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  1. Hi RC

    Video link of Dr Barbers TV session is not working.

    http://ipy-osc.no/live Friday first one for those who want to watch it.

    [Response: This is fixed now. -rasmus]

    Comment by pete best — 13 Jun 2010 @ 5:33 AM

  2. That was indeed interesting and a bit alarming to watch..Thank you for bringing this to our attention..

    ps..
    Your link here links back to the RealClimate home page.
    ““On Thin Ice: The Arctic and Climate Change”, video link here)”.
    I found the presentation through the webcast link.

    Comment by Harmen — 13 Jun 2010 @ 6:15 AM

  3. Thanks much for this new post. Very interesting links. I signed up for 2 newsletters already.

    Comment by Edward Greisch — 13 Jun 2010 @ 7:11 AM

  4. The video link for the Barber video doesn’t work.

    Comment by Peter Adamski — 13 Jun 2010 @ 7:20 AM

  5. Good post. Too bad nobody at the Polar Year events not once bothered
    to contact me about polar cities: but that’s the future:
    http://pcillu101.blogspot.com — I don’t call myself James Lovelock’s
    Accidental Student for nothing…..sigh!

    Comment by Danny Bloom — 13 Jun 2010 @ 8:35 AM

  6. Let’s not forget that actual temperature data in the far north is quite limited. As the ice retreats off of the northern land masses, the shoreline temperatures rise from historical values because the newly exposed water is warmer than the historically present ice cover. Then these land temperatures are extrapolated across the pole where ice (and colder temperatures) still exists, potentially exaggerating the amplification effect.

    [Response: You overestimate the impact of very local effects on the Pan Arctic mean, and perhaps you aren't aware of the in situ Arctic Buoy data that provides an independent check on this. Plus, sea ice doesn't just disappear with no reason... - gavin]

    Comment by B Buckner — 13 Jun 2010 @ 8:45 AM

  7. “Some claim that reduced sea-ice can explain cold winters in the northern hemisphere, but I’m not yet convinced. The cold winters are due to weak Arctic Oscillation, and hence a shift in the air masses bringing frigid polar [air] southwards, and this air is replaced by milder air in the polar region. Hence, a shift in the wind system as well as milder temperatures may favour less Arctic sea-ice.”

    Sure. Changes in the wind system during weak Arctic Oscillation (AO) episodes will increase the heat transport towards the pole, not just directly but perhaps also by affecting oceanic surface currents.

    But you haven’t addressed the question: what causes the “weak AO”? The whole point is that if this is related to changes in sea-ice we have a feedback loop: reduced sea-ice –> weaker AO –> increased heat transport to pole –> reduced sea ice. In itself this would suggest future snowy NH winters are likely.

    The critical question, though, is whether the increase in poleward heat transport is sustainable or not. If it isn’t, and the heat store, presumably in the waters of the North Atlantic (NA), cannot be recharged fast enough, then eventually the AO will start to strengthen again allowing the sea-ice to return. There’d then be a delayed negative feedback loop in the system: weaker AO for years/decades –> depletion of heat store (NA cooling) –> stronger AO. This would allow the positive feedback loop to go into reverse: stronger AO –> reduced heat transport to pole –> increased sea ice –> stronger AO.

    Any delayed negative feedback in the climate system, or in any other complex system for that matter, will lead to oscillatory behaviour. I explored the issue on my blog a while back.

    Any internal oscillation of the climate system will of course be affected by external forcings.

    Comment by Tim Joslin — 13 Jun 2010 @ 10:22 AM

  8. The government has some good links about the Arctic.

    “Warming of the Arctic continues to be widespread, and in some cases, dramatic. Linkages between air, land, sea, and biology are evident.”—Arctic Report Card Update for 2009 (NOAA)
    http://www.arctic.noaa.gov/reportcard/

    See also NOAA’s Arctic theme page
    http://www.arctic.noaa.gov/

    and their new site Future of Arctic Sea Ice and Global Impacts.
    http://www.arctic.noaa.gov/future/

    Comment by Snapple — 13 Jun 2010 @ 11:09 AM

  9. ……The exceptional cold and snowy winter of 2009-2010 in Europe, eastern Asia and eastern North America is connected to unique physical processes in the Arctic,” he says.

    Planetary waves may have had something to do with what was just cited, however its a lot of snowfall which causes an albedo effect which cooled down Europe and the Southeastern USA. No one should mention that it was cold last winter to any Canadian, from Arctic to Pacific to Atlantic oceans, it was the warmest Canadian winter in history. And it got colder in places like Georgia, Washington DC, Sweden and Germany because it snowed a great deal, its the reverse of what is going on in the Arctic right now, with ice melting very fast from a growing feedbach less albedo effect. So for people who thought your winter was cold and snowy, you’ve just got a lesson in albedo effects. Hansen and Rasmus love the fancy words like Arctic Oscillation, which is an observed pressure pattern over the Arctic Ocean, not particularly well explained, really not understood as to why they happen.

    The Arctic Ocean had much thinner ice last winter, along with the thinner ice, more leads, thinner ice means more heat from the Arctic Ocean released during the long night along with great heat injections from more numerous leads. So last winter was a warm one over the Arctic and Canada, not strictly because of planetary wave configuration, but because it was cloudy, either in the Arctic or Canada, especially enhanced by El-Nino giving more clouds, what I call ‘anvil seeding’ , bringing the joys of more snow especially for places with winter temperatures near 0 C, after all, there is more evaporation when the winter is warmer.

    Comment by wayne davidson — 13 Jun 2010 @ 1:56 PM

  10. #6 B Buckner

    I wanted to add what may be relevant perspective to your view.

    Around 38 minutes into the presentation Barber mentions:

    “All the shore reporting stations are all reporting minus 20, minus 30 and it’s minus 2 or minus 3 over the open ocean. . .”

    I don’t know all the contexts surrounding this, however, it may be reasonable to consider the thermal radiative force of the land vs. the ocean. Land can radiate heat much faster than ocean. So the shore measurements should fluctuate more than the sea temperatures.

    I realize this is an oversimplification, but I think it at least illustrates what seems to be a probable serious flaw in the argument you are presenting.

    And as Gavin mentioned, there are buoys deployed to measure the temps in the Arctic ocean and out on the ice flow.

    http://nsidc.org/data/g00791.html

    http://iabp.apl.washington.edu/maps_monthly_deployhist.html

    http://www.arctic.noaa.gov/essay_untersteiner3.html

    http://psc.apl.washington.edu/northpole/index.html

    http://www.youtube.com/watch?v=YZqWMDYFtcE


    A Climate Minute The Greenhouse EffectHistory of Climate ScienceArctic Ice Melt

    ‘Fee & Dividend’ Our best chance for a better future – climatelobby.com
    Learn the Issue & Sign the Petition

    Comment by John P. Reisman (OSS Foundation) — 13 Jun 2010 @ 2:17 PM

  11. Thank you very much for this!

    For an interested teacher, stuff like this is really good to have.
    It’s deeply frustrating to watch how our norwegian media (as the BBC)
    have now in about seven months managed to “cancel” global warming all
    over, just because we’ve had our first somewhat “cold” winter since
    1986-87 here in southeastern Norway and parts of Europe. This doesn’t bode good for the possibilities to at least avoid the worst warming scenarios in the future. A lot of people seem more than ever hell-bent on denying the realities just for the sake of their quasi-religous beliefs in consuming ever more.

    Comment by Karsten V. Johansen — 13 Jun 2010 @ 2:41 PM

  12. Rasmus,

    Thanks for posting this! Dr. Barber’s slide presentation was fascinating, but not always clearly shown (and sometimes obscured); is it available anywhere on the web? I’ve checked without success at:

    1. The IPY: http://ipy-osc.no/article/2010/1271167116.96
    2. CEOS: http://www.umanitoba.ca/ceos/
    3. CFL: http://www.ipy-cfl.ca/
    4. Dr. Barber’s site: http://web.me.com/barber1818/D.G.Barber/Welcome.html

    Is it possible for Dr. Barber to post a copy here? It would be of great value for those learners like myself.

    Thanks,

    Daniel the Yooper

    Comment by Daniel the Yooper — 13 Jun 2010 @ 2:41 PM

  13. Sorry Tim, bu I think your conclusions are flawed. Yes, the AMO exists. Yes, there are cycles in climatic elements. However, the sea ice is not melting so much from above as below, so the role of winds is the more minor actor here. Ocean Heat Content is the primary driver, coupled with reduced albedo.

    Winds do play a more dominant role wrt the transport of sea ice out of the Arctic.

    Also, the AMO is cyclical within a wider climate. While the AMO may cause a perceived cooling, it is only perceived. In reality, the imbalance of heat transport onto and off the planet doesn’t change because of the AMO. The AMO – along with El Nino/La Nina – will only serve as a mask.

    I’m all for the AMO helping return ice to the level it was 30 years ago, but don’t see it happening.

    Cheers

    Comment by ccpo — 13 Jun 2010 @ 3:06 PM

  14. 7 Tim Joslin “A few decades down the line, the planet will be a lot warmer and we’ll be seeing much heavier precipitation in some regions.”
    Much heavier precipitation is already being seen here in Illinois. Corn seed has been washed away twice this year in Mercer County.

    Everybody: Be sure to call AND email your senators and the president about GW at least 3 times per week. If you live near D.C. and can spare the time, go to the Senate and actually lobby.

    Thanks everybody who has added very interesting links.

    Today’s Climate Progress has a story entitled: “New York Times public editor files final report, never mentions the paper’s dreadful global warming coverage” at
    http://climateprogress.org/2010/06/13/new-york-times-public-editor-global-warming-coverage/?
    The NYT article is at
    http://www.nytimes.com/2010/06/13/opinion/13pubed.html?ref=opinion
    Go there now and comment on the NYT coverage of GW.

    Comment by Edward Greisch — 13 Jun 2010 @ 3:13 PM

  15. Tim Joslin wrote in 7:

    The critical question, though, is whether the increase in poleward heat transport is sustainable or not. If it isn’t, and the heat store, presumably in the waters of the North Atlantic (NA), cannot be recharged fast enough, then eventually the AO will start to strengthen again allowing the sea-ice to return. There’d then be a delayed negative feedback loop in the system: weaker AO for years/decades –> depletion of heat store (NA cooling) –> stronger AO. This would allow the positive feedback loop to go into reverse: stronger AO –> reduced heat transport to pole –> increased sea ice –> stronger AO.

    Any delayed negative feedback in the climate system, or in any other complex system for that matter, will lead to oscillatory behaviour. I explored the issue on my blog a while back.

    Good question. Out of curiosity and strictly as a non-expert I decided to look up the data and see whether it exhibited the kind of behavior that you suggest. And while it would take someone with a better background in statistics than myself to say just how significant it is, from what I see there is a quasi-periodic phenomena similar to what you suggest — although it is superimposed upon a larger trend.

    For the data I went here:

    National Oceanographic Data Center – Yearly heat content form 1955 to 2009
    http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/basin_data.html

    It has a link to the following data file here:

    Atlantic (3-month anomaly, 0-700 meters, heat in 10^22 joules)
    ftp://ftp.nodc.noaa.gov/pub/data.nodc/woa/DATA_ANALYSIS/3M_HEAT_CONTENT/DATA/basin/yearly/h22-a0-700m.dat

    … and I produced a chart here:

    https://docs.google.com/leaf?id=0B-57vongYoiAMTE5M2FlNGYtMjg3Zi00MmNjLWFhMGMtNTE5OWM2MTFjYzU4&hl=en

    As one would expect, the underlying trend would appear to be distinctly nonlinear. I give the quadratic trendlines, the formula and R-squared for both the Atlantic Ocean and North Atlantic.

    Comment by Timothy Chase — 13 Jun 2010 @ 3:51 PM

  16. Good talk. I’m interested in learning more about Prof. Barber’s remarks in the beginning concerning new satellites being able to monitor ice thickness. Are there any good references for how this is evolving and how good are current methods for doing this?

