Aging weather stations contribute to high temperature records

New paper finds that aging weather stations record much higher daytime temperatures, 1.63°C higher than new stations

While we are all watching the heat wave developing in the US southwest, here is something to consider. Albedo on the surfaces of weather station shelters changes with time, something I and the volunteers have documented with the Surface Stations project. For example, here’s a aged weather station where the whitewash coating is coming off and the bare wood is becoming exposed:stevenson_screen_12-27-07.jpg

Back in 2007, Pat Michaels wrote in an American Spectator column “Not so Hot“:

“Weather equipment is very high-maintenance. The standard temperature shelter is painted white. If the paint wears or discolors, the shelter absorbs more of the sun’s heat and the thermometer inside will read artificially high. But keeping temperature stations well painted probably isn’t the highest priority in a poor country.”

Now there is proof that changes in station shield surfaces affect temperature

A paper published  in the International Journal of Climatology finds that aging of the solar radiation screens on weather stations is causing a large positive bias in measured temperatures of 1.63°C, which by way of comparison is more than twice the global warming of 0.7°C recorded since the end of the Little Ice Age in 1850.

According to the authors, “During the comparison [of the new vs. 5 year old] and 1 to 3-year-old screens, significant temperature differences were recorded at different times of the day. The differences, wider than the uncertainty amplitude, demonstrate a systematic effect. The temperature measured with the older screen is larger, and the maximum instantaneous difference was 1.63 °C (for 0–5 years comparison) in daytime hours.

During night-time the two AWS’s measure the same temperature (within the uncertainty amplitude). This behaviour, increasing with increasing solar radiation intensity and decreasing with increasing wind speed, is attributed to a radiative heating effect. The screen ageing has compromised the shield effectiveness introducing a significant change in the temperature evaluation.” The paper is yet another blow to the unreliable, biased, and highly upward-adjusted temperature record.

The paper: http://onlinelibrary.wiley.com/doi/10.1002/joc.3765/abstract

Comparative analysis of the influence of solar radiation screen aging on temperature measurements by means of weather stations DOI: 10.1002/joc.3765

G. Lopardo et al

Abstract:

Solar radiation screens play a key role in automatic weather stations (AWS) performances. In this work, screen ageing effects on temperature measurements are examined. Paired temperature observations, traceable to national standards and with a well-defined uncertainty budget, were performed employing two naturally ventilated weather stations equipped with identical sensors and different only for their working time. Three different tests were carried out employing different aged AWSs: a 5-year-old AWS (AWS5) was compared with a new device (AWS0), a 1 year old (AWS1) was compared with both a 3 years old (AWS3) and a new one devices (AWS00). Due to solar and weather conditions exposure a degradation of the screen reflective coating is evident for the older AWSs (5 and 3 years old) and so a qualitative estimation of how different conditions of ageing affect the temperature drift was done.

During the comparison 0 to 5 and 1 to 3-year-old screens, significant temperature differences were recorded at different times of the day. The differences, wider than the uncertainty amplitude, demonstrate a systematic effect. The temperature measured with the older screen is larger, and the maximum instantaneous difference was 1.63 °C (for 0–5 years comparison) in daytime hours. During night-time the two AWS’s measure the same temperature (within the uncertainty amplitude). This behaviour, increasing with increasing solar radiation intensity and decreasing with increasing wind speed, is attributed to a radiative heating effect. The screen ageing has compromised the shield effectiveness introducing a significant change in the temperature evaluation.

The experimental results of a further comparison, between 0- and 1-year-old screens, confirm the same conclusion showing a negligible ageing effect, within the uncertainty amplitude.

h/t to The Hockey Schtick

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81 thoughts on “Aging weather stations contribute to high temperature records

  1. Cafeful, the warmists will start insisting that the stations get painted black to soak up the maximum heat levels….

  2. I have a question, how many of the weather station housings are older than 5 yrs? From what I recall of the station surveys I looked at I would have probably considered a 5 yr old housing as just a baby.

  3. Just something else demonstrating all those hundreds of billions of dollars being spent on ‘climate change’ are totally worth it.

    Can’t they make these weather stations out of white, UV resistant plastic? To be still using wood for these shelters seems almost archaic

  4. I also looked at the Las Vegas weather stations (see above). I can’t imagine that these sites are very accurate, as close to heat sinks as they are. And to think that our entire body of surface data is based on sites like these. YIKES!

