A couple of days ago there was a guest post from Russ Steele citing a California study “Feeling the Heat” on global warming that just didn’t seem to add up. One of the stations cited as having climate change related warming was Reno, NV. So, I decided to do a field experiment to test this. The results show clearly that UHI exists in Reno.
Here is what Russ wrote a couple fo days ago:
Feeling the Heat was published by Environment California a non-profit group a few weeks ago, claiming 2007 was the tenth warmest year on record and that the mountain west was experiencing above-average temperatures. Full report here: Download feeling_the_heat_ca.pdf One of the examples given for the high western temperatures was Reno Nevada with a average temperature of 55.3 degrees in 2007, four degrees higher than the 30 years average temperatures from 1971 to 2000.
…Up front in the EC report the author dispatches UHI as having any influence on the climate change, citing studies by Easterling, PD Jones and Parker…
Well I decided to test this myself tonight, since I’m driving through Reno on my return home, I arranged an overnight stay. With me is my NIST calibrated data logger, NIST Calibrated temperature probe, a vehicle mounted Gill IR shield, my laptop computer, and my trusty vehicle. See my previous post “Road Kit”
I chose Virginia Street as the transect route, since it remains relatively straight, level, and crosses all of Reno, including the built up southern suburbs and downtown. It is the original “main street” for Reno.
Here is the result of my South to North transect driving Virgina Street overlaid on a Google Earth image oriented to match the timeline of the transect:
Click for larger image
The weather tonight was perfect. Light winds, clear skies.
Here is the data from the Reno airport ASOS, which also happens to be a USHCN climate station:
Time Temp Dew RH Wind Wind Vis WX Sea Level Altimeter Station
Point Dir Speed Pressure Setting Pressure
(PDT) (f) (f) (%) (mph) (miles) (mb) (inches) (inches)
1:55 am 44 25 47 CALM 10.00 CLR 1023.0 30.30 25.788
12:55 am 48 24 39 CALM 10.00 CLR 1023.4 30.31 25.797
11:55 pm 51 23 33 WSW 3 10.00 CLR 1023.7 30.31 25.797
10:55 pm 54 23 30 S 6 10.00 CLR 1024.1 30.32 25.805
For those interested, I have the raw source data from my datalogger in CSV form for the South to North Reno transect here. (PDF)
Note the placement of the airport, which has it’s ASOS weather station used in many climate studies essentially in the north end middle of the airport. The Reno UHI bubble does extend into this area.
Click for a larger image
I also did a reverse transect, driving the same route in reverse immediately. Plus a route near the airport. I’ll have more tomorrow, its 2AM and I’m tired.
UPDATE:
Jeff Id inquired in comments “how is it mounted to the car?” Here is the answer:
The temperature sensor (inside the Gill IR shield) mounted on the vehicle using an improvised window mount.
Also, the time of night that I made the transect (11:15PM to 11:39PM) allowed me to maintain a nearly constant speed during the transect due to the lack of traffic. Plus Virginia street has stoplights set for all green unless there is cross traffic. I was fortunate to have to stop only once during the entire drive, and that was in the downtown area. I kept an eye on the temperature reading during the stop, and no change was recorded.
I’ll have a complete post in the next day, still catching up from my trip.
This entire thread illustrates the difficulty inherent in discussing global temperature, anthropomorphic effects, and data collection.
Truism: all things do not remain the same.
Truism: it takes money to staff a weather recording site. It takes more money to connect a weather station to a structure with a cable.
Truism: airports were extensively used to collect weather data, because of the need for weather information for the use of aircraft landing and taking off. Example: the weather station in Washington, DC was downtown for a number of years. It was moved to Reagan National Airport because the data was needed there anyway, and the station could be permanently staffed. And airports are paved with black asphalt these days, which absorbs heat.
Truism: whatever the effects of UHI, those effects are related to population density.
Truism: too few of the existing weather stations meet all of the CURRENT criteria for measurement of temperature, wind speed and direction, relative humidity, and precipitation. It is possible to imagine measurements which would demonstrate the difference between a weather station in use and a nearby (5 miles, let us say) station which fully meets CRN1 requirements. I do not know a method for projecting any such difference into the past, before urbanization.
Truism: an equally spaced grid of weather stations would be hideously expensive, and is not under consideration.
The entire collection of arguments, over tenths of a degree celsius, is more heat than light. Remember that Galileo made one of the FIRST temperature measuring devices, and that the technology to draw a glass tube with a uniform internal diameter came more than a century later!
I wish everyone would take a deep breath and stop imputing motives, and see some more devotion to collecting good data!
The IPCC claims that UHI is almost negligible
Are you sure? I think everyone acknowledges that urban areas are significantly warmer than rural ones. The IPCC certainly do …
“Clearly, the urban heat island effect is a real climate change in urban areas” (Box 2.1)
but the question in a climate change context is how significant is this real effect on the observed global warming trend? And this breaks down into two related questions: are urban areas warming at a faster rate than rural areas and is the effect of increased urbanisation significant? The IPCC conclude that the answer to both is that the impact on the global trend is insignificant.
They base this on an array of evidence (see the above link), including a comparison of the trend for all stations and rural-only stations which show a difference of about just 0.05C over the period 1900-1990, and similar comparisons of the surface record with glacial, borehole and sea temperatures, all of which agree well with the global trend but obviously cannot be influenced by urbanisation.