    Comment by Chris Colose — 13 Jun 2010 @ 4:30 PM

  17. Re: Comment #16

    Chris Colose says:
    13 June 2010 at 4:30 PM

    “Good talk. I’m interested in learning more about Prof. Barber’s remarks in the beginning concerning new satellites being able to monitor ice thickness. Are there any good references for how this is evolving and how good are current methods for doing this?”

    AFAIK, here’s some current info on satellites for that role:
    1. NASA’s Icesat completed a 7-year mission in October 2009.
    http://icesat.gsfc.nasa.gov/icesat/

    It’s replacement, Icesat-2, is scheduled for launch in late 2015:
    http://icesat.gsfc.nasa.gov/icesat2/

    2. Cryosat-2 launched in April 2010 by the ESA:
    http://www.esa.int/esaLP/LPcryosat.html

    Currently in a six-month calibration phase.

    3. GRACE, launched in 2002 & operational:
    http://www.csr.utexas.edu/grace/

    GRACE just had its service mission extended until 2015.

    Hope this helps.

    Cheers,

    Daniel the Yooper

    Comment by Daniel the Yooper — 13 Jun 2010 @ 8:48 PM

  18. Quick point…

    In response to Tim Joslin’s 7, ccpo wrote in 13:

    Sorry Tim, bu I think your conclusions are flawed. Yes, the AMO exists. Yes, there are cycles in climatic elements. However, the sea ice is not melting so much from above as below, so the role of winds is the more minor actor here. Ocean Heat Content is the primary driver, coupled with reduced albedo.

    ccpo sees this of course, but it might help to point out that the “heat store” that Tim Joslin refers to in 7 as needing to be “recharged” if “heat transport” is to be “sustainable” is in fact the “ocean heat content” that ccpo is refering to. And ccpo is quite right — the ocean heat content is far more important in terms of driving the earth’s climate system than atmospheric circulation or land and atmosphere heat content. The heat content anomaly of the atmosphere and land relative to 1950 amounts to less than 10×10^21 joules. The ocean? 200 x10^21 joules, easily more than 20X that of the land and atmosphere combined.

    Please see figure 1 “Earth’s Total Heat Content Anomaly” from:

    How we know global warming is still happening
    John Cook, Monday, 28 September, 2009
    http://www.skepticalscience.com/How-do-we-know-global-warming-is-still-happening.html

    My comment at 15?

    Just looking at the “heat stores” that are the Atlantic and North Atlantic Ocean heat content. But what is ultimately driving this is an imbalance between rate at which radiation enters the climate system and radiation leaves it. A lower albedo means that less light is scattered to space and more light is absorbed, heating the system, then radiated as thermal radiation that the atmosphere is partly opaque to.

    As long as the imbalance exists the heat content of the climate system will rise. And carbon dioxide reduces the rate at which thermal radiation leaves the system.

    You can see that here:

    CO2 experiment: Iain Stewart demonstrates infrared radiation absorption by CO2
    http://www.youtube.com/watch?v=SeYfl45X1wo

    … and here:

    PIA11186: AIRS Global Distribution of Mid-Tropospheric Carbon Dioxide at 18-13 km Altitudes
    http://photojournal.jpl.nasa.gov/catalog/PIA11186

    … where thicker carbon dioxide over industrial centers means that infrared radiation in certain electromagnetic bands isn’t able to escape except at higher, colder altitudes.

    Consequently the climate system has to heat up until it is able to compensate for an atmosphere that has become thicker (“more opaque”) to thermal radiation. At that point a new equilibrium is established at a higher heat content and higher surface temperature.

    Comment by Timothy Chase — 13 Jun 2010 @ 9:20 PM

  19. The most significant immediate result of the collapse of Arctic sea ice that now seems to be underway is the likely acceleration in the melting of the very shallow sea bed in the continental shelves, especially those north of Siberia. The resulting dissociation of methane hydrates, and the release of huge stores of free methane below, would be a significant “discontinuity” that could discontinue all of us.

    Comment by wili — 14 Jun 2010 @ 12:44 AM

  20. Re. ccpo #13: Actually, I agree that oceanic heat transport is more significant than the AO wind patterns. I touch on this a bit more in another post on my own blog, where I try to clarify the one I referred to in #7.

    The oceanic transport of heat poleward is driven by temperature differences. My point is that the strength of the circulation process (i.e. the thermo-haline circulation, or THC) must, logically, be variable, and is perhaps cyclic. Specifically, I hypothesise that this is the case on decadal timescales.

    When polar waters are covered by insulating sea ice, heat can’t be lost from the water except by melting ice from below. Unless the ice melts through, most of the heat is retained in the water/ice layer rather than released to the atmosphere or radiated away. Heat therefore builds up underneath a thinning ice layer.

    The situation is quite different for areas of sea which are ice free at the start of winter, where the surface waters can cool more rapidly. This process and in particular saline deep water formation accompanying freezing not only releases heat from the water but also strengthens the oceanic circulation.

    I disagree that “the imbalance of heat transport onto and off the planet doesn’t change because of the AMO”. The “heat transport off the planet” is affected by surface changes. These include the positive albedo feedback. I suggest, though, that there is a negative feedback as well – melted sea ice allows more heat to escape from polar oceans.

    The changes in wind patterns – the Arctic Oscillation (AO) – are a consequence of the flow of heat. I hypothesise that a weaker AO results from more heat being released to the atmosphere where sea ice is absent (or thin and fragile), most significantly at the start of winter. As this also results in more snowy NH winters, surface albedo effects (reflection of light from lying snow in spring) might be another negative feedback. I’ve put a proof of principle calculation on my blog, but obviously more work is required to determine whether and the extent to which the effect of areas of increased snow cover in weak AO winters outweighs that of areas of less snow cover.

    Increased export of sea ice along the E coast of Greenland during weak AO episodes may also be important, as this allows more ice to form the next winter. It may also prevent the Arctic waters from freshening, which would tend to reduce the formation of deep saline water. A little more detail here.

    TimC #15: “Out of curiosity and strictly as a non-expert I decided to look up the data”. Ditto: I looked at the CET (Central England Temperature) record over a longer timescale and provide some plots here and here. Sudden series of cold winters from 1740 and 1940 after periods of warming cry out for an explanation. It would dramatically improve the credibility of climate change forecasts if it becomes possible to do better than dismiss such socially important phenomena as “natural variability”.

    My main point is that it may be unwise to point the media at the short-term Arctic sea ice record in the unqualified way that is happening.

    Comment by Tim Joslin — 14 Jun 2010 @ 5:14 AM

  21. Are there any implications from this for calving (ablation/disruption) of glaciers?

    Comment by J Bowers — 14 Jun 2010 @ 5:41 AM

  22. Does the nature of the ice’s volume (thickness) throw on new light on the ability of GCMs?

    I am presently and have been for some time having a debate with one IPCC member and one other climate related person who both appear to totally deny the entire idea of the idea of a global mean temperature as data sources and methods of normalisation (for want of a more accurate word) are incorrect and show bias towards warming. I cant convince them of AGW world because they both are Oxford educated and see me as some oik even claiming then RC is biased towards warming and the memebrs of RC are not are suitable intellectual rigour etc.

    I have read every article here and more besides but intellectual snobbery seems to abound and there seems to be IPCC members who flatly deny AGW for a plethora of reasons especially when it come to climate gate etc.

    This presentation yestersday and the recent 2010 temperatures thus far this year along with Arctic amplification appear to even be overcoming the reticence and conservatism of even the most AGW scientist assessment. However its not only deniers that cannot be turned, its also climate science people by the looks of it.

    IPY year material seems very good to me and a testing time for deniers especially concerning ice extent and thickness.

    [Response: Please note that the members of IPCC are the governments, not individuals. And also note that anyone can review IPCC reports. People pulling a 'I am an IPCC member/reviewer' card and insisting they are correct are simply trying for an inappropriate argument from authority - regardless of what university they went to. - gavin]

    Comment by pete best — 14 Jun 2010 @ 5:47 AM

  23. Re: ‘The cold winters are due to weak Arctic Oscillation, and hence a shift in the air masses bringing frigid polar southwards, and this air is replaced by milder air in the polar region.’

    The AO is very strongly related to atmospheric pressure at 80-90°N. A negative AO corresponds to high pressure at the pole and weaker pressure at latitudes between 50°N to 50°S latitude. So, we are talking of a shift in the atmosphere here, and a plot of pressure over time will reveal the oscillation. Currently, polar pressure is increasing and it has been doing so since 1990 in the Arctic and about 1999 in the Antarctic.

    Looking at the episodic short term shifts pressure can be seen to increase and decrease at both poles simultaneously. As atmospheric pressure increases at the pole/falls at low latitudes so also does tropical sea surface temperature and global temperature. So, its possible there is a weakening of pressure in the subtropical high pressure cells as polar pressure increases and a resulting increase in cloudiness at lower latitudes.

    Seems that this is what one might call a ‘natural climate oscillation’ with a period of sixty years or more.

    [Response: There is no apparent '60 year' period in the AO - indeed most of its variability is at much shorter periods (days to months). - gavin]

    Comment by Erl Happ — 14 Jun 2010 @ 6:13 AM

  24. If it’s OK I’d like to point out that I recently started a little blog that concentrates on news and data concerning the Arctic sea ice. I’m writing regular updates on sea ice extent, minimum sea ice extent predictions by scientists and laymen, interesting theories, and things like the influence of the Arctic Oscillation.

    I’ve linked to this article in my latest SIE update. I’m hoping the smart people will come over and liven up the comment section with explanations and interesting remarks during the 2010 melting season.

    Comment by Neven — 14 Jun 2010 @ 6:19 AM

  25. “My main point is that it may be unwise to point the media at the short-term Arctic sea ice record in the unqualified way that is happening.”

    However, it’s fine to use the Arctic Ice record data we have, which gives the same picture.

    What’s unqualified and unwise is to point to your feedback mechanism and posit that we’re going to get a return to 60-year-old ice extents “any day now”, based on partial physical models.

    Comment by Completely Fed Up — 14 Jun 2010 @ 6:51 AM

  26. Karsten Johansen,
    Unfortunately, media failure in science is not a new phenomenon. BBC coverage of science has always sucked. It appears the BBC tends to attract the artsy-fartsy contingent of Snow’s Two Cultures. Fortunately they have no memory as well as no processor, so they will reset as soon as they have a hot summer.
    [edit]

    Comment by Ray Ladbury — 14 Jun 2010 @ 6:59 AM

  27. B. Buckner,
    Thank you for explaining how melting ice is actually a sign that things aren’t getting warmer. Can you even keep a straight face while you type this stuff?

    Comment by Ray Ladbury — 14 Jun 2010 @ 7:02 AM

  28. Re #23, Thaks for that feedback Gavin, it is appreciated.

    Comment by pete best — 14 Jun 2010 @ 7:27 AM

  29. Thanks for posting the links to the conference videos! I hope you do the same for any other climate related conferences. There is probably no good way for a lay-reader to keep apprised of these events, so that is a gap-filler which I appreciate.

    And while a bit short on details, I found Mark Parsons talk on data availability interesting. On the other hand, I was pretty disappointed when I tracked down the site: http://piccloud.arcs.org.au/piccloud/DataSetFindForm . Huge lists of keywords with no data sets behind them.

    Comment by Ron Broberg — 14 Jun 2010 @ 8:46 AM

  30. CompletelyFedUp #26: You quoted me and then wrote: “What’s unqualified and unwise is to point to your feedback mechanism and posit that we’re going to get a return to 60-year-old ice extents ‘any day now’, based on partial physical models.”

    I never “posited” anything of the sort. Basically you’re misrepresenting what I’ve said, which is a little rude. And btw, all the “physical models” we have are incomplete, which might be a point worth bearing in mind.

    Where I started from (see my blog, op cit in #7) was the seriously detrimental effect on public opinion, vis-a-vis action on GW, of the recent cold NH winter, especially when the odd climate scientist was on record saying that such a thing would not happen.