  5. I just read yesterday that daytime maximum temperatures have NOT risen, but nightime minimums are higher, and averaging them results in the higher average readings. This was in a piece on PJ Media. I will try to find it again. What kind of paint degrades that much in just five years? The pictured Stevenson Screen appears to have been sand-blasted!

    Data is only as good as the party paying for it needs it to be, as a rule. Looking for changes in the tenths, or even, ludicrously, hundredths, of degrees, with thermometers accurate to +-0.5 C, is meaningless. Tell this to a Democrat!

  6. “The temperature measured with the older screen is larger, and the maximum instantaneous difference was 1.63 °C”

    The paper is paywalled as usual. Anybody know what the mean, median, or average difference they found was, compared to the “maximum instantaneous difference” of 1.63C?

  7. “As we have come to expect from this president on global warming and energy, yesterday’s presentation included many basic science mistakes and inappropriate cherry picking of data. For example, Obama’s assertions about abnormally high temperatures and the extent of Arctic sea ice melt are either meaningless or simply wrong. Last July, new average U.S. temperature records were set by one-fifth of a degree Fahrenheit. This is meaningless since the measurement uncertainty in most of the record is one-half degree Fahrenheit. Similarly, last July’s record temperature was not based on the highs of the day. A record was set merely because the nights were slightly less cool in July 2012 than those experienced in the 1930s. So, when the high and lows of the day were averaged, a record average was established. Nevertheless, the highs of the day in the 1930s still exceeded anything experienced in July 2012.”

    This is from an article by Dr. Tim Ball and Tom Harris about Obummer’s Climate Speech.

  8. Anthony,

    During some of the surveys that Ellen and I made, not only were the shelters paint pealing, many were grimy with dirt. They had not been cleaned or painted in years. Even some of the automated stations had dirty and discolored covers. We found one totally covered in tall grass in Hot Springs South Dakota.

  9. Weathering (a degradation mechanism) of materials will certainly alter their emmisivity/absorption properties… but so too will dirt deposits

  10. Don’t those slats admit copious amounts of radiation from surrounding asphalt, etc?

    The lack of whitewash is undoubtedly related to excess exportation of US whitewash to supply UK “independent” investigative panels.

  11. now we know where that nonexistent 1/2 of a degree comes from…..

    please don’t tell me they are tuning the satellites to these results…….snark/

  12. Latitude;
    please don’t tell me they are tuning the satellites to these results…….snark/
    >>>>>>>>>>>>>>>>>>>>>

    Heh. Have they checked the paint job on the satellites?

  13. Can’t get at the whole paper, but it seems as though they tested four (4) Stevenson screens, aged 0, 1, 3, and 5 years. The differences appear large and one would think that NOAA/NASA would want to test lots more screens to confirm this observation. If the effect holds up, and enough screens can be tested to discern a quantitative relation with time, it would be possible to back-correct the temperature record. (We know NASA/GISS can do that, since they’ve been practicing back-“correction” for years!)

  14. What happened to underground temperature measurement? It seems to have been well established in the 1880s. It obviously doesn’t give useful information for daily needs, but it must be the best way to compare long-term trends.

    Let Nature do the averaging!

  15. This reminds me of a discussion I had with Zeke over at Lucia’s. Zeke had an article about how the new MMTS stations had a negative bias compared to the old CRS stations.

    http://rankexploits.com/musings/2010/a-cooling-bias-due-to-mmts/

    This bias correction, by the way, is one of many made to the temp data. So even if the newer MMTS stations don’t have the problem, their readings are still adjusted up to make up for their supposed negative bias. This means that the above problem spreads wider than just the old stations that suffer from bad paint diminished albedo.

    I asked Zeke how he knew that the problem that needed ajusting was MMTS negative bias, rather than CRS positive bias. After all, the MMTSs were coming newly calibrated from the labs, and the old CRSs were loosing their albedo. Zeke never answered that question. Much like Zeke never explained how his UHI reduction algorithms were not simply smearing the UHI effect evenly across all stations.

  16. So is it now time to switch to white vinyl?

    Although you can get metal siding with effectively-permanent bright white coating. That should make for a quickly-responsive housing.

    Should there be a material upgrade, even though this style of shelter is basically obsoleted by the use of the new electronic sensors?

