Above: Mt Erebus, Antarctica
picture by Sean Brocklesby
A press release today by the University of Washington makes a claim that Antarctica is warming and has been for the last 50 years:
“The study found that warming in West Antarctica exceeded one-tenth of a degree Celsius per decade for the last 50 years and more than offset the cooling in East Antarctica.”
…
“The researchers devised a statistical technique that uses data from satellites and from Antarctic weather stations to make a new estimate of temperature trends.”
…
“People were calculating with their heads instead of actually doing the math,” Steig said. “What we did is interpolate carefully instead of just using the back of an envelope. While other interpolations had been done previously, no one had really taken advantage of the satellite data, which provide crucial information about spatial patterns of temperature change.”
Satellites calculate the surface temperature by measuring the intensity of infrared light radiated by the snowpack, and they have the advantage of covering the entire continent. However, they have only been in operation for 25 years. On the other hand, a number of Antarctic weather stations have been in place since 1957, the International Geophysical Year, but virtually all of them are within a short distance of the coast and so provide no direct information about conditions in the continent’s interior.
The scientists found temperature measurements from weather stations corresponded closely with satellite data for overlapping time periods. That allowed them to use the satellite data as a guide to deduce temperatures in areas of the continent without weather stations.
…
Co-authors of the paper are David Schneider of the National Center for Atmospheric Research in Boulder, Colo., a former student of Steig’s; Scott Rutherford of Roger Williams University in Bristol, R.I.; Michael Mann of Pennsylvania State University; Josefino Comiso of NASA’s Goddard Space Flight Center in Greenbelt, Md.; and Drew Shindell of NASA’s Goddard Institute for Space Studies in New York City. The work was supported by grants from the National Science Foundation.
Anytime Michael Mann gets involved in a paper and something is “deduced” it makes me wary of the veracity of the methodology. Why? Mann can’t even correct simple faults like latitude-longitude errors in data used in previous papers he’s written.
But that’s not the focus of the moment. In that press release they cite NASA satellite imagery. Let’s take a look at how the imagery has changed in 5 years.
NASA’s viewpoint – 2004
Click for larger image
NASA’s Viewpoint 2007 (added 1/22)
NASA’s viewpoint – 2009
Earth’s viewpoint – map of Antarctic volcanoes
From the UW paper again:
“West Antarctica is a very different place than East Antarctica, and there is a physical barrier, the Transantarctic Mountains, that separates the two,” said Steig, lead author of a paper documenting the warming published in the Jan. 22 edition of Nature.
But no, it just couldn’t possibly have anything at all to do with the fact that the entire western side of the Antarctic continent and peninsula is dotted with volcanoes. Recent discovery of new volcanic activity isn’t mentioned in the paper at all.
From January 2008, the first evidence of a volcanic eruption from beneath Antarctica’s ice sheet has been discovered by members of the British Antarctic Survey.
The volcano on the West Antarctic Ice Sheet began erupting some 2,000 years ago and remains active to this day. Using airborne ice-sounding radar, scientists discovered a layer of ash produced by a ’subglacial’ volcano. It extends across an area larger than Wales. The volcano is located beneath the West Antarctic ice sheet in the Hudson Mountains at latitude 74.6°South, longitude 97°West.
UPDATE 1/22
In response to questions and challenges in comments, I’ve added imagery above and have a desire to further explain why this paper is problematic in my view.
The author of the paper himself (Steig) mentions the subglacial heat source in a response from “tallbloke” in comments. My issue is that they don’t even consider or investigate the possibility. Science is about testing and if possible, excluding all potential candidates that challenge your hypothesis, and given the geographic correlation between their output map and the volcanic map, it seems a reasonable theory to investigate. They didn’t.
But let’s put the volcanoes aside for a moment. Let’s look at the data error band. The UAH trend for Antarctica since 1978 is -0.77 degrees/century.
In a 2007 press release on Antarctica, NASA’s describes their measurement error at 2-3 degrees, making Steig’s conclusion of .25 degrees Celsius over 25 years statistically meaningless.
“Instead, the team checked the satellite records against ground-based weather station data to inter-calibrate them and make the 26-year satellite record. The scientists estimate the level of uncertainty in the measurements is between 2-3 degrees Celsius.”