    What I’m trying to gently point out is that I frequently read in the UK and other media that (to paraphrase) “the Arctic sea ice is disappearing even faster than expected”. Encouragement seems to be being given to the unjustified logical leap from this to “GW is worse than expected”. Since there’s a credible school of thought that suggests Arctic sea ice melt (strictly, reduced summer extent) is affected by natural cycles as well as GW, then, if it turns out that the melt has overshot – which is, after all, the sort of thing that happens in complex systems, cf the economy – then we’re simply inviting the public to conclude for as long as headlines read “Arctic sea ice disappears slower than expected” – which could be a decade or so – that “GW is not as bad as thought”. Or worse, if the ice stages a recovery.

    The scientific significance of month on month changes in Arctic sea ice extent is minimal, but it’s being reported as if we’re watching a football match.

    Putting myself in the shoes of the average Daily Mail reader, what’s coming across to the public is that melting Arctic sea ice is supposedly proof of GW, but the recent cold winter is “natural variability”. Since, to a layperson, this is obviously inconsistent, it doesn’t add up to a very persuasive message.

    All I’m trying to get across is that it might be worth mentioning occasionally that internal variability in the climate system (e.g. the so-called AMO), as well as GW, could influence the extent of Arctic sea ice.

    Comment by Tim Joslin — 14 Jun 2010 @ 9:27 AM

  31. Re Gavin’s response to comment 24. As I said: “a plot of pressure over time will reveal the oscillation”.

    Comment by Erl Happ — 14 Jun 2010 @ 9:35 AM

  32. I will delve into these links as soon as time permits. I’ve been waiting a long time for this conference.

    IPY was bound to be significant because many of the rebuttals of AGW information were based on lack of field data from the poles. From what I’ve read here, Antarctica did not reveal any long term warming trends, but I suspect there is strong localized warming and the instrumentation is now in place to detect any changes anywhere on the continent, especially the speed of ice flow from the inner continent outward.

    I think we all know that, long before it gets warm enough to melt, Antartic ice sheets will migrate toward the sea as the ice becomes less rigid. We will be able to measure that flow. So, for some years at least, Rush and others will say “warmer in the Artic, colder in the Antartic. Doesn’t sound “global” to me”, that is until we report real losses of ice mass and real increases in migratory speed.

    And somewhere along the way, it will be understood by more and more current deniers that the properties of ice sheets that is one mile high are different from those at sea level. We’ve always known that Antarctica would be the last to go, and that it wouldn’t be a “signal”, it would be evidence that the rest of the planet is well into the melt phase.

    Which it clearly is. 2010 may very well be the next “spike” year that we’ve been waiting for since 1998. I know it’s coming soon.

    We can’t help the fact that deniers want to use bad math and compare one year to a decadal average, but we will be happy to use their very own methods, once 2010 is in the books, to show them how the warming has suddenly “reappeared”.

    I do have one question, which perhaps will be answered from the conference materials:

    Try as I might, I have never been able to find an illustration which shows the permafrost band at the top of the planet, and how it may have changed over the years. If I’m not mistaken it is on a retreat, and it would be quite useful, I would think, to compare that band on the same date every year.

    Does such an illustration exist?

    Comment by Walt Bennett — 14 Jun 2010 @ 10:46 AM

  33. “I never “posited” anything of the sort.”

    http://www.realclimate.org/index.php/archives/2010/06/a-conclusion-of-the-4th-international-polar-year/comment-page-1/#comment-177572

    No, you left out the physics and said it could reverse any moment now.

    Obviously I was too generous to you in my statement and you felt the need to correct me on it…

    Comment by Completely Fed Up — 14 Jun 2010 @ 11:16 AM

  34. “Putting myself in the shoes of the average Daily Mail reader, …”

    Yes. Definitely too generous of you.

    Comment by Completely Fed Up — 14 Jun 2010 @ 11:16 AM

  35. Re. 33 Walt Bennett

    Not a map, but is CALM of any use at all?
    http://www.udel.edu/Geography/calm/data/north.html

    http://www.udel.edu/Geography/calm/
    http://www.udel.edu/Geography/calm/data/data-links.html

    Comment by J Bowers — 14 Jun 2010 @ 11:23 AM

  36. Rasmus: “The cold winters are due to weak Arctic Oscillation, and hence a shift in the air masses bringing frigid polar southwards, and this air is replaced by milder air in the polar region.”

    Most references to the AO seem incomplete, and one can’t expect several paragraphs to explain it in the top post. I want to mention though that whether a winter seems cold or warm depends on location. This past winter was quite warm overall but cold in places, due to a very strongly negative AO on top of El Niño. The largely wind-driven Gulf Stream went farther north along the east coast than usual. Not so much ice was blown out of the Fram straight, but the warm water underneath got to it.

    Gulf Stream last winter

    Some people (not here) seem to think that when the AO is negative, upper atmosphere descends over the arctic and cools and rushes south. This does not seem to be the whole picture. Warm surface air moves north along western North America and perhaps along the east at sea.

    So what’s my point? Just trying to stir up some input on the AO.

    Comment by Pete Dunkelberg — 14 Jun 2010 @ 11:26 AM

  37. Karsten @ 11: Very good points about the current situation in Norway, (and the rest of Scandinavia, by the looks of it). One single winter with normal temperatures and the place turns into a denialist hotspot of epic proportions. An overwhelming amount of reports of “climategate” nonsense and long debunked BS regurgitated by people who should know better (and probably do know better). I can count on one hand the number of articles mentioning the record breaking global average temperatures over the past 6 months. Funny thing is, when you explain the high global temps and the reason for the cold winter temps (AO), most folks actually grasp the point. Problem is that the press basically don’t mention these things. Makes you wonder why. The local “it’s the sun” guys have turned quiet, though, after receiving an unjust amount of press last year, during the La Nina. With global average temps at record high levels during an almost record solar slump, that theory doesn’t quite carry the same punch anymore. If the press would spend as much time on things like the dramatic failures of the “sceptic’s” cooling predictions from 2008 as they do on reporting on minor issues in the vast IPCC report, we would see a rapid change in the public opinion.

    Comment by Esop — 14 Jun 2010 @ 11:28 AM

  38. Erl Happ # 24 You may be thinking of the AMO – Atlantic Multidecadal Oscillation.

    Comment by Pete Dunkelberg — 14 Jun 2010 @ 11:40 AM

  39. Walt@33: For the sake of political action that will help lessen future warming, a record setting 2010 is crucial. However, considering the weather related luck of the denialists (AO causing cold temps in NA and Northern Europe, record snow right in DC, etc) it would not surprise me if a coming La Nina brings the temps down so that 98 barely stays on top. A few more years and the 98 record will be absolutely shattered, but that would be a few more valuable years with political inaction. Even though GISS, HadCruT and RSS temps should break the record, the endless series of adjustments to bring the UAH anomalies down will most likely make sure the UAH numbers stay slightly below the 98 record.

    Comment by Esop — 14 Jun 2010 @ 11:50 AM

  40. Re: #40

    Esop,

    1998 is no longer on top. 2005 and 2007 exceeded it, and 2009 probably did.

    What we’re all waiting for is not the next record year; they occur with regularity. No, we’re waiting for the next SPIKE year.

    1998 was .26*C warmer than ANY PREVIOUSLY MEASURED YEAR.

    An enormous leap.

    We are waiting for the next one of those. 2010 might be the year. If land temps come in at .9 or more above the mean, it would be a leap of at least .13, which is only half the 1998 leap but would still be enormous.

    I have a hunch that one of these next several years will be a full degree above the mean. When that happens, I think we’ll see some headlines.

    Comment by Walt Bennett — 14 Jun 2010 @ 12:34 PM

  41. 37 Pete, AO is an acronym describing pressure spatial variations. While
    ENSO seems much like a better Oscillation, I live in the Arctic and its a curiosity which a few find interesting. I don’t see much into it, As pressure systems usually move around very fast, sometimes they hang out at the same spatial location for a couple weeks at best.

    Esop #40 : “a record setting 2010 is crucial. However, considering the weather related luck of the denialists (AO causing cold temps in NA and Northern Europe, record snow right in DC, etc)”

    2010 will likely surpass 1998 as did 2005, because ENSO was in perfect sync
    with warming the planet. El-Nino during NH winter, La-Nina during NH summer.
    1998 had also a strong La-Nina for bottom half of that year.

    As far as deniers having luck? Beats me, they don’t know that more snow during winter implies a warmer atmosphere. Is it lucky to be ignorant????

    #40

    Comment by Wayne Davidson — 14 Jun 2010 @ 1:23 PM

  42. True that 05 and 07 beat 98 in most of the datasets. However, with the UAH data being the skeptics dataset of choice, that is the year that gets repeated exposure in the media. It is not until the UAH dataset breaks the 98 record that the “no warming since 98″ meme endlessly repeated by the media, will go away (one must hope).

    Comment by Esop — 14 Jun 2010 @ 1:54 PM

  43. Wayne @ 41:
    Unfortunately, in the eyes of the general public, snow means cold. Easy point for the skeptics. The simple fact that warming means greater accumulation of humidity in the atmosphere, thus more snow in the winter, isn’t considered by many.

    Comment by Esop — 14 Jun 2010 @ 2:11 PM

  44. #43 Esop, They are not lucky then, these skeptics are doomed to believe in nonsense.

    Comment by Wayne Davidson — 14 Jun 2010 @ 2:22 PM

  45. “Unfortunately, in the eyes of the general public, snow means cold”

    Only to those who really don’t know what snow is. EVERYONE who has known frequent snow knows “it’s too cold to snow”. It’s those who never really have snow except on the rare occasions that don’t (and then it’s easy to talk to some old-timer who knows it, or read up yourself: this IS supposed to be “the information age” isn’t it?).

    But arguing against more snow = warmer weather is a great talking point and comes across easy to those who DO NOT want to know what’s going on.

    It is, however, a great noise, all sound and fury, signifying nothing.

    Comment by Completely Fed Up — 14 Jun 2010 @ 2:28 PM

  46. “However, with the UAH data being the skeptics dataset of choice, that is the year that gets repeated exposure in the media.”

    That’s a problem with the Media being denialist. And THAT is a problem of the people who don’t take them to task.

    People like you and me.

    So do it already.

    Comment by Completely Fed Up — 14 Jun 2010 @ 2:29 PM

  47. Tim Joslin wrote in 20:

    I disagree that “the imbalance of heat transport onto and off the planet doesn’t change because of the AMO”. The “heat transport off the planet” is affected by surface changes. These include the positive albedo feedback. I suggest, though, that there is a negative feedback as well – melted sea ice allows more heat to escape from polar oceans.

    You wrote, “… there is a negative feedback as well – melted sea ice allows more heat to escape from polar oceans.”

    True — and this is why when winter comes after a great melt ice will return more rapidly. Without the arctic sea ice covering it the ocean cools off much more quickly and then the ice forms just as when breaks in the ice in late fall and early winter will release a great deal of steam prior to freezing shut, and as we have seen in recent years the winter extent will tend to be greater. But this is on an annual level, and we are talking about new ice and first year ice. You have yet to propose a credible mechanism that would result in something on so much as a decadal scale. The same would seem to be true of your snowy NH winters. Annual, not decadal.
    *
    Tim Joslin wrote in 20:

    Ditto: I looked at the CET (Central England Temperature) record over a longer timescale and provide some plots here and here. Sudden series of cold winters from 1740 and 1940 after periods of warming cry out for an explanation.

    “1740″?

    A stratospheric volcanic eruption by Tarumai at 42.7 latitude with a volcanic explosivity index of 5 in 1739 followed by Oshima-O-Shima at 41.5 latitude with a volcanic explosivity index of 4 in 1741 perhaps? Stratospheric aerosols similar to Pinatubo will stay up in the stratosphere for a few years, VEI is a logarithmic scale, and volcanos at lower latitudes tend to have a greater effect upon world temperature. Additionally, as you are taking your temperature readings strictly from central England, I would remind you that the smaller the region the more variable temperature tends to be as less of the variability is averaged out in accordance with the law of large numbers.

