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Climate Audit 
307 Comments
Pretty much nightlights=0 đ
Ken Fritsch comment on models vs data in the Antarctic:
http://www.climateaudit.org/?p=2698#comment-217196
That is a lie. You are intentionally covering up your previous reference to what you referred to as a “money quote”. A quote which said:
“Bottom line: A cold Antarctica and Southern Ocean do not contradict our models of global warming. For a long time the models have predicted just that.”
Do you still wish to place money on this quote? Or don’t you?
From looking at various data sources, the general timeline I observe (YMMV):
* 50’s, 60’s, early 70’s: Antarctica shows a warming trend
* Late 70’s, 80’s, 90’s: Antarctica shows a cooling trend
* Last decade: Antarctica temperature trend flat (ish)
Conversely, if we look at the output of climate models:
* Late 70’s, early 80’s showed “polar amplification”, Antarctica rapidly warming
* Mid to late 80’s start to switch to show Antarctica cooling
It seems to me that climate models seem to respond to the recent atmospheric trends. Are the recent atmospheric trends good predictors of future climate model behaviour? Could be! Who wants to estimate the typical lag time? đ
Interestingly, the reason given by the modellers (or, at least, the recent RealClimate explanation) seems to be that the reason Antarctica cooled in the 80’s and 90’s is due to the lag in the Southern oceans; that SSTs would be slow to respond and keep Antarctica cool. Kenneth’s diagram here shows that the models appear to have entirely the wrong mechanism. (This was also touched on in a recent RPJr post)
I suggest we do not make any temperature adjustments, the effect of the stuff under the surface has a negligible impact. đ
John V, what is the source of this quote:
Is this “money”?
Kenneth Fritsch says:
I agree. Completely. Assertions of “match” or “mismatch” must be supported by data plots.
John V says:
The problem statement was the “money quote”, mentioned in #3. The statement you now seem to refuse to acknowledge:
This “money quote” was provided during a discussion on UHI/land cover effect in NH vs SH. Not only was your reply OT, you have since refused to support your assertion that this was a money quote.
I myself made no statement other than I was not so sure of the accuracy of that quote.
Everyone recognizes that model prediction accuracy in the Antarctic is critical. Why did you want to discuss it then, but not now?
The IPCC hindcast for the 20th century is in Figure 9.1, see http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_Ch09.pdf page 675. The GHG change is panel c and the sum of all forcings is shown in the bottom right panel f. This represents their postdiction of what the 20th century would look like if the models are correct. The Antarctic region is at the bottom right corner. It clearly shows the effect of…scissors. But peeking around the edges, sure looks like polar amplification in the model output.
#3 bender:
We must understand the “money quote” differently.
To me, “A cold Antarctica and Southern Ocean” means that the *average* for Antarctica and the Southern Ocean is cold. (That is, relatively cold compared to other trends, in the context of the original article). The quote was given in the context of refuting claims that less warming in the SH was evidence against AGW.
Perhaps you thought I was saying that every small region of the Antarctic and Southern Ocean agreed with the models. I was not and would not say that. From what I have seen, the model-vs-observation agreement is not good at that scale.
Although not statistically significant at the 95% level, the Antarctic and southern ocean are likely to very likely warming less than the Northern hemisphere. The model runs I have seen also show the Antarctic and southern ocean warming less than the Northern hemisphere.
That’s the point I was making. If you wish to extend the argument to finer details, then your argument is with someone else.
Re #9 Scissors! So John V is right! Saved by the scissors!
But that is not what the “money quote” says.
Are you saying you retract your statement that this quote has any value?
#12 bender:
Explain to me what you think the “money quote” says.
As I said above, to me it says that the Antarctic and Southern Ocean warming less than the NH (on average) is consistent with the models.
Re #10
Yes, yes, the scissor plot of IPCC Fig 9.1. Well done, old boy. That is certainly one way to cool down the model ensembles in the Antarctic region
I’m pretty sure the “money quote” says that a cold Antarctica and Southern Ocean do not contradict the models of global warming, that for a long time (post 1988?) the models have predicted just that.
What did you mean by calling it a “money quote”? That you agree or disagree with it?
Hey. Cut that out!
I assume the IPCC explains the missing data near the surface of antartica but I can’t seem to find the explaination. Is there one?
cce says:
I echo Ken Fritsch’s remark that any putative local/regional match between model and observations be shown without resorting to the mental overlay of fuzzy images of different projections covering different time scales.
The alleged match in warming trend in the peninsular area may well be stronger than in other areas or over larger spatial scales. I’d simply like to see the numbers. If we want to focus on that specific area, let’s do a time-series trend comparison.
#9 Why would you cut out parts of a hind-cast? Fore-cast, I could see.
From reviewing the GISS station data from Antartica, here is what I believe can be said: The historical instrument data from Antartica is spotty and many stations do not have a sufficiently long or continuous record to make conclusive statements regarding temperature trends at these stations. A handful of stations (suggest that this portion of Antartica has had a consistent warming trend for the last 50 years or so by perhaps 1-2 C over that time period. There is no conclusive data that other parts of Antartica have warmed at all and in fact may be slightly cooling although the data is so noisy and/or incomplete that any such trend is probably not statistically significant.
jmt from scanning the station data,
Bob North
Could someone please provide a brief explanation of this thread, been away and I’m a little lost. What cut out?
#21 Nothing was cut. We’re trying to find out what John V meant when he said that the RC statement in #3 was a “money quote”. This has to do with predicted vs. observed warming trends in the Antarctic region.
Context can be gleaned from #425-#428 in the Georgia Tech thread:
http://www.climateaudit.org/?p=2708#comment-217001
I’m basically whipping John V for breaking a blog rule, suggesting Steve M is not even-handed. I’m trying to show him his own lack of balanced, informed judgement. We were relegated to the rumpus room here to attempt to salvage something productive from the exchange.
18:
Look at the projections for the 1990s in Hansen’s ’88 paper for scenario B.
Go to the GISTEMP website, click on “Maps.” Enter 1990 as the beginning year and 1999 as the end year. Generate maps for annual, summer, and winter. This will allow you to compare observations with the model “predictions,” albeit the modeled anomalies are in relation to the 100 year control run. The biggest divergence between the models and observations is in the Arctic during NH summer.
Sorry, I meant NH winter.
#15 bender:
Please paraphrase your interpreation of the “money quote” in your own words, as I have done.
If you agree with my interpretation, then there are two parts:
1. Southern Ocean and Antarctica are warming less quickly than other regions;
2. Modern models predict the same;
I believe Figure 9.6 on page 685 of IPCC AR4 WG1 Chapter 9 demonstrates both parts. In particular, the fourth row shows the observed and modelled trends, with uncertainties.
Click to access ar4-wg1-chapter9.pdf
In a previous thread I provided links to IPCC AR3 graphics showing similar patterns:
http://www.climateaudit.org/?p=2708#comment-217172
I also generated trends with uncertainties from GISTEMP data, which show that the SH warming is likely to very likely less than the NH warming.
http://www.climateaudit.org/?p=2708#comment-216960
=====
#23 bender:
Although your loyalty to Steve McIntyre is admirable, I think enough is enough. I asked a snarky rhetorical question. The next day I said I probably wouldn’t have made that comment on most days. I later apologized. Everyone else has moved on.
#24 My issue is with “match”, cce, not mismatch. If modeled trend (w/error bars) is flat and observed trend (w/error bars) is flat, then does this support AGW-generating GCMs?
The match in the Antarctic peninsula (warming) is presumably not that type of match: here, both observed and predicted trends are strongly positive. (Still, would like to see trend statistics.) Maps that subtract between two arbitrary time points are vulnerable to cherry-picking. Not so with trend statistics. But thanks for the link.
This has nothing to do with the money quote. Nothing. Yet you keep retrenching to this. The issue in the money quote is predicted vs observed trend.
And what kind of match is that (Fig. 9.6 bottom, right)? The kind of match where, region-wide, no trend observed matches no trend predicted. This is consistent with AGW-generating GCMs? This is “money”?
I re-iterate Fritsch’s request for a map of local trend correlations. Prove to me that the positive trend in the peninsular region is both predicted and observed. Prove to me the opposite is true elsewhere.
Then I will accept your “money quote”.
p. 685 IPCC 4AR:
Why would anyone look to the poles for warming signal trend correspondence, when it is the tropics where signal-to-noise ratio is highest? According to IPCC 4AR any local correspondence in short-term “trends” at the poles is highly likely to be spurious. The more localized the response, the more likely it is a product of internal climate variability, which is maximal at the poles.
Yes, polar amplification is expected. But it will be buried in noise.
@Paul–I think the “cut out” bit, and the scissors discussion refers to this image:
Ross M. mentioned it above.
I’d seen GCM runs with the lower regions snipped like this before, but they only showed pressure. I assumed since the Antarctic is covered with tall mountains, the snipped corner reflects the fact that the air/solid interface is at high elevation. Is the average elevation of the Antarctic 4km?
Anyway, I don’t see any “blue” for cold in the Antarctic post-diction.
Bender – move on, mate. John V is an (in my view) an honest and open contributor.
He may not share your (or my) opinions, but he contributes towards serious discussion.
If CA is to have real value (as envisaged by SM) we must treat all serious contributors with courtesy, patience and respect.
We all say dumb things from time to time and JV has acknowledged this.
#32
I’ve moved on. I don’t care about what John V has said. I care about predicted vs. observed trends in the Antarctic. John V can back away from the subject he introduced if he chooses. That doesn’t mean it isn’t there.
Re #31
lucia,
Thanks for posting the image. It is pretty hard to comprehend a rationale to have excluded that area from calculation or presentation when no other parts of the globe are snipped. Certainly an explanation is in order.
A cycnic might observe that by having no model prediction in that area, any trend in the observed real-world data could be classified as ‘not inconsistent with the model predictions.’
bender:
As I have said before, if your argument is about small scale details in the Antarctic region then your argument is with somebody else.
The “money quote” referred to the large-scale, model-vs-actual average trend in the southern ocean and Antarctic regions. It simply stated that less warming in that region “did not contradict” the models. That’s all I’m saying.
Are you willing to state the opposite?
Are you willing to say that the large-scale, model-vs-actual average trend in the southern ocean and Antarctic regions contradicts the models.
If not, if you are unwilling to say that the statement is wrong, then why are you still attacking me about it?
By the way, “money quote” is a slang term that means the key statement, the one that wraps it up, the one that people would pay to see/hear (in an entertainment venue).
To summarize.
Everyone knows NH is warming faster than SH. This is uncontroversial. The question is ‘why’. Two commenters on the GT thread responded to Judith Curry, wondering if UHI/land-cover effects, integrated across large areas, could be part of the explanation. JV missed the point and gave a tngential RC song and dance about the good fit between observations and predictions (forecasts? backcasts? both?) in the Antarctic. I bit my tongue, but was skeptical.
Now that UHI in the SH is topical again I am asking about the empirical basis for this alleged “fit” between models and data.
RE #9, #!! and others:
Perusing the charts of the referenced IPCC report (AR4/WG1, Chap 9, pg 675, Figure 9.1) there is a less sinister explanation for the “scissored” out areas. Note that the average continental elevation south of Lat 80° is between 4,000-6,000 meters. The mean of those numbers…3,000 meters…is about at the 700mb level. This would place most of the areas below 700mb below the ice/land surface. The legend on the left side of the charts clearly shows that the whited out areas are below the 700mb surface threshhold.
A similar, but much smaller whited out are in the NH appears to correspond to the latitude at which a major landmass is the elevated Greenland Plateau.
Someone might want to comment on how IPCC dealt with model vs observations for Antarctica.
Re my previous post #37:
Sorry about the cross post. I didn’t see Lucia’s #31 when I hit the submit button.
Lucia,
South pole station is 2835 meters. With much of the continent above 3000 meters. According to wikipedia.
I think that’s what we are working toward.
Steve: I meant with quotations about how they reported the matching of models to results by continent – it’s interesting how they did it.
Was the output scissored, or was there no output for those cells? Look at the patterns in the profile. It looks scissored to me, the way the red is cut out. I read Santer et al 2003a cited in the caption and did not see these diagrams explained there.
#45 bender:
That’s what I thought.
I said there was no contradiction; that less warming in the SH does not contradict the models, that the models also show less warming in the SH. I’ve provided links to model output to back it up. I’ve calculated trends to back it up.
…
snip
Steve- c’mon guys. I can’t spend all day on this foodfight.
John V, why don;t you respond to Steve’s #38. You’ve clearly been thinking deeply about the subject for some time.
foodfight, foodfight!!!!!
Sorry, the community theatre put on a melodrama this weekend, and I haven’t gotten over it yet.
#44 Well for a guy who’s forced to apologize all the time he sure doesn’t sound apologetic to me.
I am done.
#44 bender:
Apparently it’s the term “money quote” that has you confused.
Now it’s not related to the observations or model output.
Now it’s about my choice of colloquialisms.
Interesting.
Allow me to tweak my original statement:
Instead of saying “Here’s the money quote:” I should have said “The key statement is:” to avoid confusion.
That is, to refute the argument that less average warming in the southern ocean and Antarctica means AGW is not real, the key statement is that modern models also predict less average warming in the same regions. The statement says nothing about model-vs-actual comparisons on a smaller scale.
SteveMc, I posted after the scissors came.
Please snip my last post (and this one) as well.
Steve, I am interested in reading the quotes from the IPCC matching the models to observations by continent. If that is what this thread is supposed to be about, please post them with your comments.
As far as I can tell from JohnV, there is nothing at all that would contradict the models. The models can simply not be contradicted.
The rule is simple. Don’t say things you can’t support with data. Can’t stand the heat? Get out of the kitchen.
JohnV
Which “modern” models predicts this data?
1998 0.457
1999 0.219
2000 0.192
2001 0.329
2002 0.375
2003 0.371
2004 0.299
2005 0.329
2006 0.287
2007 0.214
http://www.cru.uea.ac.uk/cru/climon/data/themi/s17.htm
Hey bender and John V: Who gives two flying “leaps” (censoring myself) about this bickering? Both of your arguments can be summarized as follows:
Bender: Antarctic is cooling
John V: But the models predicted that that would happen.
