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.”
Zeke:
No trend is needed. If you put a pot of cold water on a hot stove it will warm up gradually. And the larger the pot the more gradually it will warm up. The only way to disprove this would be to have accurate temperature records going back much longer than 50 years.
Yes, even to the point of quoting an uncertainty of 2-3 degrees on an estimation of 0.1 deg per decade.
Zeke: Volcanoes? Yes, really.
You are missing a fundamental point of the empirically based skeptics. We do not deny that there was a period of warming late last century culminating in the 1998 El Niño event. Warming trends are exaggerated at the poles. Therefore, a warming in Antarctica late last century is not surprising. However, since 1998 there has been an overall average global cooling and that too has been more profound in Antarctica. The AGW alarmists are having difficulty resolving the new trend (predicted, by the way, years ago by the solar scientists). So they turn to master alarmist computer modeler, creator of the hockey stick that served Mr. Gore so well.
West Antarctic has many very active volcanoes, even several below the ice sheet. It is warmer in the west than the rest of Antarctica where all indications are that it is distinctly cooler there. For a decade now, things are globally cooler. Why is it so difficult to understand that the West Antarctic volcanoes contribute to an anomalous warming in that area?
In an AP story 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.”
Zeke and others
The author of the paper himself mentions the subglacial heat source in a response from “tallbloke” above. My issue is that they don’t even consider or investigate the possibility. Science is about 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.
They’ve not presented a paper focused on attribution, so how is it reasonable to expect them to deal with all possible influences?
given the geographic correlation between their output map and the volcanic map, it seems a reasonable theory to investigate
A correlation with a map marking volcanos some of which have been extinct for how long? And where there is no evidence of temporal correlation in terms of vulcanism and temperature trend? A correlation which you suggest might account for continent-wide temperature trends? Do you apply the same hypothesis to vulcanism in the U.S., which is about two-thirds the size of Antarctica and has far more active and extinct volcanoes? A hypothesis does not seem reasonable unless it can be expressed in terms of plausible cause and effect, which can then be investigated. Perhaps it is plausible, but I’m not aware of any case that’s been put (with figures, that is) to suggest that local vulcanism could significantly warm an entire continent. It certainly seems unreasonable to me to expect Stieg et al to spend time in their paper addressing this, and it actually seems irrelevant for now. They’ve put forward an analysis of temperature trends (which I actually think it’s wise to treat with caution just as it would have been wise for all those trumpeting ‘Antarctic cooling’ to treat that analysis with caution!). If others wish to examine attribution then they can.
REPLY: the test is simple, if your data is measured over a weak point in the earth’s crust (as demonstrated by the volcanoes both active and dormant in the area) then it stands to reason that the area under you may be getting heat from that. I recall a news article from a couple of years ago where some group sent a submersible under the ice in areas around the Ross ice shelf and found vents, and a variety of marine life that was warmer water variety. To dismiss the possibility is reckless, and let’s face it, this press release (while the publicly funded paper itself paywalled) is about MEDIA ATTENTION. They would have to know that even if they made no attribution to cause in the paper, that a reversal in temperature trend for Antarctica would be assimilated into the entire “global warming” issue on the PR hit the news stands.
Here is an example from the AP story: http://news.yahoo.com/s/ap/20090121/ap_on_sc/sci_antarctica
If they claim “we have no expectations on the cause”, then they are exposing themselves to be clueless of the process of a press release. Just look at Michael Mann’s comment to AP:
Gosh, Mann’s and Shindell’s post facto reference to “the trend” in the context of the quote seems like attribution to me. – Anthony
[snip – none of that here]
wattsupwiththat (10:22:57)
You should add this as an “update” to your lead story, Anthony. It is priceless!
REPLY: I was doing that while you wrote this comment
The language of the paper is very confusing and seems to say that temperatures over Antarctic as a whole over 50 years are pretty much as they were 50 years ago. They don’t seem to know whats causing the temperatures to be the same as 50 years ago (or maybe slightly higher, they don’t say by how much). They also seem to suggest that when the ice melts hen sea levels will rise catastophically, as far as I know only the sea ice around the peninsular itself might be thinning, I haven’t seen any evidence presented to say that the land ice is melting at a more rapid rate.