    As for 1940, I believe the mainstream view is that reflective aerosols (sulfates and nitrates) due to the due to ramp up for WW II were the culprit — after roughly a decade of economic stagnation — and it was principally an issue for the northern hemisphere:

    The “smooth” versions show that while the northern hemisphere did indeed cool for several decades mid-century, the southern hemisphere did not — exactly what we would expect from sulfate-aerosol forcing. In fact, the smoothed version tends to smooth the very brief southern-hemisphere cooling a little too much; the annual numbers show that the southern hemisphere mid-century cooling is pretty much confined to a single year, from 1945 to 1946.

    Hemispheres
    August 17, 2007
    http://tamino.wordpress.com/2007/08/17/hemispheres/

    *
    “Ditto:…”

    The data that I looked up shows a “discharging” and “recharging” of “heat stores” — primarily the heat content of the North Atlantic Ocean. And for several years the mid-year heat content will be above the background trend, for several years it will be below. As such the system seems to has memory, pink noise as opposed to white. Common in natural systems. Changes in ocean circulation, perhaps. However the underlying trend in North Atlantic Ocean heat content would seem to be pretty clear: increasing with a quadratic trendline that has an r-squared of 0.92. It is increasing at an increasing rate.

    Please see the graphic I directed you to in 15:

    https://docs.google.com/leaf?id=0B-57vongYoiAMTE5M2FlNGYtMjg3Zi00MmNjLWFhMGMtNTE5OWM2MTFjYzU4&hl=en
    *
    Tim Joslin wrote in 20:

    It would dramatically improve the credibility of climate change forecasts if it becomes possible to do better than dismiss such socially important phenomena as “natural variability”.

    Moreover, when climatologists attempt to match the behavior of El Nino by means of physical equations or to explain the temperature record by reference to such things as anthropogenic aerosols they aren’t simply positing that enough existed at one moment or another to result in a given effect. Instead there are studies, both in terms of economic history and the contamination of ice cores by industrial aerosols in annual layers of packed snow that independently establish what the aerosol levels were, where they were being produced and even how they were being distributed by atmospheric circulation.

    And this is taking place in peer-reviewed literature. They aren’t simply waving their hands and dismissing things in terms of natural variability or anthropogenic for that matter. However, for someone who is simply looking at the trends such as you or I it helps to keep in mind the fact that there will be variability — but the actual scientists do in fact seek to explain that variability in a detailed fashion in terms of how energy flows through the system.
    *
    Tim Joslin wrote in 20:

    My main point is that it may be unwise to point the media at the short-term Arctic sea ice record in the unqualified way that is happening.

    Do you think this criticism is applicable to David Barber – the fellow whose talk is the subject of discussion in the above essay? Seems to me he has had his boots on deck and on the sea ice in the arctic a great deal recently. He isn’t considering simply the albedo or even the spectra of ice as measured by satellite — looking only at its surface — but has been busy poking holes in it to see what’s underneath.

    Please see for example:

    On Thin Ice: The Arctic and Climate Change
    http://video.hint.no/mmt201v10/osc/?vid=55

    Comment by Timothy Chase — 14 Jun 2010 @ 4:52 PM

  48. Re #38 Pete Dunkleberg You may be thinking of the AMO – Atlantic Multidecadal Oscillation.

    No, I am not. I am looking at the data and seeing the oscillation. After 1978 the AO index is relatively high from November to March representing a failure of atmospheric pressure to rise at 80-90°N to the extent that it had in prior years. Relatively high pressure in mid latitudes and low pressure at the poles translates into a movement of warm air northwards in winter. That is now reversing as atmospheric pressure at the poles gradually recovers.

    Comment by Erl Happ — 14 Jun 2010 @ 5:39 PM

  49. Meanwhile Arctic sea ice extent went below the 2007 minimum around mid May and has stayed that way. Given that this started before we should have started seeing strong El Niño warming effects (SOI hit a relatively strong negative around June 2009, and as I recall there is a 12 month lag before this translates to a temperature peak), it looks to me very likely that this will continue through to the peak of the melting season.

    A new low in sea ice extend coming out of a deep solar minimum is not good news.

    Comment by Philip Machanick — 14 Jun 2010 @ 7:19 PM

  50. Ray Ladbury: “Thank you for explaining how melting ice is actually a sign that things aren’t getting warmer. Can you even keep a straight face while you type this stuff?”

    I actually said the amplification effects are potentially exaggerated. It is obvious from my statement that I acknowledge it is getting warmer in the Arctic, how can you exaggerate something that does not exist?

    The point of my post was that GISS is the only major temperature data set that covers the Arctic, and it is the warmest of the data sets because of the Arctic amplification effect it reports. I provided a rationale as to why the GISS method may overstate the polar temperatures. Gavin replied, politely, that I was overestimating the local effects on the Pan Arctic mean. It seems to me that extrapolating shoreline data 1200 km across the Arctic does precisely that kind of overestimation. I was told that buoy data provides an independent check on the GISS method of extrapolation. I have never seen such data but would be quite interested in reviewing it if available. It seems obvious to me that a shoreline temperature station abutting sea ice would read a lower temperature than a station abutting open ocean as sea ice by definition is colder than sea water. While the temperature at the station abutting open water shows a real increase from its former frozen state, I contend it does not represent conditions 1200 km away on the ice pack.

    Comment by B Buckner — 14 Jun 2010 @ 7:59 PM

  51. David Barber’s lecture mentions the impact of warming water on bottom melting of the multi-year sea-ice. There is also another mechanism at work, the increase in inflows of warmer waters into the Arctic Mediterranean from the North Atlantic and the Pacific. This might be the result of increased down welling of dense waters under the sea-ice during the winter months. As the sea-ice area expands, there is brine rejected in the process. This results in densification of the water below, which can sink in shallow coastal shelf areas, such as that poleward of Siberia. Any waters which sink into the depths of the Arctic Mediterranean eventually add to the overflows across the Greenland-Iceland-Scotland shelf, which separates the Arctic Mediterranean from the North Atlantic. These waters sink and produce part of the North Atlantic Deep Water, which lies just above the even denser waters produced by similar action around the Antarctic.

    The yearly cycle of sea-ice growth and decay appears to be increasing, since the minimum extent is declining faster than the maximum extent. This may result in increased production of THC waters in the Arctic Ocean. The freshening of the surface waters in the Nordic Seas could reduce the THC in that location, which would ultimately tend to bring more warm water into the Arctic and thus speed the rate of decline in the sea-ice minimum. There is a weak indication of a reduction of THC sinking in the Western Greenland Sea, which may impact the AO and thus change weather patterns. I suggest that this may have happened last winter and contributed to the colder than usual weather over Northern Europe and parts of the US.

    E. S.

    Comment by E. Swanson — 14 Jun 2010 @ 8:28 PM

  52. Why “Arctic Mediterranean?” To emphasize that the Arctic Ocean is relatively land-locked?

    Comment by Kevin McKinney — 14 Jun 2010 @ 10:33 PM

  53. “The yearly cycle of sea-ice growth and decay appears to be increasing, since the minimum extent is declining faster than the maximum extent.”

    The maximum extent being limited to how long and where there is no sunlight, not to the temperature (well, very much less).

    It’s why maximum sea ice extent is not an indicator of temperature, whilst minimum is.

    Maximum sea ice extent IS a good indicator of axial tilt, mind.

    Which is also an effect in the Milankovich cycle.

    Comment by Completely Fed Up — 15 Jun 2010 @ 2:22 AM

  54. “I actually said the amplification effects are potentially exaggerated.”

    In what way?

    “The point of my post was that GISS is the only major temperature data set that covers the Arctic”

    Not really. The Russian dataset is quite large.

    “and it is the warmest of the data sets because of the Arctic amplification effect it reports.”

    Circular reasoning: there’s an arctic amplification because the GISS shows a greater warming because it’s including the arctic which has an amplification of warming in it, which is there because the GISS shows a greater warming because…

    “It seems to me that extrapolating shoreline data 1200 km across the Arctic does precisely that kind of overestimation.”

    Unless that point you’re extrapolating is actually spatially anomalous in a cooler sense. (Why would it not be?). Therefore there’s an UNDERestimation going on there.

    There is no GISS amplification of warming. There’s an “inclusion of the Arctic increase in uncertainty”, or amplified uncertanty, but uncertainty goes both ways. NOT just warming, but cooling too.

    Please reread this post:

    http://www.realclimate.org/?comments_popup=3607#comment-177478

    It explains your issue correctly.

    Comment by Completely Fed Up — 15 Jun 2010 @ 2:30 AM

  55. B. Buckner,
    If trends continue, there will likely be lots of bouys where the ice used to be to measure temperatures directly.

    Comment by Ray Ladbury — 15 Jun 2010 @ 4:20 AM

  56. I suggest, though, that there is a negative feedback as well – melted sea ice allows more heat to escape from polar oceans..

    Huh? Are you saying the albedo effect doesn’t exist, which is nutty, or, are you acknowledging that there is a heat loss when the fall sea ice forms, which is true? If the latter, it doesn’t compensate for the heat gained by the lowered albedo, nor does it result in radiative transfer to space. The formation of the ice merely transports some heat from the water to the air, which is reflected in higher anomalous fall Arctic air temps.

    Your “the AO will save us” ain’t happening, and I see no mechanism by which it would.

    Comment by ccpo — 15 Jun 2010 @ 6:09 AM

  57. “Huh? Are you saying the albedo effect doesn’t exist,”

    No, he’s ignoring it because it’s devastating to his case.

    Comment by Completely Fed Up — 15 Jun 2010 @ 7:08 AM

  58. #56–

    I think the idea of “melted sea ice allows more heat to escape from polar oceans” is meant to refer to [assumed] heat transfers from ocean to atmosphere during what we might call “minimum season.”

    The problem is that there is no quantification of the various effects involved in this imagined scenario. How–and how much–does the ocean (assuming it is warmer than the lower atmosphere) warm the air? How much additional evaporation (with attendant heat transfers) takes place?

    The biggest questions I have are:

    1) why assume the heating is even predominantly ocean-to-atmosphere during the “minumum season?” This when air temps are elevated; why shouldn’t a good percentage of direct heat transfer in fact be in the opposite direction?

    2) To what extent can atmosphere efficiently sink/source heat from the ocean anyway, given the heat capacities of each? Seems like the atmosphere would be rather a poor “counterweight” in this sense–which brings us back to the importance of the albedo feedback again.

    Comment by Kevin McKinney — 15 Jun 2010 @ 7:27 AM

  59. Sanity check, please.

    I was looking at the animation of Arctic ice melt at Cyrosphere Today and felt I could actually see the swirling motion of the Beaufort Gyre. In fact, it almost felt like there were two (or that it shrank and grew), one off the north coast of Alaska, and another centered on the north pole that seemed stalled/inhibited as the ice bunched up against Greenland.

    It appeared that Greenland, Svalbard and Ostrov all formed a wall that both helped to direct the gyre, and caused the ice to lock up. It was as if it were trying to swirl the ice around, but it would all get congested and compacted with no place to go.

    I don’t know if this was just an optical illusion, or if it really happens.

    My thought was, however, that the presence of enough ice there was a key factor. I went back and looked as far back as 1980, and only 1997 and 2005 showed any gap of open sea off the coast of Ostrov, and then only a sliver at the very end of the melt season.

    My line of thinking was that if the ice melts early enough to open a noticeable gap off of the coast of Ostrov, then the “swirl” may be able to become more pronounced, and literally spill some of the ice out (path of least resistance) into the open ocean by redirecting it south into the Norwegian and Greenland seas, rather than packing it up against Greenland. This would in turn open the gap further, and thus greatly accelerate the rate of melt.

    If this is the case, then this would represent a physical (mechanical) tipping point.

    Does anyone know much about this? Or is it all just ill conceived rubbish caused by misleading Internetelligence (which is like real intelligence, except it’s available to any fool with an Internet connection)?