  17. So homogenization should have gone the other way – the HadCrut and GISS thumbtack method of altering the temperature record (early 20th Century down, late 20th Century up) by sticking the tack in 1944 and rotating counterclockwise should have been rotated counterclockwise. Okay, let’s take the amount the 1936 high was reduced, multiply it by two and rotate it up. There, 1936 temp is still far and a way the highest in the instrumental record of the USA. I know that the Canadian record all time high was 45C at Midale and Yellow Grass, Saskatchewan in July 1937 and 44.4C at Emerson, Manitoba in July 11th, 1936 (at the North Dakota border by the way). I can’t believe that it got cooler in the central plains below the Canadian border with the US.

    http://en.wikipedia.org/wiki/List_of_extreme_temperatures_in_Canada

    We Canadians don’t have the budget of the US weather agencies which seem to number up to about half a dozen. This means that we didn’t reach back and cool these down at great expense. We have Environment Canada, who are as warmy as you can get but there is no way they are going to get $50M computers. So here is an experiment. Lets see what the temps were in North Dakota.

    Hottest in ND was at Steele in July 6th (5 days earlier than the Emerson, MB one), 1936 at 49C (120.2F) about 300 mi southwest of Emerson, Manitoba. Probably the dickered temperatures done by GISS, NOAA, etc. are a degree cooler or so. Anyone?

  18. Anthony, an extension to the surfacestations project: from the pictures, estimate the age of the paint job (if there isn’t logged maintenance record) and make a correction to the US average temps. Since the night time temps were unaffected, one may make an algorithm that would correct the daytime from it. Wow if we can chip off another 0.2 to 0.4C, what would that do to the divergence between IPCC forecasts and the observed and what would that do to the climate sensitivity: <0.5 per doubling?

  19. Aren’t AWS’s like the MMTS, not Stevenson screens as pictured? No painting required, though they still might degrade.

  20. Until the temperature anomalies exceed the rounding “errors” of the historical record, such as it is/ after adjustments.
    Is there even a “known” to plug into the equation ?

  21. So I’m sure someone will come on here and claim that homogenization practices should correct for this through their statistical methods. I say probably not…and almost certainly not with 100% success. There statistical methods are looking for high frequency step changes…nearly of the instantaneous variety…right? So if someone cuts down a tree that was previously right next to the sensor, if they erect a building right next to sensor, change paint colors of the neighboring building, install new A/C next to the sensor, move the station, etc–then homogenization might work. It should also work to filter out instantaneous negative biases like the installation of a sprinkler system.

    But homogenization will often fail (or even work in reverse of how it should) when experiencing slow/gradual interferences to their measurements. This is because the bias being introduced on the signal is in the same frequency range as the signal of interest–and therefore the range being passed by he homogenization “filter”. Thus, something like UHI can get in easily. A new building right next to the sensor–easy to filter out since it may cause a 1 C change in the signal that goes from zero to the full effect in a couple of months. But what about a building 3 blocks away that only introduces a 0.05 C effect, for instance? Doesn’t seem like much until one of those buildings was put in every other year for 20 years…a full 0.5 C increase at that point…added in nearly a linear fashion

    So how does homogenization treat something like what we’re seeing with the aging weather stations? Here’s my hypothesis…the aging effect is a slow change in the signal and for practical purposes a continuous function (the exception being something like a large storm causing a step-like function if it severely damaged the paint). Thus, we get a warming bias in the signal that isn’t filtered out–because it’s a smooth, continuous function. This bias is present, to some degree, in every single station experiencing weathering.

    A scenario: one day, after ~20 yr of operation, people tending a station decide to put fresh paint on the station. This gets the raw data back to unbiased, but since it happens as a step change, the homogenization process sees it as a problem (“station change”) and “corrects” it back to be in line with all the other neighboring stations that have been experiencing the same creeping bias! Worse than that, a few years later one of the neighbor stations that was used to justify the “correction” of the raw data will be repainted, seen to experience a step change, and then its raw data will be “corrected” back up to be in line with the others that are experience a slow warming bias! And the first station in the scenario, already “adjusted”, will be used as part of the justification for this “correction” because it will have resumed the weathering process after being painted fresh.

    Now, all that said, I’ve not played with the statistical methods employed for the homogenization processes, so it’s possible that my scenario given above couldn’t play out. If so, will someone please explain to me how situations like the above could not affect the results with a bias?

