You’d think the answer would be obvious, but here we have a NOAA operated USHCN climate station of record providing a live experiment. It always helps to illustrate with photos. Today I surveyed a sewage treatment plant, one of 4 stations surveyed today (though I tried for 5) and found that for convenience, they had made a nice concrete walkway to allow servicing the Fisher-Porter rain gauge, which needs a paper punch tape replaced one a month.
Here is what you see in visible light:
Here is what the infrared camera sees:
Note that the concrete surface is around 22-24°C, while the grassy areas are between 12-19°C
This station will be rated a CRN5 by this definition from the NOAA Climate Reference Network handbook, section 2.2.1:
Class 5 (error >~= 5C) – Temperature sensor located next to/above an artificial heating source, such a building, roof top, parking lot, or concrete surface.”
Now a caveat: There had just been a light rain, and skies had been overcast, it had just started to clear and you can see some light shadows in the visible image. Had this rainfall and overcast not occurred, the differences between grass and concrete temperatures would likely be greater. Unfortunately I was unable to wait around for full sun conditions. The air temperature was 58°F (14.4°C) according to my thermometer at the time.
Here is another view which shows the NOAA sensor array, the sky, and the evidence of recent rainfall as evidenced by the wet parking lot:
Why NOAA allows installations like this I’ll never understand. And this station is a USHCN climate station of record, used in who knows how many climate studies.
I’ll tell you more on this station and others I surveyed tomorrow.
Well I think that adds some additional buckshot to what the Rev (and i) have been banging on about concerning the LeRoy CRN “estimates”.
Not to mention the Yilmaz (2008) and LaDochy (Dec. 2007).
And the Rev’s earlier accounting of the “Baltimore rooftop” comparisons.
A picture is worth a thousand words! (And I will indeed be adding a few thou on this particular subject!)
The color on the MMTS shield is a shade of purple that, from eyeballing the color scale, leads me to think it is 1/3 of the way from 10 to 24, or about 14.5C. When you say that “The air temperature was 58°F “, does that mean the air temperature at the MMTS, or is that a representative average of the surrounding area?
If it’s the former you could have measured the microsite bias at this station if you wanted to, but you didn’t. Take the temperatures over the concrete, and then over the grass and show us how much they changed.
If the latter, then we can reasonably conclude that the microclimate issues with this station are small.
REPLY: I don’t think you can conclude that at all and I think you miss the point. There’s a standard, (CRN1-5 or COOP 100 foot rule, take your pick) that has been ignored. There’s good reasons for such standards. Though given your defense last year of your UofA USHCN station in the parking lot, I suppose I can see why you don’t see much issue here. Your defense of the UofA station suggested you don’t think siting is important.
Unfortunately, I didn’t have a portable calibrated thermometer and portable aspirated IR shield with me, which would be required to do a proper job of air temperature measurement. The air temperature value I gave came from the vehicle thermometer, as I drove up. I’d call it anecdotal.
You aren’t the first person to ask why comparative temperatures aren’t being taken at these sites at time of surveys. The answer is that I (and volunteers) can’t do the job of a complete study when often there are only a few minutes of time at these stations. A couple of spot readings isn’t enough.
But the new datalogger and shield (see previous blog post) I’ve designed has just completed its first parallel trial at a COOP site, so we’ll see what it says when I get back and get the data from the COOP.
This really should be NOAA’s job of understanding microsite bias issues. And it wouldn’t be needed at all if exposure/placement standards were adhered to. But they aren’t paying attention or even enforcing their own 100 foot rule.
The key here is not any instantaneous air temperature, but the average of Tmax/Tmin for the day. What does that heat sink of concrete (and the environment of the sewage treatment plant) do for the Tmin which is much more capable of being affected than Tmax and how does that affect the daily average?
Its all about artificial heat sources. That concrete mass releases heat slowly. The IR shows that even the light rain didn’t do much for cooling it similarly to nearby things. We don’t know what the picture looked like before the rain (which would affect the low mass gill shield more than the concrete) so how do you know it wasn’t reading higher before? How do you know that the air temperature will read accurately in full sun with no rain? I don’t and you don’t. But the siting standard suggests there is an issue. The IR picture shows the heat sink effect clearly.
The point here is siting: don’t put a thermometer next to a heat sink like a walkway, driveway, active parking lot, or building and you don’t have to do the disentanglments in the first place.
Fascinating.
Note how weathered the concrete is. Its albedo will have changed substantially from when it was laid, introducing a spurious cooling trend to daytime temperatures and probably a warming trend to nighttime temperatures.
That picture goes a long way toward explaining the long term decrease in diurnal range seen in the temperature record.
http://climate.uvic.ca/common/papers/cldyn.2003.20.435-445.pdf
(read it for a description of long term changes in diurnal range)
R2D2
====
The White Knight disarmed.
=================
You betcha there had already been a lot of cooling of the sidewalk from energy of evaporation.
=============================
Look at the temp of the galvanized post! If this is typical of most installations, a calm wind situation would have heat rising into the MMTS on any site not in the shade. That post would be warm for hours after sunset. Those posts should be white fiberglass.
What a mess!
Do you think that Al Gore, when he was Vice President, knowingly had the sidewalks installed, resulting in higher recorded temperatures in order to bolster his “Global Warming” farce.
😉
Atmoz,
Sheesh,
Mike Bryant
What I think… is that anyone who uses any of these grade 4 and 5 sites, and pretends they represent anything other than distortion and bias, is attempting to commit fraud.
Leave it to the scientists to form a consensus based on garbage. I’m sure more than one PoorHaplessDope reviews the data.
I may be a bit confused here. I keep hearing (from some of the warmers) that just because the station has a CRN of 3,4,or 5 doesn’t really mean anything because the error would have been over a long term and wouldn’t effect the trend. I have some thoughts on this an may be confused.
1. If the average reading is elevated 3f degrees above a station with out micro-site bias and this happens at enough stations would that increase the average regional/global average? (3f is an arbitrary picked our of the air number)
2. If the average regional/global average is increased due to micro-site bias introduced in the last 40/50 years it would appear to make readings increase over that time frame.
3. If more and more sites are being upgraded with new equipment but also for convenience of operation micro-site bias is being unintentionally introduced to the sites would tend to make the regional/global average increase even more again due to micro-site bias.
My thoughts would be that the USHCN record has been compromised and I doubt that any algorithm would be able to completely remove all micro-site bias. With the introduction of more and more sites with micro-site bias that the trend would artificially be upward and would be man made due to the introduction of the bias.
Let me state that I agree that the climate has been warming for the last 100+ years. I do believe that we (humans) have caused a small part of that warming by producing heat to produce energy and using energy which produces more heat. I also believe that most of the warming is part of a cyclical rhythm that nature is in control of and that we will not be able to any time in the near future be able to change to any significant amount.
I do believe that elimination of pollution should be one of our priorities. Declaring a naturally produced gas (CO2) that is required to sustain life on this planet makes no sense to me. There are many more harmful pollutants that need to be controlled and that is where we should be putting our resources. I do believe in conservation and have changed many of my daily activities to conserve. I have changed over to mostly fluorescent lighting, I have reduced daily travel, I grow much of my food at home in the garden. I do believe that we need to develop alternate energy sources but not because of CO2 levels but for national security and economic reasons.
Perhaps I am confused but to me common sense is needed in this area and open not closed scientific study with no replication possible. Our controlling authority (NOAA) should enforce its own rules controlling the placement of weather stations. They should also insure that stations that have problems are either
A. repaired
B. relocated
C. removed from service if A and B can not be accomplished due to
urban encroachment or commercial site development.
We just need to get it right before we make a big mistake and cause more harm than the natural progression of climate would.
Just some thoughts from some one not a scientist.