    Comment by Bob (Sphaerica) — 15 Jun 2010 @ 7:30 AM

  60. Addendum: I know Arctic winds are supposed to affect things… perhaps it’s the wind and ocean current and not the land which locks the ice, in which case a clear path would probably not matter (because it’s not clear, the wind is still there). I should probably think about things longer before I post. More research would probably help, too…

    Maybe I could start a new approach, one where people think carefully before they post, only after educating themselves thoroughly from varied and valid sources. Perhaps I could lead the way to a new age, an age of rebirth, a Renaissance!…

    Naaaaaahhh!

    [Apologies to Steve Martin/Theodoric of York, and SNL.]

    Comment by Bob (Sphaerica) — 15 Jun 2010 @ 7:38 AM

  61. Re: #52, Kevin McKinney

    The name “Arctic Mediterranean” is used to denote the similarity with the Mediterranean Sea. The Arctic Ocean and the Nordic Seas are connected thru the relatively deep Fram Strait. The resulting basin is separated from the North Atlantic by the ridges between Greenland and Iceland and between Iceland and Scotland. The water which sinks as part of the Thermohaline Circulation (THC) anywhere within that basin must eventually add to the overflows across the shallow sills in the Denmark Strait and the Faroe Bank Channel. These waters flow into the North Atlantic, where they tend to sink deeper into the ocean, the amount of flow increased by entrainment with surrounding water. Add in the sinking waters from the Labrador and Irminger Seas and what results is called the Atlantic Meridional Overturning Circulation (AMOC).

    E. S.

    Comment by E. Swanson — 15 Jun 2010 @ 7:41 AM

  62. RE:#56
    The albedo effect in the Arctic is minor. When the sun is at its highest (now) the Arctic is almost entirely covered in ice. When the ice reaches its minimum in September, the sun is low in the sky and the light reflects off the ocean surface. The albedo effect would be more prominent at the edges of the ice in the northern Pacific and Atlantic where a pull back of the ice would expose the water to more direct sunlight in the summer.

    Comment by B Buckner — 15 Jun 2010 @ 9:43 AM

  63. “The albedo effect in the Arctic is minor.”

    Have you done the calculations, BB?

    Comment by Completely Fed Up — 15 Jun 2010 @ 10:11 AM

  64. #20, Tim, you might want to get more samples about Western European temperatures. Here are some anomaly plots starting with the 1659 English data going up to 1800. These included the Cen. England, DeBilt, and others from Upsalla, Berlin. Paris. Rimfrost http://www.rimfrost.no/
    is a good source for these early temps. The 1750-2008 data includes those records starting before 1750. The 1800-2008 data are those records starting prior to 1800.

    http://www.imagenerd.com/uploads/lt-temp-1650-2008-1-Rxrdy.gif
    http://www.imagenerd.com/uploads/lt-temp-1750-2008-4-EyvXd.gif
    http://www.imagenerd.com/uploads/lt-temp-1800-2008-14-9ZSv8.gif

    Using a Fourier convolution lo-pass filter of 40 years, one can get a picture of some of the secular changes going on, especially at the end points. Unfortunately we do not have ocean records back that far.

    Comment by J. Bob — 15 Jun 2010 @ 11:24 AM

  65. ccpo #56: I’m not saying “the AO will save us”. Quite the opposite, in fact. I’m saying the AMO might confuse our perception of GW. Its effect needs to be determined as a priority, so that when it enters a different phase people aren’t saying “the Arctic ice isn’t melting any more, maybe GW has gone away”, undermining political action.

    There’s virtually nothing on the AMO in the 4AR. I suggest that the next AR redresses this situation, either taking it into account or refuting the idea.

    I started investigating the AMO back in February when I saw how Professor Latif was treated in the UK media, as detailed in a post on my own blog. It didn’t seem to me that he’s obviously wrong and I’ve found nothing since to suggest that conclusion.

    I asserted that “melted sea ice allows more heat to escape from polar oceans”, which you seem to think is a crazy statement.

    How can I explain this point without being called “nutty”?

    Let’s consider the marginal case of the last km2 of ice up towards the pole. Either this bit of ice melts or it doesn’t. Compare the two cases.

    Note first that the minimum Arctic sea ice extent is in mid September, the start of winter. I don’t think the albedo effect is very powerful in winter.

    Case 1: The water under the last km2 of ice could be several degrees above freezing and still not have time to melt it right through before the start of winter. Ice insulates. Most of the heat will remain in the water all winter.

    Case 2: If the ice does melt through, though, then it’s going to refreeze, extracting all the energy that was put in to melt it. But a lot more heat will be taken out of the water than in case 1. First, we were melting freshwater, but because the water mixes we’ve now got to freeze saltwater, which requires cooling the water to a lower temperature. Second, convection will carry cold water downwards so that we have to cool a significant depth of water in order to freeze the surface. Third, we have to overcome physical effects during freezing (the same applies to areas of thinner ice that never melted in the first place). If ice cracks, vast amounts of heat escape to the bitterly cold atmosphere – I read somewhere up to 1000W/m2 – and you can end up with pressure ridges of ice 30m deep.

    A lot of weight is given to the temperature of the Arctic being warmer than usual in winter. But we need to consider the heat in the system. Yes, a higher temperature means there’s more heat at the surface, but that heat has been exported there from elsewhere. It is being radiated away. All else being equal, the planet loses more heat the higher the Arctic winter surface temperature.

    Consider this analogy. If I go out in winter in a thick jacket, but no gloves or hat, then I lose heat from my head and hands, that is, from the parts that are at a higher temperature to the touch or to a thermal imaging camera.

    Basically, Arctic warming is one way excess heat trapped by GHGs is escaping from the planet. All my previous comments on here have been trying to do is highlight the politically important point that there’s no reason to suppose Arctic warming is a linear process.

    A final point. Sure, the albedo effect reinforces the warming of Arctic waters in summer, causing more ice melt. But if more ice melts, that just means more is going to freeze in winter. Even in the first approximation (i.e. ignoring the fact that you have to take more energy out to freeze the water again than you put in to melt it), it’s a zero-sum game.

    What we should be more concerned about is decreases in the maximum ice extent (e.g. loss of the Odden ice tongue), because that indicates we’re starting to reduce the capacity of the system to lose excess heat. The minimum ice extent tells us a lot less about that.

    Comment by Tim Joslin — 15 Jun 2010 @ 1:36 PM

  66. 65 (Tim Joslin),

    There are few points you make that don’t jive with my understanding.

    If the ice does melt through, though, then it’s going to refreeze, extracting all the energy that was put in to melt it.

    Ice does not extract heat when it refreezes, it releases it. That is, if you have water at 1C, and air at -1C, the water drops to 0C and freezes, and the air rises to 0C (having absorbed the latent heat of fusion from the water). Of course, I’m using temperatures incorrectly and somewhat arbitrarily to make a point, but you get the drift.

    …but that heat has been exported there from elsewhere. It is being radiated away. All else being equal, the planet loses more heat the higher the Arctic winter surface temperature.

    and

    Basically, Arctic warming is one way excess heat trapped by GHGs is escaping from the planet.

    You sort of jumped tracks here. Yes, the heat is being shifted (atmosphere to ocean, or vice versa, and in H2O phase changes), but how do you jump all the way to “radiated away” and “the planet loses?” It’s no longer in the water, or air, but that doesn’t get it all the way out into space. It just moves it around within the system. You can’t defeat GHGs just by phase changes from liquids to solids and back again, or moving the heat from the equator to the poles, or vice versa. Shuffle, shuffle, shuffle, but it only leaves the planet through infrared radiation, period.

    But if more ice melts, that just means more is going to freeze in winter. Even in the first approximation (i.e. ignoring the fact that you have to take more energy out to freeze the water again than you put in to melt it), it’s a zero-sum game.

    What leads you to this conclusion? Who says “as much as melted last year must freeze this winter?” That’s an assumption without foundation, and you yourself contradict it later when you talk about the maximum extent chaning. There could easily be a situation where less re-freezes, and you have a lower maximum extent. Or more re-freezes, and you have a larger extent, but then maybe the subsequent rate of ice loss the following spring-summer-fall is so rapid that it still leaves you with a lower minimum. There is no reason to assume anything here.

    And you don’t take out more energy to freeze than you put in to melt… 1st law of thermodynamics and all that. When you freeze at the poles, you are taking the heat out of the water and putting the heat back into the atmosphere in equal measure.

    What we should be more concerned about is decreases in the maximum ice extent (e.g. loss of the Odden ice tongue), because that indicates we’re starting to reduce the capacity of the system to lose excess heat. The minimum ice extent tells us a lot less about that.

    But again, we’re not “losing” anything, it’s just moving from atmosphere to ocean or vice versa, and being tied up or released in a phase change. This part (the energy shuffling) is a zero-sum game.

    Except that if the minimum gets low enough, then there’s no more opportunity to extract heat from the atmosphere (through the melt process), and it has nothing to do except hang around to make the rest of the planet feel a little more toasty. So yes, the Arctic acts as a sort of air conditioner, absorbing excess heat by melting, and releasing heat by freezing, keeping the overall heat content of the atmosphere relatively stable (as long as there’s not more coming in than is going out, i.e. the effects of GHGs).

    What we should be concerned about is the melting of the Greenland and Antarctic ice packs, and glaciers, because this is melt that is not undergoing a subsequent re-freeze. That is, the act of melting is ice absorbing heat from the atmosphere to change into water. It holds atmospheric temperatures down by doing so (although I did the calculation once, and I don’t think it’s by much on an annual basis), until the day there is nothing left to melt, and any excess heat at that point has no place to go.. and raises global temperatures that much more.

    Comment by Bob (Sphaerica) — 15 Jun 2010 @ 3:03 PM

  67. http://www.realclimate.org‘s done it once again. Superb article!

    Comment by Winifred Jefferson — 15 Jun 2010 @ 3:44 PM

  68. Bob, thanks for that. Saved me a lot of effort.

    Tim, you’re either excited about an idea that you came up with and are not seeing the forest, is my guess. You are shooting heat exchanges at the water/air tranistion all the way through miles of atmosphere, ignoring the large body of info on colling between 1940 – 1970, ignoring the 160 year trend, etc.

    There’s no there there.

    Cheers

    Comment by ccpo — 15 Jun 2010 @ 8:27 PM

  69. The May NCDC numbers are out–there’s a whole lot of “warmests” going on, even as we say goodbye to El Nino for this turn of the cycle.

    http://www.ncdc.noaa.gov/sotc/?report=global

    Comment by Kevin McKinney — 15 Jun 2010 @ 9:40 PM

  70. Kevin McKinney wrote in 69:

    The May NCDC numbers are out–there’s a whole lot of “warmests” going on, even as we say goodbye to El Nino for this turn of the cycle.

    http://www.ncdc.noaa.gov/sotc/?report=global

    Actually it is when El Nino collapses that you expect the temperature to go up. Don’t understand the exact mechanics, but roughly speaking the warm water that upwelled during the El Nino is at that point circulating to other parts of the world’s oceans. Thus the peak world temperature generally follows the peak of the El Nino by a few months. However, the peak 12-month average global temperature will be the better part of a year after the peak of the El Nino.

    And in the meantime? The monthly anomaly will rise and fall, a bit like a swing that goes forward and back, but never quite as much either way once the initial force has been removed.

    The peak anomaly for NCDC for any given month was set back in February of 1998 at 0.8288°C. A bit higher than the 0.6853°C of May 2010 or even the March 2010 anomaly of 0.7784°C but certainly well above the May 1998 value of 0.6311°C.

    And we have nearly set a new record 12-month average global temperature for NCDC. The previous record set by the period Oct 1997 – Sept 1998 at 0.6365°C as the result of the Super El Nino. Our much more modest El Nino? So far this year the 12-month average global land and ocean temperature anomalies have been 0.5649, 0.5747, 0.5971, 0.6106, 0.6236°C. Wouldn’t be particularly surprising if the June monthly anomaly puts the NCDC 12-month anomaly up over the top.

    Of course with NASA GISS we have already been breaking the 12-month records for a bit. Prior to 2010, the last 12-month record was set in Jan 2006 – Dec 2007 at 0.6217°C. For the 12-month periods ending in the months of 2010? 0.5825, 0.6050, 0.6358, 0.6567. 0.6633°C. We never managed to break the statistical tie with the peak 12-month average set back in 1998 — until March of this year. And it continues.