That is from this 2007 NASA press release, third paragraph.
http://earthobservatory.nasa.gov/IOTD/view.php?id=8239
Also in that PR, NASA shows yet another satellite derived depiction which differs from the ones above. I’ve added it.
Saying you have a .25 deviation over 25 years (based on one-tenth of a degree Celsius per decade per Steig) with a previously established measurement uncertainty of 2-3 degrees means that the “deduced” value Steig obtained is not greater than the error bands previously cited on 2007, which would render it statistically meaningless.
In an AP story Kenneth Trenberth has the quote of the day:
http://news.yahoo.com/s/ap/20090121/ap_on_sc/sci_antarctica
“This looks like a pretty good analysis, but I have to say I remain somewhat skeptical,” Kevin Trenberth, climate analysis chief at the National Center for Atmospheric Research, said in an e-mail. “It is hard to make data where none exist.”
Simon Evans (11:03:24) :
Hmm, well there’s long history here of people objecting to efforts that have been made to take account of, and adjust for, observational inadequacies, so I won’t attempt a brief answer, beyond saying that trend is of much more importance than the calibration of an instrument in a particular location, IMV.
This isn’t about ‘calibration’ it is all about “NEVER let your precision exceed your accuracy. – Mr. McGuire”
We have a precision of 0.1 put on data with an accuracy of 1.0. That is exactly backwards. My chemistry / physics teacher in high school would give you an “F” any time you did that, even if the rest of the problem was perfectly understood and computed. It was one of the things he stressed most because it was one of the most stupid of errors and made most often.
Then again, he also insisted that we learn to do problems with a slide rule so that we would have a basic understanding of what we were doing rather than putting blind faith in calculators with 10 digits of precision processing data with 2 digits of accuracy. I can not thank him enough. To this day the ‘order of magnitude’ sanity cross check used with slide rules still runs in my brain in the background of any math problem… Mr. McGuire, i salute you!
I can only assume that you and Mann both grew up in the calculator age where everyone uses 10 digits of imaginary precision so it’s ‘no problem’… the bottom line is that there is no trend because the result is lost in the error band of the data accuracy. The precision is false and you have no idea if the real number is -0.9 or +0.9 or anywhere in between.
I repeat: “NEVER let your precision exceed your accuracy.” Full Stop.
Sidebar: Mr. McGuire was a retired Lt. Colonel in the Air Force and a retired chemist from U.S. Steel. He taught high school because he wanted to. He also made most of the reagents we used by upgrading raw materials just to keep his hand in and to save the school some money. And yes, he had all the discipline in the classroom you would expect from a Lt. Colonel…
Leon Brozyna (02:58:58) :
So is this the way modern ’science’ works? Come up with a belief, then look for data that supports the belief while ignoring data that doesn’t conform? I think I’ll self-snip myself here before I let loose my frustrations on this latest display…
Leon – The technique described is typically used in “Humanities” departments at any typical University.
Perfect for “Opinions” – falls down if “Facts” are required.
Ray (13:12:50) :
You might hope so, but that seems not to be the case in Antarctica (and it certainly isn’t in the Arctic):
Monaghan AJ (2006) Insignificant change in Antarctic snowfall since the International Geophysical Year. Science 313, 827-831.
Abstract: Antarctic snowfall exhibits substantial variability over a range of time scales, with consequent impacts on global sea level and the mass balance of the ice sheets. To assess how snowfall has affected the thickness of the ice sheets in Antarctica and to provide an extended perspective, we derived a 50-year time series of snowfall accumulation over the continent by combining model simulations and observations primarily from ice cores. There has been no statistically significant change in snowfall since the 1950s, indicating that Antarctic precipitation is not mitigating global sea level rise as expected, despite recent winter warming of the overlying atmosphere.
JimB,
“Simon:
(Me)”I’m rather puzzled as to why some here did not make the same point when previous analyses have suggested Antarctic cooling? It does seem to me that the accuracy of measurements, whether surface-based or satellite, only comes into question here when they are suggestive of warming.”
(You)I have a different opinion. I believe that what gets questioned here is poor science, not just accuracy of measurements.
I wish I could agree. I’d find the site more interesting if I thought so. For example, I refer you to any discussion there’s been of Beck’s paper on historic C02 levels. I can’t immediately think of a more obvious example of ‘poor science’, yet AFAIAA it got very gentle treatment here (and indeed has been enthusiastically supported by some) from those who are virulent in their criticism of the likes of Mann and Hansen. This gives a very strong impression of partisan inclination rather than disinterested commentary upon good/poor science, in my view. As for this paper in question, there have been many negative comments made here by those who cheerfully say they’ve not read the paper – is that your notion of questioning poor science? It seems to me to be simply an expression of prejudice, which is hardly much use in science.
