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
A discussion of Rothera together its screen location in summer and winter was discussed here….. http://wattsupwiththat.com/2009/12/13/frigid-folly-uhi-siting-issues-and-adjustments-in-antarctic-ghcn-data/
Robert says:
June 19, 2010 at 6:37 pm
Thanks, Robert, much appreciated.
Geoff Sherrington says:
June 19, 2010 at 7:53 pm
Guys, those graphs are not showing temperatures. They are showing temperature trends.
w.
Willis: The authors of this Science paper claim that references 14 and 15 demonstrate a 6 degC rise in winter temperature on the WAP over the last 50 years. The abstracts for references 14 and 15 (below) provide no support for this claim. The proper way to challenge their statement is to consult these references and understand why they make this claim. When you fully understand the evidence behind their statement, then you can demonstrate why they are wrong – assuming you still think they are. If anyone challenged one of your analyses, I’m sure you would want them to take the trouble to fully understand your work before criticizing it.
The WAP is one of three areas in the world allegedly showing the greatest “rapid recent regional” (RRR) warming. (They cite AR4 WGII Chapter 15, but a text search of this chapter didn’t uncover a discussion of three such regions.) Alarmists are claiming that these regions are a model for the ecological damage future climate change will cause, so it would be wonderful if someone could discredit “RRR warming”. It isn’t clear why the Science authors cite surface air temperature change, but not water temperature change, in an article about marine ecosystems. Instead, they discuss changes in ocean heat content – as if water temperature hundreds of meters below the surface has anything to do with marine productivity. Even worse, none of the ecosystem changes are linked to the alleged 6 degC air warming in WINTER. And the abstract for reference 15 says that GCG’s haven’t predicted the changes seen at the WAP, so there is no evidence linking ecological changes at the WAP to GHG-induced climate change. The extreme nature of the changes at the WAP presumably represent natural variation.
“In part because of the heat and nutrients supplied by the Upper Circumpolar Deep Water, the WAP hosts an extremely productive marine ecosystem supported by large phytoplankton blooms (26). However, over the past 30 years the magnitude of these blooms has decreased by 12% (27). The changes have been particularly dramatic in the northern WAP, with declines driven by an increase in cloudy days, deep mixed layers associated with persistently strong winds, and a reduction in the marginal ice zone (27). There is evidence that the algal community composition has shifted from large to small cells (27, 28). These changes are not uniform across the Peninsula; areas in the south that were previously mostly covered with ice now have open water, allowing local ocean productivity rates to increase (27, 29). Nevertheless, the net productivity of the WAP appears to have decreased.”
The heart of the paper is Figure 1, which is probably available free online and downloadable (http://www.sciencemag.org/cgi/content/figsonly/328/5985/1520).
Figure 1 Caption: Fig. 1. Changes observed along the WAP over the past 30 years. Annual average air temperatures at Faraday/Vernadsky Station (65°15’S, 64°16’W) and Rothera Station (67°34’S, 68°08’W) have increased. There has been an increase in heat content (relative to freezing) of ACC slope water that had direct access to the WAP continental shelf (black diamonds). Average phytoplankton biomass declined between 1978–1986 and 1998–2006 (between 1987 until 1997, no ocean color satellite imagery was available). There were also large shifts in the penguin populations at Anvers Island from 1975 to 2008.
Reference 14 abstract: “Observation of the retreat and disintegration of ice shelves around the Antarctic Peninsula during the last three decades and associated changes in air temperature, measured at various meteorological stations on the Antarctic Peninsula, are reviewed. The climatically induced retreat of the northern Larsen Ice Shelf on the east coast and of the Wordie, George VI, and Wilkins ice shelves on the west coast amounted to about 10 000 km2 since the mid-1960s. A summary is presented on the recession history of the Larsen Ice Shelf and on the collapse of those sections north of Robertson Island in early 1995. The area changes were derived from images of various satellites, dating back to a late 1963 image from the recently declassified US Argon space missions. This photograph reveals a previously unknown, minor advance of the northern Larsen Ice Shelf before 1975. During the period of retreat a consistent and pronounced warming trend was observed at the stations on both east and west coasts of the Antarctic Peninsula, but a major cause of the fast retreat and final collapse of the northernmost sections of the Larsen Ice Shelf were several unusually warm summers. Temperature records from the nearby station Marambio show that a positive mean summer temperature was reached for the first time in 1992-93. Recent observations indicate that the process of ice shelf disintegration is proceeding further south on both sides of the Antarctic Peninsula.”
