the Air Vent

Because the world needs another opinion

Antarctic Experiences Record High Sea Ice Level – Within the margin of error.

Posted by Jeff Id on September 27, 2012

Just now, from the Earth’s unloved backside, just when you thought the “death spiral” of northern polar sea ice had taken full hold of the public’s mind, the stupid Antarctic hits a new ALL-TIME high sea ice area record.

All time being defined as 34 ish years of course.  Stupid sea ice doesn’t know much about climate science does it!   From cryosphere today, using the very same gridded NSIDC data so often downloaded right here.
UPDATE: I have edited the title per comments below.  Thanks everyone.

UPDATE:A small step closer the absolute max ice area was recorded in 2007  – 16.232 Million Km^2 (per Sunshinehours1).  Without any checking needed, this is way inside sensor error range.

Arctic sea ice is still well below the previous record minimum:

74 Responses to “Antarctic Experiences Record High Sea Ice Level – Within the margin of error.”

  1. tallbloke said

    Thanks Jeff, I’ll pop a couple of rocks in my whiskey to celebrate.

  2. I think still 28,255.4 below 2007. But definitely a record for the day.

  3. David Appel’s posts on “Quark Soup” seldom attract more that a couple of comments other than the vapid “Dano”. However, when David unloaded on “CharlesH” the blog suddenly gained unmerited popularity with over 100 comments.

    Once the discussion turned to the “Cryosphere” things turned ugly:

    S.Davis pointed out that the loss of Arctic ice was not important given that >90% of the world’s ice surrounds the other pole. After that the CAGW clowns lost it. How many of you can answer “bahamamamma’s” question? It is a multiple choice question so please be sporting enough to make a guess!

    I suspect that many “Air Vent” regulars will know the answer without having to read the IPCC’s WG1 Chapter 4 (Cryosphere) drafts. Why not post your comments on “Quark Soup”? They need help from people who know what hard science looks like.

    • Matthew W said

      I think I know the answer.
      It would be better if you had posted the question here instead of having to go there to read it.
      I feel like I need to wash all the stupid off after reading some of the comments.

    • Net global sea ice is decreasing, and roughly this is adding about 10% to the enhanced greenhouse effect:

      • Would you like me to fix your calculation for you?

      • Arctic Maximum Sea Ice for 2012 was 14,433,281 about 98% of the 1980s average according to Jaxa.

        I’m not worrying about a 2% drop.

        • As for the mean … using Jaxa data:

          Jaxa only gives decadal averages before 2002, so 1985 and 1995 are the decadal averages for the 1980s and 1990s.

          Barely any change from 2005. And the 2012 number is year-to-date of course … year isn’t over.

          Year Mean Ice Area
          1 1985 11523641
          2 1995 11146502
          3 2002 8788207
          4 2003 10912937
          5 2004 10663564
          6 2005 10352763
          7 2006 10229750
          8 2007 9962932
          9 2008 10460809
          10 2009 10431044
          11 2010 10198010
          12 2011 9978963
          13 2012 10443014

          • David, if you have trouble with numbers, the mean of the arctic ice is down about 10% from 1990s and 8 or 9% from the 1980s.

            End of the world!


          • Actually I find that the current yearly mean is 13% below the 1980s average, and 10% below the 1990s average. But it’s not a question of just the numbers, but of what the loss means physically for the climate — and what the future, continued loss will bring.

          • When the AMO changes back to negative and ice minimum starts to climb again we will laugh even hard at your cult. Your cult told us temperature would continue to climb too.

        • The maximum isn’t especially relevant, since it occurs when the Arctic is in darkness and the albedo change doesn’t matter. The minimum is much more relevant for the ice-albedo feedback.

          • Are you suggesting the current 15 year temperature flatline is caused by less ice at the few weeks it is at minimum ?

            I personally think the AMO at maximum has more to do with it.


          • No, I’m not. I’m suggesting (to repeat myself) that looking at the maximum in Arctic sea ice isn’t especially relevant to the ice-albedo feedback.

            PS: What makes you think 15-yrs is a sufficient time to detect climatological trends? And what do you mean by “flatline?” GISS doesn’t show a flatline. Or UAH LT. Or NCDC.

          • Giss is flatline for 11 years.


            HADCRUT is flatline for 15 years.


            RSS down for 15 years


            UAH is 0.00298036 per year for 10 years


            The albedo for melt water covered sea ice is not that high.

            Sure, snow covered sea ice has a high albedo, but you don’t see that in the summer minimum.

          • And (again) why do you think these are climatologically relevant?

            You will always be able to find some X yr Y mth period where something is “flatline” — and people like you are sure to hype it, whatever it is. But why do you think they are relevant?

          • David, you are the kind of person who denies 1997 to 2012 is “climatologically relevant”, but insists 1980 to 1998 is total proof of AGW. An extra 3 years is not proof. And you wonder why people laugh at your cult.

            As for ice albedo feedback … prove it.

