A new study from USGS by Keven Gallo and George Xian verifies what we’ve already learned and published on via the Surface Stations project; that concrete and asphalt (aka impervious surfaces) have increased near weather stations that are used to monitor climate. In this case, it is the much studied USHCN, that climate network I presented a poster on at AGU 2015. Details here.
What is most important about this paper is that it quantifies the percentage of stations that have had increased amounts of impervious surface area getting closer to the stations. As I have long since maintained, such things act as heat sinks, which increase the night-time temperature when they released the stored energy from the sun that was absorbed during the day as infrared, warming the air near the thermometer, and thus biasing the minimum temperature upwards.

In this study, they have observed over 32% of the USHCN stations exhibited an increase in impervious surface area of ⩾20% between 2001 and 2011. When the 1000 m radius associated with each station was examined, over 52% (over 600) of the stations exhibited an increase in ISA of ⩾20% within at least 1% of the grid cells within that radius.
What this suggests, is that like Las Vegas, which has had huge infrastructure boosts in the last 50 years, that the minimum temperature is creeping upwards, and that biases the mean temperature used to look for the “global warming signal”. NOAA would do well to remove stations that have been encroached upon like this, but they stubbornly hold onto this flawed data, insisting they can “adjust” it to be accurate. I say bollocks to that. Since the USA is so highly over-sampled with thousands of weather stations, it is far better to discard noisy and imperfect data, and use only those stations that have not been biased by infrastructure increases, but retain only the best stations with pristine data.
This is what you get when we did exactly that, and found a statistically significant lower 30 year trend.
Here is the new paper:
Changes in satellite-derived impervious surface area at US historical climatology network stations
Kevin Gallo, George Xian
Abstract
The difference between 30 m gridded impervious surface area (ISA) between 2001 and 2011 was evaluated within 100 and 1000 m radii of the locations of climate stations that comprise the US Historical Climatology Network. The amount of area associated with observed increases in ISA above specific thresholds was documented for the climate stations. Over 32% of the USHCN stations exhibited an increase in ISA of ⩾20% between 2001 and 2011 for at least 1% of the grid cells within a 100 m radius of the station. However, as the required area associated with ISA change was increased from ⩾1% to ⩾10%, the number of stations that were observed with a ⩾20% increase in ISA between 2001 and 2011 decreased to 113 (9% of stations). When the 1000 m radius associated with each station was examined, over 52% (over 600) of the stations exhibited an increase in ISA of ⩾20% within at least 1% of the grid cells within that radius. However, as the required area associated with ISA change was increased to ⩾10% the number of stations that were observed with a ⩾20% increase in ISA between 2001 and 2011 decreased to 35 (less than 3% of the stations). The gridded ISA data provides an opportunity to characterize the environment around climate stations with a consistently measured indicator of a surface feature. Periodic evaluations of changes in the ISA near the USHCN and other networks of stations are recommended to assure the local environment around the stations has not significantly changed such that observations at the stations may be impacted.
http://dx.doi.org/10.1016/j.isprsjprs.2016.08.006
Kevin Gallo is the Corresponding author at: USGS, Earth Observations and Science (EROS) Center, 47914 252nd Street, Sioux Falls, SD 57198-0001, USA.
Note from Anthony: Full disclosure, I was an invited reviewer for this paper, and I submitted reviews that caused improvements (according to the editor) to the paper.

But Steve Mosher, the English/Philosphy major student has explained how all this. After all, as he told us, he took “Diffy Q” taught by the master mechanics at Jiffy Lube. There is Differential Equations, shown in computer-printout class listings as Diff EQ, but “Diffy Q” you have to be “Daffy Duck” to take that one.
Don’t be a jerk.
At first I thought these people were fools. But then when I saw a meteorologist for NOAA explain on a weather show that he was fully aware of the problem and his unit would record the data from a neutral site, but report as official the compromised asphalted site, I knew it was simply fraud.
Thanks Anthony.
The key word here is “encroached” but encroaching might be used. The land use changes continue, although at some point there may be no in-filling left to do.
On the other hand: A local weather station was moved from a graveled area next to a fire station to a newly constructed and landscaped sewage facility. The weather instruments were installed on the far side of the driveway from the office. Grass and trees were planted. The trees have grown and provide much more shade than when they were planted. During mid-day the site gets full sun. Early morning in the summer and much of the afternoon hours are shaded.
This station was in the gallery. It is here: 46.969254, -120.539979
In the list at surfacestations, the coordinates put the station in a field near where the treated water dumps into the Yakima River (840 yards west). I think that’s from a State Department of Ecology list of sewage outlets.
