Guest Post by Willis Eschenbach
[see Update at the end of this post]
I got to thinking about the (non) adjustment of the GISS temperature data for the Urban Heat Island effect, and it reminded me that I had once looked briefly at Anchorage, Alaska in that regard. So I thought I’d take a fresh look. I used the GISS (NASA) temperature data available here.
Given my experience with the Darwin, Australia records, I looked at the “homogenization adjustment”. According to GISS:
The goal of the homogenization effort is to avoid any impact (warming or cooling) of the changing environment that some stations experienced by changing the long term trend of any non-rural station to match the long term trend of their rural neighbors, while retaining the short term monthly and annual variations.
Here’s how the Anchorage data has been homogenized. Figure 1 shows the difference between the Anchorage data before and after homogenization:
Figure 1. Homogenization adjustments made by GISS to the Anchorage, Alaska urban temperature record (red stepped line, left scale) and Anchorage population (orange curve, right scale)
Now, I suppose that this is vaguely reasonable. At least it is in the right direction, reducing the apparent warming. I say “vaguely reasonable” because this adjustment is supposed to take care of “UHI”, the Urban Heat Island effect. As most everyone has experienced driving into any city, the city is usually warmer than the surrounding countryside. UHI is the result of increasing population, with the accompanying changes around the temperature station. More buildings, more roads, more cars, more parking lots, all of these raise the temperature, forming a heat “island” around the city. The larger the population of the city, the greater the UHI.
But here’s the problem. As Fig. 1 shows, until World War II, Anchorage was a very sleepy village of a few thousand. Since then the population has skyrocketed. But the homogeneity adjustment does not match this in any sense. The homogeneity adjustment is a straight line (albeit one with steps …why steps? … but I digress). The adjustment starts way back in 1926 … why would the 1926 Anchorage temperature need any adjustment at all? And how does this adjust for UHI?
Intrigued by this oddity, I looked at the nearest rural station, which is Matanuska. It is only about 35 miles (60 km) from Anchorage, as shown in Figure 2.
Figure 2. Anchorage (urban) and Matanuska (rural) temperature stations.
Matanuska is clearly in the same climatological zone as Anchorage. This is verified by the correlation between the two records, which is about 0.9. So it would be one of the nearby rural stations used to homogenize Anchorage.
Now, according to GISS the homogeneity adjustments are designed to adjust the urban stations like Anchorage so that they more closely match the rural stations like Matanuska. Imagine my surprise when I calculated the homogeneity adjustment to Matanuska, shown in Figure 3.
Figure 3. Homogenization adjustments made by GISS to the Matanuska, Alaska rural temperature record.
Say what? What could possibly justify that kind of adjustment, seven tenths of a degree? The early part of the record is adjusted to show less warming. Then from 1973 to 1989, Matanuska is adjusted to warm at a feverish rate of 4.4 degrees per century … but Matanuska is a RURAL station. Since GISS says that the homogenization effort is designed to change the “long term trend of any non-rural station to match the long term trend of their rural neighbors”, why is Matanuska being adjusted at all?
Not sure what I can say about that, except that I don’t understand it in the slightest. My guess is that what has happened is that a faulty computer program has been applied to fudge the record of every temperature station on the planet. The results have then been used without the slightest attempt at quality control.
Yes, I know it’s a big job to look at thousands of stations to see what the computer program has done to each and every one of them … but if you are not willing to make sure that your hotrod whizbang computer program actually works for each and every station, you should not be in charge of homogenizing milk, much less temperatures.
The justification that is always given for these adjustments is that they must be right because the global average of the GISS adjusted dataset (roughly) matches the GHCN adjusted dataset, which (roughly) matches the CRU adjusted dataset.
Sorry, I don’t find that convincing in the slightest. All three have been shown to have errors. All that shows is that their errors roughly match, which is meaningless. We need to throw all of these “adjusted datasets” in the trash can and start over.