    Additionally, I’d say the above could actually be tested with real station data. Simple – do a one-day paint job on a station and see how the homogenization process modifies its raw data both before and after the paint job. At a different location but one with similar temperatures/insolation, paint the station in 1% increments once per week so that it takes 2 years to replace the surface. One might want to keep applying fresh coats to the already-repainted sessions while doing this. Check out how the homogenization process handles that type of data change. Is it not “corrected” in the same way or even at all? Would be an interesting test.

    -Scott

  22. This is truly terrifying. That weather station looks an awful lot like an old farmhouse that some friends and I rented back when we were in our twenties. So the POTUS and the other so-called leaders of the western world are going subject several hundred million people to policies based on readings from instruments housed structures that are identical to the dilapidated structure a bunch of twenty-somethings partied in 30 years ago.

    Hope and change!

  23. I think my method to measure day time rise and following night drop rejects these types of errors(follow the link in my name for paper). Interestingly i dont find a trend in warming.
    Anthony, with your site survey, if you or someone can provide some station numbers, I’ll extract the data, maybe some good and bad stations?

  24. There are two courses of action that should be taken here:

    1) incessant demands that GISS be adjusted for this effect
    2) a volunteer project to paint stations. Seriously. You too can help fight global warming!

  25. Probably the newest Stevenson screens on the planet are the ones they sold Anthony six years ago. Don’t that bring back memories, huh?
    :-)

  26. Andy, Tilo Reber and Scott: I participated in the same discussion with Zeke at the Blackboard. Zeke’s breakpoint detection algorithms find artifacts that result in a sudden cooling (going forward in time) with respect to neighboring stations more than once a decade in the US record. These cooling artifacts are far more common than warming artifacts, and result in corrections that lower early temperatures. In that discussion, I asked if occasional station maintenance might be responsible for a sudden correction of gradually deteriorating observing conditions that restored initial or normal operating conditions. Correcting a breakpoint caused by slow deterioration followed by restoration of earlier operating conditions would introduce a bias in the record. Slow gradual deterioration might be missed by algorithms whereas artifacts associated with maintenance would be much easier to find.

    A slow change screen albedo followed by painting or replacement would fit this degradation/maintenance scenario perfectly. Breakpoints caused by gradual deterioration of station albedo followed by painting or replacement would be easy to diagnose, because they would be found only in the maximum temperature record (and average temperature record), but not in the minimum. Major breakpoints associated would a station move would likely be found in both records.

  27. Frank says:
    June 29, 2013 at 9:12 pm

    A slow change screen albedo followed by painting or replacement would fit this degradation/maintenance scenario perfectly. Breakpoints caused by gradual deterioration of station albedo followed by painting or replacement would be easy to diagnose, because they would be found only in the maximum temperature record (and average temperature record), but not in the minimum. Major breakpoints associated would a station move would likely be found in both records.

    Hi Frank,

    Thanks for the info in your comment. Any idea whether the current algorithm considers the difference in max & min behavior as the paragraph I quote from you suggest should be possible to do?

    Thanks,

    -Scott

  28. This paper points out the danger in using a scalpel on long term temperature records.

    From Prior discussion in: Berkeley Earth finally makes peer review – in a never before seen journal – Jan 19, 2013 WUWT

    From Rasey comment: Jan 23, 2013 11:30am
    Let me nominate the occasional “painting of a Stephenson screen” as a member of a class of events called recalibration of the temperature sensor. Other members of the class might be: weeding around the enclosure, replacement of degrading sensors, trimming of nearby trees, removal of a bird’s nest, other actions that might fall under the name “maintenance”.

    A property of this “recalibration class” is that there is slow buildup of instrument drift, then quick, discontinuous offset to restore calibration. …

    It is a reasonable hypothesis that if a Stevenson Screen is painted, every 5 years for example, there is a gradual instrument drift between paintings. Then on the day of repainting, there is a sudden shift, a recalibration, of the sensor. With temperature changes on the order of 1 deg C on the repainting of the Stevenson screen, is it unreasonable to suspect that Best will preferentially slice at these recalibration discontinuities. If so, then BEST is making a biased record worse, by repeatedly incorporating instrument drift from degrading Stevenson Screen albedo as natural warming and discarding the recalibration resets that are the act of painting.

