Guest Post by Willis Eschenbach
Steven Mosher has pointed out a Science Magazine article (subscription only) about Antarctica. It is a discussion of the temperature changes in the West Antarctic Peninsula (WAP). And where might that be?
Figure 1. Location of the West Antarctic Peninsula. Yellow push-pin markers show the location of temperature stations. Yellow outline shows the enclosing area used for temperature calculations. This is the smallest area using 5°x5° gridcells that contains all of the WAP temperature stations.
The Science Magazine article contains the following statement about the WAP, which set my bad number alarm bells ringing:
Physical Changes in the WAP
Changes in the WAP are profound. Mid-winter surface atmospheric temperatures have increased by 6°C (more than five times the global average) in the past 50 years (14, 15).
I had never looked closely at the WAP temperatures. However, that seemed way high for the changes in the WAP air temperature, no matter what month we are talking about. The references for that statement are:
14. P. Skvarca, W. Rack, H. Rott, T. I. Donángelo, Polar Res. 18, 151 (1999).
15. D. G. Vaughan et al., Clim. Change 60, 243 (2003).
I couldn’t find a copy of either of those on the web … so I did what I always do. I went to get the data, to see what is happening.
Initially, the situation looks good. There are thirty stations on the peninsula. Figure 2 shows the location of some of these stations:
Figure 2. Location of the temperature stations in the WAP
So, what’s the problem? As you might imagine, many of these stations are only occupied part of the year. Others have been occupied intermittently, or have closed entirely. As a result, we don’t have anywhere near the coverage that thirty stations would imply. Here’s a graphic showing the dates of coverage for each of the thirty stations:
Figure 3. Dates of coverage for each of the thirty stations in the WAP. Only a half dozen or so show coverage over most of the last fifty years
Things are not as good as they seemed. Some of the datasets ony cover a few years. Others are longer, but very spotty. However, as they say, “Needs must when the devil drives”. Here is what all of the different stations look like:
Figure 4. Plot of all stations on the West Antarctic Peninsula. You can see the difficulty in determining an average temperature change over the area. Some stations swing quite widely, while others show much less variation.
Are the winters warming? Well … obviously, it depends on exactly which datasets you use to create your area average. Do we include the spotty orange dataset that starts about 1986, or not? What about the blue datasets that only exist for the sixties and seventies? Based on these decisions, our answers will be different.
Next I looked at the major datasets. As you know, there are several temperature datasets that cover the globe. For the land alone, we have the CRUTEM3, GISS 250 km, and GISS 1200 km land datasets. The two GISS datasets use the same surface stations. However, they differ in that they extrapolate the temperature of empty gridcells using all relevant stations within either a 250 km or a 1,200 km radius respectively.
All of these are available at KNMI, which is an outstanding resource. Here are the month-by-month trends for each of those datasets:
Figure 5. Month-by-month and annual (“Ann”) trends for the air temperatures (land only) for the area of the West Antarctic Peninsula outlined in yellow in Figure 1.
There are several interesting things about this graph. First, a simple average of all of the stations (“All Station Average”) gives results that are broadly similar to the CRUTEM results. I assume that this is because of the general similarity in the climate zones of the 30 temperature stations around the peninsula, which allows for a direct average rather than the more sophisticated methods (anomalies or first differences) as used in the global datasets.
Next, in several months there is a difference of a full degree (per fifty years) in the trends of the CRUTEM and the GISS datasets. The various datasets are often claimed to be in good agreement. But this is only globally. When we get down to a gridcell-by-gridcell and month-by-month comparison of the trends, they are often quite different.
Since they are (presumably) using the same basic data (the 30 land stations), this is odd. Note that the annual trends are in reasonable agreement, but the monthly trends differ … why should that be?
The effects of the GISS algorithm for filling in the empty gridcells are also curious. Depending on the extrapolation radius chosen (250 km or 1,200 km) they differ by up to a half a degree in fifty years.
Finally, none of the datasets show a temperature rise of 6°C in fifty years in any month, as the Science paper claims. My bad number alarm was accurate. So I’m in mystery about where that claim might come from. August has the highest trends, at three to four degrees depending on the dataset chosen. But that’s a long way from six degrees.