As the Romans used to say “falsus in unum, falsus in omnibus”, which means “false in one thing, false in everything”. Do we know that everything is false? Absolutely not … but given egregious oddities like this one, we have absolutely no reason to believe that they are true either.
Since people are asking us to bet billions on this dataset, we need more than a “well, it’s kinda like the other datasets that contain known errors” to justify their calculations. NASA is not doing the job we are paying them to do. Why should citizen scientists like myself have to dig out these oddities? The adjustments for each station should be published and graphed. Every single change in the data should be explained and justified. The computer code should be published and verified.
Until they get off their dead … … armchairs and do the work they are paid to do, we can place no credence in their claims of temperature changes. They may be right … but given their egregious errors, we have no reason to believe that, and certainly no reason to spend billions of dollars based on their claims.
[Update – Alaska Climate Research Center releases new figures]
I have mentioned the effect of the Pacific Decadal Oscillation (PDO) below. The Alaska Climate Research Center have just released their update to the Alaska data. Here’s that information:
Figure 4. Alaska Temperature Average from First Order Observing Stations
In the Alaska Climate Research Center data, you can clearly see the 1976 shift of the PDO from the cool to the warm phase, and the recent return to the cool phase. Unsurprisingly, the rise in the Alaska temperatures (typically shown with a continuously rising straight trend line through all the data) have been cited over and over as “proof” that the Arctic is warming. However, the reality is a fairly constant temperature from 1949-1975, a huge step change 1975-1976, and a fairly constant temperature from 1976 until the recent drop. Here’s how the IPCC Fourth Assessment Report interprets these numbers …
Figure 5. How the IPCC spins the data.
SOURCE: (IPCC FAR WG1 Chapter 9, p. 695)
As you can see, they have played fast and loose with the facts. They have averaged the information into decade long blocks 1955-1965, 1965-1975, 1975-1985 etc. This totally obsures the 1975-1976 jump. It also gives a false impression of the post-1980 situation, falsely showing purported continuing warming post 1980. Finally, they have used “adjusted data” (an oxymoron if there ever was one). As you can see from Fig. 4 above, this is merely global warming propaganda. People have asked why I say the Alaska data is “fudged” … that’s a good example of why.
Seeme like the next task for Surface Stations is to expand to look at all statsions used in the record and to look at the temperature history of each station.
Given how critical golbal warmin is said to be you’d think someone would want to thoroughloy evaluate at least a significant proportion of the data and validate the “corrections”. That means there should be an extensive program of evaluating appropriate justifieable transparent and independent corection algorithms.
Now Surfacestations has been doing an excelent job with volunteers and very little funding. It isn’t as if there is any shortage of funding for climate research, i mean, if they can give David Barber $153million to go on a couple of cruises to look at ice I’m sure there must be funds to take a detailed look at the instrumental temperature data and create some real science experiments to realy understand what factors affect the data set.
Maybe take an urban area and the surrounding rural area and throughly grid them with temperature stations. A major city could have temperature stations every mile say.
This isn’t something volunteers should have to do it is something the scientists should have done at the very outset.
Those coordinates do come back to Palmer AK.
There is a listing for a Matanuska Agricultural Experiment Station. I think that’s what the “AES” stands for in that listing.
So Robert, no need to keep us in suspense any more, just provide your analysis of what the temperature adjustments are all about so that it can be considered. We have, as yet, nothing to work with from you.
Robert (17:43:04) :
“What I meant was . . .”
Robert, Willis didn’t think you understood what he had said.
He was just explaining it to you again. Starting the sentence out with
“What I meant was” is a way of communicating without sounding
condescending.
I however, enjoy your posts. They remind me of why I don’t believe.
I have a more extreme view: even if the temps went up as they say, its doesn’t mean anything in the realm of “climate”. They don’t even have to make it up as they obviously have…..
Robert (17:43:04) The question was: what are the arguments in favor of the temperature record as reasonably accurate?