Bill Derryberry
Bob_L, the metal post would not stay warm for hours after sunset. Metal’s effect is more short term. That is why it makes a poor insulator. — John M Reynolds
RE the comment by ATMOZ above, am I correct in concluding (he she) they don’t know the difference between surface temps of an object vs ambient air temps, and why the two may not be the same?
I believe in the work as it’s been an eye opener for me. I agree with the concept that many of these sites are contaminated (badly) and that they may not be providing accurate results. I also agree that without visual evidence and exhaustive study how would someone be able to adjust a station back to where it should be (70% + of the US stations receive adjustments and who knows if they aren’t just adjusting the few good stations up to match the contaminated stations). Some of these stations have seen a great deal of change around them (Baltimore rooftop, U of A parking lot), but my question is about those that are contaminated that haven’t had a lot change around them.
I look at the CRN Rating Pie Chart and you can see the percentage of stations suffering from 1-5+ degree differentials, but is this differential a constant or is it a delta over the course of a century? In other words, a station like what we see above, is it 5 degrees off of average every year or is it a site that would suffer from a 5 degree temperature shift over a century? If it is the former, then it doesn’t matter as the delta over time would not change. I have had someone ask this in a conversation I had while explaining your project.
Thanks!
The response by Atmoz immediately popped this question into my head: Where have all the skeptics gone?
Faced with the evidence of siting violations you have THREE options.
1. Ignore them, wave your arms, say the warming bias will be balanced by the cooling bias. This is Jones. This is Hansen.
2. Quantify them and adjust. In the same way Karl quantified the TOBS bias, the microsite bias could be evaluated. This is hard work fellows, but a person could get a PHD proposing an approach.
3. Eliminate the class5 from official datasets. Do this at the Quality control
level of data processing.
I prefer #3. I prefer it because #1 is pure bullshit and #2 will take time.
If your standard says, dont collect temps over concrete, then………DUHHHHH
dont collect temps over concrete.
we can reasonably conclude that the microclimate issues with this station are small.
Yilmaz et alia (2008) would argue otherwise.
Jennifer Marohasy: I confess that have been a bit of a fan ever since that writeup in the Australian. I have tried to locate the negative feedback info from the AquaSat that you cite but I have come p sompletely empty. In fact the sites covering Aqua seem to avoid listing results entirely (a cynical individual might almost be led to wonder why this should be the case). I have seen many references to the negative feedback/homeostasis conclusions, but they all lead back to that same article–no independent confirmation whatever. So if you could put up any links that would help us here out in this regard, we’d be very happy! Keep up the good work (you have the support of at least one liberal).
What I think… is that anyone who uses any of these grade 4 and 5 sites, and pretends they represent anything other than distortion and bias, is attempting to commit fraud.
Think what you like. Who Decides? It is we, the laymen who decide. The expert witnesses merely inform; it is the laymen jurors who determine the policy verdict.
I will further observe that if the “experts” (supported by our taxes) had been doing their jobs properly in the first place, microsite issues would never have arisen, and if they had, they would be scrupulously adjusted for, and the adjustments would be well studied/calculated/confirmed, not merely “estimated”. Hint: “Yilmaz”–a name to remember.
Note how weathered the concrete is.
However, the darkness of the concrete isn’t from weathering. It’s wet! That’s a cooling bias.
According to the Yilmaz measurements, tempertures 2 meters over concrete or asphalt are radically higher. This would confirm the the LeRoy “estimates”.
(Energizer Bunny)Hrumph, hrumph … a minor effect … washed out by the law of large numbers … hrumph, hrumph. (/Energizer Bunny)
ATMOZ tries to conclude that the sensor shield temperature is representative of the air temperature. The sensor shield is doing its job; it is not changing the temperature of the air flowing across it and onto the sensor inside. The concrete walkway, on the other hand is warming the air that is flowing across the sensor.
Anthony, I disagree with you that ATMOZ defense of the U of A site in the parking lot shows he believes siting is not important. Instead, it shows he is willing to go to great lengths to argue rhetorically to diminish the importance and relevance of your work on the surface stations project. It is consistent with his little April Fools joke that was intended to harass you by drawing you into a situation where his friends such as TCO would then extend you written abuse. It is also consistent with when he was masquerading about the internet as a climate scientist when in fact it turns out he is just a student. He is obviously polarized and has no credibility with me, which is why I no longer visit his blog.
The pictures do speak volumes. I agree with the reader who notes the post temperature problem. Something needs to be addressed there. Has there been a gradual “creep” of these UHI / methods / materials problems, or was the system poorly-designed from the beginning? Regardless, it looks like it’ll be hard to do patchwork fixes after the visibility of your study.
Interesting and very revealing infra red picture.
Now, how much does it actually raise temperature?
It would be intersting to actually have two temperature sensors for experimental use and then put one in similar conditions as above and the other over grass at a safe distance. When both show stable temperature the concrete piece is moved away and the sensors are read again to see what actual impact it has.
REPLY: I agree and I hope to accomplish such an experiment.
Have I finally gone over the edge in thinking that a site involving manicured, green grass can’t be very desireable either?
My question is why is the media not reporting this .There is odviously a problem with the way these temps are recorded. It’s as though they want the temps to be warm.We already know the media is bias on this issue.Maybe in a couple years we could start having cold day,like earth day,Oh wait that would mean the earth may accualty be cooling and that could spell the end the global warming .
We’ve got 2 sunspots!
Cycle 24, as they are not near the equator?
From Marohasy’s website…
Cooling cometh
http://www.theaustralian.news.com.au/story/0,25197,23583376-7583,00.html
John B, I had the same thoughts, but I have since realized that there are other factors. I will use the site in this post as an example. On a year that had more clouds during the day, the bias of a nearby slab of concrete would be less. Similarly, if a high pressure system stalls over the area for months, then the bias would be much more due to the lack of clouds. The bias is just not realiable. That is the reason the standards were created. — John M Reynolds
My thoughts would be that the USHCN record has been compromised and I doubt that any algorithm would be able to completely remove all micro-site bias.
Considering the deplorable state of the station histories, I would be forced to agree. It’s obvious that if the microsite violations are not being adjusted for, they never would have been recorded in the first place. (Giving NOAA the benefit of the doubt.)
Pierre Gosselin, they have the magnetism of solar cycle 23:
http://www.solarcycle24.com/
John M Reynolds
Has there been a gradual “creep” of these UHI / methods / materials problems, or was the system poorly-designed from the beginning?
If UHI is calculated from surrounding CRN4 & 5rural stations, it is patently obvious that the UHI is woefully lowballed. To me that’s a “D-uh” conclusion.
It would be intersting to actually have two temperature sensors for experimental use and then put one in similar conditions as above and the other over grass at a safe distance.
See Yilmaz et al. (2008 ).
However, the darkness of the concrete isn’t from weathering. It’s wet
Admitedly it’s hard to tell from a picture, but the albedo of concrete is known to change over time as it weathers (from higher to lower albedo). This would introduce a trend to temperature measurement nearby. How large a trend, is anyone’s guess.
http://www.solarcycle24.com says the news sunspot(s) have cycle 23 polarity.
Is CO2 headed down?
Here’s an interesting report from the European Institute for Climate and Energy in Jena, Germany
http://www.eike-klima-energie.eu/?WCMSGroup_4_3=6&WCMSGroup_6_3=1247&WCMSArticle_3_1247=342
Quick translation into English:
Is the trend of constantly rising CO2 now ending?
Scientists at the European Institute for Climate and Energy in Jena have recently observed signals of a CO2 trend change, delayed, but similar to the current methane trend. Methane hasn’t risen in a long time. E.G. Beck writes about this in his paper (see file): “During the last two years, CO2 data from the measuring stations of the WDCGG (World Data Center of Greenhouse Gases) and the NOAA now show a change in trends, especially for the northern hemisphere.”