The obvious relevent comment to make here is that the IPCC cannot claim to understand everything about climate if they were so far off on observed vs. predicted in the antarctic. You cannot predict something, see that it is wrong, make a new prediction, and then claim that you were never wrong. If the world started cooling, would we accept a revised model with new effects explaining why we were wrong to think the Earth would continue warming and why it is now cooling? I would sure hope not. So, the important question is then: Since climate modelers first realized that the antarctic was cooling, and altered their models to reduce warming there, have they begun to deviate again? What about the second time they tweaked the models; has that tweaked model been accurate in antarctica since that point? (I dont know the answer to these questions).
Secondly, one cannot dismiss this failure on the area in question (antarctic) being too small and hence subject to too much variance; if this were the case, one would never see climate models being used to make predictions about regional rainfall totals, north pole melting, droughts, floods, etc.
Bender Bob’s answer entirely explains it.
The chart shows temperature by “pressure” and latitude. The elevation above sea level is shown on the right. If most of Antactica is at 3000 meters, then the surface is “up”. The blank grids correspond to areas below ground.
There is no “snippage” after computation. The shape is odd because there are probalby only a few grids, but basically, there is no air their.
Around the snippage, we see no cooling.
You shouldn’t (since they can’t) but shamefully you do. I requeat for media fear stories: Please at least check that the area your reporting about is warming!
The real point about Antartica isn’t that the models don’t match. It’s that it isn’t melting.
“Steve, I am interested in reading the quotes from the IPCC matching the models to observations by continent.”
I doubt you’ll find any, but give it a try. You might want to first consider how IPCC AR4 deals with Antarctica and Greenland inofrmation that doesn’t fit their narrative of warming=retreating glaiciers and northern ice cap. On the warming side they highlight the ice cap and make grandiose claims about retreating on-land glaciers not including Antarctica and Greenland. Look carefully and you’ll see inconveniently growing glaciers, like one in Kyrgyzstan (or nearby country) are accorded the causation of increased moisture budget. Growing glaciers are treated as anomalous, retreating glaciers as normal and due to warming, never decreasing moisture.
Greenland and Antarctica are treated rather sneakily. It is hardly, and certainly not straightforwardly, mentioned that in most places in those locales ice is increasing. IPCC AR4 treats both vaguely, like a lawyer in his final argument quickly going over the bad points of his case. But IPCC finds (or previously ordered in anticipation) “studies” showing in some places, allegedly, “melt water” is increasing. It gives the Report the imprimitur of science to be able to point to a “study” implicitily supporting melting/agw.
Actually, IPCC AR4 is quite cleverly sneaky in many ways. Excellent wordsmithing, its disingenuity deeply embedded.
I know why bellowed by Hansen West Antarctica is warming and loosing ice at un-prrrecedented rate. There is no single weather station record in West Antarctica:
http://www.antarctica.ac.uk/climate/surfacetemps/
Re:South pole station is 2835 meters. With much of the continent above 3000 meters.
Interestingly, that is almost exactly the depth of the ice at the South Pole – 2810 meters according to the link below.
I suspect most of the Antarctic’s surface elevation is due to ice rather than the underlying ground.
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=122982
And that’s the problem.
From this link: http://www.ucsusa.org/global_warming/science/early-warning-signs-of-global-warming-arctic-and-antarctic-warming.html
We get the statement:
I believe this statement is extremely clear. Increased CO2 will lead to polar (that includes Antarctica, yes/no?) warming. There will be even greater warming over land. Maximum warming will occur in winter.
That is simply 100% not working out for you guys in Antarctica. It’s polar, has plenty of land mass, and is cooling rathern than warming LIKE YOUR MODELS PREDICT!
Then “you guys” go and say things like:
Even though your founding father, Lord Hansen, predicted this:
See all that red down there in Antarctica? That’s not cooling that’s being predicted.
So, again, I say: “Which is it?” You can’t have it both ways. You cannot predict with your models and 12 years later say, “we never said that”.
Does or does not the “science” of CO2 global warming require the polar regions to warm? Yes or no? It’s as simple as that.
re:56 position summary
“Bender: Antarctic is cooling
John V: But the models predicted that that would happen.”
FWIW, neither characterization of these posters is accurate.
Nor is the actuality of models — in part, that is why there’s argument.
AGW theory and models predict warming at both poles — depending on time frame, that hasn’t happened. snip
The âscissorâ that R McKitrick noted above in the IPCC graphs needs to be displayed here with the graphs at the bottom of the page that apparently go to approximately 80S without the whiting effect. All of these graphs use pressure/elevation. Why the difference between the top to bottom graphs and why do not the bottom graphs go to 90S (and 90N)?
What’s the status of the Hansen code? Has anyone here got all of the steps up and running?
#63: They already did this. The discrepancy was blamed, as far as I know, on high aerosol concentrations at the South Pole. My point is this: if they didn’t know that aerosols were such a big factor in their predictions, what else don’t they know right now? Can they really say anything with any confidence about the future?
“food fight” gives it an undeserved dignity.
I have yet another idjit question. Without regard to what makes it cool or hot anywhere, why does it seem to be in general, cooler in the SH than in the NH?
Bad press? Poor records? More land? Orbital geometry? Differential industrialization?
#64, Ken. Didn’t Douglass, Christy, et. al. just show that 9.1f didn’t match the actual data? Maybe they did 1980-2007 satellite data versus the models?
@all,
You know, I’m sure the papers the RC guys discussed showed some sort of warming of some kind.
Still, my main reaction to that RC post was: Why didn’t they spend more time and write a better post? I can snip images out of articles and show next to data. Copyright permits this. Why can’t they snip images and show us whatever the heck those articles said?
Law blogs type out large blox text for reader to read so we get some context. So do political blogs, and any and all “issue” oriented blogs. Why are RC authors so sparing with quotes that the reader can’t tell what those paper’s said?
They leave the reader in a position of having to contact their library and get all those papers and read them. (Or pay $12 each to download.)
Not all readers have free access through work. Most people don’t. I would have to charge my project to get it through work, and I’m not going to do that because…well it’s not project oriented!
So, to get those papers, I have to contact my local librarian and order then through her. Then, I have hard copies. (Which I would scan if I wanted to cut and past an graphic.)
Now, because they wrote that whole darn article and didn’t show concrete information, we are all arguing here. They have failed to convince even one skeptic. So what, precisely, was the point of posting their bit?
Harumph!!! (End rant.)
I agree, lucia. I stopped reading RC, because it took too much effort to follow links and then try and determine if the paper actually said what RC claimed it said. That and their IPCC style word-smithing to evade or mislead on difficult issues.
Re #62 and related posts. The Foreword by the Co-Chairs of the Geophysics Study Committee of the US National Research Council (Philip Abelson and Thomas Malone) to the Council’s study “Energy and Climate” (1977) recognised that the projected impact of rising CO2 concentrations on the climate differed between models, but then made the following unambiguous statement:
“… the span of agreement embraces a fourfold to eightfold increase in atmospheric carbon dioxide in the latter part of the twenty-second century. Our best understanding of the relation between an increase in carbon dioxide in the atmosphere and changes in global temperature suggests a corresponding increase in average world temperature of more than 6 C, WITH POLAR TEMPERATURE INCREASES OF AS MUCH AS THREE TIMES THIS FIGURE (EMPHASIS added).
May I ask why the heating and cooling profile in the Antarctic has not changes even though the CO2 level has?
If CO2 does reflect IR then the Antarctic should cool more slowly and heat more quickly, but I have yet to see a yearly plot of the 60’s compared with, say, 1998.
Re #73. The “quantitative results of models” that were summarised by Abelson and Malone came from studies by, among others, Charles Keeling and Robert Bacastow, Roger Revelle and Robert Munk. The resulting report was published by the National Academy of Sciences. According to the Foreword, it “aimed at placing in the hands of policymakers credible information on the most likely climatic consequences of major dependence on fossil fuels for an increasingly industrialised society.”
I’m reporting these findings, not endorsing them. The projected increases in CO2 concentrations were in line with other studies at the time. The MIT-sponsored “Report of the Study of Critical Environmental Problems” (SCEP, 1970) concluded that it was “within man’s power in the next century to increase the CO2 of the atmosphere by a factor of 4 or more” (p. 53-54). The point I’m focusing on is that the most respected modellers were agreed that there’d be a much greater increase in temperatures in the polar regions, and therefore a substantial reduction in the temperature gradient between the equator and the poles.
Re #71, Phil B:
Phil, I think that many of us have stopped visiting RC regularly for the reaons you state, but also their persistent, one-sided advocacy for the AGW cause, and their aggressive censoring of counter views.
I note that their site says 5,161,845 visitors since 10 December 2004, but I also note that the number of posts and number of comments on each post seem to be dropping off lately.
In contrast, it seems evident that the number of posts and comments on posts here at CA seem to be escalating to the point where it is very hard to catch up if I go away from my ‘puter for a weekend. And that isn’t counting the traffic to the Bulletin Board which seems to be building rapidly as well. I don’t know how Steve Mc keeps up with it all.
T’would be interesting indeed to see what CA traffic numbers are doing!
I have also stopped going to Deltoid, Rabbet Run and Tamino (except occasionally) due to their one-sided, and (to me) emotional advocacy as well.
I hope I’m not ploughing old ground here. Roger Pielke, Jr., at Prometheus, had (on Feb 18) posted at http://sciencepolicy.colorado.edu/prometheus/archives/prediction_and_forecasting/001346climate_model_predic.html the same quote about the âcold Antarctica and Southern Oceanâ. On that thread I had the following observation:
Bob, if elevation explains why Antarctica is whited out in the 2007 report, why is it not whited out in the 2001 Report?
http://www.ipcc.ch/ipccreports/tar/wg1/351.htm
trevor, I don’t have a problem with one-sided advocacy. We all are biased in the general sense of the word. My issue with RC is that I can’t rely on them honestly representing the science as stated in the studies. I have come across a number of examples where they didn’t. In contrast, here at CA I can rely on honest reporting of the science, because if I don’t follow the link and check, I can be confident someone else will and their post won’t be removed. So the issue for me isn’t RC censoring counter-views, it’s RC censoring fact and source checking (as well as my early statement, which some here have characterized as RC’s ‘Retreat to the Ice’, i.e. shift the debate to where you think you have a strong case. Unfortunately for them the ice has been advancing recently).
It seems this original spar is really about semantics. John V originally said:
“A cold Antarctica and Southern Ocean do not contradict our models of global warming. For a long time the models have predicted just that.”
I would also interpret that statement as Bender (#10) did that a “cold Antarctica & Southern Ocean” would be just that: cold (showing no warming).
But John V. (#26) attempts to clarify:
“1. Southern Ocean and Antarctica are warming less quickly than other regions; & 2. Modern models predict the same”
This second statement clearly says that the Southern Ocean and Antarctica ARE warming, but at a lesser rate.
We can all acknowledge the difference between the two statements and the inherent confusion and/or misinterpretation of them. In posts here at CA, individuals such as Hansen are often criticized for sloppy work, especially outside of his area of expertise (data analysis, see: The Adjusters visit Peru). But everyone should try to be as precise as possible with their language, and not use language in a slippery way that can (or will be) misleading.
snip
The unresolved substantive issue is this: If the models “fit” the data, is it only because the models have huge errors on them?
How many of you have actually read #30 and looked at and understood the IPCC graphs referred to there?
How on earth do you expect an AGW signal out of a polar amplification effect that is supposed to be buried in noise? The signal is going to come from the tropics – if the models are correct.
#76 That is a good question, and I note that nobody has understood what I said in #42. Look at the patterns in the isotherms around the blocked out area, they are unnaturally discontinuous, sliced by the snippage. But in the source cited by Dr McKitrick, they are not. The discontinuity thus appears to arise from some snippage, not from some physical output constraint, as suggested by lucia #31 & Bob Koss #40.
#68
Yes, and I already made reference to Gavin’s rebuttal: [paraphrase] : the models actually allow for the small possibility of a tropical tropospheric cooling trend.
Say what?! This is precisely the sort of weak argument I am highlighting with respect to the “money quote”. If the models match the observations only as a result of the amount of error on the model predicitons – well it’s not exactly a ringing endorsement of the models, is it?
Why are these model error bars only shown when it suits Gavin’s purpose?
#78 The issue is, was, has been, always will be whether this putative match has been vetted through proper analytical methods. i.e. estimation of confidence limits. Two mean trend lines that seem to match means nothing if the confidence limits on the trend lines are so huge as to include zero slope.
#83
I am so pleased to finally hear it. sarc /off. Unfortunately, moral support doesn’t count for beans. Honest Opinions come cheap on the internet. Let’s see some numbers – what I’ve been asking for from the start. Ken Fritsch has outlined what he expects in terms of a proof, and I agree with his demands.
I sympathize with bender’s frustration. GCMs make predictions about future climate and the IPCC says we have to rely on them in formulating policy. So why the inability to say how accurate the model predictions are? On the face of it, it seems a simple problem. Model predicts x. Observations says y. What’s the difference between x and y?
The fact we don’t have any clear answers or solid data on this issue, merely re-inforces the view of those of us who think the GCMs have no predictive ability over a straight line extrapolation.
#92 The perpetual hindcast – that is the problem. The prevailing culture among GCMers. Why test Hansen 1988 (by using it in forecast mode, predicting temps after 1988) when you “know” the physics are invalid and you “know” the newer models are better?
Under this paradigm you will never, ever test the model. This is not science. It is pseudoscience. Ask JEG.
87
RE Karl Popper: His claim that scientists should be held accountable for the accuracy of their predictions boils down to the requirement that they have to compute in advance the reliability of their computations. For complex models, Popper wrote, this demand leads to “infinite regress”: computations of forecast skill are much harder than the forecasts themselves, and the next level, forecasting the skill of the skill forecast, is insurmountable when a complex system such as the climate is involved. Popper concluded that the positivist claims of science are in general unwarranted.
Steve M.
I find it amusing how you will let bender “foodfight” ad nauseum, and yet when I insist that Judith answer specific mathematical questions, you shut off the thread. Seem you are less and less objective in your editing.
Jerry
If the newer models are better, then again that seems an easy claim to test. Why no data to support the claim?