            Prove that bare ice with melt ponds has a significantly higher albedo than the ocean. Even better, prove bare ice with all the black carbon collected thoughtout the winter + all the dust from Mongolia sitting on the ice surface has a higher albedo than the ocean.

            You and Robert and the rest of your cult try to get people to picture sea ice with 3 feet of snow on it when you mention albedo. But those are winter conditions. Not summer conditions.

            Water on top of bare ice is as transparent as glass.

            Black carbon saturated bare ice absorbs more sunlight than the ocean.

          • Where exactly did I deny that 1997 to 2012 is climatologically relevant?

            You are trying to make hay from a small part of the picture: a 2-dimensional surface, which strictly speaking can’t hold any heat anyway.

            How about looking at something that *is* relevant to the type of energy imbalance caused by an enhanced greenhouse effect: the ocean.

            Its heat content is 1000 times that of that atmosphere (not to even mention the atmosphere’s surface).

            The thin surface layer is beset by all kinds of natural fluctuations. Foster and Rahmstorf found that, when these are accounted for, greenhouse warming continues unabated:

            “Global temperature evolution 1979–2010,” G Foster and S Rahmstorf, Environ Res Lett 6 044022 (2011)

          • If Tamino says it … it must not be true.

            I see you brought up albedo as a reason why sea ice minimum is relevant. I countered, and then you changed the topic.

            Thanks for making think about the albedo argument. I’m glad I did a little research and realized it wasn’t true or at least wasn’t a significant reasons to worry about the AMO and/or Black Carbon causing a small change in mean arctic sea ice.

          • Robert said

            Listen I will talk all day about the AMO as a contributor to Sea Ice variability and Arctic temperature change – but it is a very small contributor – it exacerbates the long term reduction when it is in its positive phase – it does not DRIVE the total change.

            Click to access Day_ERL_2012.pdf

            I’ve often felt an upper constraint of 30% is appropriate – they put a likely constraint a bit lower than that. One way or another the AMO is not driving the sea ice loss in the Arctic – nor is it the main driver or Arctic temperature change. Furthermore and more importantly I noticed you had a nice cherry pick up there – You chose HADCRUTv3 versus HARDCRUTV4 …. yet look at the difference that choice makes?


          • HADCRUT4 has no data past 2010. HADCRUT3 was good enough to start the AGW cult, why shun it now?

            As for AMO … I’ll wait for it to change to negative. Then we’ll see. Climate modelling is pathetic.

          • Robert said

            Its a fair point regarding HADCRUT4 not being updated up to present on woodfortress but that doesn’t at all excuse using the dataset that you know is biased low. In fact HADCRUTV4 is biased low still – there will be a paper submitted in the relative future that is conclusively going to show that. You know I played your little game with respect to the trends but lets be real here – the only reason they get lower slopes is because of a cherry picked start point. That’s fine – if you want to manipulate people with misleading graphs that’s your own choice – but in science one would get called out for doing so. Additionally Santer et al (2011) showed that the length of the record should at least be 17 years for the RSS dataset FYI.

            But as you said you will wait till the AMO changes and then see – so I presume you’re going to not making these assertions until that point? Or will you continue to make these mythical statements about Arctic Ice when you have shown that you haven’t got the science done to make them?

          • HADSST2 Southern Hemisphere is also negative for 15 years.


            As for “17 years” versus “15 years” …. the only reason Santer claimed 17 years is because 1940 to 1981 is flat and 1981 to 1998 = 17.

            Theee is only one real warming period since CO2 supposedly would have had a noticeable effect and it was only 17 years long. +/- depending on which GAT is used.

  4. Robert said

    So what was the point of bringing this up – or on the discussions above of Arctic maximum sea ice extent? The most important influence of sea ice on the earth’s radiation balance is the sea ice extent during summer because of its significantly greater albedo than the ocean surface below. The dynamics of Antarctic sea ice are very different from the Arctic sea ice – you used to have large areas of significantly thick multiyear ice during summer in the Arctic whereas for the most part the ice around Antarctica is first year ice that melts away each summer. Whether there’s more ice during the time of year that gets little to no sunlight is not enough to counter the large melts during the summer.

    Arctic Sea Ice = Anthropogenic Warming + Multidecadal Climate Variability + Synoptic Meteorologic patterns.

    • Robert said

      Lets not forget either that Antarctica is losing ice from its landmass as well.

      • Robert said

      • No it isn’t. It is gaining.

        • Carrick said

          I think Sunshine is right. The newer data that has a smaller systematic correction associated with it shows, as expected by models, that the land surface of Antarctica is gaining ice mass. In fact, for long term trends, other than a catastrophic breakup of the WAIS, there is virtually no way for it to lose ice mass over time in a warming climate, since warming climate + constant RH = more precipitation = more snow accumulation.

          • UAH’s SoPol 85S-60S has the trend from 1979 as -0.05C / decade

            There might be more ice because it is colder.