Reference 15 Abstract: “The Intergovernmental Panel on Climate Change (IPCC) confirmed that mean global warming was 0.6 ± 0.2 °C during the 20th century and cited anthropogenic increases in greenhouse gases as the likely cause of temperature rise in the last 50 years. But this mean value conceals the substantial complexity of observed climate change, which is seasonally- and diurnally-biased, decadally-variable and geographically patchy. In particular, over the last 50 years three high-latitude areas have undergone recent rapid regional (RRR) warming, which was substantially more rapid than the global mean. However, each RRR warming occupies a different climatic regime and may have an entirely different underlying cause. We discuss the significance of RRR warming in one area, the Antarctic Peninsula. Here warming was much more rapid than in the rest of Antarctica where it was not significantly different to the global mean. We highlight climate proxies that appear to show that RRR warming on the Antarctic Peninsula is unprecedented over the last two millennia, and so unlikely to be a natural mode of variability. So while the station records do not indicate a ubiquitous polar amplification of global warming, the RRR warming on the Antarctic Peninsula might be a regional amplification of such warming. This, however, remains unproven since we cannot yet be sure what mechanism leads to such an amplification. We discuss several possible candidate mechanisms: changing oceanographic or changing atmospheric circulation, or a regional air-sea-ice feedback amplifying greenhouse warming. We can show that atmospheric warming and reduction in sea-ice duration coincide in a small area on the west of the Antarctic Peninsula, but here we cannot yet distinguish cause and effect. Thus for the present we cannot determine which process is the probable cause of RRR warming on the Antarctic Peninsula and until the mechanism initiating and sustaining the RRR warming is understood, and is convincingly reproduced in climate models, we lack a sound basis for predicting climate change in this region over the coming century.”
The British Antarctic Survey (by the author of reference 15) says: “Since records began, 50 years ago, mean annual temperatures on the Antarctic Peninsula have risen rapidly [Turner, et al., 2005; Vaughan, et al., 2001; Vaughan, et al., 2003]. A total increase in mean annual air temperatures, of around 2.8 °C makes this the most rapidly warming region in the Southern Hemisphere – comparable to rapidly warming regions of the Arctic.” http://www.antarctica.ac.uk/bas_research/science/climate/antarctic_peninsula.php
Frank says:
June 20, 2010 at 1:08 pm
Frank, thanks for your comments. You’ve made this same claim before, but you seem to not be following the story. I have shown all available datasets, none of which support the claim. I have looked at one of the references, and found nothing to support the claim. I’m waiting to get the other, and will report when it arrives.
Now, I’m willing to put some good money on the idea that the other reference will show nothing as well. But I’m not willing to shell out $47 to read garbage. If you would like to pay for the reference and send it to me, I’ll gladly review it. Until then, I’m content to wait a couple days to get a free copy.
If I’m wrong, I’ll look like an idiot for not consulting the reference. I greatly dislike looking like an idiot.
Which is why I looked first at the CRUTEM dataset, and at the GISS1200 km land dataset, and at the GISS 250 km land dataset, and at the CRUTEM+HADSST land/ocean dataset, and at the GISS1200 km land/ocean dataset, and at the GISS 250 km land/ocean dataset, and at the UAH MSU satellite dataset, and at every freakin’ individual station on the entire Peninsula and surrounding islands, before making my claim.
And having done so, I can assure you that regardless of what the final reference has to say, there’s no way that the West Antarctic Peninsula has warmed 6°C in the winter. The datasets don’t show it, and the station data doesn’t show it.
This may represent a fundamental difference between how you do science, and how I do science. You read a paper and first go get the references.
I, on the other hand, read the paper and first go get the underlying data. I don’t trust the paper, nor do I trust the references. I trust the data, and I would rather approach it with what Zen Buddhists call “beginners mind”. I don’t want to look first at how the references see the issue, that just clouds the beginners mind. I want to look first at the facts. Observations. Those are what count for me.
PS – A final clue for me was that one of the two references was to a paper co-authored by William Connolley, which pretty much guaranteed that the authors of the original Science paper weren’t really all that interested in science …
Willis, is it worth looking at the data from a nearby island, South Orkney islands are nearby. Signy and Orcadas have weather stations.
the late great John L Daly looked at these back in 2002 HERE under the title Life- an Extreme Ecological Response.
Being so close, data from these islands may help shed light.
Willis,
Look NEWS (PDF). http://antartica.cptec.inpe.br/
The data are from Station Comandante Ferraz Brazil. Scientific data and are VERY, very interesting. Last 24 years 0C anomaly.