  29. If they always used the same type of paint, and they painted the same number each year, it might all wash away in the averaging. But suppose that the repainting rate has stayed the same but the paints have improved with time? Then modern numbers will be more accurate while the ones from long ago will tend to be too high. Oooooops! Better adjust those old numbers downward! Voila, another justification for concluding temperatures are still rising.

  30. So repainting a thermometer shelter may trick the GISS adjustment process into adjusting the station upwards because the aging process is slow and unnoticeable while the repainting event introduces one-time sudden temperature drop.
    You get positive bias if you don’t repaint. And you get positive bias if you do.
    Things are starting to make sense.

  31. A government testing lab where I worked in the 1970s was responsible for maintaining a number of Stevenson Screens, distributed across the state of NSW (Australia). Those enclosures were designed to use structural fibrous cement in the body of the cabinet and not laminated timbers. The screens did not require painting, but were progressively replaced by non-asbestos screens to comply with Australian standards by the late 1980s (or completely removed from service).
    I wonder how extensively such non-painted materials have been used elsewhere.

  32. Here is a restating of my Jan 23, 2013 11:30am comment concerning on how the BEST scalpel is the wrong tool to use in a time series populated by recalibration events such as Stevenson Screen repaintings.

    In any arbitrary temperature record let us identify time periods
    A0……A9.B0…….B9.C0…….C9.. etc.
    The spans A0….A9, B0…..B9, C0…..C9 are run periods of a sensor with instrument drift, such as a degrading paint coat on a Stevenson screen.
    A9.B0, B9.C0 are recalibration events where the Stevenson Screen gets repainted, electronic thermometers are recalibrated or replaced and other maintenance gets replaced.

    In this arbitrary temperature record, what are the time periods with the most accurate temperatures? It must be A0, B0, and C0, the times when the technician has packed tools and leaves.

    Worst case, a delibrate cherry pick, a boundary condition,
    the time series A0……A9.B0…….B9.C0…….C9.D0….. is a saw-tooth wave of gradual instrument drift, followed by a discontinuous recalibration. The BEST scalpel process will make cuts between A9 and B0, between B9 and C0. The BEST scalpel will keep the instrument drift and discard the recalibration. Drift (error) becomes signal and the periodic recalibrations (restoration of accuracy) are treaded as noise to be ignored.

    The recalibrations are vital to the long term records and must not be ignored.

  33. Hansen described satellite temperature measurements of Earth as “obviously wrong” !
    It’s far more likely that satellites are obviously right.

    I guess the adjustments needed to account for the age of the housings plus UHI would probably bring the temperature series more into agreement with CONUS and the satellites.

  34. The subject of the following Dutch report (http://www.brusselnieuws.be/artikel/stad-tot-5-graden-warmer-tijdens-zomernacht) is not the albedo on the surfaces of weather station shelters but UHI. According to recent measurements of the heat island effect in Brussels, in daytime hours it is 1 to 1.5 C degrees warmer than outside the city and even 3 to 5 C degrees warmer during night-time!

    According to the official measurements, the temperature in Uccle, a municipality being part of Brussels, the temperature rose with about 1°C per century. So the question arises whether the temperature increase with one degree in Uccle, (which is larger than the global temperature rise (about 0.6 to 0.7 degrees)), is due, in whole or in part, to the heat island effect. In 1850, the weather station was located in an area with few buildings while Uccle now has become a densely populated town with only in the southeast the cooling effect of a forest.
    One can also ascertain that the largest impact of UHI seems to happen during night-time while the impact of the albedo of the paint on weather stations is largest in daytime hours.

  35. @Carl Brannen A change in paint from whitewash to white latex circa 1979 is what got Mr. Watts headed down this road. He obtained three of the old screens to test, one bare wood, one whitewashed and one with white latex paint. Then he decided to investigate some of the local hot spots… er… weather stations, to see some in real world conditions.

    @njsnowfan Love that picture of the six stations in Las Vegas. ALL of them surrounded by gravel, concrete, asphalt, masonry buildings too, four of them at airports where the hot exhaust gasses from aircraft waft across the land all day. Couldn’t be any heated bias in the temperature readings from those.

  36. Of course, this will not necessarily enhance the observed warming over any particluar period. The key question is how has the average condition of weather stations changed over time (and how is it changing, going forward in time). Some stations have doubtless almost always been in poor condition. My guess would be that in recessionary times maintenance is pretty poor – so that the flat temperatures observed over the last decade and a half might well actually correpond to a fall in ‘real’ temperatures; though, OTOH, Anthony’s campaign may have encouraged a bit more attention to their condition (which would have reduced apparent observed temperatures!