Re #76:
The answer is that in 2001 they graphed data that doesn’t exist. See my #37 and Lucia’s #s 31 and 40. Most of the land/air surface south of 80°S is below the 700mb pressure-height and just about all of it south of 85°S is below the 800mb pressure-height. I’m guessing that someone at IPCC must have had this pointed out to them sometime between 2001 and 2007 and deleted those areas where model solutions couldn’t be real, or else built in a terrain limiting feature to the models’ graphical outputs.
Based on reams of published material from the IPCC, the idea of impossible model solutions are not hard to accept.
Note that although the scale of the ordinate is appropriately logarithmic, the scale of latitudes along the abscissa is linear. This projection grossly distorts (enlarges) the depiction of the volume of the atmosphere at the high latitudes.
#84
Because they are more averse to risk of falsification than to risk of being wrong. They are more afraid of being proved wrong than of being wrong, so they do whatever they can, set wide confidence limits that embrace almost all possibilities, use ad hoc arguments and constant revisions to fix failing theories, challenge the data rather than the theory.
Negative Temperature inversion on the Antarctic Plateau(inverse lapse rate) and a negative annual radiation balance tend to suggest some statements on predictive capabilities may um not be quite Kosher.
by the way
cryosphere today has had some problems with data from mid-feb 2008
“We are experiencing some data problems with the current timeseries data. Please disregard the current timeseries data from mid-February 2008 to present until we rectify the data issues. The spatial maps should be fine”.
If you look at the graph
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.365.jpg there is a significant straight line fall from approx feb 15
so if we take up from there, I calculate we are already above last years max ice extent. We shall see….
Also SH ice still above anomaly and interesting to see what happens this year. BTW probably none of this should be considered anomalous in the context of millenium climate. ie:Earth ain’t cooling or heating
Re: 92 Cryosphere today – the fault appears to mainly in the Hudson Bay data (click on Hudson Bay).
I’d rather say that Earth has been heating and has been cooling and that is pretty normal. Equilibrium would be completely abnormal. It has never been in “equilibrium”. It has always oscillated.
If the global sea ice extent is about the same as last year’s by this time, the world average temperatures in January were the coldest of all Januaries since 1978, our main source of energy (sun) shows little activity and is expected to continue with little activity, a huge part of Asia is unusually covered in snow and will unusually increase the albedo for at least a couple of months, and La Niña is expected for this year… Quite a number of submarine volcanos are going to have to erupt to cause some warming this year đ
RE 76 Ross,
Actually, I was just responding to Lucia’s query about elevation as it made me curious and I looked it up.
It is interesting that for several years the models have been so good they can simulate beneath the surface of the ice.(simulated boreholes??) đ I also find interesting that they most certainly made the alteration by snipping or using white-out, since it appears from the graphs in #64 they did it all the way down to about 50s. Also between 50-70n. I didn’t realize sea level was so high in those areas. đ
From the step-change use of scissors or white-out I infer the latest models are still as good in those latitudes of the world as they were then. Someone must have pointed out the lack of physicality, and they discovered white-out was in the budget, but no money for model correction. đ
Rod #93
Have you checked Cryosphere Today against the weekly plots published by the SOCC Current Arctic Sea Ice Extent?
Then John V needs to answer the question: Does or does not the âscienceâ of CO2 global warming require the polar regions (plural, both of them) to warm? Yes or no?
That too is not true.
Amundsen-Scott base temp trend: http://www.john-daly.com/stations/amundsen.gif
Casey station: http://www.john-daly.com/stations/casey.gif
Davis station: http://www.john-daly.com/stations/davis.gif
Halley Bay: http://www.john-daly.com/stations/halley-b.gif
Vostok: http://www.john-daly.com/stations/vostok.gif
and on, and on.
Antarctica is not “warming more slowly”. It’s not warming at all. That’s what the data says, and it’s 100% at odds with the AGW model predictions.
Is this a “gotcha” thread or are you guys actually interested in learning about what’s going on in Antarctica? bender seems like he’s in “gotcha” mode.
Yawn.
In Hansen, et al, 2007 (http://pubs.giss.nasa.gov/docs/2007/2007_Hansen_etal_3.pdf) there is a great deal of information comparing observations to model runs, In this case GISS Model E. Comparison is provided for various periods in some cases back to 1880 and ending in 2003.
In figure 12c, (p. 683) there is a latitude and month anomaly graph covering three different time periods, 1900-2003, 1950-2003, and 1979-2003. GISS Model E predicts warming in the Antarctic region in each time period although significantly less than is predicted for the Artic. Observations show warming only in the longest period, but the observation for that period excludes most of the Antarctic continent (I assume due to lack of pre-1950 observations). In each of the shorter periods actual cooling is observed.
I appologize for not being able to simply post the data here, but I do not have the software on this computer to copy a selection from a pdf file.
There is a great deal of meat in this paper that could possibly make an interesting audit subject. I originally looked at the paper to see which data sets were chosen for comparison purposes, but that would be off thread here.
When have “you guys” ever been interested in discussing Antarctica? You always point to Arctic ice, or the Antractic ‘peninsula” while ignoring the other 95% of the continent.
I have yet to see any major new source run the story on the record high southern hemisphere ice covereage in 2007. Not one.
Vostock hit a near record low last August (-78 Deg C?). Of course, that’s only one station. There’s been much talk about model runs, model simulations, etc… The problem is, how can one with any precision verify a model without any hard surface data? Heck, how can you even initialize a model with such sparse data?
MattN,
Maybe someone here can explain statistical significance to you.
I doubt if I am the only person who did not realise that part of the Antarctic peninsula is north of the antarctic circle. Overall the peninsula is at an equivalent latitude to much of Norway, Sweden, Finland and Iceland – where in the summer most of the snow melts.
#87 Gerry, the comparison is unfair. Judith would never, ever behave this way. First, she never bluffs. Second, she seeks criticism, does not avert it. Third, she readily concedes when whe’s made a mistake. It doesn’t take her three days to recognize she’s had her bluff called. Steve M snipped, rebuked, then isolated us. He was as even-handed as a ref can be when punches are being thrown. I suppose he could have blocked us from commenting. But is that what you want?
#100 Boris, your comment here is appropriate. I did start off in gotcha mode – yawn – but now am very interested to learn more about the Antarctic situation as it pertains to model predictions.
Don’t tell me nothing good can come out of this scrap. The Antarrctic is important. GCM credibility is important.
Boris,
Allow me to explain statistical significance to you.
If you take 20 locations which actually have no underlying trend, then take samples of noisy temperature measurements, then test for a trend correctly with 95% confidence intervals, on average one of those locations will report a statistically significant trend, even though there is none.
If you pick and choose your locations post hoc because they have significant results, your degrade your statistical significance (it becomes part of the selection criteria, rather than part of the results)
I have been to Antarctica for 3 weeks in summer 2006 (december) and mostly on peninsula and surrounding islands .
Even if this is only a circumstantial evidence , climate model “temperature predictions” of Antarctic peninsula make me rather laugh .
During this summer period a typical weather was sunny 24/24 with some high clouds irregular overcast .
In typical conditions the temperature was rather constant around 0 .
Biggest temperature variation were provoked by clouds . Also dramatic temperature changes could come when the direction of the wind changed .
When the wind turned and began to blow from the continent the cold was really impressive compared to the situation when it was coming from the ocean .
Basing on that experience if somebody told me that the temperature on antarctic peninsula has significantly varied , I would ask him how did the cloud
cover and the wind direction change .
There is also a big difference between the peninsula and the islands .
The islands are rather low and snow/ice free while the peninsula is higher (mountains rise right from the sea to some 500 – 1k) and 10 – 100 m thick glaciers descend right to the sea .
That makes a big difference both to temperature and to albedo .
Below the snow everything is black rock .
So the snowless low islands are much hotter than the continent .
I don’t know if the weather station at the Chile basis Eduardo Frei on King George Island is one of those that define the peninsula warming .
But if it does , there is definitely a big human effect .
The airport on the island has developped , there are more constructions , the russians have installed their own station beside the airport and teh snow and ice is removed everywhere to facilitate circulation .
I don’t know what this station measures but certainly not the conditions on the peninsula .
What is “Global” about the “Warming” if the Antarctic is cooling???? And, why did we hear for the first time—EVER—that the models actually showed cooling in the Antarctic in January????
Convoluted and contortionistic “Anthropogenic” warming is a more correct appraisal, but there are only a few humans responsible for this so-called “Warming.”
#110 and everything on “statistical significance”: Be sure to read #30, referring to p. 685 of the AR4. The bottom figure is priceless. It destroys the idea that you should look to the poles for a warming signal.
#109 Tom Vonk – it is precisely this noisy, noisy Arctic/Antarctic that is the problem in looking for a polar amplification signal (#112).
Boris-105
If you are going to say things like that to MattN, it’s advisable to demonstrate your own ability to apply statistical reasoning.
Why don’t you pull together the Antacrtic weather data and the climate model predictions and:
a) You find the trend in the Antarctic data. Find the 95% confidence intervals using a two-tailed tests. Tell us if any difference from zero is statistically significant.
b) You find the trend predicted by one climate model of your choice. Determine the 95% confidence intervals for the trend.
c) You compare the two trends and see if they disagree to the 95% confidence interval.’s
d) Now, you find repeat b & c, but this time, find the average trend, and confidence intervals from 10 well respected GCM’s.
Failing this, point us to someone who has done this comparison and shown the results in a formal document somewhere.
Your doing this would be much more useful than insisting we all accept that GCM’s would pass the test even though, as far as we can tell, the statistical test to discover this hasn’t been done.
Of course, we know GCM’s would pass the test if their uncertainty intervals are huge, but at least if you do the test formally (or find it for us), we’ll quantify the uncertainty intervals. That by itself might let us move forward to see what we all agree on.
Re: http://www.climateaudit.org/?p=2802#comments
My point in http://www.climateaudit.org/?p=2802#comments was that on the same page at the bottom they show 2 graphs out to approximately 80S and 80N that do not have the cut outs. On the same page and in 2007. There may be other explanations for these differences or it may simply be sloppiness on the part of the IPCC. The also cut off the graphs at approximately 80S (and 80N) for the bottom graphs. My rendition of this page is not well reproduced but if you look hard you will see what I am talking about. The peaking around the corner reference from Ross M I believe comes from those bottom of the page graphs with the one on the left showing some red leaking into the 75S latitude.
As a general aside I also did a search of the entire AR4 Chapter 9 contents on the words Antarctica and Antarctic and came up empty on any direct references to Antarctica observed versus modeled temperature trends. Maybe we should halt our discussion on this subject until the authoritative body gives us some references.
Actually more than ever I want to see some detailed climate modeled maps of the local regions within the Antarctica and copied here to this thread. A final note: we should also remember that climate models model precipitation levels and that those levels as noted in the following reference have not matched the observed values in the Antarctica.
http://researchnews.osu.edu/archive/anttemps.htm
Most recent trend analysis for Antarctica:
Monaghan, A. J., D. H. Bromwich, W. Chapman, and J. C. Comiso (2008), Recent variability and trends of Antarctic near-surface temperature, Journal of Geophysical Research, 113, D04105, doi:10.1029/2007JD009094.
they detect no trend overall using various periods, seasons, and data, with cooling at the south pole. And yet, it is insisted that it is melting away in the press etc.
Re #113
Lucia, my assumption was that Boris was referring to this post (difficult to be sure when posters don’t include the OP#).
In which case Boris’s comment is justified since the record referred to was about ~1% greater extent whereas that in the Arctic to which it was being contrasted was a record low by 23%.
#98 MattN:
I don’t think I need to answer your question, but I will.
My understanding is that both poles should warm. I believe this is true for both GHG and solar forcing, although the predicted polar amplification is much stronger from GHGs.
In IPCC AR3 and AR4, the warming is predicted to be stronger in the North than the South (ensemble means). There is however considerable overlap between the ensemble ranges for the North and South, which leaves a lot of wiggle room.
#99 MattN:
Back on the Georgia Tech thread I calculated the 10-year and 15-year trends for each latitude band from GISTEMP data ending in 2007 (data source suggested by Mike B, if I remember right):
http://www.climateaudit.org/?p=2708#comment-216960
There are details on the link above. The trends with 95% confidence intervals are copied below. The Antarctic (64S to 90S) warming is not significant at 95% (t=~1.8 for 5yr trend, t=~1.9 for 10yr trend), but from this dataset it is likely to very likely that the Antarctic trend is positive.
I am curious about the longer-term trends. 20 years might be pertinent since some of this dicussion refers to Hansen1988.
I’ll be away from my computer for most of the day, so I may not be able to respond to any counter-points until this evening.
=====
15-Year Trends (degC/decade):
Latitude__Trend_(Limits)
NorthHemi: +0.37 (+0.24 to +0.51)
64N – 90N: +1.01 (+0.53 to +1.49)
44N – 64N: +0.54 (+0.30 to +0.79)
24N – 44N: +0.36 (+0.12 to +0.60)
EQU – 24N: +0.14 (-0.03 to +0.31)
EQU – 24S: +0.12 (-0.08 to +0.32)
24S – 44S: +0.21 (+0.12 to +0.29)
44S – 64S: +0.00 (-0.13 to +0.13)
64S – 90S: +0.49 (-0.06 to +1.05)
SouthHemi: +0.16 (-0.03 to +0.28)
=====
10-Year SH Trends (degC/decade):
Latitude__Trend_(Limits)
NorthHemi: +0.28 (+0.06 to +0.51)
64N – 90N: +1.60 (+0.69 to +2.52)
44N – 64N: +0.51 (+0.23 to +0.78)
24N – 44N: -0.10 (-0.30 to +0.10)
EQU – 24N: +0.14 (-0.26 to +0.53)
EQU – 24S: 0.00 (-0.47 to +0.47)
24S – 44S: +0.05 (-0.05 to +0.15)
44S – 64S: +0.05 (-0.22 to +0.31)
64S – 90S: +0.66 (-0.04 to +1.36)
SouthHemi: +0.08 (-0.18 to +0.34)
Re #97
Yes, and they seem consistent except for the obvious data error for Hudson Bay mentioned above.
More interesting on the SOCC site is the continued massive fracturing of the ice pack in the Beaufort Sea which would seem likely to presage a major loss of multi-year ice this summer/fall.
#117. 10 and 15 years huh? Curious, what does the 50 year trend look like in Antarctica?