Willis Eschenbach says:June 20, 2010 at 1:40 pm
This may represent a fundamental difference between how you do science, and how I do science. You read a paper and first go get the references.
I, on the other hand, read the paper and first go get the underlying data. I don’t trust the paper, nor do I trust the references. I trust the data, and I would rather approach it with what Zen Buddhists call “beginners mind”. I don’t want to look first at how the references see the issue, that just clouds the beginners mind. I want to look first at the facts. Observations. Those are what count for me.
Look at the data, what a novel concept. Kudos.
Willis, Using your all temperature station curve, I can easily eyeball an average blue winter temp in the early ’60s as minus 23 degrees, and a magenta average winter temperatures in the early 2000s as minus 14 degrees and get a warming of 9 degrees C over 40 years. The authors were being conservative!! Murray
I sometimes wonder if popular books and magazine articles check sources properly. This Time article says 6 degrees C, but could they mean F? On my National Geographic Antarctica map from 2002, it says that “the Antarctic Peninsula’s average temperature has increased by about 4 degrees F since the 1950s”. Later on in the same paragraph, they quote David Vaughan of BAS saying it’s “regional warming in an area with a highly variable climate”.
Another book that I recently read is Mark Bowen’s “Thin Ice”. In that book on page 33 he makes a statement that I considered questionable:
“At Britain’s Rothera Station, on the peninsula’s western shore, for instance, temperatures rose an astounding twenty degrees Fahrenheit in the last quarter of the twentieth century.” He references this to Vaughan et al. (2001) in Science. Could this possibly be correct? I couldn’t find this article online.
Willis, I like your overhead map of Antarctica, including the yellow “first down markers”; the ones at -60 S, and -70 S latitudes.
So that puts the whole of Antarctica in the “Antarctic” ( beyond -60S), including the Antarctic Peninsula. The -70S marker is even more interesting, because exactly half of the surface area beyond -60S lies south of -68.9 S so your marker is south of that. Now if you had included the entire Antarctic circle as well at -66.5 S, one would see that about encircles Antarctica, except for the tip of the Peninsula; and one would also see that the Ross and Weddell Seas carve deeply into that area beyond your -70 line.
Which is why I stand by my statement, that there is actually more land in the Arctic, than there is in the Antarctic. That is not the same as saying that there is more sea in the Antarctic, than there is land; although that might be true too. I’m sure some expert googler, can actually come up with some land area number for Antarctica (of course omitting the sea ice shelves; since those are only temporary fixtures, that break up all the time.
But I am still bamboozled Willis, as to why the Antarctic peninsula is warmer than the Ross sea coastline of Antarctica; shouldn’t they be the same Willis; I think Robert thinks they should be.
Chad Woodburn says:
June 19, 2010 at 10:17 am
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 pretty much covers it for a lot of lawyers, doctors, economists, business experts, consultants, psychiatrists, educators, historians, theologians, and politicians….
Ah! Glad to see philosophers not on the list 😉
Robert says:
June 19, 2010 at 11:26 am
Willis should not be taking in depth analysis until reading the papers in question which are referenced……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.
I am going to start picking on you robert. you have an unwarranted faith in your peers, and you cannot see the world through your own prejudices.
willis presents data. it does not matter whatever tripe these charlatans manage to pull out of their a**e*, Willis has shown it to be unsupported by real, actual, data.
the data, like anyone, will confess to anything under torture. why bother reading the paper to see how they did it?
George E. Smith says:
June 21, 2010 at 10:51 am
George, I didn’t understand that at all, or why it is relevant. But in any case, here’s an overlay of Antarctica on the North Pole:
The white circles are the Arctic/Antarctic circles at ±66.5°.
The Antarctic has much more land than the Arctic. Let me run some numbers:
Area inside the Antarctic circle: 2.12E7 km^2
Area of Antarctica: 1.4E7 km^2, = ~ 2/3 of area is land.
By eyeball, the Arctic (inside the Arctic Circle) is about the inverse of that, which is to say 1/3 land. Hang on, let me check that … yes, Google says:
Area of Arctic Ocean: 1.4E7 km^2
So they are almost exactly opposite. Inside the Antarctic Circle is 2/3 land, while inside the Arctic Circle it is 2/3 water. So there is twice as much land inside the Antarctic Circle as inside the Arctic Circle.