(Me) Hmm, well there’s long history here of people objecting to efforts that have been made to take account of, and adjust for, observational inadequacies,…”
(You) Again, I beg to differ. The objection to those efforts have centered on the fact that the adjustors refuse to release the means of the adjustment so that the means/methods can be understood, challenged, authenticated, or tossed.
Certainly you know this…so I don’t understand the swipe? Do you not believe that the work of publicly funded scientists should be released to the public?…or that other scientists should be given the opportunity to analyze methods and attempt to reproduce/recreate results of various experiments as a point of validation?
I didn’t mean it to be a swipe, actually – more a sense of exhaustion! You’ll recognise that I’m posting on a site where the overwhelming proportion of views are contrary to mine, so one can’t cover every point. I really can’t agree that objections here are “centered on the fact that the adjustors refuse to release the means of the adjustment”. Objection to the fact of adjustments at all seems to me to be far more frequently expressed. Naturally, I agree with the general principle of openness, though I’m not at all sure it is as easily achieved as one might think. As a counter example, how open was the UAH processing up to 2005, when Mears et al. finally figured out the error in their calculations? I trust that you would be as concerned about that as about any other matter. I actually think this is changing quickly, as scientists find themselves exposed to more widespread ‘review’ than has traditionally (pre-internet) been the case.
I’m rather surprised that you don’t recognise the central point I was making, which is that commentary here is highly partisan and suggestive of double standards. This is obvious when people object to ‘warming analysis’ when they have not objected to ‘cooling analysis’. You’re not simply saying, I trust, that ‘cooling analysis’ is good science whilst ‘warming analysis’ is poor science?
ROM (04:36:06) :
“Professor Brook said it had been thought Antarctica was cooling partly because of the hole in the ozone layer, which allowed the hot air out.”
I kid you not! Check for yourself!
“The Australian” 22 / Jan / 2009
http://www.theaustralian.news.com.au/story/0,25197,24946666-11949,00.html
Kinda provides a cartoon image of the Earth “Piffing” it’s way through space propelled by all the hot air escaping from the south pole…
TonyB (15:00:23) :
Well yes of course. But you’ve chosen to highlight a very nice highly localized stalagmite proxy from the Central Alps. The proxy temperature reconstructions of relevance are those that assess global or N. hemispheric averages. There are certainly local proxies (all proxies are local!) that show highish Medieval Warm Period reconstructed temperatures. These are usually in the highish Northern latitudes. There are local proxies that dn’t show MWP warming.The global or N. hemispheric averages based on multipe proxies are pretty much in line with the original Mann et al reconstruction of 1998…
Anyway, I’m glad you like that nice repository of data…
E.M. Smith,
This isn’t about ‘calibration’ it is all about “NEVER let your precision exceed your accuracy. – Mr. McGuire”
We have a precision of 0.1 put on data with an accuracy of 1.0.
I think you have misunderstood my point. If a bias in a station reading is consistent, then the trend can be accurately assessed, regardless of calibration. If it is not consistent then that, of course, is another matter, and precision is irrelevant (I agree).
E.M.Smith (14:27:04) :
I have a chart somewhere I can’t find right now that shows a significant ramp up in volcanism lately world wide. I doubt that the Antarctic would be immune
This is not specifically what you are refering to, however;
In the fairly recent past I was looking into volcanic activity. The effect of volcanoes is short term and relative to the size and type of eruption. Part of my question was: is volcanic activity increasing and if it is are submarine volcanoes more active? If so, then would a significant increase in sub-surface volcanoes have an effect on ocean temperatures, thus, the climate.
Since monitoring of submarine volcanoes is limited I decided to focus on large eruptions. Those most likey to be noticed and recorded. Ultimately there was not enough data to work with. However, in the process I needed to know if there had been an increase in large eruptions (VEI 4 or greater) on land. Large eruptions also provide a better record since historic events are more complete.