          • Robert said

            Okay a couple of comments – Firstly Sunshinehours1

            The data you are referring to is excluded by RSS because of the issues the satellites have over ice sheets. RSS deliberately cuts off their analysis at 70 south for this reason. Further to the point – there are still significant discrepancies between the RSS, UAH and STAR products. The TMT data from STAR from a new 2011-2012 publication (below) has a much stronger trend then the RSS and UAH data. In previous studies (Zou et al, 2006) they have made some corrections for discontinuities. From what I understand – you will see STAR eventually put out a TLT product (which is a synthetic product remember) which will have a higher trend than UAH and RSS.

            Click to access Zou_Wang_JGR_2011_AMSU-A-1.pdf

            One way or another the RSS guys don’t trust the Antarctic data so I would rather refer to published material on the subject which find that It has not been getting colder – you can check out the O’Donnell et al, Steig et al, and several other recent ice core studies

            R. O’Donnell, N. Lewis, S. McIntyre, and J. Condon, “Improved Methods for PCA-Based Reconstructions: Case Study Using the Steig et al. (2009) Antarctic Temperature Reconstruction”, Journal of Climate, vol. 24, pp. 2099-2115, 2011.

            E.J. Steig, D.P. Schneider, S.D. Rutherford, M.E. Mann, J.C. Comiso, and D.T. Shindell, “Warming of the Antarctic ice-sheet surface since the 1957 International Geophysical Year”, Nature, vol. 457, pp. 459-462, 2009.

            A.J. Orsi, B.D. Cornuelle, and J.P. Severinghaus, “Little Ice Age cold interval in West Antarctica: Evidence from borehole temperature at the West Antarctic Ice Sheet (WAIS) Divide”, Geophysical Research Letters, vol. 39, 2012.

            As for whether Antarctica is gaining or losing ice – I was always taught in my glaciology courses (including one in Antarctica) that Antarctica would gain mass because of the increased snowfall associated with warming. However the dynamical nature of glaciers in the Amundsen Sea Embayment, Antarctic Peninsula and in several East Antarctic glacier basins (Totten glacier comes to mind) was underpredicted. Particularly with several large glaciers being grounded below sea level. I’ve read the discussion you refer to and I disagree with the conclusions.

            Swally is a good scientist and I understand the way he trusts his datasets but to be frank his is just one of a series of estimates with icesat/ERS1 and 2. I can refer you to many others if you prefer – Additionally Icesat only ran until 2008 and had two of its 3 lasers go down several years beforehand – the footprint of icesat is very small per laser so it means that you really need a lot of interpolation – hence why the incorporation of the ERS data – however the one thing is certain – ERS1 and 2 use radar altimeters that are low resolution and have trouble with steep slopes. Unfortunately it means that the most dynamical areas of the ice sheet are not reflected in the final product.

            Thomas et al (2008)
            “At lower elevations, comparison of detailed repeat laser surveys over Jakobshavn Isbræ with ERS results over the same time interval shows substantial ERS underestimation of ice-thinning rates. This results partly from missing data because of ‘bad’ radar waveforms over the very rough surface topography, and partly from the tendency for large radar footprints to sample preferentially local high points in the topography, thus missing regions of most rapid thinning along glacier depressions.”

            Hurmans et al (2012)
            “In deriving elevation change rates (dH/dt ) from radar altimetry, the slope-induced error is usually assumed
            to cancel out in repeat measurements. These measurements, however, represent a location that can be significantly further upslope than assumed, causing an underestimate of the basin-integrated volume change. In a case-study for the fastflowing part of Jakobshavn Isbræ, we show that a relatively straightforward correction for slope induced error increases elevation change rates by up to several metres per year…”

            Now I see you also referred to a recent grace study – where they found that the GIA correction reduced the amount of change. That is true and I have never been a fan of GRACE for being the “standard bearer” though it can detect accelerations in ice loss effectively.

            Barletta et al (2012) find Antarctica is losing ice using an improved GRACE solution

            Click to access tcd-6-3397-2012.pdf

            As do Sasgen et al (2012)

            Click to access tcd-6-3667-2012.pdf

            “Antarctic ice-mass balance 2002 to 2011: regional re-analysis of GRACE satellite gravimetry measurements with improved estimate of GIA”

            “Therefore, our AIS mass balance of −103±23 Gt yr−1 is considerably less negative than previous GRACE estimates. The Northern Antarctic Peninsula and the Amundsen Sea Sector exhibit the largest mass loss (−25±6 Gt yr−1 and −126±11 Gt yr−1, respectively). In contrast, East Antarctica 15 exhibits a slightly positive mass balance (19±16Gt yr−1), which is, however, mostly the consequence of compensating mass anomalies in Dronning Maud and Enderby
            Land (positive) and Wilkes and George V Land (negative) due to interannual accumulation variations. In total, 7% of the area constitute more than half of the AIS imbalance (53 %), contributing −151±9 Gt yr−1 to global mean sea-level change.”