Zero, none, you’re obviously not serious are you.
(When will the “old” MSM join the party ?)
When obamas PR team tells them too so don’t count on it anytime soon.
There are lies, damn lies, statistics, and warmist climatology.
My troll detector has gone off. See you tomorrow.
The Darwin post was v good, bowled me over. However not having the graphs of the before or after adjustment temps or anomolies for Anchorage or its neighbour made this post a bit flat, I thought. What did the pre-adjustment graph look like? What did the post -adjustment trend look like? Without that info, IMHO the adjustment graphs themselves look a bit like underwear flapping in the breeze. Much more interesting if you get a hint of what it was hiding…
‘robust’ as ever…
22 Feb: UK Financial Times: Public losing faith in science
By Clive Cookson in San Diego
Public trust in science as a whole has suffered from recent attacks on climate research, the head of the senior US scientific body admitted at the weekend.
“There is evidence that the corrosion in the public attitude to climate science has spread over to other areas of science,” said Ralph Cicerone, president of the National Academy of Sciences, citing public opinion surveys in the US and elsewhere.
Cicerone and other research leaders said scientists must work to regain public trust by being more open about their findings. “We need to be more transparent and provide more access to our research data,” he said…
But access requests need to be reasonable, Prof Cicerone said: “Some scientists are receiving requests bordering on harassment.”
Jerry North, a senior climate change scientist at Texas A&M University, agreed. “It seems that vilifying a scientist has become popular entertainment in the US,” he said.
Speakers at the AAAS conference said that neither the allegations of data suppression at UEA nor errors discovered in assessments by the UN Intergovernmental Panel on Climate Change had changed scientists’ minds about global warming.
“For many people who were not close to the science, questions arose about whether the robustness of the underlying science should be called into question,” said James McCarthy of Harvard University, who is chairman of the AAAS.
“Within the scientific community the answer is No,” he said. “If you took all the UEA data out of the package and removed the erroneous IPCC statements, it would not change the underlying science.”
Jane Lubchenco, head of the National Oceanic and Atmospheric Administration , the federal agency responsible for climate science, said the IPCC “had a wakeup call and is taking steps to address the mistakes that were made and to ensure that they don’t happen again.”…
Prof McCarthy was critical of the way the media had joined sceptics in attacking the idea of manmade climate change – as for example when they pointed to this winter’s heavy snow on the US East Coast as evidence that the world was not warming….
http://www.ft.com/cms/s/2/1700ab46-1dbc-11df-9e98-00144feab49a.html
Is the station at The University of Alaska Experimental Farm?
(History)
1917: Established as a United States Department of Agriculture (USDA) Agricultural Experiment Station
GISS data 1917 – 1990 Coincidence?
Forgive me if this has already been suggested, but how about compiling unadjusted data from a large number of rural stations and using that as a starting point? Forgive me, I’m a mere scientist working in a field where generating bogus data costs you your career.
Robert (17:43:04) :
“What I meant was . . .”
There’s what you meant, and then there’s what you said. Are you starting to reconsider the wisdom of “falsus in unum, falsus in omnibus”? I would, if I were you. Never in the history of the English language has anyone started a persuasive argument with the words “What I meant was . . .”
Robert. It occurs to me that you open your mouth and let the wind blow your tongue around. You really have nothing to say at all.
read all:
21 Feb: WSJ: Climate Change and Open Science In the Internet age, transparency is the foundation of trust
By L. GORDON CROVITZ
‘Unequivocal.” That’s quite a claim in this skeptical era, so it’s been enlightening to watch the unraveling of the absolute certainty of global warming caused by man. Now even authors of the 2007 United Nations report that “warming of the climate system is unequivocal” have backed off its key assumptions and dire warnings.