To be honest this adds nothing to our understanding and seems to be a ‘filler’. I am no wiser after reading this arcticle than before just more confused.
From Wiki:
Principal component analysis (PCA) involves a mathematical procedure that transforms a number of possibly correlated variables into a smaller number of uncorrelated variables called principal components. The first principal component accounts for as much of the variability in the data as possible, and each succeeding component accounts for as much of the remaining variability as possible. Depending on the field of application, it is also named the discrete Karhunen-Loève transform (KLT), the Hotelling transform or proper orthogonal decomposition (POD).
http://en.wikipedia.org/wiki/Principal_components_analysis
In my view no (zero, zip, nada) inferences can be made from multivariate PCA eigen-vectors. The entire statistical method is heuristic at best, and is properly used to develop questions of interest, not analyze them. The Steig paper is yet another case of misuse of statistics because it creates imaginary “data” where there are none. Component vectors are not real, period.
It always behooves scientists to use actual data and straightforward analytical techniques. When scientists drift away from clarity and simplicity, they stumble.
The study has major ramifications for sea level rise, said Andrew Weaver at the University of Victoria in Canada. Most major sea level rise projections for the future counted on a cooling — not warming — Antarctica. This will make sea level rise much worse, Weaver said.
Nice, beach front here in Ky!
Flanagan:
Lets see….$144 discount on my conference ticket or a $250,000 grant from the blind faith organizion to show that eating beans will contribute to man-made catastrophic warming of the planet.
Mmmm…
I think I’ll take the $144 dollars
NOT
Well it is interesting to see all the flak this paper produced.
First off, I am NOT going to publish the back and forth I had with Prof Steig. he did not say anything in any alarmist or strident fashion. His answers to my very direct questions were also very direct and to the point. And I am not going to point any ad hominem fingers at any of the co-authors; alkthough I do blink when some of those names come up in reports.
Trenberth of the UN’s IPCC has already said he is “skeptical” of the methodology, and maybe the results. John Christy, (UAH) who has probably read more satellite surface temperatures than just about anybody, questioned the methodology.
I’m not too alarmed by the fact that they even attempted to do this.
I don’t know the age range of the population of Anthony’s club; but to me, the IGY earth lovefest of 1957/58 really marks the beginning of what I consider to be modern climate science. That time frame was specifically chose, because it was predicted to be a sunspot peak; and if you look at the previous sunspot maxima, you can appreciate that there was considerable interest in what the IGY peak would do. Nobody oculd have known that it was going to turn out to be the highest sunspot peak of all recorded history (of sunspots).
Antarctica was just beginning to be considered somewhat habitable. The late Edmund Hillary of NZ, climbed Mt Everest in 1953, and then did his crazy cross Antarctica dash not too long thereafter (I think Sir John Hunt was the leader of that expedition too), so the weather stations set up around the Antarctic Coast in those years are probably cinsidered to be of some importance, and their records, are probably well studied..
What I gather from Steig et al paper, is that they attempted to compare satellite measurements (surface temperature) of those very same weather station locations, with the measured data for the period since 1979 when the first polar orbit satellites went up; and then based on what they consider to be agreement of some sort (maybe after calibration), they applied whatever “transform” they had come up with to the much more extensive satellite data covering the whole of Antarctica, and then they extrapolated that data for the rest of Antarctica back to 1957, based on the coastal station data going back to 1957.
Now to me, that is better than a hipshoot, and a wild guess; they used available data to try and get some handle on what is unavailable; and therefor not data. So yes, that is a bit like skating out from the edge of the lake, on ice that is measured at a foot thick, and then progrssing all the way across the lake, on the basis of some pebbles dropped from a chopper across the lake, that didn’t break any holes in the ice. Maybe cleve, but maybe pretty scary assumptions too.
But back to what Steig et al say. Antarctica is warming at about the same rate as the rest of the world; or words to that effect.
Well that is BIG news. Conventional wisdom suggests that the polar regions are supposed to warm at a FASTER rate than the planet as a whole.