          • Robert, if you don’t trust UAH satellite data, it must have many redeeming features.

            However, even with some of Antarctica excluded, the nearest area on RSS is blue … colder.

            S09 and O11 used the base period 1957-2006. 1957 was pretty cold. About .2C colder than the 1940s for example in HADCRUT3SH.

            HADCRUT3 has the southern hemisphere cooling at -.07C / decade for the last 15 years. Not far off UAH.

            GISS-M’s map has very little Antarctica coverage, but what it does have is colder than the 1981-2010 base.

            As for GRACE. I believe everytime its data is used to definitely prove X … a few months later it turns out it wasn’t true.

            “The Scientific Committee on Antarctic Research report prepared for last week’s meeting of Antarctic Treaty nations in Washington noted the South Pole had shown “significant cooling in recent decades”.

            Australian Antarctic Division glaciology program head Ian Allison said sea ice losses in west Antarctica over the past 30 years had been more than offset by increases in the Ross Sea region, just one sector of east Antarctica.”


          • Robert said

            “The Scientific Committee on Antarctic Research report prepared for last week’s meeting of Antarctic Treaty nations in Washington noted the South Pole had shown “significant cooling in recent decades”.

            Australian Antarctic Division glaciology program head Ian Allison said sea ice losses in west Antarctica over the past 30 years had been more than offset by increases in the Ross Sea region, just one sector of east Antarctica.”

            Yes – Sea Ice – not Land ice. Ian Allison wrote a paper (Allison et al 2009) which in fact discusses how Antarctica’s LAND ICE is losing mass significantly.

          • Robert said

            “As for GRACE. I believe everytime its data is used to definitely prove X … a few months later it turns out it wasn’t true.”

            No that’s false. Grace has had some large estimates (200 GT year) and some smaller ones (80 GT year) but it is certain that Antarctica is losing ice according to grace. Further to that point we have Radar Interferometry which is used by Rignot et al (2012) and they find that Antarctica is significantly losing ice. Radar interferometry allows you to actually measure the speed up in the ice – it’s actually quite incredible to use. For the record I should mention my background is in Cryospheric remote sensing.

            I’ve never been a big fan of Grace – there are a wide range of estimates available but they all inherently conclude that around 100 GT of ice is being lost right now – probably more. And that the losses from the Amundsen Sea Embayment are quite spectacular. The only measurement technique which has been systematically shown to be biased is Radar altimetry. That’s why Cryosat-2 is very important. This is a much higher resolution sensor with more advanced radar altimetry capabilities.

            I have actually discussed ice sheet measurements at skeptical science rather extensively a few years ago

            There is also an outdated presentation on Antarctic Land Ice Changes here:

            Click to access Antarctic_Presentation.pdf

          • Robert, if you link to Skeptical Science you lose.

          • Carrick said

            Robert the problem is GRACE makes systematic corrections that are large compared to the quantity they are trying to measure, and the answer to the question “did GRACE overestimate ice loss in the Antarctica?” is “probably yes”. To be clear, my worries about GRACE have always been about issues with the way isostatic rebound gets estimated and corrected for, and the magnitude of that correction compared to the measured quantity (it’s always bad when you have a systematic correction with an inexact model that results in a larger correction than the quantity you’re trying to measure).

            Mass Gains of the Antarctic Ice Sheet Exceed Losses. What I like about ICECAP is the systematic corrections are substantially smaller (if I’m reading it right they up to a factor of three smaller than those made by GRACE/)

            See also this, which argues forcibly against the larger ice loss estimates being correct.

            To balance this out, there are two main competing factors, a change in the dynamic rate of ice loss, this is expected to happen near coastlines and is expected to lead to a thinning of ice near coastal regions of Antarctica and Greenland over time, and an increased accumulation of ice in the interior of both ice sheets. Because there is much less mass along the coast lines than there is in the interior, the expectation long term (as best I understand it) is the interior ice gain will outweigh the dynamic ice loss along the coast lines.

            That said, unfortunately SkS is primarily an advocacy website. It’s unfortunate that they try and combine that with science, I find it just confuses the debate even more (because people conflate John Cook’s obviously one-sided versions of “truth” with those of a real climate science.)

          • Carrick said

            * with those of a real climate [scientist.]

            Cook is an interested layman. He started SkS to “combat” skeptics. That combination hasn’t from my perspective led to anything interesting.

            From Zwally’s abstract “Although recent reports of large and increasing rates of mass loss with time from GRACE-based studies cite agreement with IOM results, our evaluation does not support that conclusion.” Zwally’s treatment compared to Cook’s is the difference between a professional running back and a kindergartener carrying around a nerf football.

            It’ll be interesting to see the manuscript from ICECAP when it comes out.