Science is having its Walter Cronkite moment. Back when news was delivered by just three television networks, Walter Cronkite could end his evening broadcast by declaring, “And that’s the way it is.” The Intergovernmental Panel on Climate Change (IPCC) report likewise purported to proclaim the final word, in 3,000 pages that now turn out to be less scientific truth than political cover for sweeping economic regulations…
Some in the scientific community are now trying to restore integrity to climate science. “The truth, and this is frustrating for policymakers, is that scientists’ ignorance of the climate system is enormous,” Mr. Christy wrote in the current issue of Nature. “There is still much messy, contentious, snail-paced and now, hopefully, transparent, work to do.” …
http://online.wsj.com/article/SB10001424052748704757904575077741687226602.html?mod=WSJ_Opinion_BelowLEFTSecond
Referring to :
======================
Peter O’Neill (17:12:34) :
To clear up the mystery of how Mantanuska gets adjusted – the Gistemp rules have just been changed.
See http://data.giss.nasa.gov/gistemp/updates/ :
January 16,2010:The urban adjustment, previously based on satellite-observed nightlight radiance in the contiguous United States and population in the rest of the world (Hansen et al., 2001), is now based on nightlight radiances everywhere, as described in an upcoming publication. The effect on the global temperature trend is small, that change reduces it by about 0.005 °C per century.
(page last modified 17 February 2010 23:13:44)
=========================
If the ‘effect’ is that small why bother with it at all? As I read it it is just a minor modification to an adjustment factor anyway. How much effort went into that analysis? It’s not necessarily a waste of effort – knowing that different approaches produce similar results can be of interest – as Willis pointed out in teh main article for a different context – but one has to wonder why someone elected to authorize the research and then implement a change that seems to be entirely inconsequential in the general scale of things.
Why add to the complexity and confusing of historic comparison and audit byt implementing such a trivial change? Why not just note that the analysis was done and leave it at that?
Unless, of course, for some reason – perhaps even something as innocuous as professional vanity or a name on a paper, the inclusion of the change mattered.
It might just make auditing more difficult in retrospect in, say, 20 years from now. Or it maybe opens up another useful but obscure variable for fudge factoring in the coming decades.
If there is another reason for making the change let’s hear it. at 0.005 °C per century the effort of the adjustment to the adjustment value is, at first site, not worth the candle.
[If I got my facts straight, 90% of the following is stipulated as fact by most of those here as just common sense science. I felt a need to spell it out, if just for myself…]
UHI is not the only thing the homogenization is supposed to deal with. Moves of met stations is also supposed to be covered in that. Another is the change in the time of day or whether the station’s methodology was to take the daily highs (regardless of times), or temps at fixed times – day and night (and what times those were, vs some other common/standard times). We all know that.
Moves are all documented (well, almost, anyway). With the numbers of stations out there, it seems difficult to understand why stations shouldn’t be selected SOLELY on the completeness of their histories. When they are made and documented, they do not keep occurring like the steps shown; ergo, those steps would seem to have nothing to – even partially – do with moves. Even if moves were made, they would show up as some extra ‘blip’ in the steps. In the absence of such blips, I am positing that no moves were made. (But then that begs the question, “Where is the UHI in all this?”)
Looking at the steps, one would first want to ask if there is any way Willis’ arriving at the steps was wrong – if he somehow misread the before and after data. If that was nailed down, then the adjustments need to be specifically tied to those reasons for adjustments. Whatever adjustments appear in the reconstruction, (which should be equal to the adjustments actually made), those adjustments need to be JUSTIFIED, data-wise. AND RECORDED – if not for others, then at the very least for the person DOING the adjusting, so he/she knows what he did at some earlier date.
Most of our data-focused questions really amount to this:
Everyone should be asking (very strongly) Mann et al to JUSTIFY why they adjusted in the direction they did, and in the amount they adjusted. FOR EACH STATION.
Of course, no one wants to really go there, poring over every station, do we? Jones has indicated as much. Mann just bull rushes every one, hoping to intimidate them with his juvenile tactics.