  37. Wow! I never cease to be amazed at all the different factors that we assume are constant and then find out they need to be considered and normalized.

    Tree roots, paint jobs, precipitation, shear in glaciers – all kinds of stuff I’ve learned about just in the last few months. And then there is the Divergence Problem, too. And clouds. And Milankovich Cycles. And comic rays. And on and on. . . But especially when Phil Jones can’t do a simple trend line in Excel. LOL

  38. Oops! Comic rays. ROFL. . .

    Reminds me of that old comedian (LONG ago) with the bit about “You can call me Ray, or you can call me Jay, but ya doesn’t has to call me Johnson!”

  39. Screens made of sheets of pressed steel which are coated with white enamel should resist weathering effects for decades.

    But, of course, they will cost you dearly…

  40. @Rik Gheysens June 30, 2013 at 12:40 am:
    “In 1850, the weather station was located in an area with few buildings while Uccle now has become a densely populated town with only in the southeast the cooling effect of a forest.”

    Rik – Every time I see NW European weather systems on satellite images, they are coming in from the west or northwest, so a southeast forest would be on the lee side of the city and wouldn’t seem to have any cooling effect. Correct me if I am wrong.

  41. @J Martin June 30, 2013 at 12:13 am:
    “Hansen described satellite temperature measurements of Earth as “obviously wrong” !
    It’s far more likely that satellites are obviously right.”

    Right, Hansen. That is why the satellites and radiosonde balloons have agreed since 1979.

    (This was one of the first things that perked me up about the global warming issue… Which basically came down to: If two out of three methods of measuring the global temperature are in agreement, why is it that the two are considered wrong and the third is taken as gospel?)

  42. Satellite temperatures are far more accurate than surface instrumental global temperatures, the technology is far superior. Even if they both had the same error we are comparing a complete coverage of the surface area where it doesn’t miss parts of the poles with < 1% of entire global coverage. Yet still if the satellite was <1% surface area it would still be more accurate. Only those in a CAGW agenda nothing to do with science think the surface instrumental data is better. The satellite temperatures have kept them more honest with surface instrument data, but still trying it on with changing data selections to support the cause.

    How many of these data changes to instrumental stations are applied through to cover all history? The answer is none so they are even comparing a different data sub-set with different data sets over the long term history.None of them are comparing the same data points to previous periods, so how can we even say there has been any or even noticeable difference between the previous warming and cooling periods. Using the same Arctic based stations throughout the same period show no difference between the 1930's/1940's and recently.

  43. “We found one totally covered in tall grass in Hot Springs South Dakota.”

    The thought of placing one in Hot Springs made me chuckle. There must be some other good place names out there.

  44. It was a tiny chip of paint on a calibration detector that warped the huge mirror of the Hubble Space Telescope.

  45. Peter Miller says:
    June 29, 2013 at 3:33 pm
    …..Can’t they make these weather stations out of white, UV resistant plastic? To be still using wood for these shelters seems almost archaic
    >>>>>>>>>>>>>>
    1. Plastic degrades too, especially white plastic. (Black has the best UV stability)

    2. Historic screens are wood that is white washed. Any change, even a change in the type of paint will change the readings. We have seen enough manipulation of the raw data as it is without introducing another factor that can be used for fudging the data.

  46. polistra says:
    June 29, 2013 at 5:33 pm

    What happened to underground temperature measurement? It seems to have been well established in the 1880s…..
    >>>>>>>>>>>>>>>>>>>>>>
    Absolutely useless. It doesn’t give you the screaming headlines needed to scare the sheeple.

  47. talldave2 says:
    June 29, 2013 at 9:07 pm

    There are two courses of action that should be taken here:

    1) incessant demands that GISS be adjusted for this effect
    2) a volunteer project to paint stations. Seriously. You too can help fight global warming!
    >>>>>>>>>>>>>>>>
    Oh WOW, just think what would happen to the temperature record if we all got a can of white wash and made midnight painting ‘strikes’ on every surface station in our area.

  48. Steve Garcia says:
    Every time I see NW European weather systems on satellite images, they are coming in from the west or northwest, so a southeast forest would be on the lee side of the city and wouldn’t seem to have any cooling effect. Correct me if I am wrong.