Now, it is often said that the warming of the Peninsula is due to warming of the surrounding ocean. So I decided to take a look at that as well. Here are the same datasets, showing both the land and the ocean:
Figure 6. Land and ocean temperature trends for the area outlined in yellow in Fig.1
Here, the differences between the datasets are larger. For the first five months of the year the CRUTEM+HADSST dataset shows a much smaller trend than GISS, up to a a degree and three quarters smaller. The rest of the year, the datasets are much closer than in the first five months. Why would they be different in part of the year, and not the rest of the year?
In addition, this dataset makes it unlikely that the ocean is driving the warming. The trends including the ocean are almost all either the same or smaller than the land-only trends. This is particularly true of the CRUTEM vs CRUTEM+HADSST datasets.
Finally, I took a look at a shorter period, from 1979 to 2009, so that I could compare trends from the ground-based datasets with the UAH MSU satellite based dataset. Here is that data:
Figure 7. Ground and satellite data compared for the area outlined in yellow in Fig. 1. Note that these are thirty year trends rather than fifty year trends, as shown in the other figures.
Here, things get markedly odd. The satellite data shows cooling in about half the months. The overall annual satellite trend is … zero. Go figure. We see much greater differences between the ground based sets. The GISS peak warming is no longer in August, but in May. None of this makes a whole lot of sense … but there it is.
Final conclusions?
First, once again some mainstream climate scientists are exaggerating. There is no dataset in which we see a WAP air temperature rise of 6°C in fifty years as claimed in the Science paper.
Second, although it is widely claimed that there is good agreement between the various ground based datasets, as well as between the ground and satellite data, in this case we see that they are all quite different. Not only the amplitude, but in many cases the sign of the trend is different between ground and satellite data. The CRU/Hadley dataset varies from the GISS datasets. In all, there is not a whole lot of agreement between any pair of datasets.
All of which makes it very difficult to come to any conclusions at all … except one.
My only real conclusion is that it would be nice if we could get some agreement about one of the most basic data operations in the climate science field, the calculation of area averages of temperatures from the station data, before we start disputing about the larger issues.
DATA
The surface temperature data stations used for Figures 3 and 4 are identified in the GISS dataset as:
Matienzo
Teniente Matienzo (Ant South A
Racer_rock
Base Almirante Brown
Almirante_brown
Dest. Naval Melchior
Cms_vice.Do.Marambio
Palmer Station
Bonapart_point
Faraday
Petrel
Bernado O’Higgins
Larsen_ice_shelf
Deception
Dest. Naval Decepcion Sout
Deception Is. S Atlanti
Base Esperanz
Hope Bay
Santa_claus_island
Base Arturo P
Centro Met.An, Marsh
Bellingshause
Great_wall
King_sejong
Jubany
Arctowski
Admirality Bay
Ferraz
Rothera Point
Adelaide
An important element that stands out in Eschenbach’s post and the numerous responses that followed is the nature of the discussion — measured, rational, open, magnanimous, rich in data and observations. This (WUWT) is truly a wonderful place to visit.
Great post, Willis.
When I read that article a few days ago, my spidey senses also started tingling when I saw the claim of a 6-degree temperature rise in the WAP. Your exploding of this claim, as with most claims by the AGW bed-wetters, is welcome, but not a surprise.
vukcevic says:
June 19, 2010 at 8:06 am
Decline in the GMF Z-component is a good proxy of the temperature increasing trend.
The increasing population of the US is by the same argument a good proxy for the increasing temperature. [it might even be an inconvenient truth]. Just because two cherry-picked curves look the same does not mean that one is a proxy [not to speak about a ‘good’ one] for the other. Please try to increase the credibility of this blog, rather than the opposite.
John Trigge says:
June 19, 2010 at 3:24 am
Sure there is a way … you just have to be Phil Jones, then the reviewer sends you the paper and asks you about the review … just kidding, the pre-publication paper and the review comments are supposed to be secret, although the CRU emails showed large holes.