That led to this graph of VEI 4 or larger eruptions:
http://penoflight.com/climatebuzz/MajorVol1.jpg
If you note…
1850 -1900 = 23 large eruptions
1900 -1950 = 34
1950 -2000 = 35
verses
1650 -1700 = 14
George E. Smith
Now if only there was a reasonable way to connect volcanism, crustal deformation, sunspot minima, earthquakes, et. al. without resorting to planetary orbit-spin coupling and solar barycentric orbits …
The moon fits into this too. The Asian tsunami hit at full moon coincident with apogee on 27/12/2004. The recent swarm of earthquakes in Yellowstone and the rising of the dome on Chaiten was coincident with full moon at perigee on 12/1/2009. Both were near earth perihelion. New moon at perigee and earth aphelion due July 2009.
A combination of these gravitational factors and low earth magnetic activity at solar minimum perhaps?
Jeff Alberts (14:44:28)
Well yes, a number of paleoproxy temperature reconstructions done during the past 10 years (including a very comprehensive one just published by Mann et al [see my post (13:31:48)] ) have essentially tightened the confidence in the original rather tentative analysis by Mann et al (1998).
They’re all there in the scientific literature. It seems now to be a rather well-supported conclusion to the extent that one can make reliable conclusions from proxies. I don’t think scientists and policymakers are really that interested in the considerations of a blogger!
foinaven
we’re rather more confident that late 20th century and current warming is anomalous in the context of the past 100-plus years.
And what about the rest of the flatline hockey stick shaft extending back to 1000AD?
Obviously less confident than before. 😉
tetris (11:48:46) :
Anthony:
Has anyone in the Steig, Mann, et. al. team ever sat down and done a “back of the envelope” calculation to “deduce” the calories necessary to get all that ice to melt so that it actually will raise sea levels?
[snip]
REPLY: Phil. It is rude to answer a question posed to the host with a snide remark to the person posing the question. Please don’t do it again. I’ll answer my own questions, thank you. – Anthony
I haven’t read all of the responses above so hope I’m not repeating anyone’s comments. When I look at the anomalies, http://weather.unisys.com/archive/sst/, it looks like the Feb ocean temperatures near West Antarctica have been getting cooler since 2003. The Antarctic shore North of West Antarctica looks like an area where currents bring Tropical water from the North to cool, sink and release heat to the atmosphere. The satellites probably pick up this warm anomaly from the Pacific North of the Antarctic continent and Mann and company use those temperatures to raise West Antarctic temperatures just like they make assumptions in Siberia from the warmer temperatures North East of Finland. As I have said before, I think the reduced solar output, the constant clouds above the Poles almost to the Tropics is causing the Poles to cool. The cooling of the water at the Poles increases the rate of sinking of of the water and speeds up the ocean currents and heat transfer rates from the Tropics to the Poles. This looks to be apparent in the colder anomaly off the coast of Peru in SH Winter and contributes to LaNina. Also check out the currents in the Indian Ocean where the same pattern seems apparent. If solar conditions stay the same, then the Tropical oceans should continue to cool faster than they can accumulate heat. We may not see a lot of record low temperatures in the far North and South because warm ocean waters are bringing warmer temps to the Poles. As the mean ocean temperatures cool further, the Arctic ice should expand South of Iceland and closer the the UK. When this much Arctic is frozen a new Ice Age should begin because so much of the Northern Hemisphere is land which doesn’t store heat energy like the oceans. I think so far the theory has support because UAH data show the Tropical oceans cooled in December and NASA has also stated in the past couple of days that the oceans have been cooling. So for me, the “tipping point” occurs when the Arctic ice reaches an area large enough to keep warm water from circulating near the Pole. I think it’s all up to the sun.
The ice area in the Antarctic is above average this year – how can it be warmer? I have difficulty accepting anything climatologists have to say anymore, especially when Michael Mann is among the authors.
Al Gore, the biggest promotor of Mann’s data will add the Antartic Warming report to the hockey stick fabel and present it to Congress next week.
http://www.boston.com/news/politics/politicalintelligence/2009/01/gore_to_talk_to.html
PCA component vectors are NOT “interpolations.” That word is journalistic over-simplification of the actual mthodology. “Statistical voodoo” would be a more accurate phrase.
it’s interesting how it most of the time seems to boil down to “You’re not smart enough for them”! LOL
Simon Evans (12:25:05) :
Ozone depletion did not occur substantially until the late 1970s.