          • Robert said

            Umm John Cook did not write the articles above that were sent to you. Look cryospheric remote sensing is my thing – i’ve taken a lot of courses on it and actively participated in research in the field – though mostly with respect to small mountain glaciers. That being said I’ve been fortunate to work with some of the best remote sensing of ice people in the world including people who literally wrote the book on mass balance measurements and on remote sensing of glaciers. The opinions that I have heard are not in support of the extremely negative grace measurements – I have been very clear that I do not agree with the largescale Grace measurements because I too have issues with the size of corrections and the level uncertainty with GIA. That being said I also know radar altimetry rather well and I noticed that the Surveys in Geophysics paper by Zwally continues to ignore what has conclusively been shown elsewhere – that low resolution radar altimetry is biased towards mass gain versus mass loss on icesheets. His paper doesn’t even cite Thomas et al (2008) which essentially shows that the ERS based method is insufficient for dynamic regions.

            Thomas et al (2008)
            “At lower elevations, comparison of detailed repeat laser surveys over Jakobshavn Isbræ with ERS results over the same time interval shows substantial ERS underestimation of ice-thinning rates. This results partly from missing data because of ‘bad’ radar waveforms over the very rough surface topography, and partly from the tendency for large radar footprints to sample preferentially local high points in the topography, thus missing regions of most rapid thinning along glacier depressions.”

            Hurmans et al (2012)
            “In deriving elevation change rates (dH/dt ) from radar altimetry, the slope-induced error is usually assumed
            to cancel out in repeat measurements. These measurements, however, represent a location that can be significantly further upslope than assumed, causing an underestimate of the basin-integrated volume change. In a case-study for the fastflowing part of Jakobshavn Isbræ, we show that a relatively straightforward correction for slope induced error increases elevation change rates by up to several metres per year…”

            Flament et al (EGU)
            “Comparison with previous results from ERS-2 reveals large scale variations due to the variability in meteorological forcing, especially in East Antarctica. Some coastal areas are experiencing rapid changes with thinning rates reaching several meters per year. Comparison between ICESat and Envisat over the common 2003-2009 period reveals that ICESat is likely overestimating dh/dt (elevation change) in the inner continent while Envisat encounters problems that become apparent north from 70S and where surface slope exceeds 1.”

            Click to access EGU2012-1842.pdf

            I’m just saying that in general Zwally’s work though interesting – is almost certainly underestimating ice losses in Antarctica.

          • Jeff Condon said


            I know you wrote the articles and I know you claim expertise in remote sensing, however, I claim expertise in instrumentation in general, many more years than yourself, and the level of sensitivity of these instruments does not justify this conclusion – “is almost certainly underestimating ice losses in Antarctica.”

            What you have is an uncertainty which you have to correct and it is time to recognize that your chosen field is absolutely putrid with exaggeration of both knowledge and certainty. A more scientific conclusion, and politically safe for yourself, is that the balance of papers is toward the loss of Antarctic ice, however there are contradictory results which means that more study is required. Something like that gives plenty of room to let the data take you where it will while still seeking funding.

            I have studied Antarctic climate and if I had to throw my own version of your unscientific set of dice, I would bet against the severe ice loss papers. I have a lot of difficulty seeing how the minimal warming of the mid-Antarctic could cause substantially increased shear toward the oceans. The ice thickness doesn’t support the conclusion IMO.

            Sometimes, immersion in the field prevents independence.

          • Robert said

            Also from that same IsMASS

            Overview of the Ice Mass Balance Inter-comparison Exercise
            Erik Irvins and Ben Smith

            “Different Laser Altimetry groups (4) found significantly different mean rates of mass change, chiefly in East Antarctica where correction magnitudes are large compared to elevation-change signals.”

            “Combining mass-change estimates for the 2003-08 period showed all three techniques agreeing for all of the regions to within estimated errors, except for Laser Altimetry on the EAIS where corrections tended to dominate the signal.”

            “The optimum target period for GRACE intra-comparison among six research groups was 2003- 2010. The results, with nGIA models used for Antarctica, gave WAIS = -108 ± 26, EAIS = +57 ± 35 and AIS = -81 ± 35 Gt yr, while for Greenland the loss determined in the experiment is much larger: GIS = -229 ± 27 Gt yr1. Clear acceleration of loss in WAIS and GIS, and a gain in EAIS, over the target time period is identified for the intra-comparison.”

            Essentially as I said – the preferred estimate is a loss (unlike what Zwally finds) and it isn’t as negative as previous Antarctic studies (-200).

          • Jeff Condon said

            Have you ever read Ben Santer’s work where he said all temp measurements agree with climate models. Agreement in climate science is only a lack of proof of disagreement. Pay close attention to what comprises the CI in these things.

          • Carrick said

            Robert, regarding SkS, I consider it an unreliable source; preferring technical articles (even of a revenue nature) over a blog founded on the principle of advocacy. So who else writes there besides the laypersons Cook or Dana, with his wonderful little ditties “Christy Crocks” and other such specious nonsense? Why should anybody take SkS seriously? If there were a guest post, I can’t imagine anything that called into question John’s pervasive sense of alarmism.