…In any before and after presentation of data, the timing and amount of any adjustments needs to have each step (literally, it seems) verified – i.e., JUSTIFIED. When it appears as artificial as what is shown above, of COURSE someone is going to ask, “Are you SURE about that, Professor Mann?” And, “Were the adjustments to various stations done en masse, or individually, and if en masse why did you choose the particular grouping that we find?”
If the above assessement is true, how anyone could justify the regularity of the steps in the Fairbanks data defies logic. If true, and if it is also true moves were certainly not made on a regular basis, then what do they represent?. Changes in the time or methodology of temp readings COULD not be made in such a manner, not without regularly shifting the temp reading times IN THE SAME DIRECTION (and there are only so many hours in the day, so the readings would begin to come back around on themselves). Are we to believe that they kept moving the met station incrementally out away from the city center, presciently far enough and regularly enough each time to keep ahead of the curve that would be part of a database decades later?
If true, the stepped appearance is clearly ONLY an artifact of the massaging done at GISS. Yet it is hard (nay, impossible) to conceive any reason for such an obviously artificial step progression for Fairbanks, by GISS or CRU or GHCN. Nature (especially meteorological nature) would not present such a linear trend. Why would they put anything so artificial into their adjustments? Laziness? Simplification? If so, the latter, they should have documented it. for later reference – and possibly improving it later.
…Vis a vis urban met station data, all adjustments to rural stations – especially ones used as the basis for nearby urban stations – should be doubly critiqued (and with the concomitant increased security of records with which to justify any such adjustments), since they affect not only their own readings, but those of other stations. That is only scientific common sense. Jumping Matanuska in the manner indicated is like pointing a laser pointer at this station and yelling, “LOOK! We just did anything we wanted to, and no one gave a damn enough to double check us!”
The justification of adjustments – this is what is being glossed over, even in the skeptical blogs, or at least not stressed and/or focused upon enough. Where are the records of the adjustments?
There was one bit of code (pointed out by Steve McIntyre I believe), in which the adjustment factor ins Mann’s (?) code was clearly stepped, in some cases removed for a time, then re-instituted. But the trend was highest in the 1990s. The code notes should have identified why those adjustments were made, with reference to some database somewhere.
Speaking of which: THERE SHOULD BE A DATABASE OF ADJUSTMENTS USED. It is clear that the CRU people did not adjust the same for every met station, that they chose some pattern of adjustments for each station and proxy that they thought was correct above all other adjutments schema for application to those particular stations/proxies. Homogenization requires each type of proxy to be adjusted differently (probably each batch, no less).
But homogenization per se should not be needed for thermometer readings. Adjustments are not necessarily the same thing as homogenization. Homogenization is to get the readings into the same SCALE. Thermometer readings are already ON the same scale. Thermometer adjustments are only of a shift-type – up or down – not of scale.
To be good science, the reasons for instrument adjustments need to be spelled out and documented as part of the methodology AND KEPT WITH THE PROGRAM OR DOCUMENTATION USED. If this is not done, calling these people “scientists” doesn’t equate them to those I’ve known and worked with. For work this sloppy, they would have been found out in very short order and canned.
In good science, EACH TYPE of adjustment also needs to be treated in isolation. As an example, a station might have had a UHI effect, PLUS a shift in location, and those two might be in the same direction or opposite direction. A “time of reading” change might take place at the same station, necessitating a third adjustment to the same raw data, and that could be either positive or negative, too.
Without such isolated adjustment factors being listed FOR EACH STATION, reconstructing by peer reviewers or replicating by other scientists would be like shooting gnats – it would be impossible to hit, because the amounts blend together. making it impossible to know what was being done.
For Mann/GISS or Jones/CRU to produce raw data without, it would be impossible for anyone to follow up and verify the work. And if the peer reviewers did not undertake to replicate at least SOME of the results, the peer review was worthless.
These two graphs (if correct) are strong evidence that the data was just arbitrarily pushed in certain directions. In Fairbanks’ case, the direction is in the cooling direction; in Matanuska it is both cooling and warming.