Please enlighten me: How did they measure the ozone over Antarctica from 1900 to 1970? Or was some other baseline used to detect this ‘depletion’? If so, what base line was that and how was it measured?
foinavon (15:32:40) :
I don’t think scientists and policymakers are really that interested in the considerations of a blogger!
Are you certain about that?
http://www.cejournal.net/?p=607
Denounce bloggers if you must, but, realize in this age a great deal of advancement, and at times correction, comes from those bloggers.
And when all is said and done…
It would seem logical to conclude that the current bout of warming in the Western Antarctic could be attributable to the recent almost three-decade-long bout of ENSO activity that has been dominated by El Nino events.
http://bobtisdale.blogspot.com/2009/01/recent-antarctic-warming-attribution.html
John Galt (14:45:13) :
re: your request for climate scientists to “debate” the deniers”, and my comment about the frutlessness of that:
you said:
I wasn’t meaning them debating you John. I meant the climate scientists “debating” the “deniers”. First of all it really is fruitless (rather in the same vein as the fruitlessness of scientists “debating” creationists where a meeting of minds is not possible). After all the “deniers” have, and have had, plenty of opportunities to debate with scientists. The problem has been that they don’t seem to like the nature of debate within the scientific sphere (scientific literature/scientific meetings) and have chosen to remove themselves from the scientific debate. And so they organise their own pretend “meetings” and attempt to pursue agendas via the web.
A couple of examples: Roy Spencer (with John Christy) published a series of downright incompetent analyses of satellite temperatures from microwave sounding units (MSU) which repeatedly had to be corrected by other scientists (a series of papers in the scientific literature over 15 years culminating in a rather embarrassing critique in Science in 2005). Spencer seems to have taken himself completely out of the proper scientific arenas now and attempts to sell dubious messages direct from his web pages.
Or Dr Richard Lindzen. He pursued for a number of years the dubious notion that enhanced tropospheric water resulting as a feedback to greenhouse gas atmospheric warming would result in a cooling effect in complete contradiction to the predictions from our understanding of atmospheric physics. He pursued much of this by editorialising in articles posted on the websites of “think tanks” of the sort sponsoring the Heartland Institute “meeting” and newsaper articles, even ‘though he was quite clearly incorrect. At some point (early 2000’s and onwards) his position on this matter became unsupportable, even in non-science channels….unfortunately he still pursues deliberately contrary positions (as is his right if he so wishes, of course). But he’s taken himself out of the normal arena of scientific debate…
tallbloke (15:35:08) :
I corrected that typo on a post above [ see foinavon (13:37:27) ]. “100-plus years” should read “1000-plus years”
Incidentally, well done for getting the correct spelling for “foinaven” (the mountain) rather than “foinavon” (the horse and fence). “Foinaven” was already taken when I first used it as a webname so I’ve had to resort to “foinavon”…
Lee Kington (15:47:22)
I agree with you about peer-review. However peer review is only a small part of the process. The correctness/reliability/usefulness of a paper really starts to be assessed once it appears in the literature. It stands or falls in relation to subsequent research, analysis and publications. I think you’re absolutely right that blogs might be a very good way of obtaining pre-publication opinion/thought on a paper (I’ve never thought of doing so!).
However the problem with blogs in general is that unless one has the requisite knowledge one might not be in a position to assess the competing shower of opinions, nonsense, considered thought and so on, that constitutes blog message boards (like this one!). A good many of them are devised to pursue agendas.
I’ve no problem with any of that (other than that many people get taken in by nonsense I think, or at least choose to use them to reinforce their dodgy political positions). The value of peer-review and scientific publication is that the cream rises very noticeably and objectively to the surface…
Bob,
This study uses a different satellite form RSS/UAH. If you can get the data, (maybe on CA website; comment 70) how would this look? Was going to leave a message on your website but not another login to remember !!
foinavon,
You attack Spencer and Christy…. call their work incompetent. But the IPCC and others rely on the UAH data, despite the prior minor instrument error. Hence, are you saying that the IPCC and those who use UAH data sets are incompetent as well? Is it not incompetent to use the work of incompetents?
Which is more incompetent…. having an error in data while using fairly new technology (UAH) or just making data up (Mann, Briffa)?
Simon Evans (12:25:05) :
If that is true, why did Gordon Dobson devise the Dobson Spectrophotometer in the 1950s for ground-based study of an unusual stratospheric ozone concentration anomaly?