Jan
It’s the Paint, Stupid! Bad paint jobs cause growing anomalies in global temperature data
A typical Stevenson Ground Temperature Measuring Station
Back in 2007, climate ground station researcher, Anthony Watts came to the attention of the world’s climate scientists afer he surveyed over 75% of the 1200-plus U.S weather stations and found many to be inaccurate by more than 2°C, largely due to being located within 10 meters of an artificial heating source. But another little-reported fact that Watts uncovered was that modern paints now applied to the temperature measuring boxes (called Stevenson screens) are also seriously contaminating the measurements of global ground temperature stations.
Watts said, “You don’t read anything about this on repainting of weather shelters worldwide because there’s no maintenance record to correlate the painting, its been done ‘ad hoc’ by local operators of the stations.”
Watts had discovered that the modern paints absorb far higher levels of solar radiation than the old-fashioned whitewash traditionally used on these stations. The newer paints cause greater absorption of heat unlike the old-fashioned whitewashed variety, thus increasingly contaminating the temperature data.
So what is the temperature contamination effect of paint work? Well, paints that appear “white” and reflective in visible light have different properties in infrared. Some paints can even appear nearly “black” and absorb a LOT of infrared, and thus biases the thermometer readings. This is something easily overlooked by the casual observer because it isn’t only the energy from the sun we see in the visible spectrum that creates a heating effect on Earth, the invisible part of the light spectrum also plays a major role in warming our planet.
This is how Anthony Watts explained the issue:
“In a nutshell, nobody seems to have experimentally investigated this issue. It seems that weather station shelters known as Stevenson Screens (the white chicken coop like boxes on stilts, housing thermometers outdoors) were originally painted with whitewash, which is a lime-based paint, and reflective of infra-red radiation but its no longer available, and newer paints have been used that much [sic] different IR characteristics.”
Stevenson screen interior
According to Wikipedia, a Stevenson screen or instrument shelter is an enclosure to shield meteorological instruments against precipitation and direct heat radiation from outside sources, while still allowing air to circulate freely around them. It forms part of a standard weather station. The Stevenson screen holds instruments that may include thermometers (ordinary, maximum/minimum), a hygrometer, a psychrometer, a dewcell, a barometer and a thermograph. Stevenson screens may also be known as a cotton region shelter, an instrument shelter, a thermometer shelter, a thermoscreen or a thermometer screen. Its purpose is to provide a standardised environment in which to measure temperature, humidity, dewpoint and atmospheric pressure.
The standardised global weather station was perfected and commissioned in the 1890’s and the originally specification was that they be painted with whitewash. However, since the mid 1970’s whitewash was no longer freely available as modern, more versatile paints replaced traditional and less convenient longer-drying types. Like most of the major international exterior paint manufacturers, Merck, has a host of proprietary pigment families such as Iriodin®, Xirallic®, Miraval®, Colorstream®, Pyrisma® as well as Biflair®, Minatec® and Solarflair.
Merck has been manufacturing these new paints transparent to IR since the 1960’s because of their superior weather resistant properties. But an issue not uppermost in the minds of paint manufacturers was that modern synthetic paints, which dry far quicker on application, do so largely because they absorb so much extra invisible IR energy – unlike slow-drying whitewash which is very good at reflecting heat-inducing near-infrared radiation.
It seems that by pursuing the important customer-driven need for faster drying paints companies such as Merck are adding the infrared-absorbing pigment Minatec® which speeds up the drying process of the paint coating – a boon for practical purposes but giving an unintended consequence to climatologists’ ground temperature readings. As Merck states in its sales literature, the newer paint products are “geared specifically towards the goal of increased production capacities along with reduced energy costs.”
