cooling thereafter — until human influences outweiged it, perhaps as early as several thousand years ago, if you follow Ruddiman’s work.
Timothy Chase says
Nigel Williams (#245) wrote:
The sea ice in the Arctic is still dropping fast judging from the updates at Cryosphere Today today, but we are still getting images from the north pole. Looks like something out of Disney’s 101 Dalmatians, but the camera is still there:
http://www.arctic.noaa.gov/latest/noaa4.jpg
Note: at the time of this posting, the date was saying Aug 25, 2007 and time 20:52 – but undoubtedly subject to change – judging from the path…
Larry says
Re: 245
Actually the North Pole Web Cam has a replacment Cam on the ship Polarstern. The cam was transmitting on the ship when it was heading for the north pole earlier this month, but headed south in early august for some reason. It started back north a few days ago, and they resumed the pictures. The ship is now at 86 north according to the polarstern web site. Looks like about 8/10 to 9/10 ice at this point. Not a good place to drop a camera off.
The old web cams have drifted from 89 north in april to 86 north in august. Those original cameras are closer to the thick ice that is outflowing from greenland (see weather data page off of the north pole web cam page). I don’t think cam 1 or 2 has sunk yet, but it may in the next few months as it head south. No pictures from the third however (should had been one on August 17, based on faulty data transmission for camera 1 and 2), and no weather data since the 13th, however people may be on vacation.
It would be nice if they update the site more often, rather than forcing us to deduct it from data from several differnt web sites; considering its the International Polar Year and also the year of the tipping point. Nice Coinicidence.