Atmospheric physicist Dr. Borchert, who has worked closely for years on the Svensmark Effect; the influence of cosmic rays on cloud formation, has reached the same conclusion. Taken by aback by the stagnating trend in methane concentrations seen for years, he has also studied recorded data from the major CO2 measuring stations worldwide. He has reached identical results.
It matches up excellently with the report from the AWI, which states the oceans have again started to cool down. Should we be indeed witnessing a change in trends, then temperatures begin to fall, then methane, and then the CO2? The near future will be suspenseful.
Edited by Michael Limburg
And the sunspots have suddenly returned – cycle 24
http://www.spaceweather.com/
I just went to ,sun cycle 24, web site. A new sunspot has formed just north of the equator but they say it ‘t with cycle 23 magnestism.
Hmm… What about the temperature of the pole holding the MMTS? I notice it’s a bit warmer than the MMTS itself and of course is directly below it. Has anyone examined measured temperature of an MMTS with a pole vs without? Stevenson Screens didn’t have such a heat source directly below them. Could this be a reason why a switch from Stevenson Screen to MMTS might show a slight jump in average temperature?
Anthony:
Thank you, Thank you for the work you are doing. I have a comment along the line of measurement integrity of instrumentation aside from the terrible conditions in which the instruments are placed. Most of my professional life work was in the field of Metrology (science of Measurement) – NOT METEOROLOGY. In the last years of my employment, I was the chief scientist of a large military organization responsible for the calibration and repair of test and measurement equipment used throughout the US Air Force. (Something like 1.2 million instruments) We had responsibility for the oversight of over 150 calibration labs worldwide, and the Primary Standards Laboratory. When measurement audits were conducted of the labs, I was always amazed how far off of the true value some of the measurements were. That was in spite of fairly uniform training of personnel, calibrations standards used, and a most benign environment in which to make their measurements. Further, their traceability was checked to make sure that all certificates of measurements for their standards and cal lab instruments were on hand and current.
Further, the act of making scientifically valid measurements requires a generally accepted process or procedure, properly calibrated and certified equipment and standards, qualified personnel, an error analysis of the process, and proper statistical treatment, handling, and interpretation of the data.
That being said, I see no way on this God’s Green Earth that the temperature measurements going back over 100 years could be expected to have any validity. The measurements from NOAA and other sources fail almost every criteria for accurate measurements that I have mentioned above. It looks to me like most of the temperature measurements made are pure garbage considering the conditions under which they are made, both from the standpoint of environment and instrumentation integrity.
I believe that the Global Warming theory will turn out to be far more hoax than fact as time passes, and the truth comes to light.
That will be extremely unfortunate as I believe we need to conserve carbon resources for future generations. We may have already passed the peak of the ability of the world to produce petroleum. We have a longer lasting supply of coal, but those reserves will diminish all too quickly. The US and the world definitely need to find alternative sources of energy. Ethanol, wind power, sea waves, geothermal, and solar panels just will not get the job done. Nuclear energy is some help, but not the total answer.
We need to conserve petroleum for the things it alone can provide such as chemicals, medicines, lubricants, plastics, and a host of other products.
Hope you find these comments of interest. I have not found anyone yet who commented on the total lack of measurement integrity of NOAA and other temperature measurements made around the world. Everyone knows the old cliche: Garbage In – Garbage Out. And that is what we have. I just do not think there is any way anyone can go back and retrieve measurements that mean anything with one possible exception.
I do believe the Satellite temperature and radiation measurement intruments are more trustworthy than almost anything else for their purpose. From my understanding of their design, they are almost continuously compared with a stable (once calibrated) on-board reference standard. And from what I have read, their results almost always refute global warming claims.
Big M
REPLY: An error here, and error there and pretty soon you’re talking real garbage. 😉
Sat measurements show a warming trend, a bit less than that of the surface trend. But the question is, what is the on-board reference calibrated to? What is the science and error band behind it?
Admitedly it’s hard to tell from a picture, but the albedo of concrete is known to change over time as it weathers (from higher to lower albedo). This would introduce a trend to temperature measurement nearby. How large a trend, is anyone’s guess.
True enough. But that would be a warming trend, not cooling, as asphalt has an even worse effect than concrete. (I think.)
La Dochy (Dec. 2007) says that not only offset, but also trends [SIC] are increased by UHI heat sink effect!
And Yilmaz rousingly vindicates the LaRoy “estimates” (as does our humble Rev with his “HOT-L Baltimore” observations).
Anthony,
Have you located an example of an “ideal” weather monitoring station and published a picture of that?
REPLY: Corvallis, OR, operated by the soon to be retired George Taylor, the OFFICIAL STATE CLIMATOLOGIST OF OREGON, is a good example of a CRN1 station.
http://gallery.surfacestations.org/main.php?g2_itemId=3343
Karma is going to come back and bite that idiot Governor Ted Kulongoski of Oregon on the ass.
I wonder if the bias of small items like the pole would be small enough not to register. I thought the thermometers had a single decimal place as its last significant, and thus most error prone, digit. i do get a chuckle when GISS tries to claim that the temp anomoly has changed by 0.67 C. Perhaps this pole test would be another good test. Does anyone have 3 MMTS sensors? And do the specs have anything to say about the material of the mounting pole?
John M Reynolds
NitWits
Notice the concrete is still wet and it was 22-24c. Had it been dry it would be interesting to see how much of a difference there would have been between the concrete and the grass. Why would they change the way they have recorded temps for years at there stations unless they’re wanting to get a different reading.If you’ll notice concrete turns darker as it ages too.
On a slightly different subject, The International Climate Science Coalition has released the list of signatories to the “Manhattan Declaration on Climate Change”
http://www.climatescienceinternational.org/index.php?option=com_content&task=view&id=66&Itemid=1
The text of the declaration is at;
http://www.climatescienceinternational.org/index.php?option=com_content&task=view&id=37&Itemid=1
I was happy to see one Anthony Watts among the signatories. Although I was a bit disappointed that Prof Lindzen was not among them.
Jennifer: RE: Australian article: Could be a watershed.
J. Peden
Indeed, grass is probably not the best reference either, but some kind of reference area is needed still.
Temperature sensors meassures local temperatures. With local i mean it often meassures the area close to the sensor, not what it is 10-1000m away.
What would an optimal senosor position be? It very much depends on where it is.
In a small city that is surronded by a forrest the sensor should be in the forrest. In agricultural areas it should be placed out in the fields.
Now considering how much of the earths surface that is covered with forests and deserts, how many sensors are placed in the middle of those? Not many I would guess.
Also as jmrSudbury mentioned above, even the material for the mounting pole could affect the readings if it is not well defined.
It is so rare that information on the Internet is not derivative. Here is an original story, with insight and interpretation (not to mention legwork.) My highest regard for some push-back against the corporate media who abuse science to advance taxation agendas.
True enough. But that would be a warming trend
I’m no expert on concrete, but I understand that the albedo of most concrete will decrease over time. Decreasing albedo will turn a heat reflector into a heat sink. So the daytime trend (as albedo decreases) would be cooling and the nighttime trend probably warming. Of course there would be a warming step change when the concrete is first laid.
Anthony may I ask what type of equipment you are using to take those infra red photos? I have a use for something like that (not climate related).
REPLY: See this http://www.professionalequipment.com/flir-thermacam-bcam-sd-infrared-thermal-imaging-camera-bcam-sd/flir-thermacam-infrared-cameras/
This is an interesting post – does anyone know when the sidewalk was poured? Maybe at one time the station conformed to 100 foot rule and, as stated, it appears the sidewalk was poured for convenience of maintenance. This means the station was already there. Reasonable. The person who installed the station may have been aware and the person who installed the sidewalk unaware. Just a thought…
Mars
the daytime trend (as albedo decreases) would be cooling and the nighttime trend probably warming.