“WHY?” For both is the entirely correct question to be asked.
Mann needs to justify his steps.
He needs to justify why he was adjusting a rural station at all. When it is moving up and down like a yo-yo, how is comparison to it supposed to make any sense?
He needs to justify why he was adjusting Fairbanks when it was essentially a rural outpost.
And like Wills asks, “Do others have to re-do all of this from the ground up?” Arguments by Jones (as he makes in his recent Science interview) that others can just take the data (20% of which is not public still) and reconstruct it are garbage, and he knows it. If different adjustment figures are used, different results will come out of it all. And then it will be Jones/Mann et all vs the other studies, arguing back and forth as to who did what and – literally -when.
OT, but temperature ralated. Finally! Summer has arrived here in Sydney, Australia. Inner west, is as ~37c, being touted as a “scorcher”. 37c a scorcher for inner west, Sydney?? I don’t think so. 47c you might be getting there….but 37c is well within usuall variability for this time of year with the current prevailing winds (Westerly).
And then there are my friends in the UK who fly back to Sydney tonight who said to me last night that London Heathrow was closed due to snow. No reports of that here in the MSM. Can’t have stories of cold here, that does not fit well with KRudd747, Mzz W(r)ong, Mzz Gillard and Pete “How can we stop our beds burning” Garret.
“Since people are asking us to bet billions on this dataset,”
Trillions, Willis. Trillions.
Robert (17:43:04) :
I find your impetuous taunting of every contributor to this site rather comical really. You’ve become the Frenchman in the tower at WUWT:
[youtube=http://www.youtube.com/watch?v=9V7zbWNznbs&hl=en_US&fs=1&rel=0]
Re Robert..
I want someone to provide peer reviewed evidence that Robert has ANY scientific credentials, and that he is in an intelligent person. If such evidence is not provided, I will conclude that he has none and he is dense.
21 Feb: George F. Will: Global warming advocates ignore the boulders
Science, many scientists say, has been restored to her rightful throne because progressives have regained power. Progressives, say progressives, emulate the cool detachment of scientific discourse. So hear the calm, collected voice of a scientist lavishly honored by progressives, Rajendra Pachauri.
He is chairman of the United Nations’ Intergovernmental Panel on Climate Change (IPCC), which shared the 2007 version of the increasingly weird Nobel Peace Prize. Denouncing persons skeptical about the shrill certitudes of those who say global warming poses an imminent threat to the planet, he says:
“They are the same people who deny the link between smoking and cancer. They are people who say that asbestos is as good as talcum powder — and I hope they put it on their faces every day.”
Do not judge him as harshly as he speaks of others. Nothing prepared him for the unnerving horror of encountering disagreement. Global warming alarmists, long cosseted by echoing media, manifest an interesting incongruity — hysteria and name-calling accompanying serene assertions about the “settled science” of climate change. Were it settled, we would be spared the hyperbole that amounts to Ring Lardner’s “Shut up, he explained.”
The global warming industry, like Alexander in the famous children’s story, is having a terrible, horrible, no good, very bad day. Actually, a bad three months, which began Nov. 19 with the publication of e-mails indicating attempts by scientists to massage data and suppress dissent in order to strengthen “evidence” of global warming.
But there already supposedly was a broad, deep and unassailable consensus. Strange.
Last week, Todd Stern, America’s special envoy for climate change — yes, there is one; and people wonder where to begin cutting government — warned that those interested in “undermining action on climate change” will seize on “whatever tidbit they can find.” Tidbits like specious science, and the absence of warming?
It is tempting to say, only half in jest, that Stern’s portfolio violates the First Amendment, which forbids government from undertaking the establishment of religion. A religion is what the faith in catastrophic man-made global warming has become. It is now a tissue of assertions impervious to evidence, assertions that everything, including a historic blizzard, supposedly confirms and nothing, not even the absence of warming, can falsify.
http://www.washingtonpost.com/wp-dyn/content/article/2010/02/19/AR2010021903046.html
Re: George Turner (Feb 21 17:32),
As I said, NASA’s change “in so far as it relates to some areas I am familiar with, does drag at least some “rural” stations into the 20th/21st century as UHI adjustment candidates, but does also produce some amusing consequences”.