The Arizona State University department of Physics and Astronomy has reported on the problem of paint pigments and their reaction to infrared:
“Almost all the paint pigments have the same properties as Si and Gallium Arsenide. They are transparent to infrared light. This transparency to IR occurs because the paint pigments are nearly all oxides (such as titanium white, titanium oxide) or sulfides (such as the red vermilion, mercury sulfide). In pure form, they are insulators or semiconductors with almost no electrons available for light absorption in the IR.“
Anthony Watts explained in greater detail how this is bad for the Stevenson temperature stations:
“This means that the infrared radiated from the sun, ground, and nearby objects goes straight to the wood, heating it, and likely biases the thermometer inside the shelter.“
Watts maintains that the steady switch in paints has gravely distorted modern temperature records because it is not officially monitored by any of the main agencies entrusted with collecting the climate data. Mr. Watts first raised his concerns among scientists in 2007 but since then climatologists who have been aware of this problem have done nothing to account for this anomaly. It seems they would rather just shrug their shoulders and use the data anyway.
Coupled with other documented biases, skeptics of the man-made global warming theory may have stumbled on to a very important point at a time when it’s becoming clearer that the data collection methods used to get surface temperatures may be riddled with biases and errors.
Thanks to the research of analysts such as Anthony Watts it seems that the world, in the midst of the worst winter in 30 years, has been given further good cause to doubt climatologists’ findings, knowing there is the distinct possibility that significant measurement bias has crept in with this paint issue.
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It is incredible that the “data” gathered from these monitoring stations could be deemed “safe enough” to base a “science” on ,which would eventually result in the exchange of Tri$$ions of Dollars between hucksters ,governments and TAXPAYERS.
The state of the equipment shows a wholsale lack of care in the detail which should be required in physical measurements if accuracy and repeatability is to be assured.
If this is the “STANDARD of CARE” typical of the whole project run by the IPCC then their “efforts” are not worth a candle.
Who is the BIG DADDY they were trying to please.
OK, but how do the IR absorption properties of CaCO3 (cured whitewash) compare to the newer paints??
How come the ‘issues’ concerning temperature data almost always skew the data higher?
This has been a known issue for a lot longer than 3 years. I can remember our researchers having this discussion 25 years ago. It was skewing their phenology modeling.
@jae. Thanks for pointing this out.I’ve contacted several paint manufacturers for reliable industrial numbers on the relative absorption properties of modern paints versus cured whitewash. Once I get a response I’ll let you know.
Thanks!
I’m waiting with bated breath..
It strikes me that the hypothesis that new paints used on these Stevenson screens is eminently and inexpensively testable. Duplicate temperature monitoring devices could be set up at a couple of dozen representative locations, one painted with the old whitewash paints, the others with the more modern paints. Over a period of a few years we would very quickly determine whether the type of paint affects temperature, and if so by how much. Of course such research will not likely be conducted, since it is too logical and inexpensive, inasmuch as the total cost of such a project would likely not exceed a few tens of thousands of dollars. Government granting agencies would never bother with any project involving such a tiny outlay, particularly if it might risk demolishing the results of research the government has funded which involved spending tens of millions of taxpayer dollars.
Spartan79, what you mean like actual scientific method???
Why bother, AGW is a mature and established
scientific factreligion (didn’t Burton J, in England, outline a number of tests to determine whether a philosophical belief falls within the remit of employment regulations on religious discriminations recently?) and the CO2 tax is the new Indulgence (for those who don’t know what that is, look up Catholic Indulgence)…Interestingly, one of those tests referred to above is that [it] is a belief and not an opinion based on currently available information…
Excellent point, Spartan79. The obfuscation of the facts is made to assist the warmists who divert millions in funding grants from maintaining reliable data collection into dubious and esoteric computer models that give GIGO.
To add to the confusion and unreliability of the warmist numbers I’m still finding further procedural errors causing contamination to global temp records. For example, the ongoing unreliability of data includes the conversion in recent years from manual reading to remote automatic reading of the temperatures in the Stevenson boxes. During the manual days, opening the door of the box increased ventilation, thus cooling the instruments just prior to being actually read. Today, with automatic monitoring, the box door is hardly ever opened and so the temperature recorded will be slightly higher, thus giving an impression of warming of perhaps one or two tenths of a degree.