    Comment by Timothy Chase — 16 Jun 2010 @ 1:43 AM

  71. PS

    My calculations are here:

    NOAA Calculations, land and sea (NCDC)
    http://spreadsheets.google.com/ccc?key=0Au57vongYoiAdGp5Vi1hc2lXMHdfZ3hUS2U4MjRPMUE&hl=en

    NASA GISS land and sea
    http://spreadsheets.google.com/ccc?key=0Au57vongYoiAdEQwRWdLT0lRWjFhNGY3NnpKb1J1d0E&hl=en

    Comment by Timothy Chase — 16 Jun 2010 @ 1:47 AM

  72. Bob #66: Thanks. Taking your points in order:

    1) Oops. Yeah, you’re right, that sentence about extracting energy doesn’t quite compute. I suspect I was thinking that if all the energy to melt the ice came from the air it would have to be returned to the air to refreeze the ice. But in actual fact what’s happening is:
    - heat from Arctic water which, since it can’t warm in situ under a layer of ice, must have warmed elsewhere, melts the sea-ice in summer (with some assistance from incident sunlight and air warmed elsewhere).
    - the sea then freezes over again in winter, which would indeed leave us back where we started if we assume the heat released on freezing is returned to where it came from to melt the ice. Except, as I argue in #65, the refreezing process involves cooling of the water column and the formation of briny cold deep water, i.e. removal of heat that has arrived from elsewhere by oceanic circulation. The sinking cold water draws in more (relatively) warm water to continue the process.
    - but, since the only thing colder than the water that’s freezing is the air, the actual latent heat of fusion is almost all lost, now I belatedly think about it clearly, to the atmosphere.
    The net result of the melt and refreeze process is therefore to extract heat from the Arctic waters. To labour the point, the melt and refreeze process can only happen if the ice actually melts.

    Thinking about it further, this process also occurs to a lesser extent even where the sea-ice doesn’t melt through, as it is thinned from below in summer taking heat from the water, and refreezes from above in winter, losing heat to the atmosphere. The heat flow is greater the thinner the ice. As I said, the ice is an insulating layer.

    2) Re. “jumping tracks”: maybe I should have said that what we should be most concerned about is heat in the oceans. As far as storage of heat is concerned, the atmosphere is bordering on irrelevant. Pretty much all the extra heat we manage to get out of the Arctic ocean in year x compared to year y is going to leave the planet. E.g. snow and rain may be fluffy white and wet stuffs, respectively, that come out of the sky, but they are also part of a fairly efficient mechanism for moving heat a few thousand feet up into the atmosphere from whence it can more easily be radiated away.

    This point simplifies the discussion somewhat. Basically, tropical oceans gain heat over the year and transport it N & S, and oceans at higher latitudes lose this excess heat over the year to the atmosphere and ultimately to space. My argument centres around the point that this loss of heat can happen more or less efficiently depending on the configuration of ice, in this case in the N.

    3) Annual amount of ice melting: yes, I was conscious of this assumption as I wrote. It’s a justified simplification. The change in maximum or minimum ice extent is small compared to the amount of melt and refreeze of the ice each year.

    4) Apparent violation of laws of thermodynamics: the point is that the Arctic ocean is not a closed system. In order to refreeze the surface layer, the water below has to lose heat that has arrived from elsewhere to the atmosphere as it cools and eventually freezes, as described in #65. As discussed in my point (2), once heat is in the atmosphere it can be radiated away, especially at high latitudes in winter. It can’t be if it’s in water, trapped under ice.

    I put it to you that we do “lose” energy from the planet. In terms of radiative balance, polar regions have a net loss of energy over the year; tropical regions a net gain. Energy moves from tropical to polar regions to approximately balance the equation each year.

    It’s not an exactly zero-sum game. The extent of the planet’s net gain or loss of energy over the year depends on a number of factors including the polar ice configuration (other factors are GHGs, ocean currents e.g. affected by El Nino, aerosols, surface albedo and moisture content etc).

    5) The Arctic won’t really ever export heat, because it’s colder than adjoining oceans, it can only ever import it less efficiently. But, the greater the annual fluctuation in sea-ice extent and volume, the more heat the Arctic will be able to import. This potentially sets up an oscillation in the system, as I argued in my earlier comments.

    Basically the Arctic is a cunningly designed machine to pump heat out of the North Atlantic (NA) and to a lesser extent the North Pacific (through the Bering Strait). It sucks in warm water, takes the heat out, and returns a cold deep current of water. It can’t do this so efficiently if it is clogged up with ice at the start of winter, so it gets behind on the job and the NA, in particular, warms. On the other hand, if too much of the Arctic ice melts in the summer because the NA water being drawn in is so warm, then the Arctic fridge will get ahead of itself and over some years drain so much warm water from the NA that the NA starts to cool. But that cuts off the supply of warm water and the Arctic sea-ice starts to rebuild… Hence, I suggest, the possibility of an Atlantic Multidecadal Oscillation, or AMO.

    6) Agreed. We should be concerned about loss of the Greenland and Antarctic ice-sheets.

    Comment by Tim Joslin — 16 Jun 2010 @ 5:50 PM

  73. I was wondering how much of a difference between albedo effect there is between ice and snow. To clarify, when I speak of ice, I’m talking about a clear ice. I could possibly see a potential for more freezing rain type events in my area. I’m asking out of curiosity. Thank you.

    Comment by JRC — 17 Jun 2010 @ 7:01 AM

  74. 72 (Tim Joslin),

    I put it to you that we do “lose” energy from the planet. In terms of radiative balance, polar regions have a net loss of energy over the year; tropical regions a net gain. Energy moves from tropical to polar regions to approximately balance the equation each year.

    But this energy isn’t lost by the planet as a whole, it’s just moved from tropics to poles. It’s only lost if it’s radiated into space (only!)… and that loss is primarily governed/modulated by the temperature of the planet (higher temperature = more IR) and greenhouse gases (which reflect the IR back, making it harder to escape into space).

    It’s not an exactly zero-sum game. The extent of the planet’s net gain or loss of energy over the year depends on a number of factors including the polar ice configuration (other factors are GHGs, ocean currents e.g. affected by El Nino, aerosols, surface albedo and moisture content etc).

    [See my note on El Nino's at the end of this comment, but for now...]

    I think, for me, the heart of where the hardcore denial crowd get it wrong is that too many people get caught up in all of the complex mechanations of the globe as a very intricate, complex, interwoven series of heat pumps and sinks; troposphere, atmosphere, ocean surface, deep ocean, ocean currents, winds, phase changes, etc. all shuffling the heat from here to there to there to there.

    But this is all just moving heat around inside of the system.

    What really matters, what it really comes down to, is the radiation imbalance between the planet and space. You can talk all you want about moving heat different ways, but in the end, if more energy is coming in than is going out, the planet is warming. That’s the core, undeniable problem. Detecting that warming is hard because it is so unevenly distributed and constantly shuffled, but it’s still there if the imbalance is there, no matter how you choose to try to measure temperature, or even if you fail to properly measure it.

    So the only important factors are:

    1) Solar irradiance, which is the total amount of energy received from the sun over a period of time, and which has been proven to be fairly constant.
    2) Albedo, which reduces the effects of solar irradiance by reflecting it back out (or not, as more ice melts).
    3) GHGs, which increase the effects of solar irradiance by reflecting it back inward before it escapes (until the planet heats enough to balance radiation out with radiation in).
    4) Feedbacks of any of the forms of 2 and 3, which either counter or amplify the effects of 1, 2, 3 and 4.

    Arctic ice is of importance for two reasons, no matter how much you dissect it:

    1) It has the potential to reduce the planet’s albedo, accelerating warming.
    2) It is further evidence of a warming world.

    Everything else is important for understanding how things work, but not for the final temperature of the planet. No matter how complicated a path you can configure to move the heat around, it’s still here in one form or place or another.

    On a side note, I’ve also come to realize that the importance of El Nino and La Nina is not that El Nino’s make the planet warmer. They don’t. They actually probably cool the planet, by exposing a larger surface area of warmer waters and subsequently warmed air, which will then radiate more heat into space more efficiently. Yes, it makes the measured temperatures of the planet warmer at that time, but the planet was the exact same temperature during the preceding La Nina. But the La Nina piles up the warm waters, keeping them from radiating their heat away and being noticed, so while the planet appears cooler during a La Nina, it is actually accumulating more heat.

    Everyone should root for more El Nino’s, to help slow global warming.

    I should take the time to do the calculations, to see how much an average El Nino might slow global warming by temporarily increasing outbound radiation, except my list of to-dos is far too long already. If anyone else wants to give it a try, I’d be grateful.

    Comment by Bob (Sphaerica) — 17 Jun 2010 @ 9:01 AM

  75. Bob #74: I hope you don’t think I’m part of the “denial crowd”.

    I’m confused, since you realise correctly that El Nino events raise the average surface temperature, but in actual fact cool the planet, or at least cause it to warm more slowly than would otherwise be the case, in the sense of causing it to lose more heat than it would without the El Nino. Exactly the same applies when there is less Arctic ice. The more relatively warm water is exposed in a given winter, and the less ice cover there is, the more heat the planet radiates away.

    I fully appreciate that moving heat around the planet doesn’t in itself do anything to reduce or modify the long-term effects of global warming. In my previous comment I explained how heat moves to the Arctic purely in order to show how it could either be trapped under ice or, when the ice is absent, lost to the atmosphere and hence much of it radiated away.

    Comment by Tim Joslin — 17 Jun 2010 @ 4:39 PM

  76. I guess I found my answer here as far as a range.

    http://en.wikipedia.org/wiki/File:Albedo-e_hg.svg

    Is this a fair reflection (no pun intended) of the ranges for albedo?

    Comment by JRC — 17 Jun 2010 @ 7:55 PM

  77. Bob (#74),
    The distribution of heat affects the radiation emitted. Obviously the temperature profile of the atmosphere is very important but there’s another matter to consider: the amount of radiation emitted by the surface is not exactly a function of the average surface temperature. If you have an object with two halves which have different temperatures, the radiation emitted will not be a function of t1 + t2 but of t1^4 + t2^4.

    Comment by Anonymous Coward — 17 Jun 2010 @ 8:20 PM

  78. I think I’ve learned more plodding through all your comments than anywhere else about how the science applies. Sometimes I wish I saw more “common sense” observations, but realize if the common sense matches the theory, that’s getting close to bingo. There was a graphic of the Gulf Stream going up by Greenland, which matches the frozen European story. There’s Sphaerica’s exposition of the complicated parts of the simple truth, that unless heat leaves our atmosphere it’s still here. And others …

    I’m not a big fan of ongoing exchanges with trolls, but perhaps there are others like me who learn from the answers if they are technical and not too repetitive or contemptuous. Not that the provocation isn’t there, but allowing it to kidnap the conversation once what’s really going on has been properly explained and illustrated gets a mite boring.

    Great links, if somewhat sad.

    On a lighter note (not exactly) if any of you didn’t see this:
    http://www.nakedcapitalism.com/2010/06/rachel-maddow-rewrites-obamas-oval-office-address-on-bp.html
    I wish!

    And for anyone delving into hurricane history Chris Mooney did a good complete job in Storm World a few years back.

    Comment by Susan Anderson — 17 Jun 2010 @ 11:06 PM

  79. 75 (Tim Joslin),

    I see your point about more exposed water, but I think both the total surface area of the Arctic, the time period during which more water than usual is exposed (due to extended melt — and it’s only the additional area that counts, not the total area), and most importantly the relatively low temperature of the Arctic as compared to the tropics means that the radiation loss due to more ice melt is minimal as compared to something like El Nino. I suspect that factor is inconsequential as compared to the change in Albedo (which admittedly suffers from all of the same limitations).

    Again, I wish I had time to actually do the math, even back of the envelope calculations to see how the two compare. It shouldn’t be two hard. The basic question is “does 1 square meter of open water at average summer Arctic ocean surface temperature emit more or less energy in IR than is reflected by 1 square meter of ice?”… taking into account the fact that GHGs will trap some of that IR, where it has no effect on the reflected sunlight.