I may for example admit to some doubts about the newly acquired rural status of Baghdad and of Kabul Airport, but I will leave it to others more familiar with such areas to pass judgement. I’m just implementing Gistemp with enhancements to examine how it works, not writing the original code at NASA.
And apologies to the good citizens of Mantanuska for misspelling the name of their town at one point above.
News alert for WUWT. Sea level paper withdrawn from Nature Geoscience. I don’t know any other way to contact you guys.
http://www.guardian.co.uk/environment/2010/feb/21/sea-level-geoscience-retract-siddall
Two points:
1. Re Peter O’Neill’s post: “January 16,2010:The urban adjustment, previously based on satellite-observed nightlight radiance in the contiguous United States and population in the rest of the world (Hansen et al., 2001), is now based on nightlight radiances everywhere…”
Perhaps relying upon temperature devices located solely in North Korea will solve these snarky UHI adjustment problems. :~)
2. The best way to deal with “Robert” (who I’ve now seen trolling in two unrelated threads in the last two days) is to simply ignore him, here and everywhere. He’s obviously unworthy of anyone’s time or aggravation.
Peter O’Neill (17:12:34)
Peter, many thanks for that most recent information. Fascinating. However, I still don’t get it. How could satellites produce information useful for adjusting Matanuska downwards in say 1940? Or for adjusting it upwards in 1973? The fact that it is graded as “Urban” or “Suburban” today means nothing about what it was like in 1920. If it was still rural in 1920 (and there is absolutely no question that it was), why should the 1920 value be adjusted? This procedure makes no sense.
Gotta admire their balls, though. The scale of brightness goes from zero to 186, and anything over 18 is adjusted …
Also, their brightness numbers seem bogus to me. Care to guess the brightest site? New York? London? Cairo? Los Angeles?
No way. It’s Montreal … here’s everyone with a brightness over 150:
Philadelphia, 151
Riyadh, 153
Baltimore WSO City, 154
Sevilla/Tablada, 157
Valencia, 157
Atlantic City State Marina, 159
Jeddah, 167
Madrid/Retiro, 177
Edmonton Muni, 178
Shuwaikh, 181
Montreal Mcgill,Qu, 186
Shuwaikh is the second brightest temperature station on the planet? Really? If so, then brightness may not be a useful measurement.
At the other end of the scale, Srinagar is a city with a population just under a million, a population density of 6,400 people per square kilometre, and a brightness of 6, so it is rural. Baghdad has a brightness of 8, as does Jiuquan, China, population one million. Bangui is the capital of the Central African Republic, population half a million, brightness zero. Zero is also the score for Nanchang, China, population four million. … riiiiight. I looked up all of these on Google Earth, the temperature station is inside the city in all cases. And all of them will be used to homogenize other stations …
My sense is that we have the same problem here. Someone had a good idea (use brightness). But they didn’t detail an intern to actually look up each and every station to make sure that the brightness made sense.
Next, their weighting system is ridiculous. Examination of your posted data shows that the stations are weighted based, not on which nearby stations are closely correlated, and not on which stations are in the same climatological zone. They are weighted solely by distance … the formula for the weight is distance (km) / -500 +1.
I can think of no theoretical justification for that procedure. At least GHCN requires that their adjusting stations be correlated with the adjusted station, but GISS make no such requirement. And if you are going to weight by distance, wouldn’t correlation be likely to fall off by the square of the distance?
Finally, could you post a link to the “GIStemp log” you refer to above (or alteratively, post the stations used to adjust Anchorage)?
Many thanks for your outstanding contribution, science at its finest.
w.