According to Yilmaz (and LaDochy) you don’t get cooling at TMax with a heat sink. You get warming. (And even more warming at TMin.) A heat sink does NOT suck up heat, leaving cooler air above it! It retains the heat and bleeds it out joules at all times.
Have I finally gone over the edge in thinking that a site involving manicured, green grass can’t be very desireable either?
Grass definitely absorbs/reflects/exudes less heat than either soil or concrete/asphalt. Both at surface and 2 meters above the surface (Yilmaz, 2008 ). The figures are actually quite staggering: Grass-concrete/asphalt: at surface >11°C, 2 m above surface >7.5°C (Conditions: 24 hour average, during summer, masked by UHI).
is this in Arkansas? I think I’ve been there…? That would also explain the Al gore/clinton reference. Seriously where is this?
REPLY: Fayetteville NC, Wastewater treatment facility
jerker and Evan, thanks for the responses on grass and problems with siting in general concerning just what any sensor is actually measuring. Even apart from the concrete and post, to me that sensor just kinda looks out of place – like it might sometimes be in the midst of people having a picnic or playing golf or football, or something, instead of being a scientific station protected from immediate human influences as much as possible.
Just a thought but it appears from the picture that the sensor is placed on a slight elevation between two parking lots. I can wonder if that might make the site even more biased especially for the Tmin on calm evenings with the rising of the heat from both parking lots following the contour of the site. I believe that the side walk isn’t the only problem but the parking lots on both sides. To me it appears that the sensor might be placed on a containment levy with asphalt to either side and concrete below. Not good.
Bill Derryberry
oh you want them to walk on the grass huh? and maybe get some mud on their shoes if it’s raining. or worst wet grass
you’re a cruel person
discipline yourself
i say they should also build shaded walkways with boze speakers and soothing music with a water cooler, coffee, donuts and a nice leather couch from ikea for days when they need rest
Once again, zero proof of bad data from the station, zero proof of any bias from the data, zero proof of heat effect on the sensor.
Evan, I don’t think we are disagreeing.
My point was that weathering of the concrete over time will introduce a spurious trend to the temperature data.
This trend would be independent of the effect of the concrete relative to grass. So, the concrete probably introduces a warming bias to the station, and in addition the size of that bias will change over time as the concrete weathers resulting in a spurious trend.
You may well be right and the trend is a warming trend. Although, I would add that the effect would vary between day and night, and probably between seasons as well. And only a well structured experiment would tell us the answer with confidence.
BTW, my view is, it’s impossible to separate out these different effects and a station like this should be used. I.e. just use the good stations.
Chas Bee:
If you don’t think asphalt or concrete affects readings in the air well above it, read Yilmaz, et al. (2008). Short, but sweet.
http://www.ejournal.unam.mx/atm/Vol21-2/ATM002100202.pdf
I think you will it will fry your socks off, then boil your head off.
You are right, we do basically agree.
Although, I would add that the effect would vary between day and night, and probably between seasons as well. And only a well structured experiment would tell us the answer with confidence.
Check this out (Yilmaz). it has a 24-hour graph.
http://www.ejournal.unam.mx/atm/Vol21-2/ATM002100202.pdf
There is a big difference at all hours, but especially at TMax (which I did not expect).
Chas Bee: I think you should follow that link. I suspect you will find the results quite surprising.
Jerker Andersson wrote, “Now considering how much of the earths surface that is covered with forests and deserts, how many sensors are placed in the middle of those? Not many I would guess.”
The trouble is with sorting out the real temperature trend. Conditions are too inconsistent in a forest. The sites have been planned for consistent results. As you point out, it will not give an accurate average global temperature, but it was the best plan they had until satellites came around. Really, they don’t need an accurate 1.5m above ground global temperature. What they need is to see how the temperature 1.5m above ground changes over time. Inconsistent shade in a forest would produce confusing and difficult to interpret results.
Then again, enthalpy might be a better measure than temperature anyway.
John M Reynolds
Evan
the study focused on 15 cloudless windless days. The difference seen is not typical of the whole year. Read the last two paragraphs of the study.
That said, we all know concrete is a no-no, but its effect, as the study notes, and as I have repeatedly said, is modulated by other conditions, clouds and wind being two important ones.
So when looking for microsite bias you really have to have some other data,
like wind conditions and cloud conditions to find the bias signal reliably.
What needs to be done is a full year-round study on the issue. I would certainly welcome it.
In the meantime it seems that LeRoy may well have had his head screwed on straight.
And don’t forget the Rev’s “HOT-L Baltimore” comparisons. That seems to support LeRoy’s estimates, as well.
(How do I put this gently?)
Who f*#&ing cares?
The world aint perfect and so long as you understand and control for the variations ….. it doesn’t bl**dy matter.
What do you want? Every measurement to be taken from a some parallel universe where there are no external influences? Are you on crack? Externalities are what you are trying to measure.
Please, get a grip.
JM… I care, and so do many others. Apparently, the NCDC also cares. Besides, this IS about controlling variations. You must have missed something. No one here has used harsh language, why have you? Why won’t you use your real
name? I don’t know where you’re from, but where I live you would be considered very impolite.
Thanks,
Mike Bryant
Mike
Because this whole insane, twisted project is based on the idea that each and every site that isn’t completely perfect against some unspecified standard, can be excluded for totally arbitrary reasons that are different every time.
So long as the physical conditions at a site don’t change, the physical conditions don’t matter. We’re looking at changes, right? So why do have to start with nonsense of “oh, those measurements have to be excluded, there’s concrete there”
It’s rubbish, just absolute rubbish.
REPLY: Well one man’s rubbish is another man’s treasure. The fact that the director of NCDC invited me to present the finding of this project in two days of meetings in Asheville on April 23rd seems to suggest that it may be “treasure” to them.
The metadata we are gathering can help verify a proper adjustment. NCDC wants me to continue the project to collect more metadata so that they can get a better feel about how well the new USHCN2 methodology is working towards removing step changes introduced when a thermometer is placed next to such biases. These aren’t being caught in many cases right now, and the undocumented step change can produce an increased trend.
For example, Lampasas, TX, a move resulted in a warming spike, USHCN1 adjustments have not caught or removed it from the climate record:
http://wattsupwiththat.wordpress.com/2008/02/14/how-not-to-measure-temperature-part-51/
The constant bias can also result in an offset that will boost Tmax and may create situations where long standing records are broken. Baltimore USHCN is a good example. NWS voluntarily closed this station down because it was creating a series of false Tmax readings.
See this:
http://wattsupwiththat.wordpress.com/2008/01/23/how-not-to-measure-temperature-part-48-noaa-admits-to-error-with-baltimores-rooftop-ushcn-station/
The fact that NWS chose to close the Baltimore station due to the errors introduced by it’s siting shows clearly that this study is not rubbish. I think I’ll go with the opinion of NOAA/NWS and NCDC on this issue over yours. But if you wish to continue to defend poor quality control in measurement environments, be my guest.
Oh and by the way.
Could you please answer this question: Why should a measurement station be excluded because there’s a concrete path next to it?
You guys have really jumped the shark this time.
REPLY: Actually I’m sorry to say that it is you that are incorrect sir. There are siting standards for weather stations, the most basic being the “100 foot rule from NOAA”, and then there’s the CRN rating system. The idea here is to keep bias influences away from the thermometer. In this case, the concrete will act as a heat sink and provide a bias to the measurement.
Constant biases will not affect trends if the data is processed properly. A constant bias of this type will affect the offset, and may result in higher Tmax, or Tmin. But, undocumented change points when the sensor and concrete were placed in proximity with each other cause an offset and resultant increase in trend slope. This is what the new USHCN2 methodology is going to to; catch and remove such steps so that the trend is truly correct.