Based on the last 5 years, looks like the sea ice extent is +2million km^2/decade…..
Phil. says:
Old ice breaking off an mixing with new during freeze up is perfectly normal according to what I read. I would not read too much into it. Especially with recent reports indicating that the ice is 10-30 cm thicker than it was last year.
@Phil– 116
It’s pretty hard to keep track of this thread. Boris didn’t number his snark, but I was sort of asssuming Boris’s retort was to MattN’s most recent comment prior to Boris’ (102). That’s a general comment about not seeing news stories — which is just a personal observation, so I don’t know how statistics is germain to that. Alternatively, Boris was making a crack about MattN posting links to data (see 99), which we could eyeball.
Why either of those comments should trigger a crack that MattN learn about statistical significance, I don’t know. Sure, MattN didn’t do the statistics on his data, but presumably if Boris thinks someone should show MattN how to do that, Boris could.
Given Boris’s first remark on this thread is to question people’s desire to learn, and complain that this is nothing more than a gotcha thread, it’s rather odd for him to do nothing more than to immediately start posting “gotcha” cracks.
I, for one, would be interested in knowing if the antarctic is warming/cooling or not, and I’d like to know if it does or does not agree with climate models. I don’t have time to do it myself, so I’m reading here. But if Boris is interested in this (as one might supposed based on his cracks) maybe he could do the heavy lifting and do the statistics on those data.
Right now, Boris seems to be hanging his hat on not doing the statistics required to support his position and supporting his position by criticizing others for not providing statistical proof to disprove his contention.
phil, at one point this winter, Arctic sea ice extent and thickness was greater than at the same time last year. Given that this year is shaping up to be a lot cooler than last, it is likely that the Arctic will not melt this year to the same extent as last. It will be very interesting to see what happens.
================================================
lucia says:
I’m not interested in validating models on a regional basis*, since we already know that models need work in this area. This is doubly true for an area for which we have fewer observations and that is experiencing changes in wind patterns likely due to ozone depletion and GHG forcing (see Arblaster and Meehl 2006, Journal of Climate, Thompson and Solomon 2002) So there’s the polar amplification problem and there’s the ozone depletion problem and sorting out if models got it right long ago is not very telling in light of more recent observations. That said, Schindell and Schmidt 2004 gets good results with the surface trends when ozone depletion is thrown into the mix.
* Okay, I’m interested. But it doesn’t really tell us much at all, especially about what CS is likely to be.
Word-smithing
‘a cold antartic does not contradict our models’. Tout Ă fait correct.
The antartic has been below zero (that’s cold where I come from) for many thousands of years and will remain so for many thousands more. I know because it will take more energy to melt cubic kms of ice than will be available in the next few thousand years. Models are right, rubbish but right.
121:
Please. Saying that the arctic and the antarctic both set “reocrds” and everything is all “even steven” is misleading. Sometimes I point out misleading statements.
#117
Also, did you look at any other data than GISS? Reason I ask is, we’ve seen some, uh… inconsistencies, in Hansen’s data.
That the Arctic is warming, but not Antarctica can be explained by cosmic rays and clouds, and gives support for that hypothesis. See http://arxiv.org/abs/physics/0612145
MattN:
The 10-year and 15-year trends were relative to the conversation at the time. As I said, I would like to see some longer trends as well. There is a link to the GISTEMP data in my original post (linked above). I don’t have time right now, so perhaps you could look into the longer term trends.
As for other sources, hopefully Bruce will take a few minutes to calculate HADCRUT3 trends. There may be an issue with HADCRUT3 trends in the polar regions since I believe they truncate at both poles.
Again for posterity save this graph
with correction, NH ice is very rapidly on way to going anomalous high re mid February “adjustments”
“We are experiencing some data problems with the current timeseries data. Please disregard the current timeseries data from mid-February 2008 to present until we rectify the data issues. The spatial maps should be fine?.
JohnV –
If I recall, a concern I had with the trends you computed is that they used the homogeneized and gridded data from GISTEMP rather than the actual station data. Reviewing the available station data from GISS, it appears that stations on the Western Peninsula have shown a warming trend which is probably statistically significant. However, stations across the rest of Antartica have either not warmed or possibly have cooled. However, the data from these stations is so noisy that it is unlikely that there is any statistically significant trend. So we can’t really say Antartica has warmed more slowly nor can we really say that it has cooled. Regardless, it is still damn cold.
Regards,
Bob North
John V, discussing your trend lines is something we may need to move over to the forum.
There are some technical issues here about trend fitting when you have non-white-noise variability in the data that isn’t explained by the model that probably should be explored.
Briefly we have annual and 11-year solar cycles that provide a gigantic amount of variability compared to the very small trends that we’re interested in measuring. Typically what you would do is low-pass filter the data to remove the short-term variability, then decimate the data to remove correlations in the data caused by the filtering. Trying to fit the data without these large causal but not-modeled variability, especially when the effect you are looking for is either comparable to or smaller than the non-modeled variability, is questionable.
The uncertainties that you get from the fit in this case likely aren’t meaningful.
“Vostock hit a near record low last August (-78 Deg C?)”
Huh … I believe one more degree colder and CO2 would start to condense out of the atmosphere in the form of frost.
RE 117 John V.
Interesting figures you put about the trend in different bands.
What was the reason for dividing the bands unequally? Eight bands seems such an odd choice. It certain isn’t done by area. Since you were doing bands I would think equal latitude bands would have been the way to go. 18 would probably be too many, but nine is only one more than the number you used and six is only two less. It seems to me one of those would have been more appropriate. If you didn’t try those band sizes, would it be possible for you to do them and post the same type results? If you did do them, and still have them, maybe you could post them up. It would be appreciated.
Thanks
Re #133
That was done by GISTEMP not John.
Boris–
It’s fair enough you don’t want run statistics on this issue. But what’s sauce for the goose is sauce for the gander. So… if you aren’t interested in regional validation, and you don’t value statistics comparing the temperature to local values and you don’t feel any need for them when defensing your point, why in the heck are you denigrating MattN for posting links to data without running full statistical tests?!
If you want to use statistics-free defenses of your position, you have to let him do so also!
As for Schmidt and Schindle, published in 2004. The data alone tells us those results can’t possible be validated.
But beyond that, as far as I can tell, that paper provides no uncertainty intervals on temperature which is what we are discussing here. It doesn’t even quantify the agreement between hindcast temperature and data (as far as I can see.)
So, could you please quantify “good agreement”. (For everyone’s convenience, the free copy is available here
It would appear the sum total of comparison of their hindcast temperature predictions to data is in the right hand column of the figure below. The S&S “quantify’ the agreements for temperature using these words:” reproduced observed trends…. quite well”. (Uncertainty intervals are provided for geopotential heights and sea level pressure.)
If you can quantify what “quite well” means, let us know! Any statistial measure what-so-ever would be appreciated.
When you are explained to use the statistical meaning of “quite well”, feel free to explain how great their predictions did when compared to data. Good luck though– the predictions are for 2050. Note that everything warms.
@Boris–
You lectured MattN– a specific person– for not knowing statistics. If your reason is that saying a record is a record is misleading, you are being silly. Breaking a previously recorded extreme is breaking a previously recorded extreme, both in weather and the Olympics. There is no statistical principle that one must break a record by a statistically significant amount or it doesn’t count.
If your point was that lack of news coverage was appropriate because record wasn’t exceeded by as large a margin, you should have said so specifically. This has nothing to do with MattN’s understanding of statistics or lack of it.
If you’d defended the media this way, then no doubt, people would correctly point out , the newsmedia generally cover all records no matter how trivial. So, MattN may still have a point vis-a-vis news media not covering this.
Matt’s comment was not misleading. His observation about the media has nothing to do with lack of understanding of statistics. I can’t see why anyone who understands statistics would try to connect uncertainty intervals to his comment.
First off, I never made any claim about models accurately predicting Antarctic temperature changes. Please don’t put words into my mouth. What I have said is:
1. Once models more completely modeled the southern oceans, the “polar amplification” became more of an “Arctic amplification.”
2. Ozone depletion, and to a lesser extent GHG forcing, have further acted to keep Antarctica from warming.
Now, if you think Schindell and Schmidt are wrong, then hack away. If your analysis is good, then get it published as a comment. I’m not here to defend models wrt Antarctica. I am here to say that Antarctic is one cold and complicated place and if you’re going to say that the models’ predictions in Antarctica mean anything, you need to at least be aware of the research in the area and the confounding issues in an Antarctic regional forecast.
As for MattN, his point was and continues to be nonsense. My “statistics” comment was more of a jab. It doesn’t take complicated statistics to know that breaking a record by 1% is not comparable to breaking a record by 23%. I am a bit surprised that you are defending him.
I thought it would be obvious. Who knew?
RE 134 Phil,
Thanks for that.
Never mind John V.
I still think it is an odd choice using eight bands. There doesn’t seem to be any physical reason for it.
@Boris–
My discussion of S&S is in response to this comment:
This thread is discussing surface temperature in the Antarctic.
I didn’t say S&S was wrong. You just volunteered this as a model that gets “good” results, with no quantification of “good”. I’m asking you what “good” means. Because quite honestly, I can’t tell. The paper makes no quantitative comparison even for hindcasts.
What it appears to show is that:
* in 2004, models were sufficiently bad at predicting Antarcting cooling that S&S ran one and got the results published. (If models were all predicting this well, why would this work be done? Or paper accepted.)
* if we try to “area integrate” the small amount of information we are provided about surface temperature, we conclude they are off by 1C in many many areas and more than 2C in some places. After all– the way those projections work, the region near the outside of the circle represents much more area than the center.
* the authors did two cool overlaping a locations measured as cool; they also predict cooling where it doesn’t belong.
* we know nothing about the northern hemisphere in this computation.
Is this “good”? “Bad”? I guess it depends on your standards.
As a general question, I would like to know what people who think GCM’s give “good” results mean by “good”. Model accuracy is something that is amenable to statistical description, and it would be nice if modelers actually quantified “good”.
I realize you may not be able to quantify what you mean by “good”, which I guess is fine. But, I’d like to see it, so when someone tells me model are good, I ask what they mean.
If someone quantifies, then I can figure out if I agree or disagree. Otherwise, I don’t know. For all I know their “good model” is my “heuristic toy to facilitate thought experiments” (or vice-versa.)
On this:
Well, how I could tell that’s what you were jabbing at. After all, MattN did not say breaking a record by 1% is the same as breaking it by 23%. Matt said this:
It’s a comment about the behavior of the news media.
Matt has an entirely valid point about the media. The media normally cover news stories involving even the most trivial of weather records (and not just ones about AGW.) But they aren’t covering this.
Anyway, I guess you are right that you weren’t making any claim about validating models. I assumed that was the point of your “jab”, because as far as I could tell, your “jab” only made sense if it applied to Matt’s previous discussion of temperature data and comparison to predictive models. In that case, there would at least have been a remote logical connection between doing a statistical test and what Matt was discussing.
But, since you weren’t making a jab at MattN’s providing data with no statistical analysis to compare to models, the things I said about you expecting Matt to do that when you wouldn’t you said were wrong. So, sorry for that! đŠ
To complete my task of searching through the AR4 WG1 material for information on antarctic observed and modeled temperatures (or precipitation), I word searched all of the chapters and intros that I though might contain pertinent information. Below I have listed all the comments that have some relevance to the subject at hand. I found no direct comparisons and it appeared to me that the subject was deliberately avoided.
The hints to what might be affecting the Antarctica’s lack of warming in the excerpted comments are Southern Annular Mode (SAM) and the ozone hole. These are the same items noted by Shindell and Schmidt in the paper GEOPHYSICAL RESEARCH LETTERS, VOL. 31, L18209, doi:10.1029/2004GL020724, 2004 and as excerpted below.
I may need to pay $9.00 to see some modeled climate maps of the Antarctica unless someone here has an unpaid reference or can give a detailed summary of the Shindell paper.
From Shindell and Schmidt:
Excerpted from the IPCC AR4 WG1:
AR4 WG1 Technical Summary Page 62
AR4 WG1 Technical Summary Page 62&63
AR4 WG1 Technical Summary Page 64
AR4 WG1 Technical Summary Page 74
AR4 WG1 Chapter 8 Page 620
AR4 WG1 Chapter 3 Page 248
AR4 WG1 Chapter 3 Page 256
AR4 WG1 Chapter 3 Page 280
AR4 WG1 Chapter 3 Page 293
AR4 WG1 Chapter 3 Page 317
AR4 WG1 Chapter 3 Page 318
Some graphs of the Antarctic, as referenced from WCR’s Dr. Michaels:
http://www.worldclimatereport.com/index.php/2008/02/27/antarctica-ain%e2%80%99t-cooperating/#more-312
Warming?
re 141 Kenneth,
There is a suplimentary pdf for chapter 8 that has nothing but graphs of model output. If you think might be something your interested in, I can send you a copy or you can get it from the same location as ar4. They all seem to be global graphs.
Wow, I am quite the topic here it seems.
Boris, nice strawman! Creating that whose sense that I equate breaking a record by 1% and 23% as the same. Wow, man. Classic!
I have no doubt you are more statisically inclined than I am. I only have an Engineering degree and my statistics classes were a long long time ago in a galaxy far far away. I couldn’t tell an eigenvalue from a hole in the ground.
But, what I do know is Antarctica is, on the whole, not warming. And that’s a problem for you and your models. McCall posted a quite timely article with nice 50-year trend graphs. So go put you confidence intervals on all those graphs and let me know if anything changes. I suspect it won’t.
Re @122
The Arctic seaice extent is just about what it was last year (a slightly positive anomaly in the Bering Sea and negative for Baffin/Newfoundland, Greenland, Barents Sea and Kara Sea regions. The thickness is almost certainly less than it was last year. I don’t accept your given (shaping up to be a lot cooler than last) for the Arctic at least. I’d be very surprised if the seaice extent didn’t fall below the previous record again this year.
Re #120
I’m sure it is but Environment Canada should know something about seaice and they headlined it thus: “a massive fracture of the Beaufort Ice pack was observed west of Banks island.” Where is the ice thicker, does that take into account the multiyear ice that disappeared last summer? This year the Atlantic side is showing a significant negative anomaly.