            I will till you I am disinterested in the answer her, I am not particularly interested in the “horserace” between ice loss and ice gain, having no vested interest in who is “winning”. I just know that Grace is not a reliable method for measuring ice loss, and if the large changes we’ve seen in estimates coming from it over the years certainly bear this out.

            In terms of who is more knowledgable, I’d say careful who you get in a p*ssing contest with. I think you might be surprised who would come out on top in that balance sheet, whether it be publications on experimental gravimetry, methods for remote sensing, instruments deisgned for remote sensing, vplanetary/solar modeling, or a variety of other topics (peer review publications? Number of citations? etc) Regardless of which of us came out on top would be irrelevant, science isn’t decided by pedigree. Even Dick Feynman was wrong once in a while (including in a dispute involving my own work), nobody is infallible, and I certainly don’t make that claim. It’s just the wrong road to go down in a dispute.

            I’ll put my money on Zwally on this one, and it has nothing to do with net balances of mass loss/gain budget sheets, but the arguments he lays down. Perhaps you can tell me why you find Irvins more persuasive, instead of just asserting it’s the “preferred estimate”.

            The preferred estimate by whom?

          • Carrick said

            Perhaps Robert could point to a peer reviewed publication similar to the one I pointed to, where Zwally lays out his case.

            I am open minded to other views on this, but something more than an abstract is needed here. (Wishing I had a copy of the proceedings.)

          • Mark T said

            Perhaps you can tell me why you find Irvins more persuasive, instead of just asserting it’s the “preferred estimate”.

            The preferred estimate by whom?

            The people that told him it was preferred. Lacking knowledge in a subject area, it is not uncommon for people – regardless of other education, to defer to those they “believe.” The irony, of course, is that their deference actually disqualifies them as objective arbiters of relevant merits of any argument (save those that cannot muster even fundamental truths).


          • Robert said

            This is certainly not a p*ssing contest nor do I intend for it to become one. I apologize if you have taken it that way. I don’t really have time this evening to go through this but I will get back to it tomorrow or the next day.

            “I’ll put my money on Zwally on this one, and it has nothing to do with net balances of mass loss/gain budget sheets, but the arguments he lays down. Perhaps you can tell me why you find Irvins more persuasive, instead of just asserting it’s the “preferred estimate”.The preferred estimate by whom?”

            I have given you two articles already:

            Importance of slope-induced error correction in volume change
            estimates from radar altimetry

            Click to access tc-6-447-2012.pdf

            A comparison of Greenland ice-sheet volume changes derived from altimetry measurements

            But if you would like some more here are some:

            Antarctic Ice Sheet and Radar Altimetry: A Review
            Frédérique Rémy * and Soazig Parouty
            “Depending on the technique (altimeter or gravimetry) and on the used methodology the western part
            is found to loss mass between −50 to −150 Gt and the Eastern part is found to gain mass
            between 0 to 60 Gt [115].”

            Dynamic thinning of Antarctic glaciers from along-track repeat
            radar altimetry
            Flament and Remy (2012) – Journal of Glaciology

            Click to access j11J118.pdf

            Horwath et al 2012
            Consistent patterns of Antarctic ice sheet interannual variations from ENVISAT radar altimetry and GRACE satellite gravimetry

            As for the preferred estimate – if you listen to the talks associated with the workshop and read the abstract I sent you previously – that abstract summarizes the state of the science. In it they state that the only form of significant disagreement was amongst the 4 groups doing Laser Altimetry estimates for eastern Antarctica – Zwally being one of those groups. If you read through Zwally et al (2005) which he uses as his preferred estimate in the Surveys of Geophysics paper, you will realize that the two papers I sent above are very relevant in that they point out that Zwally’s “preferred” estimate is without a doubt underestimating ice losses. There is no debate there – his paper underestimated ice losses. As for the abstract to his mass gains discussion (i’m assuming soon to be a paper) – many of the discussions above pertain to this paper – particularly the abstract citing the significant disagreement between icesat measurements in EIS, but also how icesat overestimated elevation change in the EIS (Flament et al EGU). Alternatively we have GRACE, Envisat Radar Altimetry and Radar Interferometry all giving a similar signal of ice loss. If you are going to be skeptical of GRACE then you certainly have to be skeptical of the Zwally abstract – and particularly of the Zwally et al 2005 paper.

            The truth is that there are papers and strong evidence that GRACE overestimates and that the altimeters underestimate, though in significantly different ways.

            Earlier on Carrick you stated that you have an issue with GRACE in that the corrections they make are larger than the signal – well you should be equally concerned about the results Zwally et al presented considering that their mass gains in the east are wholly dependent on this very same process whereby the corrections are greater than the change signal in many cases.

            “I have a lot of difficulty seeing how the minimal warming of the mid-Antarctic could cause substantially increased shear toward the oceans. The ice thickness doesn’t support the conclusion IMO.”