Even so, biases such as concrete can still create false readings, such as assistant in breaking new record highs for a particular day, for example. A site like this can cause readings five degrees or higher warmer due to the concrete influence. For example, see this paper by Yilmaz which shows a 7.5 degree difference between Asphalt/Concrete and grass:
http://www.ejournal.unam.mx/atm/Vol21-2/ATM002100202.pdf
I’ll also point out that I presented this photo of the USHCN station in Fayetteville both in visible and IR exactly as you see it in this blog to the staff at the National Climatic Data Center in Asheville, NC on April 23rd, 2008. In the meeting were Dr. Thomas Karl, director of NCDC, Sharon LeDuc, assistant director, Dr. Gary Baker, chief scientist of the Climate Reference Network (CRN) among others.
Nobody stood up or raised a hand to protest or came up afterwards to say “you’ve jumped the shark” or even suggested “that image exaggerates the problem”. They were in full agreement that the problem I identified was real. The applauded the use of the IR camera and plan to purchase some for their own use.
So yes, this is why you don’t put an official thermometer over concrete. Sorry, but you are the one with the problem not us.
How long’s the path been there then? When was it installed? Was there an earlier version such as ashphelt?
Unless you can answer these questions you don’t have a case.
Another way of doing it is the filters that Andrew stupidly applied to the whole record about a week ago. They’re good for finding this stuff in individual sites, but completely wacky for the combined series.
And what really gets me is that when the GISS guys do apply corrections, Andrew goes nuts and accuses them of manipulating the data.
You can’t have it both ways.
REPLY: My biggest complaint with GISS is that they don’t catch these undocumented change points either, and in some cases, the adjustments they apply (homogenization) make the problem even worse. See the Miami and Lampasas examples on this blog showing how the GISS adjustments used the present spikes as hinge points and made the past cooler, resulting in an increased (and exaggerated) temperature trend for the last century at these stations. The problem is not unique to these two, but is happening at other stations also.
“Another way of doing it is the filters that Andrew stupidly applied to the whole record about a week ago. ” Sorry you’ll have to enlighten me about what flter you are referring to. I don’t recall dong any analysis about a week ago that was presented here. A week ago I was in transit to North Carolina for the NCDC meeting.
Sorry, not Andrew, Anthony
But my main point is still. We’re looking at the delta’s not the absolute values.
REPLY: The deltas are affected by undocumented change points. If you add a change to the environment, or move the sensor, resulting in a new warm or cold bias, then there will be a step offset in the record. That step offset (if not caught and corrected) will change the trend.
You see the problem is that NCDC doesn’t know the environment has changed, they often don’t get detailed information about the measurement environment such as we provide. When I first started this project I thought they’d know, but now it is clear that they don’t.
As far as “throwing out” these sites, NOAA/NCDC has recognized the problem and already decided to do so, and is modernizing the network to remove such biases in the future:
see the press release they provided me on the day of my visit:
http://wattsupwiththat.files.wordpress.com/2008/04/press_release_042408_climatereferencenetwork.pdf
So long as the physical conditions at a site don’t change, the physical conditions don’t matter.
That’s what I used to think. But LaDochy et al (Dec. 2007) finds that the presence of a constant heat sink causes an actual increase in trend (sic).
Could you please answer this question: Why should a measurement station be excluded because there’s a concrete path next to it?
According to Yilmaz, 2008 The mean temperature during summer 2 meters over concrete is 7.5 degrees C warmer than over grass. 8C warmer using Tmax+Timin average, which is the way they measure temperatures. You would be very surprised at the effect of nearby concrete. (If you want to warm a greenhouse, all you have to do is put a big rock in it.)
Also, the NOAA has not adjusted for microsite violations. therefore whatever offsets are introduced usually wind up getting counted as trends.
It’s hard, I don’t know who I’m talking to here, but.
“Even so, biases such as concrete can still create false readings, such as assistant in breaking new record highs for a particular day”
So concrete appears and disappears from day to day does it? Interesting property. I wasn’t aware of it.
REPLY: You’re talking to the blog owner, Anthony. I never claimed that it disappears, but sensors do get moved to/from fairly regularly. For example in my last “doomed journey” I located two stations where the sensors had been moved to/from large concrete and asphalt biases in the last 6 months. One resulted in a cooler environment, the other a warmer.
And you totally miss the point or maybe you just don’t want to see it. A sensor over concrete/asphalt can read 5-7 degrees C warmer than the surrounding area. So let’s say we get a particularly hot day. and the record high for that day is 35C The air temperature reaches a max of 33C but over concrete that sensor reads 33C + 5C = 38C a new record high.
How much do you want to bet on the fact that the new record high makes the newspaper, and gets included in some climate change study looking at frequency of record high temps. yet it is entirely false.
See here’s the thing, I don’t need to convince you, the people that really matter, the director and staff at NCDC, have already been convinced by the work of surfacestations.org. You’re just another bad mannered anonymous angry poster that want to see the project shut down because they see it as threatening, which they mask by calling it “stupid”.
The project will continue, regardless of such negative opinion, since NCDC has shown they want to work with us. If you don’t like it or remain unconvinced, tough noogies.
“Sorry you’ll have to enlighten me about what flter you are referring to. ”
Sorry, I misattributed that. I was talking about Basil Copeland’s post ” To Tell the Truth: Will the Real Global Average Temperature Trend Please Rise? Part 2″ 13/3/2008
In that post he uses the “Chow” test to show several breaks in the global record on a monthly basis since 1978/9.
He says :
‘a “structural break” doesn’t necessarily prove anything. It merely suggests that things were different in some way before the “break” than afterward.’
So something has to be different before and after the break, hey? Good, I agree.
Basil’s analysis shows breaks at about (he’s not very clear) 1997, 1999 and 2002 using monthly data.
So what changed on a global scale (because he’s using global data) on those dates? What physically happened there? What justifies the quite substantial discontinuous breaks Basil finds, literally from one month to the next?
Nothing. This sort of stuff would insult the intelligence of an idiot.
On the other hand, if you, or Basil, can explain Basil’s conclusions in real physical terms rather than the rubbish outcome of poorly applied statistics – I’ll listen to you.
REPLY:
I can’t speak for Basil here, perhaps he’ll chime in.
“The deltas are affected by undocumented change points. ”
Only on an individual station basis, and the change points are very infrequent. Concrete doesn’t come and go like rain.
More to the point, GISS and HAD correct for this stuff. Your doomed journey to look at the details doesn’t undermine the basics.
REPLY: “concrete doesn’t come and go like rain” No it doesn’t need to, only ONE significant undocumented change point can screw up the entire series.
“GISS and HAD correct for this stuff”: I beg to differ, GISS’ own graphs show otherwise that they fail to remove such undocumented change points.
See Miami, AZ GISS graph showing unadjusted and adjusted data overlaid, the present is used for a hingepoint, making the past cooler. Only problem is that the present is terribly biased by the location:
Graph:
http://wattsupwiththat.files.wordpress.com/2008/02/miami_az_giss_raw-homogen520.png
location:
http://wattsupwiththat.wordpress.com/2008/02/17/how-not-to-measure-temperature-part-52-another-ufa-sighted-in-arizona/
The same thing happens in Lampasas, TX
graph:
http://wattsupwiththat.files.wordpress.com/2008/02/lampasas_giss_rawhomogen.png
location:
http://wattsupwiththat.wordpress.com/2008/02/14/how-not-to-measure-temperature-part-51/
“doomed journey” Hmmm…wishful thinking perhaps? I arrived home safely, and NCDC is asking for more metadata (photos) like we’ve been doing so far. I’d say the fact that I completed the journey safely, got 20 more stations surveyed, and got the full attention of NCDC would count as a success.
Why not simply admit you can’t stand the idea of citizen scientists doing the work that professionals should be doing in the first place?
The web community appreciate and congrats You for the good job!!
Thank You Very Much!