OK Phil, I bet you 1M quatloos that the extent minimum this year will be entirely unremakable.
Phil. says:
Nothing on their site implies that the the ‘massive fracture’ was unexpected or a sign that a bigger melt would happen this year. The boffins at Environment Canada want people to be interested in their data so the play it up a bit – no big deal as long as one does not try read too much between the lines.
The artic ice is likely affected more by ocean currents than global warming. If the PDO regime shift has happened then we will not see an unsual melt on the pacific side this summer. OTOH, ADO will not switch for another 10 years which means we will likely see continued melting on the atlantic side.
With two competing processes it is difficult to predict how the total ice cap anomaly this summer will look compared to historical averages. However, even if it is lower that does not provide evidence of AGW. In fact, a melt that occurs largely in the east would serve to refute the AGW hypothesis by demonstrating that the ocean currents are the dominate factor affecting sea ice.
This summer will be a very interesting time and will provide data that will either hammer more nails into the AGW hypothesis or resurrect it. We will have to wait and see.
Now that is a money post.
Phil, #145, Gilles Langis claims that much of this year’s Arctic sea ice is 10-20 cms thicker than last year. Why don’t you think this year will be cooler than last?
===============
Phil: think again sport.
http://www.cbc.ca/technology/story/2008/02/15/arctic-ice.html
http://sermitsiaq.gl/klima/article30834.ece?lang=EN
http://www.springerlink.com/content/8j71453650116753/?p=fcd6adbe04ff4cc29b7131b5184282eb&pi=0
regards to all the Heretics.
Oh boy! A warmer makes a testable prediction in a reasonable time frame.
And BTW, I’m assuming the record sea ice you are referring to isn’t the SH’s record (as most sea ice ever recorded this year).
Re #151
Well that is patently not true so I’m not too impressed with your source!
Also while the extent to the W of Greenland was greater than usual that to the E was less than usual, since your cite the Ice to the W has retreated.
W Greenland
Re #152
Interesting use of the word ‘ever’!
SH sea ice extent
Pssst….hey, Phil. Don’t tell anyone, but your chart in #154 only goes to 2001…..just thought you might like to know that….
Phil,
Nice try to re-write someone’s post. But the word “ever” is quite clearly modified by the word “recorded”.
In much the same way the Arctice sea ice was the lowest ever recorded
Sure wish we had satellites monitoring the arctic in the 1930s….
#155 The chart only goes to 2001 because Phil is citing the TAR. Why? What does AR4 say?
Re: http://www.climateaudit.org/?p=2802
Bob Koss, thanks for this lead. If I find anything relevant to this discussion I will scan and post it here.
Although I have not read it yet, the Shindell and Schmidt (2004) paper promoting 2 additional factors for explaining the past temperature trends in the Antarctica would imply to me that the previous models did not have it right on the Antarctica hindcast, otherwise why this paper. The authors duly note that the factors, ozone hole and SAM changes, are both attributable to anthropogenic sources and thus consistent with the consensus view of AGW.
On the other end of the globe, I think one must look through the fuzzy images discussed in general terms and look at details of how well past climate model runs have gotten the artic warming correct and how many are using new factors such as changes in prevailing winds to explain the evidently faster than predicted warming. The fuzzy talk that says the models predict that the Artic will warm (significantly) faster than Antarctica does not give me good confidence in the models. It is like claiming we got the sign right and declaring a victory of sorts.
I see nothing inherently illegitimate about adding new factors to the models to explain new evidence on observed climate, but when this happens it means the out-of-sample start date moves forward in accordance.
Re #156 & #157
Those are recorded data!
Re #154
Check out the ordinate and compare with Anomaly
RE: 161. I’d look closely at that graph again — toward the end.
Now we can check it out:
It looks like
a) 2008 is the largest anomaly ever recorded and
b) It’s at least a 4 σ anomaly.
Wow! MattN must really have known something about statistics when he posted his extensive treatis on why 1% is sometimes larger than 23%! đ
Because, as we all know, it’s the change relative to the normal variability that matters in statistics. And a 4&sigma anomaly is friggin huge!
It’s so huge one has to wonder if it’s an error.
If sea ice extent is a good proxy for temperature, then does this not help address the common complaint that “you can’t reliably infer a flattened trend simply because there is a lack of weather stations across the Antarctic continent”.
Or is this yet another double standard: “sea-ice is only a valid proxy for temperature if the trend tends toward warming.”
lucia says:
In think the point Phil is making is the graph he linked goes back to 1974 – not 1979 and appears to have a higher sea ice extent in 1974.
That said, according to Phil’s chart there was a regime change between 1974-1976 that resulted in large drop in sea ice. The sudden drop cannot be explained by GW so that leaves only two options:
1) Sea ice is a poor proxy for temperature
2) The 1974-1979 data is wrong.
Mr Russ had led 33 expeditions to the Ross Sea in the past 15 years and had never seen ice like it in January, he said.
bender–
When I was in grad school, and lots of laser doppler systems sufferred from tons of shot noise, and velocity measurements often came in batches of 1000, many experimentalists made it a practice to throw out velocity measurements with deviations greater than 3.5 sigma. There are difficulties with doing this, but we all knew there was also noise. (And of course, one can quantify the estimate the uncertainty in measurements of means and standard deviations due to throwing away tails. The shot noise could end up being anything and often was! )
So, yes, that “record” may be the “Loch Ness Monster” of data. If it’s not confirmed by later sighting, it probably is real measurement error. On the other hand, if it’s real, it’s the reincarnation of the wooly mammoth of a record.
On the arctic: Carnac predicts it will melt in the summer. One of those news stories said the perennial ice was blown south. So, regardless of warming, just being miles south will cause more to melt in summer.
I assume since the wind can’t blow the Antarctic ice sheets around, the extent of the perennial ice would tend to be a bit less variable.
(BTW. My husband was temporarily stuck on an ice breaker doing global climate change research. Why? The perennial ice sheet the served as a landing strip melted! I was constantly on line watching the location of the ice breaker and the US Coast guard, as the wind pushed that ice around. That Artic ice does travel quite a bit.)
Actually, I will add another option:
3) the rise in temps over the last 30 years is a result of ENSO and not CO2
@Raven– Ahhh… Ok.
FWIW, The two plots use different time periods for the zero point. I can’t easily integrate 1979-2000 by eye to shift mentally. I’m also wondering if they actually match. Here they are in the same frame so we can compare.
They don’t match. . .
Re #168
Ah that takes me back Lucia, we used to follow the same procedure: basically evaluate the statistics of the raw data, then eliminate the outliers and recalculate the distribution. The method was based on good stats principles and the same rule was applied to all data (only once), as I recall for a collection of N points outliers were those points which had a probability of less than 1/2N, and this came out to 3.5 sigma for 100 points IIRC.
The record anomaly you referenced is for post 1979 and actually arose during the time of rapid melting which was about 2 weeks late. The maximum extent I was referring to is the September max which is also post 1979, values earlier in the 70s being much greater though according to NIC.
Phil– The odd thing now is those two graphs really don’t match. Relative min/max aren’t in the same spots, periods of low variability exist on one and not the other. They are supposed to be the same thing…. But this mis-match is worse than comparing Hadley Crut to GISS met station data!
Re #170
No because they are relative to different means, 1973-1996 and 1979-2000, also the ordinate scale for one is 100x the other. Finally one is monthly and the other is daily.
Ozone depletion seems to more closely follow the sun spot cycle than it does CFC production.
Ahhh– the monthly/ daily explains the part of the mismatch that puzzled me. I understood about the shift.
Phil, they also have different start and end periods. And one says “sea ice extent anomaly” and the other just “sea ice anomaly”. This mismatch is curious. By the way, Phil, does the IPCC have a chart of nothern hemisphere snow cover? I may have a chart I want to compare it to…
Re #174
Phil.
There’s a lot more mismatch than that. Firstly I have serious reservations about a metric that shows sea-ice extent in units of hundreds of bi-cubic kilometers (that would be the km^6, what’s up with that?) Perhaps that should read 10^6 km^2? If that is the case then your observation that the scale differs is misplaced. If your observation is true, then this sea-ice extent of volume squared is a most novel metric indeed!
Secondly, if we can equate this measure to changes in Antarctic sea ice in the range of +/- 2 million square km then we can and should be able to infer something about the extreme valley in 1983. If these are monthly averages then certainly there must have been approximately 15 data points (if from daily data) that exceed the average for that month. Looking at the daily data from UIUC nothing in 1983 approaches a -2 Mkm^2 anomaly, much less exceeds it.
The other peak and valley mismatches are sufficient to warrant a conclusion that the two datasets don’t match.
Re #177
Check with William Chapman, chapman@atmos.uiuc.edu
I don’t know, I imagine SOCC probably does?
Just an idea…
Are these both plotting the same thing, or is one area while the other is extent? I forget the exact definitions but IIRC it’s something like:
– area includes regions of solid ice only;
– extent includes regions with more than some percentage (10%?) of ice
Hoping the rescue this thread from scope creep. Discuss sea ice extent here:
http://www.climateaudit.org/phpBB3/viewtopic.php?f=5&t=52
After Bob Koss directed me to the IPCC WG1 Supplementary Material Chapter 8, I found these maps comparing observed and modeled mean (of many models) and typical error between observed and modeled for historical temperatures and precipitations. Unfortunately these maps (shown below) are global and do not focus in on the Antarctica but they provide a start.
I would encourage posters and readers to go to the Chapter 8 Supplement as it contains a plethora of modeling versus observed climate variables including temperature, precipitation, diurnal changes, and SW and LW radiation.
John V.,
You’re right as far as how area vs extent are reported by Cryosphere. Extent is what we would associate with the term area, whereas area is the net amount of ice contained within the extent, that being the integral of dArea*dConcentration. If all ice concentration readings were at 100% the area would equal the extent. I do believe that Cryosphere tracks the extent rather than the area in it’s sea ice anomaly indices.
The figure that Phil. referenced is from the IPCC TAR, and the caption below cites multiple sources of the data. If you dig into the Knight84 reference you see that it is weekly ice calculations based on
It’s an interesting exercise combining these data. Given the glaring error in the labeling of the Y axis I’m just a bit skeptical that the information protrayed in this figure is useful for inferring anything meaningful about the past and current Antarctic ice extent.
Just wondering if the +35% southern hemisphere ice anomaly for Jan ’08 in any way counteracts the negative arctic anomaly from last summer?
http://nsidc.org/data/seaice_index/s_plot.html
Is that statistically significant? :shrug:
Sorry SteveSadlov, I’ll post any follow-up to the BB. I’ll also try to avoid the insidious it’s versus its doppleganger. :0
Re #184
Not really:
global sea ice
The discussion of sea ice extent here should be in the context of obseved versus modeled results and of course how much condifidence we have in the historical data and whether they go back in time sufficiently to allow one to see the effects of any long term cycles in them.
Some proper questions might include: Is the decreasing sea ice extent in the northern pole area happening at a greater rate than models predict? What is observed versus model predicted sea ice extent at the southern pole area?
As an aside” I took some numbers I found at this thread on the maximum sea ice coverage at the southern pole area and look at the postive trend to determine how close it was to being statistically significant. I got a p = 0.02 which would say it is significant if one ignored auto correlation. I need to go back and do a Durbin-Watson calculation.
Phil #186:
Phil,
You might want to look at the website alittle closer, you may have missed this at the top in red:
We are experiencing some data problems with the current timeseries data. Please disregard the current timeseries data from mid-February 2008 to present until we rectify the data issues. The spatial maps should be fine.
You see over the last few days Hudson’s Bay melted, but is on it’s way to recovering so not to worry. Eyeball the southern ice anomaly, and the northern ice anomaly, pre “abrupt” Hudson’s bay melt, and your answer will become: Yes
Re #188
No, I noticed the data glitch in Hudson Bay before they put the warning up and had made allowance for it in my response to:
The answer to which is still no. The global anomaly is still negative and the SH sea ice is very slightly positive
Phil,
Please do elucidate on the size the variance which makes one thing “still negative”, and another “very slightly positive”. Care to put confidence intervals on that?
Good luck tracking down the source of the Cryosphere images. The NASA algorithm for processing the satellite data gets +/- 5% best case (consolidated pack ice in winter) and +/- 15% worst case (thin melting ice in summer). Source for that tidbit is here. Don’t know if this is the algorithm used in current or recent Cryosphere imagery but I wouldn’t expect much different.
It remains that Northern sea ice was more extensive this winter than last, and according to Gilles Langis, some of it was 10-20 cms thicker. Given that this coming summer will be cooler, it is not likely that melt this summer will be as extensive as last. I know that winds are also a factor, as is the AMO. This hypothesis will be falsifiable as soon as this September, probably.
========================================
From the link below one can determine that using those data sets the southern sea ice extent trend is not significant while that for the northern sea ice extent trend is very significant. The southern sea ice extent varies much more than that of the northern and therefore it will take a larger trend to be statistically significant. The importance of this is stated in the link when they say:
http://nsidc.org/data/seaice_index
Also note that the ice extent around Antarctica is concentrated at the Antarctica Peninsula and has a slight positive trend while the SST in that area is increasing at a rapid rate (as contrasted with the interior areas of the Antarctica). It also appears that the mean climate model as represented in the IPCC WG1 Chapter 8 Supplementary Information would have projected an even warmer SST in this area.
I say there are several seeming inconsistencies to discuss here without getting side tracked with a debate of the statistical significance of the ice extent trends. Besides the ones eluded to above, why does the southern ice extent vary so much more than the northern extent?
Re #192
By about the same amount that last winter was more extensive than the previous winter and we know what happened last summer/fall.
You keep saying this but why do you suppose that this is a ‘given’?
Re #193
To me the fact that in the Antarctic the sea ice is mostly north of 70ÂșS whereas in the Arctic the sea ice is mostly N of 70ÂșN has to be a key factor.
Tamino analyzed the HadISST sea ice data here:
http://tamino.wordpress.com/2007/10/08/sea-ice-north-and-south-then-and-now/
The data is documented here:
Click to access HadISST_paper.pdf
Phil, at #194. I say that because of the present La Nina, because of the quiescent sun, and because of the thicker ice, according to Gilles Langis. Certainty, I ain’t got, but you keep ignoring Gilles Langis, and thicker.