            It’s very simple actually – the atmospheric warming isn’t the driver of ice losses it is the dynamic nature of fast flowing glaciers along the coastlines which do. Warming oceans are the key point and it has been observed that a change in ocean currents and the warming ocean around western Antarctica has pushed warmer water underneath the vulnerable parts of the western ice sheet in the Amundsen Sea Embayment. This warm water is melting the underneath of these fast moving ice streams which is reducing the backpressure on the glaciers and allowing them to move quicker. This is actually the process which is dominating the ice losses in Greenland as well for the most part. Air temperature changes over ice sheets do not cause substantial amounts of melting for a long time – however changing ocean temperatures are the real kicker and they’re the most important factor in understanding ice sheet dynamics. What is dominating the ice loss in Antarctica is that the main drainage points for the West Antarctic Ice Sheet are flowing faster than they once were. You can literally see the speed up from space using Radar Interferometry but it has been verified in situ.

            Warm ocean is eroding West Antarctic Ice Sheet (2004)
            “Satellite radar measurements show that ice shelves in Pine Island Bay have thinned by up to 5.5 m yr−1 over the past decade. The pattern of shelf thinning mirrors that of their grounded tributaries – the Pine Island, Thwaites and Smith glaciers – and ocean currents on average 0.5°C warmer than freezing appear to be the source. The synchronised imbalance of the inland glaciers is the result of reduced lateral and basal tractions at their termini, and the drawdown of grounded ice shows that Antarctica is more sensitive to changing climates than was previously considered.”

          • Thanks for the paper links Robert. I read the links you left which are non-abstract and found them interesting. It is important that I clarify my point about shear affecting ice over long distances. Certianly the glaciers flow will be accelerated when the foot gets melted by plastic strain processes, however the vast majority of the Antarctic has shown little tendency for melting and a lot of the ice is a great distance from the oceans. Some of the plots show the ice thinning all the way to the center of the continent so I hope that they are taken with a thoroughly skeptical eye.

          • Robert, one of your references you did not provide a link for (and was easy to find):

            From the conclusions:

            “Twenty years of altimetry have shown that the Antarctic mass balance is near neutral, and
            consequently the ice has no impact on global sea level change.”


            “Antarctic Ice Sheet and Radar Altimetry: A Review Frédérique Rémy * and Soazig Parouty”

            The quote you provide continued: “. However, the comparison between the mass balance derived from ERS and
            Envisat for two different periods (see Figure 10) suggests that the strong temporal variability also
            explains a large part of the discrepancy, each study dealing with a different period.”

            Tsk tsk.

          • Carrick said

            Robert thank you very much for taking the time to post and for putting up with us cantankerous folk.

            About the only wise crack I have (and I’ve got a million of them) is Grace has varied so much in its estimates over time, it would probably agree with virtually any other study with a negative sign, just have to pick the right publication to match it up to. >.<

            That was very informative. This is good stuff! I'll wait to see if Zwally can get his paper published now, and how he addresses some of the criticisms of them.

          • Layman Lurker said

            Robert, you have way to much going for you to be hanging out at SkS. “Christy Crocks”? Give me a break. I take great offense to that icon every time I see it. You might not have said it but I know damn well from reading your forum comments that it likely offends you to. The type of discussion in this thread is what science is all about. If you come here and know what you are talking about and argue point rationally you will eventually get your point across (even to the most stubborn of us). On the flip side, you might learn a few things that will cause you to rethink your views as well. 🙂

          • Carrick said

            Footnote: Updated, improved GRACE model published today in Nature: Looking more like I was right, regarding ice loss in Antarctica. (Three brief summations: “group think”, “confirmation bias” and “science is not a democracy.”)

    • “its significantly greater albedo than the ocean surface below”

      I think you might be confusing ice in the winter when it is covered in snow versus ice in the summer when there is no snow cover.

      “Because ice is so transparent in the visible wavelengths, increasing the grain size does not appreciably affect the reflectance. The probability that a photon will be absorbed once it enters an ice grain is small, and that probability is not increased very much if the ice grain is larger. In the near-infrared, however, ice is moderately absorptive.”

      There should be little change in albedo between sea ice in the summer and open ocean.

    • “Light levels beneath ponded first-year ice are at least a factor of three greater than those beneath white ice of the same thickness (Grenfell and Maykut 1977).”

      When would you find ponded ice? In the summer.

      • Robert said

        Where would you find first-year ice? Antarctica… where did you used to find multiyear ice – the Arctic. That’s a very important distinction between the ice in both areas in that multiyear ice tends to have a higher albedo than first year ice.

        • You were arguing less ice means a lower albedo. I’m pointing out that albedo changes in the summer in the arctic may not be that different.

          I suspect the thin translucent ice melts first in the arctic. Meaning albedo changes would be minimal. And would only last for a month or so near minimum.

          Your albedo changes = major climate changes is weak and poorly researched and badly argued.