Unspecified standard?? Apparently you know nothing about what’s going on here. There are very specific standards for placing these stations, and they’ve been violated left and right, that’s what this is about. Violations cause problems. I suggest you find out before you open your piehole.
So concrete appears and disappears from day to day does it? Interesting property. I wasn’t aware of it.
It appears and does not disappear. The jump in temperature is not adjusted for and is recorded an an increase in trend. After that, the trend itself is exaggerated by the Heat Sink Effect.
The problem is that exurban creep is overtaking the stations at a MUCH faster rate than it is taking over the surface of the globe. This results in a false reading of both temperature and trend.
Only on an individual station basis, and the change points are very infrequent. Concrete doesn’t come and go like rain.
Unfortunately the switchover from Stevenson Screens to MMTS equipment has directly resulted in a massive number of violations, all occurring since the 1980s. The switchover to MMTS is why there are so many CRN4 violations.
More to the point, GISS and HAD correct for this stuff.
One would have though and expected so. But, according to SHAP records, unfortunately not. Yes, it is both inexplicable and inexcusable.
Don’t be too harsh on the man, Jeff.
His questions and concerns are easily answered. Let us merely correct hat we see as his errors, direct him to what we deem to be the accurate answers and allow him to assuage his concerns. He considers himself to be in “enemy territory”. It is therefore incumbent upon us to put the case to him in as reasonable and open a manner as possible.
I didn’t mean “doomed” in that sense, sorry if you took it that way, and I’m glad you got back safely.
I also think it’s excellent that you’re providing this information to NCDC. What I would focus on is the somewhat poor state of the enclosures you often turn up. Those are built to a standard design, and if they’re not properly maintained the measurements become unreliable.
What I am trying to say is that you’re drawing too much out from your observations.
1. You’re trying to extend the standard design of the box to the siting of the box. They’re supposed to be measuring what’s actually there, not some measurement of what might be there if you completely rebuilt the site.
[REPLY: No I’m not, I don’t know where you get this from.]
2. What you’re looking at is noise. All data series have noise. How often does that concrete path get replaced? Not too often and it will only cause a single step jump in the series, not invalidate the whole lot
[REPLY: Noise is omnipresent, but a step change is not noise, it is a constant bias up or down, and if not removed/adjusted for, will create a false trend. Station moves or siting changes create those steps, that’s the issue.]
3. Changes in the site will not always cause that step jump to be one directional. As I say noise. [REPLY: As I point out, it could be up or down. Shading/tree growth sometimes makes Tmax go down, but could make Tmin go up due to IR reflectance at night. Point is, we shouldnt have to disentangle this stuff from the data in the first place. Gavin Schmidt at GISS says we could get by with 60 stations, I’m betting we’ll be able to find that many in the USHCN data set that are relatively bias free.]
4. (key point) You’re arguing that noise invalidates the signal itself. How? (This is the sense I meant with “doomed”, your venture to use noise to invalidate a signal is doomed)
[REPLY: noise, true noise, is bideirectional in amplitude over time, again step changes are what we are looking for. Put a slab on concrete under a sensor, you get a step change that remains. Put a sensor closer to a building, you’ll get a step change that remains, build up an asphalt parkign lot around the sensor where there was none before, you’ll get a step change that remains. If these are not detected and appropriately adjusted, you’ll end up with a time series trend that is not truly representative of the air temperature measurment for “climate” but one of the changes in the local measurement environment.
THOUGHT EXPERIMENT: Think of it this way, you have a slow flashing on/off lightbulb and a photocell in a room, and you have a meter connected by wire to the photocell to measure peak output when on, but you don’t get to look into the room. If you are trying to measure the decay in luminance peak output on the incandescent light bulb over time as the filament ages, and somebody started adding other syncronized slow flashing light bulbs to the test room, at random, your graph of light output would change. If you don’t know when those were added you might miss them depending on the magnitude of the bias. Many small additions might not be caught, yet they would add to the overall peak output. ]
Last quibble. Please don’t dig into your blog data, extract my name and use it publicly – I have good reasons for not wanting you to do that, including contracts I’ve signed in my employment.
Do you have a privacy policy here? Cause I think you may have just violated it.
REPLY: Sorry I just addressed you as I would anyone, you name in email appears in my form. Removed.
I doubt any reasoned explanation will help. He obviously came here to poke fun and call people names, not to debate.
A step change – aka ‘glitch’ is not noise? If I render these data series as an audio signal, that step change will sound like a click. Noise in other words.
And so long as I look at deltas rather than absolutes, it will look even more like noise.
Sorry, don’t buy the argument.
(Thanks about the name thing)
REPLY: I’m familar with audio circuitry and signal processing, and while a step change will indeed sound like a click, it essentially becomes a DC bias to the signal that shifts the AC component of the signal upwards or downwards, depending on what the step change is.
Here’s a good example of a step bias from about 1998 to present:
http://data.giss.nasa.gov/cgi-bin/gistemp/gistemp_station.py?id=425724650000&data_set=1&num_neighbors=1
Ok, noise, but a DC bias. I can agree with that. Good metaphor, but I can remove the bias by using deltas. I still think it’s noise, but nevermind.
And sorry I can’t see any bias in your Goodland/Renn example. When did the environmental/siting change occur and what was it?
Can I approach this from another direction? How many stations are there in the US and the world? Lots. We’ve agreed that these step changes occur infrequently, and can go in both directions.
How often does a positive (meaning increased temperature) change occur in the population of stations? 5% a year you reckon (sounds about right, once every 20 years)
How long’s the modern warming period? 30 years. So approx 7% of stations have seen a one-off step change.
Now in the combined series that constitutes noise, a fair bit of noise no argument, but not enough to obscure the signal.
What I think you’re trying to do is to argue that the noise is driving the signal. That there is more or less no signal and that what we are finding is not a signal, but a positively skewed DC bias.
Can I be a bit rude and characterize that as disingenuous? GISS (and also Hadley I believe) control for this by comparing nearby stations. So if there are 10 (say) stations in a cluster and 1 undergoes an environmental change every 3 years or so, that will constitute only a small error which will be washed out in the processing. Errors like this occur all the time in all sorts of different situations and we’ve got pretty good at compensating for them, particularly in the physical sciences where ropy data is often used to validate a model. Arhennius’s heat balance model is not particularly complex, so ropy data can go a long way to supporting it. Which is what we find.
Now I believe that GISS didn’t start to apply that correction until after the “heat island” criticism was leveled at them, and that they reran their datasets, and found the differences to be marginal. Isn’t that correct?
REPLY:
“…but I can remove the bias by using deltas. I still think it’s noise, but nevermind. And sorry I can’t see any bias in your Goodland/Renn example. ” My point exactly. If you don’t know the bias was introduced by some other means, how would you know without a site survey? Right now, using USHCN1 methods, they simply don’t know. They have no metadata to correlate site quality and potential bias. Which is why stations like Miami, AZ and Lamapsas, TX get missed, and homogenization makes them worse. USHCN2 will do better at catching changepoints, but it won’t catch all.
“We’ve agreed that these step changes occur infrequently, and can go in both directions.” Yes they can go both directions, but the majority are positive. As for “infrequently”, no we have not agreed on that, that is what you think. As it stands now, only 13% of stations on the USA surveyed so far meet the siting criteria of either the older 100 foot rule or the newer CRN siting system. That means 87% have some sort of bias. Most observed biases are positive. ROW is even less quality controlled.
See the chart on the front page of http://www.surfacestations.org
Any experiment where 87% of the data has bias issues would not be considered acceptable by any engineering or scientific standard, yet here we are, arguing the issue. Go ahead, defend it. The real point is, NCDC has recognized that the old USHCN network is systemically polluted with biases of varying magnitude, as we’ve demonstrated, and NOAA is replacing it. See the press release on April 24th. Your argument about replacing sites is past tense. The decision has been made.