======================================
It’s not a ‘given’. It’s a NOAA forecast. As credible a forecast as any regarding ENSO summers.
But Phil, why do you try to twist what kim says? You know that the truth of proposition “A implies B” is independent of whether A is true or false. You know the NOAA forecast, A. You might want to be a little more careful when attacking what people say.
Ah, Phil, also, we may be using the term ‘given’ differently. I mean it to mean ‘if’; you interpret it as ‘because’.
===========================================
Thanks, bender, you beat me to that insight by four minutes.
====================================
You may have noticed that I have neither the maths nor the scientific knowledge to keep up with the pack of scientists. The sleigh I ride, though, is aptitude for rhetoric, and it has allowed me to keep track of what is up front.
===================================
What change in Ice extent will disconfirm a model?
That depends on which set of error bars we apply this week.
The dial on my error bars are +/- infinity. And they move themselves to the appropriate position; look, it’s warming!
đ
Ahem.
In my continuing quest to find out what temperature it is where I have gone to Antarctica.
You may be pleased to know it’s a nice time of year there. Depending on where you are that is.
High: Rothera Point 40F
Low: Amundsen-Scott -66F
Our favorite location Vostok is at -63 (Well, it was 5 hours ago when it was last updated).
-63F, 38%, dew -71, wind 12 mph west, 12 miles visibility, 11,220 feet elevation
AAXX 29124 89606 49998 02610 11526 21570 36224 47759 58001
http://www.wunderground.com/global/stations/89606.html
http://www.wunderground.com/stationmaps/gmap.asp?lat=-78.44999695&lon=106.87000275
Other selected readings:
Henry -59
King Sejong 33
Larsen Ice 20
Lettau -7
Linda 3
Maitri 25
Manuela -6
Marble point 9
Mawson 67.60S 62.87E 19
Mawson 68.65S 61.12E -14
McMurdo 9
Minna Bluff -1
So what temperature is it in Antarctica?
It’s 21F, because that’s the temperature at the airport.
AAXX 2916/ 89612 46/// ///// 11062 39312 4//// 5////
http://www.wunderground.com/global/stations/89612.html
http://www.wunderground.com/stationmaps/gmap.asp?lat=-66.27999878&lon=110.80000305
Oh, wait, Vostok is tagged as an airport also. Let’s see…
-63 + 21 = -42
-42 / 2 = -21
So it’s not 21F, it’s -21F Ah, what’s a sign between friends. I mean it’s only 42 degrees of spacing. Well, averages you know, they’ll be off a bit now and then. Now let me adjust that for {super secret adjustment method} and…. Okay, the temperature in Antartica is 0
Man, climate science is difficult!
Ah, come on, they’re only 1360 KM from each other and at a bearing of 3.7 degrees, so that fits into the{super secret adjustment method}. So as you see, that’s well within the distance and heading parameters.
đ
Anyway, here’s more fun:
http://www.wunderground.com/cgi-bin/findweather/getForecast?query=antarctica
Uhoh! looks like we might need to “adjust” the ice cores! đ
But the ice cores are prefect and exactly reflect the composition of the air. They need no adjustment. Besides, they’re independently verified with another method, being teleconnected to the tree rings and everything, you know?
Biggest error bars ever? lol
I don’t think I said that, but I sometimes make wry observations based upon somebody else’s comment or something that just pops into my head as a good quip, so um I dunno.
Say it ain’t so Shoeless Joe.
Re: http://www.climateaudit.org/?p=2802#comment-218874
I would like to review and analyze the following link provided by cce.
Click to access HadISST_paper.pdf
In this paper the authors use some rather proximate measures of sea ice and extrapolations of SSTs to look at the effects of SST and sea ice coverage going back to the late 1900s. I took away that these adjusted data will be used for inputs to and checking outputs of climate models.
If you have problems with the current measurements you might need some major convincing on what this paper concludes. The main jest is that sea ice coverage is down significantly in the Northern and Southern hemispheres since the early 20th century (see page 4). My primary interest would be in comparing the SSTs to the pre and post satellite era sea ice coverage that ends up in the official data sets.
Cold. Really, really cold.
Re #199
Given:- an established fact or situation, if you meant to say ‘If’ why not do so.
As well as the places where the sea ice said to be thicker there are others where it is thinner and in some cases non-existent.
My construction is correct English. Your misunderstanding it is your problem.
As I’ve said, the hypothesis that there will be less Arctic melt this summer can be falsified by September. We shall see.
=====================================
kim says:
I tend to agree with kim here. The function and meaning of the word given is determined from context. The way it was used it means if. If the sentence was a given … or it is given that … then the meaning of given is different.
Re # 204 Sam Urbinto
More fun.
How do you do a TOBS adjustment at the South Pole? What day is it, what time is it?
Don’t the adjustments used (say) in the USA for land temperature lose some meaning in the Antarctic?
1. The sun does not shine for months, so solar irradiance is a bit of a problem.
2. In looking for rural comparison sations within 1000 km, are there any? If there are, are they on the same day or different day times? Are they night at one and day at the other?
3. More seriously, if the methods used in the USA to adjust temps become useless at polar latitudes, who determines where the boundary lies and which methods should be discontinued at which latitudes? I can’t recall seeing a reference to this factor in my reading.
Variables as “lights” change (electricity is expensive near the Poles), ground albedo changes in the primary sense (snow) and the secondary (soot on snow). Ice thermal properties such as heat absorption and emission are not the same as land or sea. You can see that we people who live away from snowfall don’t know much about how the Polar regions are modelled in GCMs.
if A then B
given A, B
c’mon Phil
My linguistic 2 cents:
Not that it matters since kim has already clarified her intended meaning, but I read “given” as “since” or “because”. Where I live that’s the by far the more common meaning.
It must be a regional thing.
Back to more substantive matters…
Aj #167
This link to your Ross Sea Ice observation works
It’s not regional. It’s whether you deal in logic:
“If you take A as given, then you must accept inference B”
kim was not judging the veracity of the cool summer forecast A, but highlighting the link between that forecast and its necessary consequence. Phil was trying to put kim’s point in question by focusing on the condition A, rather than looking at the whole inference A implies B. If A is false, the inference A implies B can still be true.
A word-parsing spinmeister can twist any phrase around to mean something that was not intended. On a global blog where people have different backgrounds it helps to grant someone the space they need to clarify their meaning. Or you could do like Phil, jump down someone’s throat and start ripping. There’s a reason he chose that approach.
Heh, more thanks, bender. Let’s look at it this way. ‘given’ in that construct can stand for ‘if it is given’ or ‘because it is given’. It’s not a matter of locale to think the first meaning ‘if it is given’ is the one intended. This is the construction of a hypothetical, as bender points out. To characterize a hypothetical as an assertion requires a deliberate misreading which Phil. highlighted by denying the assertion, an assertion of a future event, by the way. Then he compounds it by persisting after explanation. It’s regional, alright, but not a geographic one.
Phil is still trying to wriggle around the claim that the sea ice was more extensive this winter than last with the weak assertion that the ice was ‘non-existent’ in places. Langis Gilles’s claim, if I’m not mistaken, was that some of the sea ice was thicker by 10-20 cms. Phil. can still believe that it was thinner in places, and that may be so. It is my claim that this year northern sea ice got more extensive than last. There was, briefly, a Greenland-Iceland ice bridge, after all.
It remains a testable hypothesis. I don’t think this summer’s northern sea ice will melt to the same extent it did last year. What do you think, Phil?
=====================================
I’ll be just a little more harsh. I said before that I make my judgments about these scientific matters on the quality of the rhetoric. John V. and Phil. have been sophistical on this matter, which is bad rhetoric. Why should I trust what they say on scientific matters, the science of which I cannot judge well, when I cannot trust their rhetoric, a matter which I can judge well?
===================================
Oh, boy. Andy Revkin promises an article in the March 2 New York Times addressing this very issue. It seems, though, that the preponderance of his experts will predict this recent cooling to be just a blip in a warming world.
I hope there is a little cheese with the cherry pie.
==========================
I have to agree with Bender on Kim’s usage of given not being regional. I am from a region well outside the US (positively antipodean) and yet I had no problems understanding the intent.
kim and bender:
Re-reading my post, I can see that my “read” may have been interpreted as present tense. I intended it as past tense. That is, I *originally* read kim’s “given” as “since” or “because”. I now understand and accept that it was supposed to mean “if”.
I started by saying “not that it matters since kim has already clarified her intended meaning” — I absolutely accept your clarification and am not saying that’s not what you meant.
Either interpretation is valid. In the sentence “Given that the tense of word ‘read’ was ambiguous, it is not surprising that I was misunderstood.”, “given” has the meaning “if”. This is exactly the same structure as kim’s original sentence.
Anyways, I just wanted to clarify that I was not doubting kim’s intent.
Now that I have clarified, can we move on?
#222 Correction:
When I said:
I meant
#208
Well put (emphasis added).
If your original language is not English, or even if it is….
Mayhaps perchance before jumping to conclusions, one might attempt to discern both the meaning and intent of the other party or parties involved in the conversation.
As far as given:
American Heritage Dictionary
giv·en (gÄv’Én) Pronunciation Key
v. Past participle of give.
adj.
Specified; fixed: We will meet at a given time and location.
Granted as a supposition; acknowledged or assumed: Given the condition of the engine, it is a wonder that it even starts.
Having a tendency; inclined: My neighbor is given to lavish spending.
Bestowed as a gift; presented.
Law Issued on a specified date. Used of legal documents.
n. Something assumed or taken for granted. Often used in the plural.
The American HeritageÂź Dictionary of the English Language, Fourth Edition
“Given the forecast, you might what to rethink your state of dress.”
Whether you actually want to rethink your state of dress depends if you accept the forecast. Some may, some may not. kim was not being presumptuous. Simply pointing out that acceptance of the model-based forecast has consequences.
Folks, put the dictionary away and quit the parsing. The topic is models vs. data in the Antarctic.
Give the devil his due.
According to the Merriam-Webster Online Dictionary, the adjective “given” can mean (Definition 3b):
“assumed as actual or hypothetical : GRANTED (given that all are equal before the law)”
If mathematicians chose their words as carefully as they choose their numbers, and constructed their sentences as carefully as they do their equations, they would communicate more clearly and precisely.
Given that I think bender is a reasonable construction (as much as it makes my positrons sometimes get in a sparky (not mathy) state) it is time to focus back on models v data in the Antarctic, indeed.
So, anyone disagree that
#228 OT. Models, data, antarctic. Focus.
Re#228, Sam Urbinto:
So far, I found only one antropogenic factor comparable with natural processes on geo-global scale. From Wiki:
http://en.wikipedia.org/wiki/Nitrogen_cycle#Human_influences_on_the_nitrogen_cycle
Everything else (including AGW) just does not compare with natural cycles.
Bender: Not OT. Antarctica, how specifically are “the concentration of atmospheric constituents or properties of the surface that absorb or scatter radiant energy” being modified by human activity elsewhere? What gets into the atmosphere and ground in Antarctica from elsewhere on the planet? Since of course the continent is basically uninhabited.
Andrey: It’s all about oxygen and nitrogen, really. 99% of the atmosphere. Plants like it. And it makes a great breakfast even better.
#230, #231 definitely OT. Models, data, antarctica. Please keep this thread focused.
“Antarctica” “Discuss here”
Other than normal natural variability, Antarctica is basically only is influenced by humans from what they do in the North and South hemispheres, driven by the weather patterns that govern everywhere.
The question is: Did the models show Antarctica cooling? Cooling being defined by a mean anomaly in the negative. Or did they show less warming, being defined by a mean anomaly in the positive lower than previously?
In other words, did the models show less warming than before or not?
It’s a simple yes or no question. Did the obvious accepted most likely model show that the Antartica is in some way not as warm as before. If the model we think true show that the anomaly was at (making this up) .5 and went to .2 At .2 and went to -.2 Was at -.5 and went to -1
Define the parameters and demonstrate the models reflected what the Antarctic did.
All four major global temperature tracking outlets (Hadley, NASA’s GISS, UAH, RSS) have released updated data. All show that over the past year, global temperatures have dropped precipitously. That is more then any annecdotal evidence we have now.
The sun is more powerful then the scientific community as a whole were professing.
One hotspot predicted by climate modelers refuses to show itself, the midtroposphere in the tropics should warm 1.6 times faster than the surface. The data indicates the tropical mid troposphere has been cooling for 5 years, and some would argue for over a decade.
Is everyone going to jump on the bandwagon as the globe cools, I have been there for years ?
Re #218
I think that given the extensive leads in both the new ice and perennial ice and the mild winter in the N Atlantic and N Eurasia then this summer’s extent will be close to last year’s and possibly even exceed it.
I said I wanted to review this paper,
Click to access HadISST_paper.pdf
but was disappointed that it did not include discussion of the items about Arctic and Antarctica temperatures and ice areas that I was most interested in. I will do the review, but then I want to go on to a discussion in future posts at this thread dealing with climate modeling of the Artic and Antarctica and determine why they have been not been particularly accurate in modeling more recent changes in the polar regions.
The paper linked in this thread by cce at post:
http://www.climateaudit.org/?p=2802#comment-220752
covers the updates of the sea ice and SST for HADISST1 and the night time marine air temperature NMAT data sets. They use interpolation and homogenizations procedures based on linear algebra calculations and a number of assumptions in their updating process. The update was done to provide data to be used for climate modeling evaluations and climate model forcings. There were evidently many missing areas of data that needed to be âfilled inâ. I am not in a position to pass judgment on the linear algebra used for the filling in of missing data and could only judge the assumptions made by more background reading. The authors do point to areas that need further investigation, like the bucket and ship measuring techniques used for obtaining SST measurements.
The sea ice areas and extents are discussed for the satellite era (1979-present) of passive microwave measurements and then go on to discuss using the Walsh compilations for 1901 -1995. Some of the pre-satellite data seems to be almost anecdotal in nature and I would need to check other sources to confirm how reliable these data are considered by other workers in the field.