I have long held that at the end of the review process, reviewer’s comments (positive or negative) should be published and the reviewers names should be added to them, whether the paper itself is published or not. In part that is because I’m tired of being anonymously stabbed in the back … and also for the sake of science.
jcrabb says:
June 19, 2010 at 5:19 am
Truly, you gotta love the stones on these guys. The three major records disagree, showing different warming rates for the various months. They all disagree with the satellite record, which show no warming at all for the area in question since 1979. We have only short, spotty ground records, none of which go back before the 1940s. As a result, we don’t even agree on the present warming trends.
Yet they claim that the warming is “unprecedented” over the last two millennia. Here’s a tip for people just entering the field. If a study contains the words “robust” or “unprecedented”, it is neither.
The Vaughan et al paper, which was one of the 2 sources cited by the recent Science paper by Schofield et al for its 6dC figure, does report a 11.0dC/century trend for Faraday winters, using 1950-2001 data, which would be 5.5dC/50 yrs. However, the se on the 11.0dC/century is given as 9dC/century, which would make it only insignificantly different from 0 (despite a mysterious claim of significance in the last column of the table).
Is this consistent with the data you found, Willis?
Vaughan et al say they corrected for serial correlation using a method of Trenberth (1984) and vonStorch & Zwiers (1999), but I haven’t checked their calculation or those sources.
OSU doesn’t have the Svarca paper (Polar Research, 1999), which was the other one cited by Schofield et al. in Science.
A few snippets from the 2003 Vaughan, et al, paper are below.
After reading the paper, I would say it was very objective and clear that the warming was a local condition without correlation to AGW and in disagreement with the Antarctic continental record.
…. BEGIN SNIPPETS ….
Whichever weighting we choose, there is only weak evidence of significant overall warming in station data from continental Antarctica, and we find no evidence that this is significantly greater than the global mean warming during the 20th century (0.6 ± 0.2 ◦C, Houghton et al., 2001). Thus, we find no ubiquitous polar amplification of global warming in the Antarctic station data.
….
While the Antarctic Peninsula has warmed 1979–1999, nine out of twelve of the stations from the rest of Antarctica, show cooling, although none achieve 5% significance.
….
The west coast of the Antarctic Peninsula is the only region of Antarctica where a strong correlation between sea-ice extent and near-surface air temperatures is ob- served (Weatherley et al., 1991);
….
In detail, the zone of greatest negative trend in sea ice duration (>5 days per year) coincides with the two stations showing the strongest warming trend (Faraday and Rothera).
….
Farady Station ONLY (this was the highest trend):
Period Trend (degC/century) Significance
1951–2000 +5.6 ± 2.1 5%
1961–2000 +4.5 ± 2.5 10%
1951–1980 +4.8 ± 4.7 Not sig.
1961–1990 +4.6 ± 4.3 Not sig.
1971–2000 +3.6 ± 4.2 Not sig.
….
[ note: at one point they state that borehole thermometry records do not correlate with met station warming]
….
we interpret this to imply that the RRR warming may not have made current temperatures equal to the Holocene- maximum, but that recent warming is exceptional in the context of the past 1800 years (Pudsey and Evans, 2001).
….
Among the local impacts of continued RRR warming would be, continued retreat of ice shelves, retreat of low-altitude glaciers, increased seasonality in some snowfields. Biological habitats will continue to undergo changes in extent, although it is unlikely that any particular species would be seriously threatened (Convey, 2001). Similarly, there would probably be few global impacts resulting from changes on the Antarctic Peninsula (Anisimov et al., 2001) – some contribution to sea level change is expected, although its sign is unpredictable at present.
….
The 50-year rapid warming may, or may not, have its root cause in global anthropogenic climate change, but whether or not it does is relatively unimportant from the point of view of impact assessment and adaptation. The same may be true for more populated areas of the world. In which case, regional climate changes will most probably have a more profound impact on human activities than global mean warming.
…. END snippets ….
So, the referenced Vaughan, et al, paper seemed very reasonable. But maybe used out of context in the Science article?
Cheers,
BillN
It seems that all too often the definition of “scientists” is this: Educated fools who can manipulate and distort the data and the theory in such a skillful way that they can convince large segments of the population that they know what they’re talking about and that their conclusions are truth, and not just propaganda.
Then again, that pretty much covers it for a lot of lawyers, doctors, economists, business experts, consultants, psychiatrists, educators, historians, theologians, and politicians, etc. etc.