As for adjusting with nearby stations, not knowing (and they don’t, GISS has no site quality factor, neither does Hadley) which are contaminated by microsite biases and which are not then homogenization makes assumptions without evidence to back it up.
“What I think you’re trying to do is to argue that the noise is driving the signal.” No. I’m not. Noise and offset are different. What I’m arguing is that there has been a systemic series of offsets, mostly positive, and that has created an overall systemic bias.
“Can I be a bit rude and characterize that as disingenuous?” Sure why not, that’s been your MO so far. Look, if it was disingenuous, NCDC would not have invited me to speak there, and offered full access and interaction with the staff on April 23rd/24th. If the work wasn’t relevant, they’d never have offered. They’d just ignore it.
The point is, they agree that siting matters. They are replacing the USHCN network with a new one that will have quality control, and they want me and the volunteers to continue documenting the condition of the old network. Why? Because they have no metadata to show them the site quality, unlike the new CRN which has that from the beginning.
If siting quality is not important, the new CRN would not exist. The new USHCN-M network which will replace the old USHCN would also not be happening.
This is just a comment, but I can’t let this go:
“[REPLY: No I’m not, I don’t know where you get this from.]”
Your posting here is basically a recommendation that concrete paths not be built under weather stations. So what I get from that is that you *are* saying that the site should be rebuilt.
I got my comment directly from the implication of this posting. The only alternative is that you’re saying something along the lines of “measurements from this site are rubbish and should be ignored, but let’s not do anything to correct the problem”
So should this site be rebuilt or not?
REPLY: Well its a moot point because NOAA is abandoning all these older USHCN sites for the reasons I’ve specified, undocumented biases, and setting up new ones. See the press release from my day 2 visit to NCDC. My goal was to find the best sites of the USHCN network so that a bias free signal could be examined. That is still the case. The issue is finding the one that are uncontaminated so that the best record can be extracted from them. NOAA has no adjustments to properly account for microsite bias in USHCN1 algorithms. The new USHCN2 algorithms may fix some of these issues but may not catch them all.
JM: It’s not two-way bias that’s being introduced. They are almost exclusively heat sink and waste heat biases. These biases are not only not being adjusted for, but they are corrupting the UHI adjustment because urban sites are being compared with corrupted rural sites.
Consider that a sort of “positive reinforcement” of warming bias.
Anthony, are you going to respond to my (18:40:56) comment that remains unmoderated?
Once that’s done, I’ll respond to your reply to my (18:58:49) comment.
REPLY: Pushy aren’t you? You don’t even give a guy time to type it out. Done
JM (22:22:52) :
“So concrete appears and disappears from day to day does it? Interesting property. I wasn’t aware of it.”
Sure it does. On sunny days it has a huge effect. On cloudy days it has a small effect. On sunny days in June (especially northern US) it has a bigger effect than sunny days in December. When it gets cold and snowy enough to be under a couple feet of snow it has no effect.
Hey, how about if we specify some standard for placement of weather stations such that the data may not quite measure what people experience in their daily activities but that the data is the least corrupted by variables that are being mostly ignored. Better yet, let’s use the standard you want to discard.
Hey, I got another idea – how about if climate researchers looking at ground stations pay more attention to wind, clouds, snow cover and use it all to come up with an order of magnitude more questionable studies. That should keep the dialog frothing.
Seriously – there ought to be some interesting statistics lurking in some of that data. Not much point in digging into it given how much controversy we have with just temperature data. Still, there are a lot of good reasons to keep raw unadulterated data around for future use.
What I think you’re trying to do is to argue that the noise is driving the signal. That there is more or less no signal and that what we are finding is not a signal, but a positively skewed DC bias.
I (generously) estimate that the one-directional noise exaggerates the trend by a factor of two since 1980.
“I (generously) estimate that the one-directional noise exaggerates the trend by a factor of two since 1980.”
How do you know that when you don’t even know the magnitude of the “bias”?
Take this site. Your argument is that the thermometer is being heated by concrete right? Concrete that can be as much as 4-5 degrees hotter than the air? Is that right?
How does that radiative heat reach the thermometer (which is in vented box)? It has to heat the air above it which by your own account here was about 5C less.
And that’s a large mass of open air for that concrete to heat, any hotter air would mix pretty quickly. A radiator 5 degrees hotter than the ambient temperature is not much of a radiator.
Now since you disagree with on this, I’ll give you a challenge. Take the record from this site, and find the bias. See if you can identify when the concrete went in. You won’t be able to find it. I betcha.
And if you can’t do that, find out what this station recorded as the temperature for the time you were there. I’d bet on pretty close to the 14.5C you measured yourself (perhaps less as I presume your thermometer was both hand held and exposed to direct sunlight)
“Any experiment where 87% of the data has bias issues would not be considered acceptable”
Firstly, I don’t accept your estimate of 87%. Let’s assume that over 30 years 87% of the stations had an environmental change that positively affected them. On average that change would occur at the 15 year point. Therefore only 43% of the data has “bias issues”
Secondly, in nearly every scientific experiment there are what you call “bias issues”. They can be filtered and controlled for, and they are.
Thirdly as I said to you before, I can’t see radiative energy in this case having much of an effect.
And I’m also perfectly ready to accept that there are problems with this data. It’s called noise, and analysis can still recover the signal. I do not believe that the noise is the signal itself.
But I can be persuaded otherwise if there is sufficient evidence. Do the exercise with this site and tell me the magnitude of the “bias” and the date on which that concrete was placed. If your argument is correct, you should be able to find it in the daily record (it can’t have taken more than a day to lay that concrete).
REPLY: Well I guess for now, until I can get the daily data in ASCII form we’ll have to agree to disagree. At least you aren’t calling the project “stupid or doomed” anymore. NCDC does not publish daily in ASCII form, only monthly. I have asked them for several data sets, when and if they provide it I’ll be able to d an analysis.
“It’s called noise, and analysis can still recover the signal. I do not believe that the noise is the signal itself.” Ok fair enough for now, but we still differ in opinion. But here’s the thing. Prior to now, (and still pending for network wide use) NCDC was not doing an analysis to remove this type of noise aka “step functions”. I have test case sites already where we know when the change was made and we’ll be able to run that and see if the new USHCN2 catches them.
In the meantime, see the Yilmaz paper which shows 7.5C for over concrete exposure compared to grass if you don’t believe “radiative” effects. Both Lampasas,TX and Miami, AZ show effects of placement change also.
Finally, ‘Firstly, I don’t accept your estimate of 87%.” Its not an estimate, it’s a measurement from survey data of station siting now. Right now 87% of the USHCN network has siting issues by either the older NOAA 100 foot rule or the CRN rating system. NCDC accepts it, and one of the USHCN2 authors used it in a study he presented to me there, which is good enough for me.
Oh, and please try to find the temperature recorded at this site for the time you were there. You say you have good relations with NCDC, you shouldn’t have too much trouble getting their help.
“NCDC would not have invited me to speak there, and offered full access and interaction with the staff on April 23rd/24th. If the work wasn’t relevant, they’d never have offered. They’d just ignore it.”
This doesn’t surprise me at all. You’re driving round the country doing free site surveys for them (that they probably haven’t had the money for) and basically making a business case to get that money. Money they need to improve their service and fulfill their mission.
You should be congratulated, it’s a public service.
It still doesn’t mean that noise is a signal.
Yilmaz: You can’t expect me to take that seriously. Refer figure 3 of his paper for the locations of the stations (the study was conducted at an airport, it also has nothing to do with climate but is talking about the comfort of cities and whether grass is a better surface for open space than concrete)
Concrete: Right next to the runway. Jet engines are hot you know
Grass: Between 2 runways, but not that close to either
Soil: Quite some distance away in what looks like it might be a service area
Do the exercise for this site please. If the effect is there, you’ll be able to find it.