Below I have shown the important graphs from the paper showing that the Antarctica ice extent (actually SH since it includes inland lakes) has decreased for the early 1900s to the satellite era by an estimated 20% where it has leveled off for approximately 30 years. For the Artic regions (includes the NH) the ice extent appears to have decreased less than Antarctica (SH) from the early 1900s to present but with a much faster recent decline in the satellite era that comes from mainly from the summer time melting. It is also important to mote that in the Antarctica the seasonal ice melts back by Ÿ whereas in the Artic melt back was only 1/3 until more times where it is more like œ. This phenomenon, I would think calls for very different interpretations of the changes in antarctic and arctic ice coverage.
Not sure if anyone referenced this here but…
Click to access antarctica_white_paper_final.pdf
Graphs of station data!
MattN, on WattsUp, points out that right now both polar regions are gaining ice.
===============================================
Re #238
As they do this time of year.
Sure, some years.
==========
Kenneth you might find this 1979 paper worth a 20-minute read, for comparison with the one you reference. It examines a 25-year period in Arctic sea ice fluctuation.
Not sure if this link way referenced.
Shows Arctic Ice cover in 14 areas over 1 year period.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.13.html
I have a question, not directly related to sea ice extent, but related to ice coverage, depth, and proxy CO2 and temperature readings.
How do we know that the artic continually gained ice for the last X thousand years. Would it be reasonable to assume that in past warm periods it lost some???? How would that affect the proxy CO2 and Temperature readings for distant times?
(Some PC configuration changes tested)
Above, I wrote partly in jest “What time is it at the South pole? What day is it? How do you do a TOBS adjustment?” The answers to all questions are not related to climate. They are set by convention.
At the Tropics, there is definite day and night. At the South Pole the sun cannot be seen for weeks each year. So, a day at the tropics does not equate to a day at the Pole, for climate purposes. Neither do some of the adjustments that are used, like the one that compares stations 1,200 km away.
Somewhere between the tropics and the poles there is a grey area where conventional temperature adjustments fade logically into uselessness. I wonder if this effect is taken into account in models?
re: 239 (rebut to “both polar regions are gaining ice”) “As they DO this time of year.”
More appropriate would be to say “sometimes/infrequently… DO”
A mid-FEB Antarctic ice minimum is not common. So this year is relatively noteworthy on that basis, particular given it followed a CWP maximum less than 5 months earlier, plus the ice trends of both polar regions moving in the same direction. However, none of these are meaningful, climatically, any more than Katrina was.
I plan to review the literature on the agreement of the climate models in modeling past Artic and Antarctica temperature trends and ice extents versus observed trends over the past approximately 50 years. I hope to be able to do this in localized areas of the Polar Regions. I was thinking that I would use the reviews of the IPCC’s TAR and FAR WG1 sessions as a basis for the comparisons.
What I see from my preliminary reading on this subject is that on the one side you have observers noting that the warming of the Polar Regions as predicted by climate models has been wrong in the Antarctica (being too low) and in the Arctic (being too high) but not specifying the time periods when these differences are occurring. With sufficient global warming it is rather evident, as DeWitt Payne has pointed out that the Polar Regions will warm more than the rest of the global areas. From Post #352 in the thread Unthreaded #31:
On the other side we have those who would say that the models predict more warming for the Arctic than Antarctica but are never clear on the differences between the models modeling of past climate with observations. It is these fuzzy images that I see (they may be self imposed through ignorance) that are frustrating in evaluating objectively what is transpiring.
I have also seen the very dry air of the Polar Regions given as a reason for the faster warming in those areas due to increased GHG concentrations because the GHGs can be more dominating than H2O.
Click to access antarctica_white_paper_final.pdf
This reasoning appears to me to be opposed by what DeWitt Payne showed from a Gavin Schmidt graph where the GHG forcings for a doubling of CO2 were smallest at the polar areas and much smaller at the southern polar area. (Post #338 in the thread Unthreaded #31).
We also have Shindell and Schmidt paper (GEOPHYSICAL RESEARCH LETTERS, VOL. 31, L18209, doi:10.1029/2004GL020724, 2004)
http://pubs.giss.nasa.gov/abstracts/2004/Shindell_Schmidt.html
indicating that shifts in the Southern Annular Mode (SAM) and the effects of anthropogenic ozone hole on SAM and the resulting climate vortex protecting inland Antarctica from warming by the Southern Ocean are responsible for the Antarctica inland cooling and the Antarctica Peninsula rapid warming. This paper in my view points to previous models having it wrong on the Antarctica and that the models are being âfitâ as the need arises to make them agree with observations.
Any help from posters keeping me on the correct path in my review will be greatly appreciated.
Ken #246,
Ok, the SAM keeps warm air from the tropics from reaching Antarctica. Anything that blocks advective heat transfer to high latitudes would increase the temperature gradient. But does that explain why the entire SH isn’t warming, or is warming much slower than the NH? I see (finally) that indeed the trends for all and almost every part of the SH for ten and 15 years (except -24 to -44, 15 year) cannot be distinguished from zero.
“It’s the ocean” is not a sufficient explanation. Plots of heat flows and corresponding SST changes would be nice. Predictions might even be testable.
The following story appeared in this mornings (March 8) Edmonton Sun (part of a large national chain). Other than the fact this appears to be a quasi news story about a non event there are a few things here I’m suspicious of, but don’t have the expertise to venture writing a letter to the editor. Any help pointing out sins of commission or omission so I don’t write something foolish?. Thanks, and apologies if OT
Headline: âArctic’s vanishing ice spurs climate alaramâ
Sub-head: âScientists warn of more violent weatherâ
Body:
Artic ice will continue to shrink as the climate heats up, says a University of Alberta researcher.
Christian Haas says that last summer’s sea ice in the Artic ocean set a record for minimal southern extent, but is expected to keep getting smaller.
âWe do see the area of sea ice decreasing dramatically âonly in the Arctic, though, not in the Antarctic.â
That, he suggested, may mean the Northwest Passage could soon become open to shipping.
Haas is predicting evaporation of sea ice will mean more moisture in the air available for precipitation.
Haas prediction comes on the heals of news that 100 Canadian scientists are penning a report warning of increasing numbers of violent storms.
The report has not been made public, but leaks have suggested it will predict Canada will see more extreme weather such as ice storms, torrential downpours, droughts, and more days of extreme heat or smog.
Some areas of the country will see more rain while others, such as the West, may see shorter winters but longer, drier summers leading to droughts.
A reduction in sea ice will play a part in global climate change, said Haas.
Haas said he doesn’t know specifically how weather patterns may change because of the effect, but he said the earth’s hydrological cycle will intensify with increased moisture levels.
Haas said Arctic ice is being thinned from above and below.
Average air temperatures are increasing which melts ice, and winds were responsible for last year’s record minimal ice extent.
At the same time, ocean temperatures are rising and the Atlantic is pumping hotter water into the Arctic.
Near the North Pole, it has resulted in the ice thinning by approximately 30% in the last 15 years, said Haas, while closer to Ellesmere Island there has been much less thinning.
Ron
Re #248 Edmonton Sun: Most of the Sun papers had that or a similar article.
There is not much you can actually say because you cannot audit their “research” as the details will not likely be published. So you have to ask pointed questions about their data and methods. The ice decreasing is based on 15 to 30 years of observations, in other words about half of a cycle at best. Nobody measured the thickness 70 years ago. They believe that the warming will continue approximately linearly and the ice will disappear in the summer months. I do not know if this person (Haas) is on the ship that is sitting in Amundsen Strait for a year, but there are some from Manitoba there. How do they expect to come up with a conclusion based on a years work? Some of those 100 scientists that are a part of the “disaster forecast” are retired from the government.
Re #245
Really, according to sources that I’ve read: ” Usually the Arctic minimum occurs a little ahead of the Antarctic maximum due to the effect of continentality.”
E.g. http://seis.natsci.csulb.edu/rmorris/seaice/distrib.htm
Since when is March 7th ‘mid-Feb’?
The Antarctic minimum is much less variable than the Arctic usually falling with a few days of Feb 25th.
Re #250
Oops I pasted the wrong piece!
Based on Gloerson ’92 cited in the above webpage the antarctic minimum precedes or is approximately coincident with the arctic maximum.
So what would be the effect of this ‘continentality’ on Arctic maximum?
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Oh, boy, we can also argue about ‘sea ice area’ and ‘sea ice extent’ because they don’t mean the same thing.
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It looks too me like it comes down to how often the Antarctic minimum precedes the Arctic maximum by this much. I don’t see the data for that, but it certainly isn’t the usual for March 7 for both to be gaining.
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Re # 246 Kenneth Fritsch
You quote a quote
I would imagine that near the Poles the surface temperature would be close to that of the ice; and the huge ice mass at the S Pole would take a lot of heat exchange to alter its temperature. Is there enough latent heat carried to the S Polar region to make much difference in the period of decades to centuries? There seem to be no melting unconformities in the last 100,000 years or so.
Or are people maintaining that air above the polar regions should warm/cool faster than air above the tropics? That is a different concept.
On the sub-sub quote
I would take this as a test of proxies. If heat flow equations indicate that the poles should change more slowly, then that puts a question mark above the proxy approach.
DeWitt Payne # 247
DeWitt, I was thinking along the lines of Schmidt and Shindell fitting the model for the Antarctic but than the model getting it wrong for other parts of the SH and globe. If you look at the model simulation versus the observed in the maps in their paper I see the simulation getting it hotter for the SH (that is that part that can be seen on their map down to approximately 50S). I noticed in this paper, as well as some color differentiated maps showing differences in observed and model simulated temperature anomalies or just temperatures that were presented in the WGI AR4, that the colors are divided by large increments.
Re #254
Really, why, you say you have no data?
Antarctic minimum occurs within a few days of Feb 25th while the NSIDC says that the Arctic maximum occurs in March, so it would appear that this is normal.
NSIDC
Geoff #255,
But you don’t have to warm the whole ice cap, just the surface. How fast that can happen depends on the heat capacity and thermal conductivity of snow and ice. I should really look them up, but considering that heat can only flow by conduction, then it is very likely that only a small depth will need to warm. Snow probably has a significantly lower thermal conductivity than ice, see for example igloos. The obvious limit is the heat of fusion, but the average temperature of the Antarctic is far below the melting point of ice, so quite a large temperature change can occur without the need for a vast energy input.
So I believe that it is indeed the air above the surface that is predicted to warm faster than the tropics. The heat content of low specific humidity air in the high latitudes is much lower than humid tropical air.
Of course none of that explains why the atmosphere does not appear to be warming faster than the surface in the tropics.
Ken #256,
Actually, that’s the behavior I would expect if the heat flow to the highest latitudes is blocked. The rest of the hemisphere should warm faster. The fact(?) that this isn’t happening seems to imply that they have left something out of their model.
indeed
Phil, you already wrote that the Antarctic minimum precedes or is co-incident with the Arctic maximum. So the question is how often it precedes it by this much. Are you being dense or sophistical? Don’t bother to answer.
==================================================
Forgot the details,annual radiative flux in w/m2(positive gain,negative loss)
OK, I can see how you might be neither, forgive the snark, please. Still, it is unusual for the Antarctic minimum to precede the Arctic maximum by this much, and it will get even more unusual until Arctic maximum is reached. I have learned a lot from the exercise.
=====================================
If you want to view polar ice conditions without the intervention of the NSIDC or the Cryosphere Today with their radar-generated algorithm-manipulated reports, you can use the MODIS satellites.
The MODIS polar orbiting satellites produce visible pictures of the entire earth in real-time (maybe an hour or two delay.) They are produced in the visible spectrum (in other words actual pictures versus software-produced images). Various resolutions are available from 4km to 250M and they have false-color versions which helps sort ice from land, water and clouds.
Unfortunately, being visible pictures, they only work in the day-time or when there is sunlight over the poles (ie north pole pictures right now but full coverage of the south pole) and cloud cover can get in the way.
Takes a little getting used to (and if you save it to your favourites menu you have to edit off the date in the link or it will just take you to March 9th every time.)
Here’s the link.
http://rapidfire.sci.gsfc.nasa.gov/realtime/
re: 249 “Since when is March 7th âmid-Feb’?”
re: 250 “Oops, I posted the wrong piece”
You posted the wrong 2007-8 Antarctic ice area minimum — it was mid-FEB!
And the rest of my post stands, as well. Try again…
maksimovich #260,
Correct me if I’m wrong, but isn’t the slope of the contours in your chart proportional to heat flow? So if there were no heat flow from the tropics to higher latitudes then there would be no excess in the tropics or deficit at high latitudes in net radiative flux.
Re #265
Sorry I didn’t post an ice area minimum. I response to a statement on March 7th that “MattN, on WattsUp, points out that right now both polar regions are gaining ice.” I posted that this was usual for that time of year since the Antarctic minimum is normally around Feb 25th and Arctic maximum around mid-March.
But then you post data, Phil., saying that the Antarctic Minimum either co-incides with the Arctic Maximum or precedes it. I don’t see the data that the Arctic maximum is ‘mid-March’.
Look, if that is true about the timing of the two events, and I’ve little reason to doubt it, then there are some years when ice is accumulating at both poles at the same time. What I’ve been trying to get you to understand, and you seem awfully resistant to the idea, is that this is an unusual year. There is an extended, compared to most years, period this year when ice is accumulating at both poles. Unusual, I say, unusual.
Please don’t make me consider again that you are being sophistical. It’s amusing to retract apologies, and I hate to be so amused.
=========================================
Given that this is an unusual year, it is becoming increasingly likely that this summer’s Arctic minimun will have more sea ice extent than last year’s. There, take that.
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Re #268
Perhaps you should apologize for making things up?
I have not commented at all regarding the duration of the period between antarctic min and arctic max, just that it is not unusual for the one to precede the other (quite the contrary according to the cites I made). No doubt that it is indeed an unusual year, as was last year, again not disputed by me. Look at your original post which I commented on, no reference to duration. Your failure to understand plain english doesn’t make me a sophist! Amuse yourself anyway you choose.
And look how I responded, “Sure, some years”. This is one of them, but it is unusual for the length of the overlap. It amuses me how hard you try to avoid ceding a point. The overlap is long because the weather is a lot cooler this year. The weather is cooler probably because the PDO has flipped. You’ll get it after we cool for awhile, but I suspect that is why you are so resistant to the idea. Yes. you amuse me.