There’s good reason for that. I have asserted many times, that the earth DOES NOT cool from all the ice at the poles. The emittance of the earth surface goes roughly as the fourth poweer of temperature, somewhat following black body radiation laws, so the biggest cooling (loss of energy), actually is happening at the height of the noonday sun, in the hottest tropical deserts of the planet, where surface temperatures get up to +60C and maybe higher. The radiation rate there is over ten times the miserable emittance at the cooler polar regions.
Also the Wien displacement law comes into play, when you consider the CO2 greenhouse effect. At the coldest polar temperatures, the peak of the earth thermal radiation spectrum, is sitting at 15 microns; right on the CO2 14.77 micron absorption band; so the CO2 GH effect is maximised at the poles leading to even lower rates of energy loss.
On the other hand, at the hottest tropical Desert surface temperatures, the wien displacement has moved the peak of the thermal radiation all the way down to about 8.8 microns; which moves the CO2 absorption band even further down on the long wavelength tail of the spectrum, thereby greatly reducing the effect of CO2. Now the CO2 band will be wider due to the doppler broadening at the higher temperature; but the effect of CO2 absorption is lower in the tropics. The spectrum is even shifted below the 9-10 micron OZONE absorption line, which is right on the peak, at the global mean of about +15C. BB radiation theory shows that almost exactly 25% of BB radiation is emitted below the spectral peak, and 75% at wavelenghts longer than the peak. Never forget that earth thermal radiation is only approximately black body, but that is the safest base assumption. The range of temperatures from which near BB radiation is being emitted also complicates the spectral shape.
So bottom line is, if GHG effects based on CO2 are warming the planet, and for other reasons, the polar regions ought to warm FASTER that the rest of the earth. So if Antarctica is only warming at the same rate as the earth as a whole, it is reasonable to conclude that we are doing better than we are supposed to be as regards global warming.
I think Steig et al tried a clever idea at getting some pseudo data where there is none, and far too much is being made of it by the popular media. I have no basis to cast any clouds over Eric Steig.
Have you noticed where Larse A&B are ? Every day, the whole Atlantic ocean and Pacific ocean go sloshing back and forth through that gap between the Antarctic Peninsula and Tierra del Fuego, and when the tide goes Westerly those storm wavs come surging in right on A&B; which icidently are outside the Antarctic circle; so they never get 24 hour night time. so stuff melts there; big deal!
My Greenland Iceman, Svend Hendriksen, also studies antarctic glaciers, sinc ethe satellite comes chugging over his place all the time, and can download his pictures for him; and Svend sent me a photo of the Wilkins ice shelf breakup, and he circled an even larger area immediately adjacent to the broken piece, which stands out like a sore thumb, because it is encirceld by a big cliff that separates it from the main ice sheet. Reaosn for that cliff, is that that even larger piece all broke up around 50 years ago (almost IGY time), and grew back, but is shy of 50 years of accumulated precipitation; hence the ice cliff).
George
“foinavon (09:41:48) :
Flanagan (07:24:18) :
Yes it’s pretty dreary (a gift of $144 if registrants to the Heartland Institue pretend Climate “Science” meeting sign some petition devised by a tobacco company propagandist nearly 10 years ago). I wonder who they consider might be taken in by that!?
The list of cosponsers (click on the poster with the gallery of rogues on the Intro page of the meeting site) gives a pretty good indication of the purpose of this sort of “meeting” and perhaps helps to understand the dubious thinking that considers that dodgy petitions have anything to do with science…
http://www.heartland.org/events/NewYork09/newyork09.html
It should be a blast!
”
Why don’t people like Mann and Hansen attend and debate the issues publicly? I’m sure that since the science is clearly on their side, they’ll have no trouble persuading the deniers to get on board before it’s too late.
Retred Engineer,
Several questions: If the warming in the west exceeds the cooling in the east, shouldn’t there be less ice overall? How can Antarctica have more ice?
It doesn’t have and, yes, the trend has been one of reducing ice mass at an increasing rate (I’d stress that there is uncertainty, but that’s the best judgment).