Sorry a reference in case you can’t find it: http://www.ejournal.unam.mx/atm/Vol21-2/ATM002100202.pdf
REPLY: No worries, Evan Jones posted it here oroginally.
“Right now 87% of the USHCN network has siting issues by either the older NOAA 100 foot rule or the CRN rating system”
I think you missed my point here. The data extends over 30 years (or even longer), and I don’t think very many stations would have been installed initially in violation of those standards. So the siting issues must come from changes that occurred in the surrounding environment *after* installation. On average those would have occurred at the half way point.
That means that only about half the data exhibits the “bias” you’re referring to.
You’ve also pointed out that stations are frequently resited, presumably because the old site is no longer compliant but the new site is.
So while I can accept that there is probably some positive skew, I can’t accept that it is all positive. Resiting most probably introduces negative “bias”
it also has nothing to do with climate but is talking about the comfort of cities and whether grass is a better surface for open space than concrete)
Yes, which I noted earlier. it makes me more likely to believe it, not less, as it is not tied up in AGW politics.
Also, if it was conducted under typical airport UHI, the differences would be masked and made to appear smaller than they actually were.
But Yilmaz is merely in support of the LeRoy estimates from 1999, which are included in the NOAA/CRN handbook.
(Rev: You could have included the “HOT-L Baltimore” observations.)
You’ve also pointed out that stations are frequently resited, presumably because the old site is no longer compliant but the new site is.
. . .
Resiting most probably introduces negative “bias”
Your presumption, while not unreasonable, as such, turns out, on closer examination, to be not correct (or even close). Don’t blame yourself. Blame (grossly) inadequate SHAP on the part of the NOAA.
The MMTS switchover was the main reason for resiting. And that is the main reason there are so many CRN4 violations. Cable issues drew them right next to their housing. Result: massive numbers of violations. (Not adjusted for.)
For increase in trend (as opposed to offset), see:
LaDochy, Medina, Patzert. 2007. Recent California climate variability: spatial and temporal patterns in temperature trends. Climate Research, 33
http://www.int-res.com/abstracts/cr/v33/n2/p159-169/
“Also, if it was conducted under typical airport UHI”
Aren’t we talking about microclimate? An airport runway is a pretty hot microclimate. I agree differences would be masked – by engine exhaust – and this study doesn’t compensate for it. Rather than smaller, the differences would be larger. (In fact, given the heat and volume of air from turbine exhausts the differences shown are more likely to be somewhere around 100% due to engine exhaust IMHO)
I can’t see the energy being radiated by a few square meters of concrete being anything like the same as required to get a plane in the air, it’s just silly.
What you have over the little slab is a small volume of air being heated and mixing with the much larger volume in the surrounding environment. No doubt you’ve been in front of a bar radiator? You’ll know then that you get very little convective heating, it’s all radiation, which the thermometer is shielded from.
I just don’t buy it. But if you want to prove me wrong, by inferring the installation date of the path and the magnitude of the “bias” from the data record – be my guest. How long before Anthony gets the data? A few days or will it be in June?
ps – LaDochy is looking at different regions and locations, not surfaces – at least as far as I can make out from the abstract, so I don’t think it’s that relevant to this particular site.
No need to buy it. There will be more studies. But considering specific examples (e.g., lampassas and Baltimore) I would be willing to hypothesize what those future results would be.
Jet exhaust effect would cover both concrete and nearby grass. This would not exaggerte the effects. If anything it would minimize them. Assuming he chose active areas of the airport (which I doubt).
I am happy to wait until further results are in. (I also guess the effects would be even greater at sea level.)
And, of course, there is LeRoy (1999) which is where NOAA got those estimates.
The gold speck in what LaDochy shows is that a constant sink exaggerates not only the offset but the actual trend. I repeat, the trend.
“Assuming he chose active areas of the airport (which I doubt).”
It’s at the end of the runway! That thermometer is going to get regular blasts of hot air.
The grass one is directly between the two runways (which are not close together) ie. at the side of both away from direct exhaust blasts.
Secondly, your measurement site here is dealing with radiated heat, not convected heat. Thermometers are protected from radiation but open to convection.
And he’s an architect. Since when do architects get training in experimental design?
Lots of runways are used hardly at all. But, as we don’t know, it’s a consideration.
Radiation vs. convection experimentation should be done, too.
Also to be considered is altitude (c. 2000m) and that Yilmaz measures 2m from the ground while surface stations are at 1.5m.
The Rev usually rates airport stations as CRN3, not CRN5, btw.
So far, LeRoy, Yilmaz , and the Lampasas and Baltimore observations all seem to be singing the same basic tune. Lampasas and Baltimore both used hooded stations.
Also, the new CRN station is wonderfully sited and will be running in tandem with the old USHCN stations, so we’ll have that comparison too, before long.
I will be willing to wait for further study. Since this is a “hot topic”, I am confident we’ll have a lot more to look at Real Soon Now.
Evan: “Lots of runways are used hardly at all”
I’ve been in this part of the world, and during summer they can be used heaps (tourist traffic). It’s also military, just north of the Kurdish area of Turkey, which has been of concern to the government for decades. The area is not sparsely populated at all – like most of these areas in Europe and Asia there is just heaps of stuff going on.
Some detail. That airport is mixed military/civilian, and there are 21 towns within a 5nm radius. The closest one is Gezkoy 2.1nm to the south, population about 4300. (Reference: http://www.fallingrain.com/icao/LTCE.html)
So this statement from section 2 of the paper “There are no buildings or human activities around the station except for the cultivated area which is 4 km from the station”
is flat out wrong. Check out Google Maps, apart from planes (which I count as human activity, but the author doesn’t), the place is surrounded by villages, small towns and at least one national highway (that’s the E80 to the south) and a railway line.
Here (http://www.farecompare.com/flights/Erzurum-ERZ/city.html) there’s a little more data on the airbase itself. Over 28 flights (scheduled) a week and 4500 passengers. In summer that could be higher due to charters (and there are a lot of charters in this part of the world during summer. Often they outnumber the scheduled flights, but I don’t know if that happens here). Don’t know how many private flights, but maybe not many.
I can’t get military data, but in this part of the world military activity is frequent and continuous. The Kurdistan area is just to the south where the Turks have been suppressing a revolt for years, and just south of there is Iraq. It’s got two runways so I’d expect a fair bit of activity.
By comparison, Santorini, an extremely popular Greek Island destination has only one even though it is big enough to have two.
If you’re unfamiliar with European package tours you also may not have realized that the beaches to the north are plenty accessible from here for charter flights, and Turkey is a popular destination right across Europe. It’s much cheaper than Greece and very similar in culture and beaches.
Another point, the mixing effect could very well be small, last para Sec 2 ” calm (windless or less than 2 m/s daily) [days]”. This airport is also in a valley surrounded by hills about 10km away on all sides.
The guy who did this is a landscape architect, not a scientist so maybe the quality of his work isn’t all that good.
I’ll put my money on turbine exhausts.
REPLY: I’m glad you agree that we should throw out airport weather station observations due to such influences as turbine exhausts. Many USHNC stations are now located in taxiway areas of airports.
I have worked in the broadcast television industry since the early 1970’s.
When we installed local weather monitoring station the temperature sensor was placed in a enclosure made of wood, with slats, painted white, and about 6ft off the ground. It was located far away from any pavement and buildings in a grassy field, void of trees and shrubs. I was told that this was the standard used by the weather service. Any deviation from this standard would produce inconsistent temperature readings. As you introduce other elements like concrete, trees, shrubs, nearby buildings, along with clouds, rain, wind this will further alter your readings.
It is apparent that people have spent much time and money attempting to correct these variations using complex calculations.
Growing up in Texas taught me one thing. When barefoot, II would rather be standing on a grassy field than a concrete slab.