Congratulations in order for the authors and for you. Knowledge is often gained painfully slowly at personal cost. You can be assured that this community knew you were trying to shed light. TY
Professor Obama, the greatest human and scientist ever to be born to Earth.
Quote from Michael Savage. “Obama’s legacy. Hatred of white people and violence.”
Truly, truly his legacy!
In regions with a real winter, the amount of water running in the sewer could increase the ground temperature several meters away.
Whoa. A journal reached out to you, but your not a credentialed climate scientist.
While Sydney has had higher average temps lately my own region on the mid-coast of NSW was hottest between 1910 an 1919 going by mean monthly max. Both facts being utterly trivial, of course.
If you can find a rural site with a long and continuous record in static environs and which is dry and cloudless (cloud being the biggest scrambler of all) you might get some trivial indication of trivial warming or cooling at that site. That’s if your into trivia.
Maybe when old seaports like Birka, or Port-Royal, or Deal, or Ostia, or Ephesus are no longer land-locked…maybe then, wake me up and I can show some trivial concern.
It is amazing that the raw data drawn from flawed sites which do not reflect true, natural temperatures due to nearby constructions, all has to be adjusted upwards by the government. Those programmers in their air-conditioned offices are so good at knowing the outside temperatures, I wonder why they even bother having weather stations when they are unrepresentative of “reality”. Shut those lying thermometers down & save the money.
Ray Boorman said:
“It is amazing that the raw data drawn from flawed sites which do not reflect true, natural temperatures due to nearby constructions,”
That is the true natural temperature. What ever the temperature at at a give location is, is the true natural temperature. If you want to know about temperatures you have to include these places too. Just you have to allow for their relative size. If you want to look at how much warming goes on minus the effect of these regions, then you exclude them, but then you are measuring something different.
If the satellites keep telling the truth, they’ll not last.
========
Why does the graph end at 2008?
The alarmists are likely to portray this finding as irrelevant, on the basis that urban areas – and therefore UHI – are a tiny proportion of the total surface and therefore have negligin
ble effect on measured global temperature. But this argument is incorrect, because the effect of each station is spread over surrounding areas in the averaging process, and the majority of stations are urban. Some time ago, on WUWT, I suggested a method of ensuring that UHI does not affect other areas in the averaging process, but none of the temperature organisations use it or anything like it. (Nevertheless, I tend to agree with those who say the whole surface temperature system is fubar).
It has often been observed that the trend should be adjusted downward because of UHI. Instead, it is always adjusted upward. From the graph:
Compliant stations: 0.204 deg. C per decade
Non-Compliant stations: 0.319 deg. C per decade
Adjusted: 0.324 deg. C per decade
This story from 2010 shows a small long term trend from 1900 for rural stations using raw data. (using end points 0.6 deg. per century, 0.06 deg. per decade) Naturally, the adjusted trend is about twice that.
By considering much longer records, the 2010 study by Long engages the fundamental question of UHI effects much more incisively than the work featured here. It shows not only the effect upon century-long trend, but also the rapidly growing discrepancy between raw urban and rural records in the last five decades–the unmistakable consequence of urbanization.
The shortcoming of that study is the meager set of records considered: only one station per state in the contiguous USA. But in 2006, I found very similar discrepancies between urban and non-urban records using a larger set of records, more geographically representative of the contiguous USA. Expressed in terms of the deviations from the 20th-century mean, the discrepancy looks like this: http://s1188.photobucket.com/user/skygram/media/Publication1.jpg.html
Quite in line with Long’s findings, it shows a 20th-century increase of ~0.7 degrees in urban records not found in the corresponding non-urban set.
Well don’t forget the Berkley earth research on whether the urban heat effect is skewing warming data.
They say:
The Urban Heat Island effect is real. Berkeley’s analysis focused on the question of whether this effect biases the global land average. Our UHI paper analyzing this indicates that the urban heat island effect on our global estimate of land temperatures is indistinguishable from zero.
http://www.scitechnol.com/2327-4581/2327-4581-1-104.pdf
Griff – That’s BEST being biased in favour of BEST. I say that they are a victim of circular logic, because the algorithms that they use for dealing with UHI are based on the same principles that they use for assessing the impact of UHI on results. You only have to see the BEST documentation to understand that each station influences a wide area, including neighbouring stations, and that UHI is therefore spread through their results. As I said, on WUWT I proposed a method for ensuring that no station could influence any other station and that therefore UHI did not spread through results, but the thinking behind that method (or anything like it) is absent from BEST and from the other surface temperature organisations. BEST is riddled with cross-station contamination.
Well then I look forward to sometime seeing your methodology applied to the station data.