For example, it has been shown that the warming of the 1920s may have been partly influenced by changes in the measurement procedures from that of mainly `fixed times’ to one of maximums and minimums only (Ellsaesser & MacCracken et al, Global Climatic Trends as Revealed by the Recorded Data, Reviews of Geophysics,
v.24 no.4, pp745-792, Nov 1986).
If thousands of sites world-wide all change their procedures over a period of a decade or so, a distinct climate change will show up in the long-term aggregate data. While there is no dispute that a 1920s warming did happen (a warming now conceded by the IPCC to have been caused by increased solar radiation) the change in measurement procedures may have exaggerated the size of that warming – to even beyond the 1degree C. agreed by the UK Met Office, NASA and NOAA for the global temp rise from 1850 till today.
You know John..I think you really need to get a hobby..Other than this one, I mean
I take daily readings here in Alaska. Since I started 15 years ago, I’ve taken them manually. There are still quite a few of us left. Automation doesn’t fly well with all the pilots. Pun intended. And yes, I’ve noticed a cooling trend. However, a few years ago, my then supervisor told us that we had to report our boxes due to the possibility that they were painted with lead paint. I reported that I had already scraped and repainted the box a few times since then using a flat paint, as my super required. But no mention of temps being skewed form the type of paint. I am curious as to your question being answered on the correct medium to use on our boxes. I would be willing to have a second box to check the accuracy of paint verses white wash.
The small automated electronic thermometers tend to be fitted in a circular housing, made of white plastic. I’m guessing it is still packed with titanium oxide or perhaps zinc oxide (very unlikely to fill a plastic resin with lime).
It should be easily possible to figure out the effectiveness of these screens by building a bigger screen to put around the first screen. If the screen is effective then two screens would give identical temperature to one screen (presuming identical exterior conditions).
If the double-screen is different to the single screen then that gives you a good estimate of the error involved.
My experience with white plastic which sits in sunlight for a period of years is that it tends to darken or yellow. Wonder if this could impact long term temperature readings? Just a thought.
Also, how many sites still use the Stevenson screens? I thought most had been replaced by the automated thermometers.
Some great comments here. I haven’t seen anything from any of the governmental climatic bodies that clarify the issues we are raising. All of these points add more weight to Anthony Watts’s observations (see WUWT and http://www.surfacestations.org) that prove 89% of American ground stations are well below standard. If that’s typical of the most advanced nation on the planet god only knows how much worse it must be in lesser-developed countries.
It would be wonderful if those who have access to information regarding both the Stevenson screen types as well the automated electronic thermometers would put that into the public domain. For example, I’ve yet to see anything that proves modern automatic thermometers dovetail well with the performance characteristics of the older Stevenson models.
Also, there is no database that tells us how many Stevenson screens are still in use worldwide compared to automatic models, nor any humility from government climatologists willing to concede that any of the matters we’re touching on have been factored into their calculations. It strikes me that it ought to have been a crucial issue for manufacturers and world governments to resolve from the outset what standards of manufacture, testing and reliability were to be set in place for temp. measuring instruments. Without such safeguards then why should we believe them when they tell us they can measure the average global temperature within a fraction of one degree?
What we’ve identified that is consistent is the whole scale obfuscation and perversion of the scientific method by junk climatologists. Transparency of method just doesn’t exist – what we are presented with is voodoo smoke and mirrors trickery. None of these clowns is willing to fess up to the fact they failed to foresee how variables we’ve identified such as the exterior paint IR properties, the ventilation issue when manual screens are opened for access to read, etc. that all, in their own way, contaminate the data.
To be frank, if we were sat in court proceedings arguing over the evidential issues of this case I’d be asking the judge to rule that ground stations were inadmissible. The only reliable data, therefore, comes from oceanographic, radiosonde and satellite sources and I would gladly work from them. But sadly for the unscientific warmist lobby, those trustworthy data sources are proving fatal to their cause.