    [I wasn't sure which side of the fence you were on, which is why I phrased the "denial crowd" comment so ambiguously :) ]

    Comment by Bob (Sphaerica) — 17 Jun 2010 @ 11:20 PM

  80. 77 (Anonymous Coward),

    I’m not sure I see your point. Can you be more clear?

    Comment by Bob (Sphaerica) — 17 Jun 2010 @ 11:21 PM

  81. Back to basics: The extra energy retained in the atmosphere by the increased amount CO2 has to go somewhere. If it does not enter the arctic and other glacial features on the planet weakening and melting the ice, it will go somewhere else. Another place it may go is to the oceans and other water increasing evaporation, which will produce higher humidity on locations with more intense rains. If the energy doesn’t do that, it may go to the atmospheric circulation producing more intense winds (low or high in the atmosphere). If the energy doesn’t do that it may go to the heating of the land and top soil producing drought conditions. If the energy doesn’t do that, it may go to the increased organization of the plants, algae and cyanobacteria which are the only living things capable of diminishing the total amount of CO2 in the thermodynamic system called earth (without additional energy input). So, it seems there is some choice as to what may happen in the future: Glaciers may melt, rains may intensify, winds may intensify, droughts may intensify, or plant, algae and cyanobacterial life becomes more abundant. At least one of these has to happen. All of these but one is not good for animal life. Given that one of these has to happen, odds are that somewhere plant life suffers from worsened weather conditions. This will increase the third part of life, the organisms that are decayers of other matter in living things. So the 6th option due the higher CO2 levels in the atmosphere is the collapse of primary producers, plant feeders and predators in some areas (ecological collapse).

    Stopping the logixc here, I must go to tend the garden.

    Comment by jyyh — 17 Jun 2010 @ 11:46 PM

  82. “I’m confused, since you realise correctly that El Nino events raise the average surface temperature, but in actual fact cool the planet,”

    The El Nino lets more energy leave the system because there’s more IR radiation intensity at the surface where it can eventually leave for space, rather than sit in the deep ocean where it hasn’t got an escape vector (the thermohaline layer forbids).

    Rather like a lagged hot water pipe is cooler than an unlagged one but the water in the lagged hot water pipe is hotter than the water in the unlagged water pipe.

    “Exactly the same applies when there is less Arctic ice. The more relatively warm water is exposed in a given winter, and the less ice cover there is, the more heat the planet radiates away.”

    Except ice has a nearby available phase change: melting.

    Takes a lot of energy to do that, and that depends on sunlight as much as temperature. How else can ice melt when it’s still at negative tempertures?

    “I explained how heat moves to the Arctic purely in order to show how it could either be trapped under ice or”

    You didn’t explain how that heat isn’t trapped there, but melts the ice there.

    Forgetting these things while going “doesn’t this make it all so much safer and make there be no catastrophe” is how you get painted with denialism.

    It’s unskeptical ignoring of the counters to your proposal.

    Have a read of the IPCC report. It has plenty of discussion about counter proposals and probable unconsidered causes in the report.

    If you don’t know, then it would be better to ask for explanation and NOT draw a conclusion that is different from the IPCC consensus.

    Comment by Completely Fed Up — 18 Jun 2010 @ 2:18 AM

  83. Bob (#80),
    You said that movements of heat inside the system (Earth) don’t matter, only the radiation to and from space. But the movements of heat affect the outgoing radiation…
    I gave you an example on top of the more obvious ones alluded to in recent comments: moving heat from a hot place on the surface to a cold place on the surface lowers the amount of radiation emitted by the surface (because the radiation emitted is a function of temperature to the fourth power).

    Comment by Anonymous Coward — 18 Jun 2010 @ 8:12 AM

  84. “You said that movements of heat inside the system (Earth) don’t matter, only the radiation to and from space. But the movements of heat affect the outgoing radiation…”

    Yes, so those movements only matter when they move eat outside to space.

    I can move a kettle of boiling water from house to house and room to room.

    But until I pour it in a cup with some instant coffee in the bottom, I don’t get a cuppa.

    “But you have to move it to the room that has the cup in!”.

    “Yes, but that doesn’t get me a cup of coffee, does it.”

    Comment by Completely Fed Up — 18 Jun 2010 @ 9:23 AM

  85. 83 (Anonymous Coward),

    Okay, what I didn’t understand was where you were headed with objects with two halves. You’re still not entirely clear, because you’re not specifying which hot place to which cold place you are talking about.

    Yes, some movements affect outgoing radiation by increasing the exposed surface area of warmer bodies (like El Nino), or decreasing the heat of the exposed surface area (like La Nina), but these are short lived on the relevant time scales, and episodic, so they generally balance out.

    I gave you an example on top of the more obvious ones alluded to in recent comments…

    Can you give specific examples of situations where you think the decreased outbound radiation (or “sequestered heat,” if you will) is both sizable, and long lived? In this case, I mean long lived enough to actually hold global temperatures down on a time scale relevant to the current dilemma (i.e. long enough for us to run out of fossil fuels, and then wait for the CO2 to fall out of the atmosphere, which looks to be on the order of a hundred years or many hundreds of years)? Because anything on a shorter time scale than that is actually just making things worse, by hiding the heat while the planet continues to absorb more.

    Comment by Bob (Sphaerica) — 18 Jun 2010 @ 9:44 AM

  86. Bob (#85),
    I can’t answer most of your question directly because you make unwarranted assumptions. Let me clear up something first: decreased outbound radiation causes a (larger) radiative imbalance and therefore (faster) warming. It doesn’t hold temperatures down as you state. The causality is in the other direction: lower temperatures cause a decrease in the outbound radiation.
    Again, “hiding” the heat in the oceans is not the only way to cause a decrease in outbound radiation. A change in the distribution (not the amount) of heat on the surface can increase or decrease total outbound radiation as I explained earlier. You ask for an example. Due to a change in circulation, my understanding is that Greenland was warmer than usual this winter while Northwestern Europe was colder than usual. As a result, the radiation emitted by the Earth’s surface should have been a bit lower (assuming the warming near Greenland was more or less compensated by the cooling near England of course).
    Circulation changes can have much larger effects (see the hypotheses about sudden climate change in the recent paloeclimatic record or the discussion about the thermohaline circulation in AR4 for instance) and need to be taken into account which is why the pros use these complex circulation models. Circulation changes not necessarily short-lived or epidosic. You mention ENSO so please check Mike’s recent RC entry about the MWP for instance: the balance between El Nino and La Nina seems to have changed and, in some models, one mode or the other is strenghtened by global warming.
    Finally, recent papers discussed on RC have claimed that the absorption of CO2 and heat by the oceans are so finely balanced over the long run that global temperatures would remain more or less stable over many centuries after the emissions from fossil fuel stop. I’m skeptical of course but these claims aren’t totally absurd. Don’t assume that processes which “hide” the heat are short-lived or irrelevant.

    Comment by Anonymous Coward — 18 Jun 2010 @ 8:12 PM

  87. 86 (Anonymous Coward),

    I can’t answer most of your question directly because you make unwarranted assumptions.

    ? ? ? (What assumptions?)

    I don’t think I disagree with much if any of what you said, and I suspect you are merely misunderstanding what I’m saying. I’m still confused about your point about two halves of an object emitting radiation differently (which is absolutely true, yes), only because I don’t see the point you were trying to make. Everything you said in post 86 seems to be in agreement with everything I’ve said/think.

    decreased outbound radiation causes a (larger) radiative imbalance and therefore (faster) warming. It doesn’t hold temperatures down as you state.

    This is certainly true, and I don’t think I ever said otherwise, although maybe my language was unclear because it’s important to distinguish between observed temperature, actual total system temperature, and changes in energy/heat content. I did say that increased radiation (such as due to a larger surface area of warm water during an El Nino) would hold temperatures down, as in reduce the rate of warming (not necessarily cool the planet, just warm it less quickly). La Nina does the opposite (less outbound radiation, more warming, even though the global surface temperature is measured as lower).

    A change in the distribution (not the amount) of heat on the surface can increase or decrease total outbound radiation as I explained earlier.

    Again, this seems to be a repeat of what I said (again, example is El Nino). But an El Nino lasts months to a couple of years. This is not long enough for CO2 to drop out of the atmosphere (assuming all emissions stopped on a dime), so over the long run it’s going to be balanced.

    Circulation changes can have much larger effects… Circulation changes not necessarily short-lived or epidosic. …

    Again, this is exactly what I was saying… that unless you can find something that is going to increase or decrease the outbound radiation for a very, very long time (i.e. not short-lived or episodic), then arguing about one particular mechanism gaining or losing energy is pointless. I was asking for examples of/ideas for such long term mechanisms.

    Finally, recent papers discussed on RC have claimed that the absorption of CO2 and heat by the oceans are so finely balanced over the long run that global temperatures would remain more or less stable over many centuries after the emissions from fossil fuel stop.

    Again, yes, this was my point. Unless something can bury the heat for a thousand years (e.g. sucking it down into the Great Ocean Conveyor), then phases changes, tropic to pole movement, etc. just shuffle the heat around the planet, increasing outbound radiation here, or for a time, and decreasing it there, for a time… but on average, over time, it stays about the same.

    I’m not sure where we disagree, or that we do disagree.

    Comment by Bob (Sphaerica) — 19 Jun 2010 @ 11:03 AM

  88. I downloaded the data from IJIS , normalized the daily numbers for each year to the peak extent for that year, and aligned the peaks. The plot shows that this year has had an anomalously large percentage rate of decline.

    Comment by Brian Dodge — 19 Jun 2010 @ 12:26 PM

  89. Wups – left out the link – http://www.imagenerd.com/uploads/ice_melt-fwHoy.jpg

    Comment by Brian Dodge — 19 Jun 2010 @ 4:04 PM

  90. thanks Brian Dodge, it’s good to see this one too, however the maximum ice extent date is quite hard to define on some years (two closely matching peaks or a long stagnation near the maximum extent). I have not calculated it (haven’t had the time and I’m not as confident of my maths skills), but defining the maximum for each year to be somewhere in the middle of these two peaks (or long stagnation) could be more informative. As individual years are compared, the gradually steepening slope in melting (that should be happening if warming is accelerating), should become apparent and somewhat quantified.

    Comment by jyyh — 19 Jun 2010 @ 10:10 PM

  91. Now that I’ve done 61-day averaging on the IJIS-data, it is clear one needs to apply some solar correction to that too. This is somewhat hard to do since the polar night applies differently on different dates, but I’m certain someone can do that too.

    Comment by jyyh — 20 Jun 2010 @ 2:18 AM

  92. I read somewhere with interest that the sun is not strong enough to have any impact on sea ice…. Wrong….. Very wrong, Antarctic sea ice melts completely during their summer. some of it South of 70 degrees latitude, right next to a huge very albedo like glacier. Venture like a tern back to North Pole ice, Most of which is North of 70 degrees North. Only thick, very thick perennial ice acted like the Antarctic ice Glacier. Now that it is mostly gone all none melting albedo is too strong bets are off. Need I remind at Local apparent noon the sun elevation is 38.5 degrees at 75 degrees North, right now. This was powerful enough to melt the thickest ice as was in 2007. Only the clouds spare the ice from transforming to water. When its very sunny as now is the case, goodbye ice:
    http://www.weatheroffice.gc.ca/data/satellite/hrpt_dfo_nir_100.jpg

    even in March and April with outside temperatures as cold as -25 C with sun elevations far lower, there is a significant diurnal temperature effect, when at night is almost always colder than during Local Apparent Noon. Imagine now 38 degree sun unhinged by no clouds, and the ice attacked on 2 fronts, the top and the warmer sea bottom. Bye bye indeed.

    Comment by wayne davidson — 20 Jun 2010 @ 11:39 AM

  93. “Need I remind at Local apparent noon the sun elevation is 38.5 degrees at 75 degrees North, right now.”