There are real scholars and honest experts, but in my experience they are a minority in their fields. How sad!
Granting the dubious assumptions that the temperature data are accurately measured and appropriately adjusted, is it taken as mere coincidence that the west Antarctic area of purported temperature increase is also an area of widespread volcanic and subsurface geothermal activity? If geothermal has been ruled out as the cause of WAP temperature increases, how so and by whom?
Also, what has been done to rule out direct human habitation/station activity as having an effect on temperature measurements a la Anthony’s surface station survey?
Interesting. I have been looking for at temperature heads-up for Antarctica, but can’t seem to find a reliable one.
Great post yet again, Willis. I’m sorry if this is a dumb question, or if I am asking the wrong person, but how on earth can they validate their 2000-year proxies when they have such a patchy and short-lived instrumental record?
David S: Ya gotta have FAITH!
Does anyone wonder why leading figures of the alarmist movement almost always refuse to publicly debate AGW with sceptics?
Not surprisingly, they have to hide behind ‘peer reviewed’ papers published in magazines, where sceptics are viewed like jews at a nazi rally.
It would be interesting if WUWT makes a searchable data base with every crazy climate change allegation, and if possible, classified from the weirdest to the foolest. It would be a great help to future historians who will surely study the history of the fall of the occidental civilization, owed to this madness, and how it effectively destroyed all the advancements in science, technology and well being of humanity.
Roger Knights said on June 19, 2010 at 6:57 am:
Maybe a correction is called for, but that’s the wrong one.
… fifty years as claimed in the “science“ paper.
There, that’s more accurate. 😉
Is the Rothera thermometer at the airport?
Global Warming Science has coverage of
The Wilkins Ice Shelf
http://www.appinsys.com/GlobalWarming/AntarcticWilkinsIceShelf.htm
West Antarctica
http://www.appinsys.com/GlobalWarming/RS_AntarcticPeninsula.htm
and Antarctica
http://www.appinsys.com/GlobalWarming/RS_Antarctica.htm
Climate4You – Antarctic Temperature on left
http://www.climate4you.com/
Here we have a pattern of warmer winters in a polar area, but not warmer summers, and also the fact that this warming is not found in the satellite record.
To me this spells inversions. Very low winter temperatures at high latitudes are almost always due to shallow inversions, i. e. very low temperatures in a thin layer of air close to the ground because of heat radiating away into space in the clear and dry air.
However since these low temperatures only occur close to the ground they are not “visible” in the satellite record that measures the temperatures higher in the troposphere.
Such inversions can only occur when the sky is more or less cloudless, and they are only stable in still air or very light winds. Has there by any chance been an increase in cloudiness and/or winds in winter at the stations with the strongest warming trend?
Willis should not be taking in depth analysis until reading the papers in question which are referenced. If he does read them then he realizes how this claim was made. Instead he doesn’t read them and guesses how they found this and then disproves his own guess. It’s a common straw man and better quality control should be expected here. If you are to make conclusions which argue against several papers, you have to READ THE PAPERS prior to making these accusations. Like I always say, the biggest thing missing here is the lack of reading the core literature prior to mud flinging.
David Vaughan is a climate scientist with the British Antarctic survey team and a lead author at IPCC
http://en.wikipedia.org/wiki/David_Vaughan_(scientist)
William Connolley (AKA Stoat) is a former climate modeller at British Antarctic survey and lives in Cambridge very close to David Vaughan. Connelley is better known as the (former?) gatekeeper of Wikipedias climate pages.
http://scienceblogs.com/stoat/about.php
As Jonathan observed earlier the authors are;
D. G. Vaughan, G. J. Marshall, W. M. Connolley, C. L. Parkinson, R. Mulvaney, D. A. Hodgson, J. C. King, C. J. Pudsey, and J. Turner. Recent rapid regional climate warming on the Antarctic Peninsula. Climatic Change, 60 (3): 243-274 October 2003
Being neighbours and from the same warmist team don’t make the stuff that the two produce incorrect, but certainly warrants close examination.