For the moment, well, at least somebody relatively unbiased looked…
Turning it around – its unlikely that, even if there were a bias, the UHI effect is the entire explanation for surface temp trends, isn’t it?
Griff–the alleged global warming is only on the order of ~1degree C, not an implausible level of UHI effect.
Someone who lies about his beliefs, as the director of this study did, is not to be trusted.
Griff,
It’s not that the “UHI effect is the entire explanation” it’s that we have had about 1 C of warming since 1880. That’s 130 years and 0.076 C per decade. Even if the UHI isn’t the entire explanation for the surface trend, it doesn’t need to be that large to seriously skew the results of the warming trend and, as a result, greatly diminish the role of carbon dioxide, and by extension “man”, in atmospheric warming.
Who can forget the Berkley earth researchers when ya read stories like this ….
Cow farts can now be regulated in California
http://www.foxnews.com/science/2016/09/20/cow-farts-can-now-be-regulated-in-california.html
Of course the BEST study has been thoroughly refuted.
> … UHI paper …
To wit:
“Influence of Urban Heating on the Global Temperature Land Average using Rural Sites Identified from MODIS Classifications”,Wickham C, Rohde R, Muller RA, Wurtele J, Curry J, Groom D, Jacobsen R, Perlmutter S, Rosenfeld A and Mosher S
Willis Eschenbach wrote an interesting post on this paper, a while back, which identified some critical issues in the siting of the urban and rural sites, with numerous rejoinders from one of the coauthors (Moser).
https://wattsupwiththat.com/2013/04/04/berkeley-earth-very-rural-and-not/
My own view on UHI, in light of ever increasing planetary urbanization, is that we should stop thinking of UHI as some kind of ‘anomaly’, which needs to be discarded, corrected or ignored. Instead we should start thinking of UHI as just one of the many natural processes which affect weather and climate. Yes, natural, because cities and urban areas exist in nature.
To see this, let’s do a little thought experiment. Imagine a “UHI Control Knob”, which can change the ratio of urban/(urban + non-urban) land use. If I turn the Knob to zero percent then the urban areas disappear completely. But at one hundred percent, the whole planet turns into one big wall-to-wall city/airport etc. (In nature, currently, the Knob is set to about 0.5%)
Also assume that oceans are not affected by Knob, but continue to react to the land mass changes, according to the laws of nature. (We might change that assumption, in the future, if ocean areas somehow become “urbanized”)
Interesting research questions to investigate, using Knob simulations:
1) How much does urbanization affect global climate? For example what are the mean global temps as the Knob is advanced from zero to one hundred? I think (but can’t prove yet) that a fully urbanized world would be warmer than the fully rural world. But how much warmer? We need to formally quantify this, so a sub-model which predicts temperature given urbanization-knob coefficient can be developed.
2) At what minimal setting of the Knob does the UHI effect (warmer/colder etc) become detectable?
Maybe someone has already done this kind of modeling, but I’m not aware of the results. I think it is, at least, a useful way to think about quantifying and understanding the possible effects of man-made activities on the earth’s climate.
Johanus – You are basically on the same track as me. I proposed that all temperatures should be used as measured, and that the global average temperature would therefore include UHI (but the UHI would be confined to its urban areas, not spread). However, the method would also allow for the contribution from UHI to be estimated. Because urban areas are a small part of the globe, and because UHI would not be spread, the UHI part of the global average would likely be very small. I doubt that any temperature organisation would ever do it, because it would involve a lot of work, but for anyone interested I do have a much simpler method now which I think would be pretty good (as good as any method could be, given the very low quality of much of the data).
I know that anecdotal information ought to be viewed with some suspicion, but I have a rather accurate environmental thermometer on several of my vehicles. I keep track of how temperature varies near the cities that I drive around and through. Almost always, summer and winter, day and night, the temperature is slightly higher downwind and in the city–nearly always lower upwind and out in the countryside.The only exceptions I have noted are periods during a strong inversions–outbreaks of arctic air which may fill low-lying areas and then makes towns and cities in a valley colder. During -20F weather one time I sat in my car waiting to pick up someone after an evening class on a college campus separated from town, and the temperatures on campus were 1-2F higher, probably heat loss from structures, than on the road back to the city. This was even true during the extreme heat even in Tucson last June where within Tucson city limits and east of downtown along Houghton Road the temperatures were 112F, but just a few miles east of town it was 109F.
Another interesting example is from the automatic reporting system at our local airport. Last spring I noted a temperature of 20F at one hour and 21F the next, but the maximum during the hour was 27F and this showed up as the TMAX for the day. During that hour there was a jet that landed, idled at the terminal, then took off. The thermometer is well located pretty far from a taxiway, but I think the data is contaminated.