John, you are close but not exactly correct. There is an additional step that you are missing, it is called the “homogenization” phase where the raw data from multiple stations is merged and adjusted to create “high quality climate data”.
This phase includes an admission that sometimes measurement systems are changed (thus resulting in a long-term measurement error), but homogenization is based on a belief that the error can be removed by comparing multiple nearby sites and hoping they were not all changed at the same time. Thus, changes at any single site can be adjusted back to the common behaviour of nearby sites and so the error is adjusted out of the data.
You might think this sounds like getting something for nothing, actually it presumes that the climate signal has been many times oversampled and you are using the high frequency component of the signal to correlate the low frequency data (i.e. the climate data) and then pull it back out of the oversampling. The theory at least is sound, but the final outcome is a synthetic signal pieced together with chewing gum and string. No way do after-the-fact adjustments make an equivalent substitute for good quality field measurements, but I think we must give the homogenization process reasonable due consideration.
There are a number of practical difficulties. Most obviously, sometimes many things change at approximately the same time. For example, the extensive changes around World War Two. You can’t use correlation to remove your error when the error exists simultaneously in all your measurements.
In other cases it is a bit of an individual judgement which way the adjustment should apply, this is fraught with the problem of unrepeatability and there are cases where these judgement calls were not properly documented so no one really knows why the adjustment was applied.
There’s a further problem with correlation between nearby stations when one station might be on the beach, another in the mountains, etc. Again, individual judgement is necessary to balance this, with results of somewhat questionable objectivity.
http://reg.bom.gov.au/amm/docs/2004/dellamarta.pdf
Above is one of the official explanations of how the homogenization process works — certainly not a simple process to explain. There’s an unofficial worked-example of how to detect the change in measurement equipment for Darwin that happened around 1940.
http://wattsupwiththat.com/2009/12/20/darwin-zero-before-and-after/
I’d be interested to know how many of your readers can get their heads around this process and decide whether it makes the errors smaller or larger.
Sounds like “High Quality Climate Data” is an euphinism for conveniently changing the data to suit our convenience.
Just wondering..
Has anyone thought to check into how the little Stevenson screens are held together..like are they glued or nailed or screwed? What kind of screws or nails or glue is used..Is the glue white or clear..water based..where are these materials made..nails from China..? Waaait a minute. Communist China? Ah ha!
And the material..is it wood..? What kind of wood..how dense? Like is it a hardwood like hickory or ash, or is it light like cedar or pine.? Is it imported from those socialists in Canada?
And how about those little thermometers in there…who makes them and how do we know that there’s enough mercury or alcohol in there and that it’s not kool aid..kool aid? There’s another thing and who calibrates them? And getting back to the paint..are they sprayed or brushed..brushing leaves more paint and a rougher surface..what effect would that have on the sunlight hitting the paint surface..? You people are like a bunch of old spinsters gossiping at a quilting bee.. By God there’s enough nefarious goings on connected to those Stevenson screens to keep you people mumbling and yabbering for years.
@Tel. Many thanks for that. I’ve had a good read of your link and was I see your point about the ‘homogenisation’ – to me its a euphemism for guesswork as proven by the following admissions made:
http://reg.bom.gov.au/amm/docs/2004/dellamarta.pdf
“The subjectivity inherently involved in the homogeneity process means that two different adjustment schemes will not necessarily result in the same homogeneity adjustments being calculated for individual records. ” Wow- and they call this ‘science’ !
“The updated dataset remains limited to the post-1910 period because before this time the use of Stevenson screens was not consistent across Australia (Nicholls et al. 1996). Reference series prior to 1910 are unreliable … at most, about 60 unevenly distributed stations have sufficient data back to 1900, and only about 37 stations back to 1890, suggesting that reliable all-Australian averages will remain restricted to the post-1910 period.”
So we don’t even have a century’s worth of reliable raw data for Australia! This is fascinating stuff exposing the myth that climatologolists can attune their global numbers to within 0.5C accuracy – its a joke! Would you be interested in assisting me in working this up into an article?