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:
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
The thought of placing one in Hot Springs made me chuckle. There must be some other good place names out there.
It was a tiny chip of paint on a calibration detector that warped the huge mirror of the Hubble Space Telescope.
a thermometer measures its own temperature…the rest needs assumptions.
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
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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.
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…..
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Absolutely useless. It doesn’t give you the screaming headlines needed to scare the sheeple.
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!
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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.
LOL….Gail!
Isn’t this where you came in Anthony, with a study of Stevenson screens?
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.)
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.
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.
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.
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.
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.
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….
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.
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 🙂
This could be as big as UHI.
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?
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?
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So we’re unsure of past and present surface temperatures. Why spend billions because someone claims a computer model projected higher future temperatures?
(GIGO)
Village Idiot says:
June 30, 2013 at 9:19 am
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
[Snip. Russell Seitz is persona non grata here. — mod.]
http://gallery.surfacestations.org/main.php?g2_itemId=70314
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.