          • Robert said

            I did not argue that Albedo changes were going to cause major climatic changes – what I have argued is that relative to Arctic Sea Ice changes, Antarctic changes are very unimportant in terms of the radiation budget. You can always tell who is arguing dishonestly when they start projecting arguments on the other person which are not reconciled with what was actually said.

  5. Ice/water albedo is a fun topic. Smooth water is an easy enough thing to measure but water with waves becomes a complete crap shoot. There are also large variations in different kinds of ice. The link below shows the variation with incidence angle.

    Water :

    Ice has a wildly varying albedo which extends all the way up to 60% reflectivity and more.

    Looking just at the Arctic with an incident radiation of approximately 150 W/m^2, there has been about a 3 million sq km (3 trillion sq meters) difference in Arctic ice level in the last 30 years between absolute max and absolute minimum at any day of summer. If we take the total water reflectance (albedo) above 80 degrees to be 0.15 and the ice to be 0.4 then the estimated absorption of extra energy is 3 e12m^2 * 150 (.4-.15) = 1.115e14 Watts of additional absorption.

    Across the 510 trillion sq meters of globe that amounts to 0.217 watts/m^2 of additional forcing —- were the heating year round.

    Unfortunately, for advocates, the ice of the Arctic isn’t lit up year round. Generously it lasts for only 1/2 of the year, so lets say 0.106 Watts/m^w. A very small fraction of the 2ish Watts/m^2 of CO2 forcing claimed AGW advocacy groups.

    Then there is Antarctic ice, which keeps on growing and lives in a significantly lower 60ish degree latitude. The cosine difference of equinox positions (Earth Axis perpendicular to solar radiation) is visually about 60 degrees representing the Antarctic and 75 degrees representing my estimated Arctic representing nearly 2 times the available energy per sq meter at that date. I don’t have time tonight to mess with it, but this story of sea ice albedo isn’t as clean as presented by some.

    • HaroldW said

      Jeff, your 0.1 Wm-2, while obtained via “back-of-the-envelope” methods, agrees with a more involved calculation. As does David Appell’s — he gives 0.004 Wm-2 /yr, which over 30 years is about 0.1 Wm-2. Hudson 2011 takes into consideration cloud cover and the seasonal variation of insolation, and concludes that the increase in forcing due to Arctic sea ice over the period 1979-2007, is about 0.1 Wm-2. [This year’s value will be higher than that, perhaps closer to 0.15.]

      There was an earlier comment about the effect of carbon depositions on ice/snow. Over the same period, Hansen claims an increase in “snow albedo” forcing of a similar magnitude, about 0.09 Wm-2.

    • Robert said

      Tamino actually just did a post on this:

      • steveta_uk said

        It’s so hard to read Tamino’s stuff, because he absolutely cannot result throwing in gratuitous insults every third paragraph. If he has valid science and math to present regarding sea ice insolation, why for God’s sake doesn’t let let it speak for itself? I’m sure many others ignore him because of this constant nastiness – I only looked this once as it seemed relevant to this topic, but come away feeling like I’ve accidentally got caught up in someone else’s embarrasing public quarrel so will not be going there again any time soon!

      • Robert,

        I don’t go to Tamino’s blog anymore because I have to redo all of his work before it can be trusted. There is a significant amount of tweaked information there.

        I put the comment here because I thought it might stir some interest.

    • David said

      Indeed, the albedo picture is not clear. Not only is the ice at a lower latitude in th S.H; the earth is swinging closer to the Sun during the first few months of the melt. Also it is logical that there must be some night time loss of energy from the warmer currents in the artic once the ice is gone, as ice is an insulator to the ocean SST, especially during the coolest portion of the long artic summer days.

  6. steveta_uk said

    Jeff, your graphic of NH sea ice is very misleading, as it makes it look like there is a lot of noise, and that the minimum level is just a little below the long term average, and that the annual swing completely dominates the data.

    If you were a proper warmist, you’d show the data like this (preferably with the axes unlabelled):

  7. It appears I missed the 2 Antarctic Sea Ice Extent records (using NOAA data). I’m surprised they didn’t mention it.

  8. Jeff’s very recent data on Antarctic ice suggests that the present ice age will continue for a long time. The good folks who are writing the IPCC’s Working Group 1, chapter 4 (Cryosphere) report are working with data that is already eight years old so their estimates may be on the high side. Check out the IPCC estimates shown on page 17 of this document:

    The WG1 estimates cover the period from 1960 to 2004. The highest rates of ice loss they found were from 1990 to 2004 at a rate of 280 +/- 79 Giga-tonnes of ice per year.

    Thus if you believe the IPCC’s Cryosphere experts the rate of ice loss could be as high as 369 Giga-tonnes a year. That sounds really scary, doesn’t it?

    So what is the global ice inventory? About 30 million Giga-tonnes, so it wll take at least 80,000 years to melt all the ice.

    Don’t rush to sell your beach front property in Florida.

  9. Interesting post, thanks for sharing.
    I will pass this link along.

  10. M Simon said

    But wait. CO2 cracks ice.

    They have done simulations…..

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: