From the “we told you so” department comes this paper out of China that quantifies many of the very problems with the US and global surface temperature record we have been discussing for years: the adjustments add more warming than the global warming signal itself
A paper just published in Theoretical and Applied Climatology finds that the data homogenization techniques commonly used to adjust temperature records for moving stations and the urban heat island effect [UHI] can result in a “significant” exaggeration of warming trends in the homogenized record.
The effect of homogenization is clear and quite pronounced. What they found in China is based on how NOAA treats homogenization of the surface temperature record.
According to the authors:
“Our analysis shows that “data homogenization for [temperature] stations moved from downtowns to suburbs can lead to a significant overestimate of rising trends of surface air temperature.”
Basically what they are saying here is that the heat sink effect of all the concrete and asphalt surrounding the station swamps the diurnal variation of the station, and when it is moved away, the true diurnal variation returns, and then the homogenization methodology falsely adjusts the signal in a way that increases the trend.
You can see the heat sink swamping of the diurnal signal in the worst stations, Class 5, nearest urban centers in the graphs below. Compare urban, semi-urban, and rural for Class 5 stations, the effect of the larger UHI heat sink on the Tmax and Tmin is evident.
In Zhang et al, they study what happens when a station is moved from an urban to rural environment. An analogy in the USA would be what happened to the signal of those rooftop stations in the center of the city, such as in Columbia, SC when the station was moved to a a more rural setting.
U.S. Weather Bureau Office, Columbia SC. Circa 1915 (courtesy of the NOAA photo library)Here is the current USHCN station at the University of South Carolina:The Zhang et al paper studies a move of Huairou station in Beijing from 1960 to 2008, and the resultant increases in trend that result from the adjustments from homgenization being applied, resulting in a greater trend. They find:
The mean annual Tmin and Tmax at Huairou station drop by 1.377°C and 0.271°C respectively after homogenization. The adjustments for Tmin are larger than those for Tmax, especially in winter, and the seasonal differences of the adjustments are generally more obvious for Tmin than for Tmax.
The figures 4 and 5 from the paper are telling for the effect on trend:
Huairou station and reference data for original (dotted lines) and adjusted (solid lines) data series during 1960–2008. The solid straight lines denote linear trends
Now here is the really interesting part, they propose a mechanism for the increase in trend, via the adjustments, and illustrate it.
They conclude:
The larger effects of relocations, homogenization, and urbanization on Tmin data series than on Tmax data series in a larger extent explain the “asymmetry” in daytime and nighttime SAT trends at Huairou station, and the urban effect is also a major contributor to the DTR decline as implied in the “asymmetry” changes of the annual mean Tmin and Tmax for the homogeneityadjusted data at the station.
In my draft paper of 2012 (now nearing completion with all of the feedback/criticisms we received dealt with, thank you. It is a complete rework. ), we pointed out how much adjustments, including homogenization, added to the trend of the USCHN network in the USA. This map from the draft paper pretty much says it all: the adjusted data trend is about twice as warm as the trend of stations (compliant thermometers) that have had the least impact of siting, UHI, and moves:
The Zhang et al paper is open access, an well worth reading. Let’s hope Petersen, Karl, and Menne at NCDC (whose papers are cited as references in this new paper) read it, for they are quite stubborn in insisting that their methodology solves all the ills of the dodgy surface temperature record, when it fact it creates more unrecognized problems in addition to the ones it solves.
The paper:
Effect of data homogenization on estimate of temperature trend: a case of Huairou station in Beijing Municipality Theoretical and Applied Climatology February 2014, Volume 115, Issue 3-4, pp 365-373,
Lei Zhang, Guo-Yu Ren, Yu-Yu Ren, Ai-Ying Zhang, Zi-Ying Chu, Ya-Qing Zhou
Abstract
Daily minimum temperature (Tmin) and maximum temperature (Tmax) data of Huairou station in Beijing from 1960 to 2008 are examined and adjusted for inhomogeneities by applying the data of two nearby reference stations. Urban effects on the linear trends of the original and adjusted temperature series are estimated and compared. Results show that relocations of station cause obvious discontinuities in the data series, and one of the discontinuities for Tmin are highly significant when the station was moved from downtown to suburb in 1996. The daily Tmin and Tmax data are adjusted for the inhomogeneities. The mean annual Tmin and Tmax at Huairou station drop by 1.377°C and 0.271°C respectively after homogenization. The adjustments for Tmin are larger than those for Tmax, especially in winter, and the seasonal differences of the adjustments are generally more obvious for Tmin than for Tmax. Urban effects on annual mean Tmin and Tmax trends are −0.004°C/10 year and −0.035°C/10 year respectively for the original data, but they increase to 0.388°C/10 year and 0.096°C/10 year respectively for the adjusted data. The increase is more significant for the annual mean Tmin series. Urban contributions to the overall trends of annual mean Tmin and Tmax reach 100% and 28.8% respectively for the adjusted data. Our analysis shows that data homogenization for the stations moved from downtowns to suburbs can lead to a significant overestimate of rising trends of surface air temperature, and this necessitates a careful evaluation and adjustment for urban biases before the data are applied in analyses of local and regional climate change
Download the PDF (531 KB) Open Access
h/t to The Hockey Schtick
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UPDATE 1/30/14: Credit where it is due, Steve McIntyre found and graphed the physical response to station moves three years ago with this comment at Climate Audit.
Here’s another way to think about the effect.
Let’s suppose that you have a station originally in a smallish city which increases in population and that the station moves in two discrete steps to the suburbs. Let’s suppose that there is a real urbanization effect and that the “natural” landscape is uniform. When the station moves to a more remote suburb, there will be a downward step change. E.g. the following:
The Menne algorithm removes the downward steps, but, in terms of estimating “natural” temperature, the unsliced series would be a better index than concatenating the sliced segments.
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Don’t forget this paper which showed significant UHI in China’s major cities.
http://wattsupwiththat.com/2011/07/28/new-paper-uhi-alive-and-well-in-china/
A nearly candid admission, and only thinly veiled. Baby steps.
WRT the example that is the antecedent of Mosher’s ‘This’ quoted above, the BEST “ninja blender” method produces the same WRONG result as does the critiqued homogenization scheme.
And that, of course, is the intended function of BEST. It replicates the same WRONG result by a method that appears to be different, so that it can be snarkily pretended to be different by drive-by warmist apologists. This lends CAGW an air of “independent confirmation” where none actually exists.
In that regard, it is very similar to the technique whereby one temporarily pretends to be a skeptic, so that one may falsely claim to the press a short while later that he is a “former skeptic” who has seen the light, when he is really a once and future warmist who has seen a dishonest path to personal profit. That is another method perfected by BEST.
Evanmjones: ‘Homogenization takes the average of surrounding stations. If that station’s readings do not conform to the surrounding stations, it is considered an outlier and they adjust it to conform’.
They remove the outliers from the station population. It is the most significant cause of the great dying of the thermometers. By comparing disappearing stations and survivors (survival analysis), you may find with respect to this aspect 20 sigma effects, a lot more than physicists needed for the Higgs. This kind of homogenisation creates a signal from noise. I am still looking for an article explaining that the artificial signal likely goes up.
Does this paper (not to mention Anthony’s) up the ante a bit for Warmists? I wonder how long it will be before there is a criminal investigation into deliberate manipulation of global economies through intentional doctoring of scientific data, for the enrichment of a few people (such a former vice-presidents) while contributing to the near-meltdown of the western economic foundations?
Oh, I don’t want to even go there. And I think the homogenization issue is an innocent error. An egregious error, yes, but an error, after all. All you have to do is accept Menne (2010) to fall into that trap. Or even Fall et al. (2011), and Anthony and I are co-authors on that.
I don’t like talk about jailing scientists. My reaction is like Kinnon’s when Ferris starts talking about the death penalty in industry — if you get the reference: “Take it easy, boy . . .”
Besides, that sword cuts both ways. Today we sentence them? Tomorrow they sentence us.
Winning the argument and putting the train back on the tracks will be more than sufficient for going along with.
Poptech says:
January 29, 2014 at 9:21 pm
I don’t care in the slightest if a man or woman is a liberal arts major, Poptech. I care if their scientific claims are correct. If their science is correct, their major doesn’t matter.
On the other hand, if their science is wrong … well, their major still doesn’t matter.
So I don’t care in the slightest that liberal arts majors get your panties in a twist, and neither do most folks here. Give it a rest, Poptech. Stop boring us with your endless stories about peoples’ degrees and the like, and start talking about the science.
There’s no need for you to say one more word about it. You’ve repeated it ad nauseum. We all get it—you are obsessed with paper credentials … so what?
So what? Stop with your endless whining about credentials. In addition to being crushingly stupid, it’s irritating, and more to the point, it’s meaningless. Give it up.
w.
A nearly candid admission, and only thinly veiled. Baby steps.
No, Mosh is right. It’s separate. I’ve been there. Okay, I so don’t much mind stringing both together if the site rating and the mesosite is the same.
But they are separate for sure if either of those are different. They just are.
I never knew that strawberry and dead-fish milkshakes were such a favorite among AGWers!
Some people can swallow anything.
I don’t care in the slightest if a man or woman is a liberal arts major, Poptech.
Just so long as she is a premium bride.
So the correct answer to Tim Yeo’s question in the AR5 hearings would have been
“No, 2000-2009 was not the warmest decade in the instrumental record”.
I wonder if the next bunch of scare merchants start telling us that once the “adjustments” are taken out, it really is worse than we thought. We’re going into a new Ice Age.
Willis,
You may want to give Poptech a break on the credentials issue. He’s responding to offal, such as, this from the ever magniloquent Monckton and more from others.
http://tallbloke.wordpress.com/2014/01/29/lord-monckton-letter-to-martin-rasmussen-of-copernicus-publications/
I posted this yesterday at Tallbloke’s, but it was censored and never saw the light of day.
philjourdan says: @ur momisugly January 29, 2014 at 5:30 pm
What the scientists who still do real science are basically saying is what most people realize intuitively. It is not getting warmer. At best, we are holding our own, and not slipping into another LIA.
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That is my take, I just got up to a temperature of 4 °F (minus 15.5 °C) in mid North Carolina. It is 2 °F at the nearby airport.(snow on the ground) The record cold for today was 7 °F (1977) After Hansen is finished with the data I am sure we will not break any records because they add 2-4°F to all or temperatures based on my daily observations. /snark
There are other bits of information about the climate that can be used to verify/validate the ‘Offical’ temperature records.
Koppen classification system: http://www.britannica.com/EBchecked/topic/322068/Koppen-climate-classification
Movement of midwest boundries by decade: http://www.sturmsoft.com/climate/suckling_mitchell_2000_fig2_3.gif
Study finds stream temperatures don’t parallel warming climate trend:
http://www.terradaily.com/reports/Study_finds_stream_temperatures_dont_parallel_warming_climate_trend_999.html
notice how they try to justify the discrepancy missing the point that the ground is subject to the same factors as the streams.
Ice classic break-up dates: http://www.nenanaakiceclassic.com/Breakup%20Log.html
Northern Hemisphere Snow Cover:
October http://www.ncdc.noaa.gov/sotc/service/global/snowcover-nhland/201310.gif
November http://www.ncdc.noaa.gov/sotc/service/global/snowcover-nhland/201311.gif
December http://www.ncdc.noaa.gov/sotc/service/global/snowcover-nhland/201212.gif
January: http://www.ncdc.noaa.gov/sotc/service/global/snowcover-nhland/201301.gif
February http://www.ncdc.noaa.gov/sotc/service/global/snowcover-nhland/201302.gif
and
March http://www.ncdc.noaa.gov/sotc/service/global/snowcover-nhland/201303.gif
That is six winter months showing snow fall returning to “normal”
charles the moderator says: @ur momisugly January 30, 2014 at 2:18 am
You may want to give Poptech a break on the credentials issue. He’s responding to offal……….
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Can we bury the hatchet guys? There are already several threads on the issue and it does WUWT no favors to continue the in-fighting. It makes WUWT look stupid.
evanmjones says: @ur momisugly January 29, 2014 at 6:01 pm
…Well, I can tell y’all what the problem is with homogenization….
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That certainly explains why my local site (a ‘cow pasture’ town airport) is always adjusted up 2-4°F on the ‘official records’ the next day.
I hear ya Gail, and I feel somewhat the way you do, but this issue goes to the heart of the ethics and principles that brought many of us into these subjects, the quest for truth and integrity of science, wherever that takes us. The PRiPers have so distorted those principles, and created major setbacks which will come back to haunt us, that proactive pointing out over and over again what their failures have been, feels mandatory. This is not being vindictive or petty. As I wrote less than a week ago.
and The Pompous Git responded:
Engineering principles should underpin collection of data. Based on science true, but engineering none the less.
Ask a power engineer how he measures power. RMS. With a factor to account for wave shape.
Ask him how he would deal with a poorly sub-sampled in both space and time power field.
I doubt he would come up with most of what is considered ‘normal’ in ‘Climate Science’ or consider it valid either.
1sky1 says: @ur momisugly January 29, 2014 at 6:23 pm
I never knew that strawberry and dead-fish milkshakes were such a favorite among AGWers!
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And here I thought it was peanut butter and banana milkshakes they could not live without.
“Can we bury the hatchet guys? There are already several threads on the issue and it does WUWT no favors to continue the in-fighting. It makes WUWT look stupid”
Hear hear! Sadley Charles is starting sounding like “the team”.
TOBS (Time of Observation)
This is what WIKI says:
So the question becomes when were these used in each weather station? If I was an operator I would spring for the money to buy one ASAP. Who wants to go take reading at dawn or break work to take a reading at mid day? The cost would be off-set by not having to interrupt your day.
EVAN, ANTHONY, ANYONE, HELP ???
The following seems to have STILL fallen under the radar. I have NOT verified Goddard’s claim below.
http://stevengoddard.wordpress.com/2014/01/19/just-hit-the-noaa-motherlode/?utm_source=newsletter&utm_medium=email&utm_campaign=newsletter_January_19_2014
Independent data analyst, Steven Goddard, today (January 19, 2014) released his telling study of the officially adjusted and “homogenized” US temperature records relied upon by NASA, NOAA, USHCN and scientists around the world to “prove” our climate has been warming dangerously.
Goddard reports, “I spent the evening comparing graphs…and hit the NOAA motherlode.” His diligent research exposed the real reason why there is a startling disparity between the “raw” thermometer readings, as reported by measuring stations, and the “adjusted” temperatures, those that appear in official charts and government reports. In effect, the adjustments to the “raw” thermometer measurements made by the climate scientists “turns a 90 year cooling trend into a warming trend,” says the astonished Goddard.
Goddard’s plain-as-day evidence not only proves the officially-claimed one-degree increase in temperatures is entirely fictitious, it also discredits the reliability of any assertion by such agencies to possess a reliable and robust temperature record.
Regards, Allan
REPLY: It isn’t “under the radar”, I’m working another angle to verify independently what he claims. His method of overlaying graphs has limits, and there’s no point publishing anything until I have something of value to add. – Anthony
A. Scott says: @ur momisugly January 29, 2014 at 8:00 pm
…. This could only be true if the population, structures, impervious surfaces and the like stayed exactly the same in the urban area over time. There is no city in my opinion and belief that has not seen a large and significant increase in building mass and hard cover over time. And if building mass and hard cover has increased then there MUST be an increase in temperature over and above the natural warming signal…..
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Dr Roy Spencer did a study of Warmng vs population Density you might want to look at.
http://www.drroyspencer.com/2010/03/the-global-average-urban-heat-island-effect-in-2000-estimated-from-station-temperatures-and-population-density-data/
Gail Combs says:
January 30, 2014 at 3:15 am
“TOBS (Time of Observation)”
Give me a nice ‘continuous’ integrating recording to get the ‘true’ average temperature for a day, month, year, decade,….. any day (pun).
DR says: January 29, 2014 at 9:23 pm
As someone who ran chemical QC labs for years I am in complete agreement. The shoddy QC of the US weather stations (The best in the world BTW) makes me cringe. And then they say they can get temperature anomalies of 0.00°C from UNIQUE one off readings, many of which were rounded or truncated to the nearest whole number. link
Any one with any decent science or engineering training would be ROTFLTAO. That is why WUWT has so many engineers commenting. Scratch the surface of CAGW and the whole thing starts smelling of dead fish.
rogerknights says: @ur momisugly January 29, 2014 at 9:44 pm
Tonight in 20 minutes (10 PM Pacific, 1 AM Eastern), Coast to Coast AM radio will be interviewing:
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Ghost to Ghost? Home of paranormal and UFO ‘Science’?
Not Good. That lumps Skeptics in with the Flat Earthers and other nuts and fringe groups. Lewandowsky and friends must be grinning with glee.
Mindert Eiting says: @ur momisugly January 29, 2014 at 11:54 pm
Have you looked at E. M. Smith’s work:
http://chiefio.wordpress.com/2009/08/05/agw-is-a-thermometer-count-artifact/
Or Verity Jones:
http://diggingintheclay.wordpress.com/2010/01/21/the-station-drop-out-problem/
There are several thread on the subject at both web sites – happy digging.
The temperature here in sunny warm North Carolina has now dropped to 1 °F it will be interesting to see what the ‘Official Reading’ for my location is tomorrow.
charles the moderator says: @ur momisugly January 30, 2014 at 2:54 am
I hear ya Gail, and I feel somewhat the way you do…
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So let them stand or fall on their data and methods. Tallbloke has said he will post the information when I asked.
Are they ‘Fringe’, yes but my field, chemistry had its beginnings in Alchemy. Fringe does not mean you can not trip over something very interesting. So how about we let them be and see where their digging takes them. As long as they include data and methods we should not be raking them over the coals.
We just let Willis dissect the individual papers if he wants. :>) That is the correct way to do science.
Let’s not forget most peer-reviewed papers are dreck:
Won’t most of the issues with
fiddlingadjusting the record be sorted once uscrn trends are long enough?RichardLH says: @ur momisugly January 30, 2014 at 3:24 am
…Give me a nice ‘continuous’ integrating recording to get the ‘true’ average temperature for a day, month, year, decade,….. any day (pun).
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Agreed as long as it is calibrated.
I would still like to know when the min-max started to be used at weather stations. makes the Tobs adjustment questionable especially if it is across the board adjustment.
I know Anthony and Evan M Jones were looking into the matter. No wonder their eyes are bleeding!