How do they measure temps? What equipment? surfacestations project has shown some big problems with measurements in this country. Do we believe that everything at the south pole is pristine and properly working?
No, there are clearly issues with surface-based measurements in such conditions. 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.
0.1 degree C per decade? In industry, we wanted better measurement accuracy in our equipment than the thing we needed to measure. 10x was the goal. How in the (blank) can they measure 0.1 degree with equipment that is lucky to measure 1 degree with any confidence?
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.
I formally request Steve to look into the statistical method used here. This is a audit site, and here we have a great example of something that can be tested to see if it’s relevant. I think a good starting point would be the use of component vectors and to find out, yet again, if the level of uncertainty is again greater than the claimed trend (if it is, then the whole thing is toilet paper and yet another exercise on what ifs).
As I’m pretty sure that this is fluff – I think after it’s proven fluff it should be examined from a “why” standpoint.
I think I have a handle on the why. There is wordage at use in the summary that is rather telling when combined with Hansen’s comments about the paper.
In summary, I think this is why they did this and where the language is going to go: They aren’t saying this ridiculously small warming trend that ended some time ago is caused by global warming. In the summary it’s clear that they are deliberate in mentioning this. It’s my opinion that they did this because they understood that doing so would contradict previous declarations that cooling is predicted and expected. The whole paper was meant as a media piece. They seemed to understand that the media would link it to global warming and that they would see it as a debunking of skeptics major claim without actually looking at the work .
Pure PR magic. They get to debunk a claim by skeptics while at the same time not contradicting themselves. There is no way this is a winnable situation by critics of AGW. If we show that it’s wrong, then we are back as we were before, but the main stream media won’t report that. They gain 1,000,000 AGW robots saying that the cooling Antarctica was debunked…while specifically never saying it.
Anthony,
In response to your reply to my post above: I think your issue is with comments made to the press rather than with the paper itself. I agree with you that those comments suggest the findings are consistent with AGW, and that is an attributive view. However, I maintain my view that it would be unreasonable to expect the paper itself to consider vulcanism.
I am not dismissing the influence of vulcanism on a local scale. What I am simply not aware of is any figures to suggest that it could be significantly warming on a continental scale (or semi-continental, if you like). Antarctica has some current volcanic activity, but it is hardly exceptional. If your notion is that vulcanism may account for Antarctic warming, then I presume that should be considered elsewhere also? In either case, it would need to be shown that vulcanism had increased in correlation with temperature increase. The consideration of localised effect tells us nothing about that.
Protecting our environment is no doubt crucial to our existance, unfortunately the environmental movement is a little confused. Pollutants such as Nitrates, Sulfates, and other particulates are what needs to be targeted. Those are what results in smog, acid rain, and the poisoning of our water supply and soil. All this focus on CO2 is distracting from the real problems. The solution to the CO2 problem, if AGW alarmists are right, has an extremely simple solution. Stop cutting down the forests and start planting them. Ironically it is the “green” movement’s search for alternative fuel sources that is adding to the deforestation.
This site is best science in the world. (I promise to be a quiet week)
Despite what Gavin has claimed …( naturally…)
Mary Hinge: The language of the paper is very confusing … I agree with you.(100%).
As an effective member of the peanut gallery:
I do not accept these results as valid. (and logic)
For a simple reason.
If IPPC 4 is wrong by definition;
Who writes:
As it happens, the average of the 19 models in AR4 is similar to our results.
Conclusion: This is not July 4
Much celebration for anything.
Absolutely ridiculous. After years of talk by these fools that “models predict cooling in Antarctica” now suddenly because no-one near the frigid Arctic circle believes their nonsense they move their campaign to a continent that has no population with common sense to debunk this filth they call science.
I am disgusted beyond belief, true science is dead.
Computer models are not reality, Nature is reality.
—————————————
Will the Real Antarctica Please Stand Up?
http://www.dailytech.com/Will+the+Real+Antarctica+Please+Stand+Up/article14028.htm
“The real story here isn’t Antarctica. It’s the willingness to rationalize model results to fit any and all scenarios. To the modelers, their results are consistent with. . . well, everything. Whether warmer or colder, flood or drought, more storms or less — it’s all proof that global warming is real and happening now.”