    And if you look at the numbers, that doesn’t shave off too much energy:

    http://en.wikipedia.org/wiki/File:Water_reflectivity.jpg

    38.5 degrees elevation translates to 51.5 degrees off normal; as you can see, reflectivity at this angle varies between 0 and about .08.

    To be sure, that’s the maximum value. But see this paper on how all this nets out:

    http://www.atmos-chem-phys.net/10/777/2010/acp-10-777-2010.pdf

    (Hat tip to LouGrinzo, who posted this link on Neven’s new Arctic sea-ice blog.)

    LG quotes this bit from the abstract:

    A disappearance of the Arctic ice cap during the sunlit period of the year would radically reduce the local albedo and cause an annually averaged 19.7 Wm−2 increase in absorbed solar flux at the Arctic Ocean surface, or equivalently an annually averaged 0.55 Wm−2 increase on the planetary scale. In the clear-sky scenario these numbers increase to 34.9 and 0.97 Wm−2 , respectively.

    Wayne has said elsewhere that he expects a lot of clear skies in the Arctic this summer due to the emerging La Nina–hence a very large melt event.

    Don’t know if that’s what will happen or not–having had my sea-ice expectations dashed a couple of times–but early indications don’t seem especially promising for the ice to hold up. It looks pretty fragile, if you look at MODIS imagery, or even Cryosphere Today for that matter, and temps continue to be quite elevated even after the fading of the El Nino. (Do I recall correctly that temps lag by about 6 months? That would take us well through the melt season.)

    For example, the 6/18/10 UAH value was +1.38 C. That’s relative, not to the baseline, but to 2009′s date, which was already one of the highest values in the UAH record! I don’t know how it relates to 1998, since the available graph begins 1998 with August values (due to satellite changeover, I think.) But the value is higher than the peak temps–typically occurring about a month from now–for every year except 2009 and 2005.

    We’re (still) living in interesting times. . .

    Comment by Kevin McKinney — 20 Jun 2010 @ 3:13 PM

  94. Another quote from the paper Lou posted is more relevant at this point in time, I think:

    We used the same methodology to calculate the effect of
    the forecasted September total sea-ice meltdown. Even if in
    all other months sea ice keeps its climatological extent, if we
    remove it for September, the annual absorbed solar flux increases
    by 0.32Wm−2, if we average spatially over the Arctic.
    The local effect of a September ice-free Arctic Ocean
    is eight times smaller than the enhanced greenhouse effect
    (2.5Wm−2).

    It will take quite some time for the Arctic sea ice to disappear during ‘the sunlit period of the year’.

    Comment by Neven — 20 Jun 2010 @ 9:12 PM

  95. Good god! Have you lot actually sat back and read all of your comments? It’s just supposition upon assumption upon tiny changes in poorly measured data upon tiny time scales upon vagueness upon the complete refusal to concede that man’s contribution to a trace gas is a tiny percentage i.e. our ‘contribution’ to the earth’s atmosphere is minute. Before you all sound off about GHGs, make sure you take water vapour into account ( which you AGW zealots love to ignore)

    [Response: Oh please.... Have you actually read anything we've written on these subjects? Start here. - gavin]

    Comment by Tiredofitall — 21 Jun 2010 @ 4:29 PM

  96. #95–

    Au contraire, “Tired,” the water vapor feedback is an integral part of the mainstream science. Do try to keep up with what you attempt to criticize.

    And if by “tiny percentage” you mean about 35%–390/290 = 1.3448–then yes, you’re right, we’ve contributed “a tiny percentage” to the atmospheric CO2 burden.

    Too bad it isn’t a good deal tinier–we’d all be a good deal safer if it were.

    Comment by Kevin McKinney — 21 Jun 2010 @ 6:41 PM

  97. Tiredofitall, Dude, why don’t you go to the peer-reviewed literature and find something that supports your currently unsupported opinions. Go ahead. We’ll wait.

    Comment by Ray Ladbury — 21 Jun 2010 @ 8:07 PM

  98. I would like suggest RC to keep up high profiling the Arctic ice melt, as its sea ice extent anomaly is about to reach 2008 and 2009′s 2 months earlier!

    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.arctic.png

    I expected this, and I also expected huge apathy from the rest of the world, especially about the plight of Arctic sea ice (and its unique ecosystems). Many further web spotlights would help accelerate the melting of this lethargy. I know there is a few sites out there dedicated for this , keep it up guys!

    Some comments are really good like 93 Kevin, and Neven as well. But RC needs to follow this really closely.

    Comment by wayne davidson — 22 Jun 2010 @ 1:12 PM

  99. Tiredofitall – Was that your attempt at fifteen minutes of fame?

    Comment by Richard C — 22 Jun 2010 @ 3:12 PM

  100. “But RC needs to follow this really closely.”

    I agree with Wayne, but at the same time I realize that after the shock of 2007 and the expectation of even greater losses of Arctic sea ice in subsequent years (Death Spiral) that didn’t come about, polar scientists are a bit more careful with their predictions.

    You see this reflected in the first SEARCH Sea Ice Outlook: http://neven1.typepad.com/blog/2010/06/search-september-sea-ice-outlook-june-report.html

    But I expect they will go all out if this rate of melt continues unabated.

    BTW, I have just finished a blog post with a really nice animation (if I say so myself) of the eastern part of the Beaufort Sea that gives a great insight in the Arctic situation: http://neven1.typepad.com/blog/2010/06/animation-3-beaufort-sea.html

    Comment by Neven — 23 Jun 2010 @ 3:12 PM

  101. Sea ice is now below 2007 in both extent and area even within the Arctic Ocean (Bering Strait to Spitsbergen, Siberian coast to Ellesmere Island, without Kara Sea; calculated from NSIDC daily data).

    extent area / Mm²
    2005-06-24 6.729 6.016
    2006-06-24 7.019 6.068
    2007-06-24 6.675 5.348
    2008-06-24 6.866 5.725
    2009-06-24 6.828 6.019
    2010-06-24 6.626 5.313

    Sea ice area isn’t reliable at this time of the year, but low values indicate extensive melt ponds. They developed about a week earlier in 2007, but quickly catched up this year because of very clear skies in much of the Arctic in the last days. They are also clearly visible even beyond 80° N in recent MODIS images

    Current weather forcasts are good for the ice at the Atlatic side of the Arctic (and maybe the Laptev Sea), but may cause increased ice export. Much ice in the Chukchi and East Siberian Seas looks already very rotten and will cease soon (well ahead of schedule, but not as fast as in 2007). Particulary bad news for the very old ice off the Canadian Archipelago. It will not melt (completely) in place, but become more mobile, and much of it will melt later in the Beaufort Sea. Some of it may intrude into the archipelago and block the Northwest Passage the next years. The most extensive melt can be expected within the archipelago. Most fractures dates will occur ahead of schedule (which was already well ahead of climatology). The parts of M’Clure Strait / Melville Sound that did consolidate at all, seem alread to have some cracks that weren’t present last week.

    Decrease rates in extent and area aren’t likely to accelerate as much as in July 2007, because Hudson Bay has already little ice left, but if the ice volume estimates are correct, much less extreme weather conditions than in 2007 are necessary to yield a new record low in Arctic sea ice extent.

    Comment by Andreas — 25 Jun 2010 @ 8:25 PM

  102. I have been looking at the satellite photos of the edges of GrIS for years, and I have seen what appears to be water vapor rising in enormous quantities from the edges that are deteriorating most rapidly, certainly when the melt lakes drain out all at once in a particular area. I have never seen this mentioned anywhere. Why doesn’t this get talked about? For a recent like event, look upstream of the Petermann Glacier, June 28, 2010, on this site: http://ice-map.appspot.com/

    Comment by Tenney Naumer — 29 Jun 2010 @ 12:46 PM

  103. Re 102, Tenney Naumer:

    Those are clouds, not rising water vapor. You can trace them back to northeastern Greenland:

    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?T101792020
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?T101791840
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?T101791705
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?A101791550
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?T101791525
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?A101791410
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?A101791235
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?A101791055
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?A101790915
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?A101790740
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?A101790600
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?A101790425
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?T101790030
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?T101782250
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?T101782115
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?T101781935

    Note that the image on ice-map.appspot.com is a composite of the second and third image. No northern half of the cloud field has already moved on westward.

    Comment by Andreas — 29 Jun 2010 @ 3:16 PM

  104. These things are not always “clouds” — they generally occur when the melt lakes drain en masse. I have observed this many times. Well, they become “clouds,” yes.

    They also rise up out of the upstream portion of the Jakobshavn Glacier.

    Or, do you think that massive melt lakes draining out all on the same day have no such effect?

    Comment by Tenney Naumer — 29 Jun 2010 @ 6:39 PM

  105. Dear Andreas,

    You obviously know how to get the images from these locations on GrIS. In future, pay close attention to the areas where the melt lakes build up and drain out most rapidly. A particular satellite has gone offline, but it used to be possible to see the changes in the water temperature around the coast of Greenland when the melt water rushed out. You will absolutely see that there are unusual clouds just above the upstream areas of the large glaciers and also now along the rapidly melting edges on mid to north western Greenland.

    Comment by Tenney Naumer — 30 Jun 2010 @ 6:05 AM

  106. This is an old comment from 2008:

    6 Pat Neuman says: 8 October 2008 at 6:21 PM

    Phillip,

    Yes, heat released by condensation of water vapor weakens ice. Foggy periods turn lake and
    river ice black in spring.

    The significance of latent heat for snowmelt has been described by Dunne and Leopold (1978):

    “If water from moist air condenses on a snowpack, 590 calories of heat are released by each gram of condensate. This is enough energy to melt approximately 7.5 gm of ice, which when added to the condensate yields a total of 8.5 gm of potential runoff”.

    Dunne, T., Leopold, L.B. (1978) Water in Environmental Planning; pp. 477‑499.

    OK, so if numerous enormous melt lakes drain out whoosh! in a day, doesn’t this mean that a huge amount of heat exchange is going on, sufficient to create clouds above the general area?

    Comment by Tenney Naumer — 30 Jun 2010 @ 5:22 PM

  107. > a huge amount of heat exchange is going on, sufficient
    > to create clouds above the general area

    Just guessing, but a volume of water going down into the glacier would displace a comparable volume of air, that would be pushed back out the upper opening; that could condense and make a visible cloud under some conditions. I don’t know if anyone’s measured airflow around those openings. I wonder if there’s any air path through the glacier.

    I’ve seen clouds form during wintertime dry cold weather, where a limestone cave has two openings, one high and one low — air inside the cave is relatively warm and humid, and the warmer air rising out the upper opening can make a noticeable cloud, drawing in air from below. (During hot summer weather the flow is reversed, and a wind of relatively cool air flows out the lower opening.)

    Just speculating.

    Comment by Hank Roberts — 30 Jun 2010 @ 7:07 PM

  108. I have read somewhere that when the melt lakes drain out, the water eventually gushes out with great force from the bottom, and flows into the sea. One can see on the satellite photos great streams of greyish sediment coming out of the edges of the ice sheet. Last year, where the sediment could be seen flowing out to sea, other satellite graphics (not available this year) showed changes in the sea surface temperatures. I’m not trained in physics, so it is hard for me to imagine all the ways that heat can be exchanged while the lakes (which these days are staggering in their sizes) drain down in such short time frames. Certainly, the effect is not insignificant.

    Not so long ago, it was thought that the outflow from GrIS’s glaciers was the main source of mass balance loss, but more recent work shows that the melt runoff now comprises about half of the loss.

    If it is true that the mass balance loss is no longer linear but more exponential, while at the same time the proportion of melt run off to glacier outflow is increasing, then is not rate of increase in the melt run off growing more than the rate of glacier outflow?

    I shouldn’t be trying to write this at 1 a.m., but it seems to me, at least, to be one of the more important aspects of what is occurring on Greenland right now.

    On another thread there was also some mention of how the moisture hanging in the air over the ice affected the amount of melt. If the melt lakes running out created large enough clouds, wouldn’t this be a positive feedback?

    Comment by Tenney Naumer — 1 Jul 2010 @ 11:21 PM

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