    Indeed, the predominant wind direction in Uccle (Belgium) is southwest.
    Another strange phenomenon is that the wind speed in Uccle has decreased substantially since the middle of the previous century. This is partially due to higher trees and the high-rise buildings in the surroundings.
    The question remains if a correct measurement of the temperature and wind speed is anyway possible amid a fast evolving situation. (The world population grew from about 1 billion in 1825 to more than 7 billion now.)

  49. If this holds up (“Further studies are needed”!) it will give fence-sitters and worried warmists the face-saving excuse they need to jump ship. They can blame their old position on the wrong data they were fed.

    Now that this has been proven, it seems like such an obvious thing to look for. I now wonder why it wasn’t done 30 years ago … or 20 … or at worst 10, given all the hullabaloo about global warming and the well known controversy about bias in measuring–plus the well known divergence between the satellite and ground stations. A 4H club could have done the experiment, or a single kid as a high school science project.

    Perhaps that last sentence explains why “scientists” didn’t bother to do the experiment. It was infra dig. Too simple–something the laity could understand and perform.

    That snooty “attitude” is part of what’s wrong with science these days.

  50. Be interesting to factor “old” weather station data into that obtained in the Surface Stations.org data and see what the difference turned out to be.

  51. PS: This “weathering” effect in the stations used in the main US dataset may account for a large portion of its divergence from the 10-year-old high-quality network. It may not just be UHI and local-siting issues.

  52. Not really on topic, but the forecast high for Death Valley the last 2 days (Friday and Saturday) was 128, and topped out at 112 and 113 instead. Phoenix was 119 and 118 vs observed of 116 and 118 (sequential all time highs according to Weather.com records). A bit odd, isn’t it.

  53. PPS: An eight-minute episode on 60 Minutes devoted to this finding and its implications would be a blockbuster. “What boneheads! What a failure to be curious, inventive, and self-critical!” the audience would think—correctly. And (more subversively) “What an exposé of the ‘self-correcting scientific process’ as a myth.” Maybe “Organized Science” is as untrustworthy as Organized Religion.

  54. And there are also problems with newer weather stations. Check out this article:

    http://www.timesdispatch.com/news/state-regional/experts-fixing-buggy-richmond-airport-thermometer/article_dfcdc6b6-c930-5c79-b29b-a28f17431259.html

    Here, they found that bugs, dirt and grass were clogging the screen that admitted air to the temperature sensor, resulting in high readings. Also note that this is the official sensor at the airport. An excerpt from the article:

    “Weather service experts have felt for years that the airport sensor’s readings were often a little high, particularly when winds blew out of the west or southwest. That could be because the sensor lies east of the airport’s terminal and a runway — hard surfaces that absorb heat. So those winds could be blowing extra heat to the sensor.”

    So Anthony, you are not the only one to notice these biases, not that anyone else is doing anything about them….

  55. Frank: If I read you right, it still remains a positive bias that needs to be corrected for. The opposite of what Zeke wanted to do and the opposite of what is currently done. I believe that the current correction is to add something to all MMTSs.

  56. The “heat wave” in the West at the moment is obviously just a figment of Warmistas’ fevered imaginations, aging weather stations, weather stations painted with the wrong paint, urban heat island effect, unreliable, biased, and highly upward-adjusted temperature record, etc., etc..

    We’re all on message here, Tony :)

  57. So … the older a station is the more likely it will tend to give higher temperatures? The wood slats paint jobs aren’t being kept up with? Maybe the problem is the wood itself. Did any of it come from Yamal?

  58. I have to say, I’m a little unsure about the sense of jubilation about this report here. Why would this be more of a factor now than in the past? I could easily make the argument that screen upkeep 100 years ago was inferior to today – and do you really think that the observers were out wiping down and whitewashing the enclosures during the Dust Bowl?

  59. FredA says:
    June 30, 2013 at 11:41 am

    I have to say, I’m a little unsure about the sense of jubilation about this report here. Why would this be more of a factor now than in the past? I could easily make the argument that screen upkeep 100 years ago was inferior to today – and do you really think that the observers were out wiping down and whitewashing the enclosures during the Dust Bowl?