This of course has a huge effect on the climate, particularly given the location of the land in each case. The Arctic is comprised of a thin skin of colder ice over warmer water. The Antarctic is a thick skin of ice over cold rock, cold to the bone.
w.
a reader says:
June 21, 2010 at 9:56 am
a reader, thanks to the wonders of the web, you can check this yourself. Go to the GISS site. Type in “Rothera”, click “Search”, and click on the “Rothera” link on the page that comes up. You should see this page:
From there you can download and analyze the data. The temperature rise (linear trend) for the last quarter of the 20th century (1975-1999) is 2.6°C, or 4.6°F … in other words, Bowen is an alarmist who a) doesn’t check his figures, and b) doesn’t have a “bad number detector”. I don’t know of a single station on the planet that warmed by 25°F over a quarter century, the “astounding” nature of the claim should have been a huge red flag for him.
This is why I don’t first do what was recommended to me by Robert above, check the references. They are often wrong. I check the data first. Vaughn is the reference that I couldn’t find on the web, that I was castigated by Robert for not reading …
Thanks Mr. E.
Bowen’s book also contains the Himalayan glaciers disappearing by 2035 claim (on page 391). He claims to have a Phd in Physics from MIT and to have accompanied Lonnie Thompson on several of his expeditions to core glaciers, so he should have familiarity with the issues. Dr. Schmidt on RC gives the book a “big thumbs up” . In all fairness, I read a first edition of this book, so some of these data may have been corrected in later editions.
“”” Willis Eschenbach says:
June 22, 2010 at 11:38 am
George E. Smith says:
June 21, 2010 at 10:51 am
…Which is why I stand by my statement, that there is actually more land in the Arctic, than there is in the Antarctic.
George, I didn’t understand that at all, or why it is relevant. But in any case, here’s an overlay of Antarctica on the North Pole: “””
Willis, why it is relevent, is that the land in the Antarctic; comprised almost exclusively of the Continent of Antarctica; forms a substrate for the deposition of vast quantities of snow, that eventually become ice, that is much more permanent than sea ice which has a habit of melting, and collapsing. So as the arctic sea ice melts; assuming without proof, that that might be happening; the open waters should result in more evaporation in the region; and to the extent that there is a lot of land in the Arctic, there is a lot of substrate on which elevated levels of snow frall can reside; so the amount of land actually available in the Arctic is of considerable interest for that reason.
So I said:- “”” George E. Smith says:
June 21, 2010 at 10:51 am
Willis, I like your overhead map of Antarctica, including the yellow “first down markers”; the ones at -60 S, and -70 S latitudes.
So that puts the whole of Antarctica in the “Antarctic” ( beyond -60S), including the Antarctic Peninsula. The -70S marker is even more interesting, because exactly half of the surface area beyond -60S lies south of -68.9 S so your marker is south of that. “””
And in the several other places where I have made the same claim I have said basically the same.
I did NOT and doNOT say there is more land inside the Arctic Circle, than there is inside the Antarctic circle.
I said there is more land inside the Arctic, than there is in the Antarctic; and those regions ar commonly defined as beyond +/- 60 degrees; not 66.5 degrees; and I specifically mentioned beyond 60 degrees; even pointing out that half of the area in that region is beyond 68.9 degrees.
So try overlapping your +/- 60 degree circles, instead of the Arctic and Antarctic circles at 66.5. In the Arctic lies more than 95% of alaska’ all of Greenland nearly all of Scandinavia, and a vast area of Russia (Siberia).
Every climate paper reference to “The Arctic” or the Antarctic, that I have ever seen makes it clear that those regions start at 60 degrees; even to the point of mentioning that in 1850 or thereabouts there were precisely 12 weather stations “In the Arctic”; whereas Now we have some 70 odd and at one time had as many as 86 I believe.
So much for continuity of data.
But I have never made any secret of the fact that I regard those areas beyond 60 degrees to be in the Arctic or Antarctic respectively; and I always refer to the circles by name; whenever I wish to reference the Antarctic or the Arctic circles.
So my point is all that Alaskan/Canadian/Russian/Scandinavian Land in the Arctic; will be a good repository for the increased levels of Snow Precipitation which will most certainly accompany an ice free Arctic ocean.
George E. Smith says:
June 24, 2010 at 2:48 pm
I see that we have a terminology problem. While in a slang sense the “Arctic” means “that cold area up north”, in a scientific sense it is specifically used to mean the area above the Arctic Circle at 66.5°N latitude (hence the name). As one of a host of examples, the Smithsonian Arctic Studies Center says:
Thanks,
w.