tonyb
DaveJR says:
June 19, 2010 at 6:09 am
Other journal website is down at the moment
Whoa, we have a winner, kudos to Dave. DaveJR has send us the text of one of the two papers used as references for the Science Magazine claim that:
which was
Examining the paper (which features the noted Wikipedia science censorer, William Connolley), Table 4 shows the seasonal trends, with Faraday showing a warming (1951-2001) of 11 degrees per century in the winter …
So the authors of the most recent paper are blowing smoke. The WAP isn’t warming at six degrees. Instead, there is one WAP station (Faraday) which, if you pick the time period carefully (1950-2001) shows a winter warming of 5.5° per fifty years. And even that is a bit of sleight of hand, because if we take the entire period of record (1945-2009), the winter trend is 4.8° per 50 years.
A final note. The British data is here. The oddity is that it is a bit different than the GISS data. In the period 1951-2009, 45% of the months are identical between the two datasets. Another 45% have a difference of a tenth of a degree, 2% have a difference of 0.4° or greater, and three months have a difference of over a full degree.
This doesn’t make any difference in the trends … but it is another example of the poor agreement between the various fundamental datasets in the field. Surely GISS and the Brits could get together and agree on what the actual data looks like … and then we could discuss how to do areal averages …
Note that the GISS Faraday record is made up of five individual records, which are quite similar. The British seem to be using some other records, see the reference above.
RobertJune 19, 2010 at 11:26 am
You made a very fair comment that papers should (ideally) be read before they are commented on. However so much of climate science is behind pay walls that it makes it impracticable-however desirable. I spent $300 last year buying paywall articles 90% of which were a waste of time and money.
Unless I’ve missed it this paper will cost $47 to buy. Perhps we need to start a deicated paywall fund to buy such articles?
Tonyb
Thanks, Toby, for showing us the paper’s heading. Why am I not surprised that this 6deg claim has William Connolley’s name on it?
It would be nice if someone could address in a full posting a question that I’ve wondered about for a while now…
Given that the two poles are where they are and get the very small amounts of solar energy that they do as compared with the rest of the planet how is it there is any fear that they could melt at all?
It seems to me that both the arctic and the antarctic would need to have seriously large temperature increases before all the ice could melt… it’s like -50c to -70c in the antarctic and the ice sheets are what about 1.5 kilometers thick and melting ice takes 80c of heat to phase transition from ice to liquid so even if it were to increase by 70c to 0c it still wouldn’t melt for a long time! If the antarctic increased by 70c what would be happening to the rest of the planet? Let’s see Vancouver would be 87c assuming the same increases all over the planet.
It just seems that the fears of such increases are so shockingly remote in probability as to be next to nil baring the entire planet moving closer to the sun, the sun growing, a super massive continuous super nova, the silly scenario from the movie 2012, the moon crashing into the earth, an asteroid hitting the earth, a gamma ray or other radiation burst hitting earth head on, or other such very rare or highly remotely unlikely scenarios. The asteroid is about the only one that we really need to worry about…
But the point remains for even less extreme temperature increases… say 5c to 20c… would that have any effect upon the massive ice cap in Antarctica? Or Greenland?
The problem is that unless something massive happens (as described above) the poles will keep on receiving the same amounts of energy as they have for millions of years… so the Natural Null Hypothesis seems to prevail unless somehow we can lift the entire temperature of the antarctic +70c to zero +80c to phase transition it into liquid.
Could we even do this if we tried?
http://pathstoknowledge.net/2009/02/22/how-could-we-melt-enough-ice-for-a-20ft-rise-in-sea-levels
http://pathstoknowledge.net/2009/02/22/a-sea-level-calculator
Robert says:
June 19, 2010 at 11:26 am
Take a deep breath there, Robert. The paper made a claim. I did not know what the claim was based on. I did not “guess how they found this”, that’s your fantasy. I simply analyzed the WAP trends using all the available actual data. I didn’t speculate, I didn’t just say “It’s wrong.” I actually ran the numbers to see if their claim held up. It didn’t. If you don’t like an analysis based on the available actual data, you’ll have to explain why.
Now, thanks to DaveJR (see my preceding post), we have one of the papers available, and guess what? The claim was based on one single station … which agrees with my analysis. If you want to pay $47 to get the other paper, post it and we can lay this all to rest … but I know what my bet is on …