    =========================================================================
    So we’re unsure of past and present surface temperatures. Why spend billions because someone claims a computer model projected higher future temperatures?
    (GIGO)

  60. Village Idiot says:
    June 30, 2013 at 9:19 am

    The “heat wave” in the West at the moment is obviously just a figment of Warmistas’ fevered imaginations, aging weather stations, weather stations painted with the wrong paint, urban heat island effect, unreliable, biased, and highly upward-adjusted temperature record, etc., etc..

    We’re all on message here, Tony :)

    Nice straw man. Nothing like that was stated by anyone but you. At most, the effect discussed in this post would contribute 1-2 degrees to the measured high from the current heat wave. Of course, it’s only the CAGWers that are claiming a 0.7 C increase in the average global temperature will cause massive damage through increased heat waves, tornadoes, and hurricanes. At best, the data indicate that only the heat wave claim has any credibility, as the other two are trending in the opposite direction.

    -Scott

  61. Anthony, wasn’t it something to do with paint on Stevenson’s screens that got you on the road to skepticism? I can’t recall the details.

  62. FredA says:
    June 30, 2013 at 11:41 am

    I have to say, I’m a little unsure about the sense of jubilation about this report here. Why would this be more of a factor now than in the past? I could easily make the argument that screen upkeep 100 years ago was inferior to today – and do you really think that the observers were out wiping down and whitewashing the enclosures during the Dust Bowl?

    Here’s the problem–because the Stevenson Screen stations were measuring lower than the MMTS stations that replaced them, the record-keepers decided that the MMTS stations had a cool bias, and should be adjusted upward. Removal of that upward adjustment would cut the rise in recent decades by maybe one-third, per my SWAG.

    Tilo Reber says:
    June 29, 2013 at 6:03 pm

    This reminds me of a discussion I had with Zeke over at Lucia’s. Zeke had an article about how the new MMTS stations had a negative bias compared to the old CRS stations.

    http://rankexploits.com/musings/2010/a-cooling-bias-due-to-mmts/

    This bias correction, by the way, is one of many made to the temp data. So even if the newer MMTS stations don’t have the problem, their readings are still adjusted up to make up for their supposed negative bias. This means that the above problem spreads wider than just the old stations that suffer from bad paint diminished albedo.

    I asked Zeke how he knew that the problem that needed ajusting was MMTS negative bias, rather than CRS positive bias. After all, the MMTSs were coming newly calibrated from the labs, and the old CRSs were losing their albedo. Zeke never answered that question.

  63. All data are good as long as they are homogeneous. The disasterous shift from CRS to MMTS shelters by NOAA in the mid 80’s destroyed the U.S. Climate Observing Network’s homogeneity.

  64. Scott says (June 29, 2013 at 9:33 pm) Any idea whether the current algorithm considers the difference in max & min behavior as the paragraph I quote from you suggest should be possible to do?

    There was a very useful discussion at Lucia’s and links to Zeke’s the latest NCDC paper at Lucia’s: http://rankexploits.com/musings/2013/uhi-paper-finally-published-in-jgr/

    Errors made by correcting breakpoints caused by gradual deterioration of observation conditions and maintenance is discussed here: http://rankexploits.com/musings/2013/uhi-paper-finally-published-in-jgr/#comment-110147

  65. have you ever a seen a simple experiment?…gathering several thermometers in a few square meters and monitoring temperature…
    i repeat t a themometer mesasures its own temperature, the rest is assumption..i assume a themal equilibrium i assume, the box isn’t warmer and radiate .i assume the air outside the box is a the same temperature ; or is well mixed and so on…and you know that each one is false… but well we need to measure something don’t we?

  66. Gail Combs says: ”

    Peter Miller says:
    June 29, 2013 at 3:33 pm
    …..Can’t they make these weather stations out of white, UV resistant plastic? To be still using wood for these shelters seems almost archaic…

    1. Plastic degrades too, especially white plastic. (Black has the best UV stability)
    2. Historic screens are wood that is white washed. Any change, even a change in the type of paint will change the readings. We have seen enough manipulation of the raw data as it is without introducing another factor that can be used for fudging the data. …”

    We should also note that the maximum typical UPVC rated lifetime is around 25 years, while wood can happily last for several hundred. More importantly, that UPVC lifetime is a period to failure – colour degradation (thereby altering the temperature) will start within a very few years. And it will be variable, depending on how much sun an individual installation has.

    Plastic would be a VERY bad idea….

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