“This, of course, isn’t real science. A true theory require something called falsifiability — a set of conditions under which it can be disproven. So far, this is something the modelers have failed to give. It allows them to maintain a facade of unflappable certainty– but it isn’t science.”
“Among researchers who work with actual climate data, skepticism is climbing. The modelers at least remain faithful. But as of now, their predictions are rather like the gypsy fortune teller who tells you, “You will live a long life — unless you die young.”
Flanagan said
“That’s it ! I finally discovered how some “skpetics” do to have those famous petitions of “scientists” agains AGW. They actually… pay them!
I’m not kidding, check this link http://www.guardian.co.uk/environment/ethicallivingblog/2009/jan/19/1
Scientists who attend the International Conference on Climate Change to be held in New York, 8-10 March 2009 (organized by the Heartland Institute) get a $144 reward if and only if they sign the petition claiming skepticism against AGW.
Ahhh, this is science as we like it, isn’t it? Can we also receive a Macy’s card, please?”
So people who freely choose to attend a non taxpayer funded conference are entitled to get a 20% discount off a conference ticket if they sign a petition? Doesn’t it occur to you that most will be attending this conference in the first place precisely because they don’t believe the man made climate change hypotheses, and this is merely a well worn marketing promotion to bring the price down?
Do you seriously think people like Mcintrye, Spencer or Lindzen- or any of the others- are going to sign a petition they don’t believe in -and in the process bring heaps of abuse from warmists on their heads- merely to earn a paltry $144?
It seems to be ok though -as I’ve never heard you complain about it-for someone to mount a ‘man made’ climate change conference in which all the venue costs and the conference fees and the travel/accomodation costs and the research for the papers that will be presented are all paid for by the long suffering taxpayer- most of whom don’t believe in this stuff in the first place but aren’t given any choice as to the subsidy they provide. Which process are you saying is more corrupt?
If the govt funded a more balanced and rational climate change programme there would be no need for this conference in the first place would there?
TonyB
Just for giggles I just went and recorded the temperatures from 11 glass thermometers that were all stored in one beaker in my lab. 23, 23.5 ,24 ,23, 24, 23.5, 23.5, 23, 23.5, 24, and 24. Ave=23.45 std. dev.=0.41°C Now these are not meant for Antarctica, measuring about -20 to +120 C instead of down to -80 C but the total range must be similar.
Can I scatter these throughout the building and and use them to calibrate my infrared thermometer to measure the difference in building temperature to 0.1 degrees from winter heating season to summer air conditioning?
They are claiming 0.1°C per decade with 1/2 degree total ?!?!? These are the same people who lost the entire Medieval Warming Period. I wonder how many different statistical methods they tried before they came up with one that indicated warming? If you only report the ‘successes’ it is fraudulent.
foinavon (09:41:48) :
The list of cosponsers (click on the poster with the gallery of rogues on the Intro page of the meeting site) gives a pretty good indication of the purpose of this sort of “meeting” and perhaps helps to understand the dubious thinking that considers that dodgy petitions have anything to do with science…
Typical ad hom smear, laced with gratuitous sarcasm from a know-nothing AGWer. The science taking place at that meeting would blow any semblance of science taking place at any one of the UN’s confabs aka “conferences” out of the water.
“Gallery of rogues” – I guess that must be AGWer-speak for “scientists I despise because they threaten my AGW ideology, eh?”
The WU paper is not a lot unlike things such as the Vostok, and other Antarctic ice cores and the “data” that is mined from them.
Ever notice how freely we extrapolate from Vostok to the whole darn planet.
Well we do look at some Greenland ice cores too, and if they give somewhat similar data to the Antarctic cores, we sleep in peace knowing that the whole earth must be like that.
With all the statisticians who visit here and post on trendlines, and standard deviations, and all manner of other statistical paraphernalia; why is it that there seems to be a total lack of understanding of the mathematics of smpled data systems; and specifically the Nyquist Theroem, that governs the whole sicence of sampled data systems. We know the theorem is valid, because the whole of modern digital communications technology depoends on it’s validity. Anyone who ahs ever lookes at analog signals with a sampling oscilloscope, is already aware, that they don’t always show you the truth; and you can get totally false results by misusing them.