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Phil. re: ‘Making things up’. Where did your statement of ‘around mid March’ for the date of Arctic maximum come from? How does that jibe with the date of Feb 25 for Antarctic minimum ‘co-inciding or preceding’ Arctic maximum?
Look, the resolution of our disagreement depends upon how usual it is for Arctic maximum to trail Arctic minimum by 10 days or more. I don’t think either of us have the data for that.
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Re #271
Why the hell should I cede the point, I supported my point with data, you on the otherhand didn’t have a clue and just made something up that agrees with your beliefs!
Care to provide some data for those statements? Is the antarctic minimum early, by how much (I suspect it is but you seem so certain I’d like to see the data)? Is the arctic maximum unusually late, if so by how much?
The only data I have is from the sites you link. From them we have, and it is old data, that the Antarctic minimum varies a few days around February 25th and that the Arctic maximum varies by as much as a month, but either co-incides with the Antarctic minimum, or trails it. Deducing from this to decide whether it is usual on March 7 for both poles to be increasing ice requires the historical data of the dates of Antarctic minimum and Arctic maximum. That data could be analyzed to determine whether it is ‘usual’ for both poles to be accumulating ice. I don’t have that data. Do you?
========================
We can also argue about the meaning of ‘usual’. As usual, all argument is a matter of definition. I’ll concede that some years have both poles accumulating ice at the same time. Will you concede that the globe is cooling?
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OK, eyeballing the graph at cryosphere it seems that Antarctic minimum was around Feb 20, and Arctic maximum has not yet been reached. I maintain that is unusual, but I agree that is not what we started out disputing. The unusual length is a function of a cooling globe.
=================================================
By golly, there would be another metric to demonstrate the globe is cooling. I’m much too lazy and ignorant to run the data, even if I could find it, but I’d bet the periods during which ice accumulates at both poles is longer this century than for the last quarter of the last century.
=================================
I suspect you invented ‘around mid March’ from assuming that something with a range of 30 days would have a mean in the middle of them. My statistics is almost good enough to doubt that assumption.
=================================================
Wouldn’t the arctic and antarctic ice maxima be about 6 months out of phase?
Yes, with a tendency for the Arctic Maximum to trail the Antarctic Minimum. We are arguing over the trailing. I made a mistake in comment #272 on 3/9 at 8:24; in the last paragraph I wrote Arctic Minimum, I meant to say Antarctic Minimum.
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You see, fundamentally he is right. Sometimes ice accumulates at both poles at this time. But sometimes it does not. Neither of have defined terms well enough to come to a resolution, and neither of have examined the data adequately in order to define terms.
I am intrigued by the idea that the length of time that ice is accumulating at both poles is a metric for the raising or lowering of the globe’s temperature. When both hemispheres are cooling that period is longer than usual. This year, that period is (probably) a good deal longer than usual, three weeks already and counting. Maybe I’ll get off my lazy butt and look at it, but all it would tell me is that the globe is cooling, and I already know that.
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It’s really kind of neat. Analysis of these dates will tell you whether the globe is warming or cooling, if currents and winds are left out of the analysis. Who needs temperature data?
=======================
SL has also done some eyeballing on CT…
1979-1989 global sea ice annual average area/extent
whatever it is…29.865.000 km2…1990-2007: WORST WARMING
YEARS: 29.700.000 km2… 1998, a year by many considered
to be WYE… is number 4 out of 30….from top…
30.290.000 km2. SO we have 0.5 percent or 5 promille
less ice 1990-2007 than 1979-1989 Masswise doesn’t mean
much to albedo change,
right?? But we need some substantial El Niño quick, see 1998,
SH almost Âœ million km2 more sea ice than in 1997…
#283 PS…Forgot this: Years with sea ice increase in
both hemispheres: 1985(Nice and warm winter in Europe
Nice Jan 8 Tmax -1.5C…), 1993, 1998 (Lowest Tmax in
Stockholm Observatory +3.6C in month of November, thin
snowcover in the suburbs almost all month), 2000, 2003
AND 2008?? DS.
I have reviewed the IPCC AR3 and AR4 (links listed below) reports with the intent of learning something about the claims for and against the climate models performance in predicting recent climate trends in the Arctic and Antarctica. I chose these sources as I assumed that the IPCC would provide the best reviews for a layperson to start their search.
AR3 WG1 link = http://www.grida.no/climate/ipcc_tar/wg1/index.htm
AR4 WG1 link = http://ipcc-wg1.ucar.edu/wg1/wg1-report.html
I started my search confused by what I had read in the media and some scientific reports as conflicting evidence of the climate models simulating the current polar trends in temperatures and sea ice areas. I must admit that after my preliminary investigation, I remain at least somewhat confused about which I will point specifically later in this post.
In general terms the most striking observation I can make at this point is the lack of good instrumental data from before the 1970s from the Arctic/Antarctica and the wide variations in the climate model outputs for these polar regions. Much of the climate model simulations versus observed climate over the recent past as described in the AR3 and AR4 reports are compared using the observed mean temperatures (or other climate variables) and the simulated mean over the same time period. It is important to note that in this instance they are not comparing temperature anomaly trends. Following are some of my specific references.
In the Supplementary Material from Chapter 8 of the WG1 AR4 on page sm.8-5 and Chapter 8 page 609, the color shaded areas maps indicate that the average of 22 climate models simulates the mean temperature, over the approximate time period 1970-1999, too high to observed by 4-5 degrees for the Antarctica and similarly 1-2 degrees C too low for the Artic. Most of the remainder of the map shows an observed versus model mean error over this period of +/- 1 degree. These mean temperature differences seem to be nearly the same for those depicted in the WG1 AR3 report in Chapter 8 on page 480 for the months of December, January and February. This page also displays a graph showing how the models increasingly vary on the outputted mean as one proceeds to the polar regions.
My ignorance and/or skepticism comes into play with this observation in that I am tempted to relate the lack of observed data from the polar regions compared to the remainder of the globe with the wider variations in climate model outputs for the polar regions versus the remainder of the globe, i.e. the opportunity to âfitâ the model is decreased in the polar regions. The IPCC explanations for the variability in simulating the polar climates in these reports tends to be along the lines that the polar regions unique climate and climate features like sea ice coverage make the modeling task significantly more complex.
More evidence of this wide variability can be seen on page 489 of WG1 AR3 in a table presenting the errors between simulated sea ice coverage by models and the observed values in the year 1992. Page 617 of Chapter 8 in the WG1 AR4 shows the wide variations in simulated sea ice coverage by 14 different climate models. On page 485 from Chapter 8 of the WG1 AR3 one can see a graph with wide variations in climate simulations of cloudiness and how it increases dramatically at the poles.
Here, however, is where I become confused and I need any assistance I can obtain from more knowledgeable posters at CA. In Chapter 11 of WG1 AR4 report the IPCC authors deal with specific regions of the modeled global climate. A specific region discussed includes the Artic and Antarctica. The climate models most often referenced in this section are those classified as MMD. I did not come away with a good distinction between these MMD climate models and other model classes nor was I able to determine whether these models dealt exclusively with a given region of the globe without concern for how the models would perform outside the region of interest. Obviously a regional model could under these circumstances be more susceptible to fitting.
Anyway these models were used to simulate the Artic and Antarctica climates from 1906 to 2100 for the Arctic and 1951 to 2100 for the Antarctica. They used trends in temperature anomalies over this time period which obviously allowed comparison with observed trends over the instrumental period. Now here are what seem to be contradictory results to me when compared to the earlier comparisons of means (and not trends). For the Antarctica, the band of model simulations give simulated trends of 0 to 2 degrees less than those observed for the 1951-2000 period. For the Arctic, the band of model simulations give simulated trends of 0 to 1 degree C greater than those observed for the 1906 to 2000 period.
Ken; My opinion on the subject is that this is just one more example of an unknown Margin Of Error in spotty recreated data. I would guess the MOE is huge here in the first place, and also unknowable. Therefore, I wouldn’t even bother with the models, since there’s no way to prove or disprove any of it anyway. The data is just not there.
It seems once again I’m a topic of discussion. Phil, relax, I certainly did not mean to wad your panties with my observation that both poles were gaining ice at the same time. Just wanted to know if that was normal. Apparently, it is. Cool (hardy-har-har). I did not know that.
Kim raised a neat question that I don’t think has been addressed (maybe I just missed it?). What is the “normal” overlap of the two, and does a longer or shorter than normal overlap signify anything?
I do have another question. NSIDC hasn’t been updated since the beginning of the month. It’s now the 11th. Typical? Seriously, I really don’t know. It seems pretty clear to me that site is pro-AGW with all the Al Gore quotes on it, so I was just wondering if they were delaying the release of an update of ice data in hopes newer data might look better for them. After all, the planet now has a positive ice anomaly for the first time in years…
Re #287
No problem, the data indicates that is normal as I posted.
It would appear to be about 1-3 weeks, the lack of detailed data on the precise timing of the arctic maximum is probably a good indicator of how significant it is! The max is usually fairly flat whereas the antarctic minimum seems fairly sharp (perhaps a bit more so this year).
I don’t check NSIDC that often but I thought they updated their data monthly (SOCC:weekly, Cryosphere Today: daily). The data is what it is, delaying its release would serve no purpose.
Not really, the last time was December according to CT, and then about 15 months before that:
My mistake Phil. I typed NSIDC but meant to put Cryosphere Today.
http://arctic.atmos.uiuc.edu/cryosphere/
As of this morning (March 12th) the hemispherical ice data has not been updated since the 1st of the month.
#288 Phil. IF we somehow trust CT here the steep and big rise
from MINUS 3 million km2 to PLUS 1 million km2 in the last months
is UNPRECEDENTED!…
Correct me if I am wrong…still miss my glasses….
Don’t worry about your glasses, STAFFAN, Phil. would have it that things are ‘normal’.
==========================================
So, if cryosphere today is supposed to be updated daily, and it hasn’t been updated in almost 2 weeks, what are they waiting for? Better data?
MattN says:
They have had to post notices telling people to ignore bad time series data twice in the last 3 months. I suspect they have put the data on a time delay so they can review it before it gets posted. Posting wrong data is worse than posting no data at all.
Agreed.
Re#294
Plausible but I suspect actually it’s the sloppiness of html graphing, the data is updated daily and the more precise long term anomaly graphs seem to be up to date. Anyone who really wants to know should email William Chapman, I’ve found him to be responsive, last year I asked him if it was possible to produce a global anomaly and he quite quickly produced one! Of course others may have also asked.
Re #290
Of course it’s unprecedented since -3million km^2 is itself unprecedented!
RE 249 and Edmonton Sun story.
Gerald Machnee, apologies for taking so long to thank you for your comments. I suspect you may have also seen the Canwest story (in Edmonton it was in the Journal) that referenced a bigger gang of âleading Canadian scientistsâ —145 of them produced a 500 page report. However the topic was bigger than just the Canadian north, and even scarier. âCanadian scientists say climate change won’t be good: Drought on the Prairies, severe Atlantic Stormsâ. The writer quoted Quentin Chiotti of Pollution Probe warning that âwhen you put more heat into the atmosphere, you’re going to start getting more wacky weatherâŠ.â
To drive this point home the story was headlined âForecast: Unpredictable, intense weatherâ. Holy Oxymoron Batman, we’re really doomed this time!!!! It’s so bad they won’t even be able to warn us.
Ron
A four million kilometers squared rise in ice does not follow ‘of course’ from a three million kilometers squared negative anomaly. The cause of the large rise in ice is unusual cooling of both hemispheres.
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How can any data be characterized as “unprecedented” in a series that only goes back to 1979? Or is there more data than what is depicted on the graph in post 288?
I imagine the NSIDC is getting ready to revise/adjust the historical sea ice extent records again in advance of “the polar ice caps are completely melting!” season / summer reporting season.
The global ice extent numbers are getting too close to average / going above average and must be adjusted downwards now just like was done last January 2007.
Here is a Before and After animation of the changes made in January 2007.
John Lang,
Was any explanation offered for that shift? Did they hire consultants from GISS perhaps?
William Connolley has an excellent post on GISS’ Antarctic data calculation here. I meant to do a post on this last year, but forgot. It’s well worth reading.
I complimented him on the post, observing that it was a good example of something that one could do on a blog, which should be in the air, but which one wouldn’t be likely to submit to a journal. He replied that, if Svensmark relied on the flawed GISS data in a journal article, he would submit a comment. However, the real problem – the flawed GISS procedure – didn’t seem to require a journal comment in Connolley’s view. I disagree. If he would comment on Svensmark using flawed Hansen data, he should comment on the flawed Hansen data.
To Peter #301, I do not know if an explanation was ever provided. Maybe someone else knows? I do know that many people emailed Bill Chapman from the Cryosphere Today about the change and no answer was provided.
Re #298
Which of course was something that was never claimed, once again revealing Kim’s lack of reading comprehension!
In order to rise from minus 3 million km^2 the system of course have to first be there!
No it’s mainly the result of normal cooling after an abnormal warming in the Arctic.
What, Me Claim?
Here’s a claim. In your post #267, on 3/9 at 2:34 PM, you stated that Arctic Maximum occurs ‘around Mid March’. I’ve asked you where you got that figure and you haven’t responded. Six posts later you claim I don’t have a clue and just make things up. Well I say you do have a clue, and just make things up. You’ve got a lot more credibility to lose than I do.
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A curious, yet some how unsurprising double standard.
While we’re at it, let’s take a peek at causality. What is the more likely cause of a four million kilometers squared rise in the ice anomaly; an unusual cooling trend, or the starting point of the rise? Be careful; it is a trick question, but it is illustrative and pathognominic of his rhetoric.
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I have proof that a doubling of methane results in a 15 C rise in temperatures.
Just kidding.
Such a nice press release
http://www.nasa.gov/topics/earth/features/seaice_conditions_feature.html
buried in the middle is an inconvient truth.
Interesting that this release comes out as the artic ice approaches its max.
[lurk off]
“Export of ice” – are the Saudis finally realizing their dream of importing iceburgs for fresh water?
“All time minimum” – looks like they’ve found a way measure ice coverage going back bill-yuns and bill-yuns of years.
I’d still like to know if anyone really knows volumes – not just “areas” or “extents” (rumor has it that the US & Russian Navies keep tabs, but they don’t share).
[lurk on]