UHI seems to me obvious and substantial.
That people can claim it does not affect temperature time series, especially in cities in which the city has grown to absorb the airport and monitoring stations is simply mind boggling. CommieBob shows the best indication that it does, in fact, matter–the difference between the compliant stations and the non-compliant is significant.
‘weather stations that are used to monitor climate’
Weather stations monitor weather. Climate is the product of analysis of weather data.
It takes a long time (if ever) for bureaucratic entities (especially government ones) to admit error and there’s lots of money to be earned based on incompetence in the meantime.
If the past is prologue, any adjustments will be to make rural, pristine stations so that they better match the urban, contaminated stations.
Anthony, I’m surprised, but delighted, that you were asked to review the paper. The editor actually showed some intelligence (and probably courage) by asking an expert to contribute to it’s outcome.
Anthony: glad that you’re getting some well-deserved respect.
Glad that this isn’t yet another example of one side saying “hey, we think you should look at this, appears to be important”, the other side saying “know your place, uneducated peasant, we know what we are doing”, then eventually saying “look, we totally found this issue all by ourselves first, nobody else thought of it, and its at least a bit important, but it certainly doesn’t change our paradigm through which we get our funding”.
See: IPCC’s first report re: the Sun…
Here’s my front grass, concrete sidewalk, and asphalt driveway
The slope in the concrete temp is due to the sidewalk becoming shaded starting about noon, and it is all the way to the driveway by 5 or 6.
More than 20 years ago, California State Climatologist Goodridge plotted California temps binned in three boxes: those from counties with populations more than one million; those from counties with populations between 100,000 and 1,000,000 and those from counties with populations less than 100.000. His results, plotted in a single chart, illustrated both the UHI effect (differing starting temperatures) and differing warming trends. The “less than 100,000” data showed very little warming over time, while the “more than one million” counties showed the highest rate of warming. I have no doubt that this result would be duplicated globally.
Congrats on more confirmation of something that you were on top of a decade ago………and more confirmation of the science misinformation site “Skeptical Science” being fraudulent……….often blatantly and intentionally :
http://www.skepticalscience.com/WattsandBEST.html
“It seems likely that the average reader of Watts’ articles will have gaps in his or her knowledge of how scientists handle weather station data. Arguments which rely on those knowledge gaps will fail to impress anyone who has read articles like this SkS series on how weather station data is handled.”
That graph starts in 1979. Was that an outlier yea? Colder than previous years?
Anthony,
I overheard a conversation in the university cafe a couple of days ago about some office in NOAA being interested in the weather data being collected by the Wyoming Department of Transportation (WDoT) along the interstate highways. It is real-time data telemetered to WDoT throughout the day (used in a very awkward way to decide on variable speed limits and closures–I mentored a graduate student using this data), and according to the two characters having the conversation it is the real-time aspect of the data and its density across the state in two dimensions that makes it of interest (for what purpose, climatological or forecasting, I never learned); but the issue never mentioned in this conversation is that it is data contaminated by being along a concrete/asphalt highway full of over-the-road trucks and cars.
I stayed out of the conversation as I now hate to even talk about climate or weather related matters with people I don’t know. But it is interesting how people get very excited about large quantities of “data” without much regard to its quality or suitability for purpose.
Like the airport data, this WDoT data is useful for the purpose that it designed for. That being determining the status of these roads.
It has little use in other areas.
“But it is interesting how people get very excited about large quantities of “data” without much regard to its quality or suitability for purpose.”
Indeed. While quantity has a quality all its own (say, the number of Sherman tanks in the Allied arsenal), with data, smaller and better is usually better.
I’ve mentioned the Oklahoma Mesonet before …. https://www.mesonet.org/index.php/weather/local/okcn
The link is to one of the stations in the OKC area. There is at least one station in each county in OK . You can also check out the site location, with photos. The website is used by the public, farmers, and public safety folks. There is even a K-12 education section.
Can temperature be measured absolutely or only relatively , the relativists say that temperature can only be measured in relation to past temperatures and with respect to the time of year the met. office keep these records and use them to lead people to see certain temperatures as warm or cold or mild. the British national health service advises that room temperatures should not drop below 18 degrees centigrade for people who are in ill health and yet the recent heat wave in September in the UK did not rise much above this level at night in my flat. The room temperature advised by the national health centre should be seen as the baseline for judging temperatures not relative near surface temperature differences.
The bad news is that a re-education camp will now be constructed in Sioux Falls. The good news is that the VA will be in charge of the construction project and it will take three times longer to build.