On your TV set or at the movies, in your favorite horse opera, the reason why the damsel in distress on the runaway horse and carriage, is screaming her head off, is because clearly the wheels on her chariot are rotating backwards; who wouldn’t be alarmed.
That phenomenon, is a result of “aliassing noise” which corrupts ALL data, that is gathered in blatant violation of the Nyquist Sampling Theorm.
Nyquist was a scientist at Bell Telephone Laboratories, and his theorem is fundamental to data sampling.
Briefly it states, that “Any band limited continuous signal can be completely recovered from discrete samples of its instantaneous values; provided that the signal (a) IS band limited; meaning there are NO signal components at frequencies greater than B and that the continuous signal is sampled at a rate not less than 2B, or more importantly that the samples are spaced no further apart than 1/2B.
So regular spacing of samples is not required, but there must be no greater gap between samples than 1/2B.
If the signal were a simple sinusoid at a frequency (f), you would have to take one sample in each half cycle of the signal. Strictly speaking, a sinusoidal signla of frequency (f) can’t be recovered if the sampling rate is exactly 2f, because you could get every sample taken at a zero point, snd the signal would look like a DC of zero amplitude, or they could be anywhere on the rising and falling edges of alternate half cycles, so you would know there was a signal of frequency (f) but you have no idea what its amplitude is. But that is a degenerate academic case.
The wagon wheel problem results fromt he fact that movies sample the scene at 24 frames per second, and TV signals do it at 30 or 25 in some countries, and since the spoke frequency is much higher than that, you have a Nyquist violation and aliassing noise creeps in and corrupts the reconstruction, which is the movie you are watching.
If you violate Nyquist, by having a signal at a frequency B+b, the reconstructed signal will contain an errant component at a frequency B-b, so the spectrum folds around the Band limit frequency. Now B-b, is a fequency that is INSIDE the signal bandwidth (B), so you can’t get rid of it, without losing real signals too. As a practical matter, if you did have a single known out of band signal, you could put a notch filter at B-b, and jut eliminate that pesky signal.
Now what if the out of band signal is at a frequency 2B. (B+B). Well the aliassed noise signal will now be at (B-B), which is zeroi frequency and is in fact the average value of the continuous function.
So violation of the Nyquist criterion by a factor of 2 means that even the average value of the sampled data signal is now corrupted, and no amount of prestidigitation will get you a correct average for the function that was improperly sampled.
Central limit theroems and other such mathematical trickery cannot buy you a reprieve from crimes against Nyquist.
So global temperatures are a continuous function of both time and space, perhaps three variables, so you could construct some two dimensional map projection of the earth, and take snap shots of it, or at least of a bunch of thermometers spaced all over it in their own little gridded cells, and from that data,you can in principle reconstruct the whole map, and average it over time and space.
Well isn’t that what James Hansen does with his GISStemp owl box stations that Anthony escorted us around.
You see what is really wrong with GISStemp, and also with HADcrut is both of them grossly violate the Nyquist criterion, in both the time and space variables, sometimes by orders of magnitude; so there’s not a snowball’s chance in hell, that their machinations actually measure the real average surface or lower tropospheric temperature of the earth.
GISStemp anomlaies are a graph of GISStemp anomalies; they don’t even have any absolute temperature reference, and they don’t have any real scientific meaning at all, because the global sampling regimen is quite inadequate to determien the true average temperature of the earth surface.
George
Three decades of 10 year predictions for climate change disaster “tipping-points”.
Urgent need for CYA testimony.
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Gore to make climate change case to US Senate
http://www.breitbart.com/article.php?id=CNG.24df0b15eec8bf3f1ea31a4bf41d7728.f1&show_article=1
“Al Gore has been sounding the alarm on climate change for over three decades, and he understands the urgent need for American engagement and leadership on this issue,” said Kerry.”
I wonder if that older ground data was adjusted in any way?