The small contribution of UHI to the trend may appear counter-intuitive, but go back to first principles – 70% of the globe is ocean and cannot be influenced by urbanisation, of the remaining 30%, one entire continent (Antarctica) has no urban areas, Central Greenland and Central Australia have no significant urbanisation, Siberia has virtually no significant urbanisation (but shows above-average warming) and so on. Indeed if all of the continental US was concreted over it would only cover 2% of the surface area of the globe. So an insignificant contribution by the UHI effect to the observed global trend seems to me entirely plausible.
So climate scientists are well aware of the UHI and the fact that it can have significant local and even regional effects but an insignificant effect on larger areas. For example, this paper concludes a significant regional climate effect from the rapid urbanisation of China.
It was edited by James Hansen.
JP.
REPLY: Obviously you haven’t read this flawed but oft cited paper from Dr. David Parker over there at Hadley. He’d deluded himself into thinking UHI doesn’t exist, and people that are either too stupid, too entrenched, or too lazy to look for the answers themselves are following his lead.
See: http://www.climateaudit.org/?p=1718
From Parker 2006 this whopper of a wishful conjecture: …many “urban” observations are likely to be made in cool parks, to conform to standards for siting of stations.
To which McIntyre writes:
And we know from the surfacestations.org project that the majority of USHCN stations are compromised by microsite effects, which could be characterized as a form of UHI since the issues are related to urbanization around the station.
You write:
Bollocks. Care to rephrase that? You completely contradicted yourself. “…rapid urbanisation of China.” aka UHI over a wide area. Also explain why in the face of such widespread microsite bias, the lack of imagined “cool parks”, and “rapid ubanizations” such as China, that UHI only gets a 0.05 degree adjustment.
– Anthony
JimB,
The IPCC kind of admits it… they use Peterson and Parker (and Jones) to show that UHI is .02Deg C per decade. What too many skeptics do not acknowledge is that the UHI they show is after adjustment for UHI.
Peterson does not work because he used dense temperature networks in his study and the stations he used were as messed up as any that Anthony has shown. Dense networks are much better in adjusting for UHI, where sparse networks (like those monitoring most of the worlds land mass) are lousy for adjusting for UHI.
Parker used the wind proxy, windy vs calm days and how it affected the boundary layers. Parker failed to mention that he did not actually study windy vs calm days, it was actually the third windiest vs the third least windy… the third least windy were just as caable of mixing the boundary layers. Also, he failed to recognize that the boundary layers varied in thickness from station to station, skewing his experiment.
I’m not so sure if a debate on UHI would be productive… both sides would just offer a spun view which would probably lead to more confusion. I think a few good papers on temperatures and how they are affected by everything involved… UHI, Micro-climate, equipment, solar, ocean circulation, lack of data (including spatial variation over time) and etc.
Ric Werme (05:07:28) :
A little more seriously, I don’t have hard data, but I’ve noticed that between my usual parking place at work (shaded in the afternoon, at the bottom of a short hill going up to self-storage place) and the Turnpike heading north, I’ll see a 2-3 F rise. Some of it may be from sun, the temperature sensor is in the exterior rearview mirror, but I think most is from the hillside and car being in the shade at work.
How is traffic? I have done some quick calculations on how much heat a car dumps, and it is not negligable. May be you are just measuring the waste heat of the car in front of you.
The calc:
A car needs around 10 kW at the crankshaft to do 100 kph. Since an average engine is around 20% efficient, the total amount of heat produced is 50 kW. If cars are spaced 100 m apart, on traffic lanes 4m wide, the forcing is 50.000/400 = 125 W/m2. This is a considerable figure. All this heat is dumped near the surface, where your temperature sensor is.
REPLY: Anne, nice try, but no. I’m not measuring the waste heat of the car in front of me. I purposely chose that time of night because there was so little traffic, and I was careful to avoid any cars ahead.
Prior to this I did some tests in my own driveway, and the sensor didn’t pick up proximity of vehicles. Including idling my own for short periods, such as would be simulated by a stoplight. – Anthony
Hi Ric Werme I wasn’t you either… not the last time I looked in the mirror…
Coby, your two pics point to different realities. The temp anomalies pic is a composite of land, sea and satellite data that to my eye shows some pretty interesting factors: NH warming, Antarctica cooling, and landmasses warming generally more than oceans which are cooling in places. I believe we can explain it all in terms of Sun and oceans, remembering the Sun gives off 24,000 times our human output – but we might still cause a tiny NH anthropogenic warming effect. No GHG though, because CO2’s GHG effect is already saturated, it’s like adding ink to inky water. The lights picture could relate to surface stations data, so I’d like you to show a warming anomalies map drawn ONLY from surface stations data.
Nobody here is saying UHI accounts for all the recent warming. Please correct your representation of skeptics as saying “The apparent rise of global average temperatures is actually an illusion due to the urbanization of land around weather stations, the Urban Heat Island effect”. People here just note that surface records have been shown to be suspect regarding UHI, and that this evidence suggests the IPCC corrections are way too small.
Yes, McIntyre makes the same category error and attacks the same Straw Man.
One of the main IPCC creeds is that the urban heat island effect has a negligible impact on large-scale averages such as CRU or GISS. The obvious way of proving this would seem to be taking measurements on an urban transect and showing that there is no urban heat island.
Except the IPCC completely acknowledge the existence of UHIs, as does Parker. It is entirely possible to have island hotspots, if you will, that have a negligible effect on the global trend, given the relative size of the globe and the urban areas. You say China is a ‘large’ region yet it is a similar land area to the US, about 2% of the globe’s total. The effectively unpopulated Antarctica has >50% more area. To repeat myself, the UHI effect is real, but its influence on the long term global trend is massively diluted by the oceans and the vast areas of the planet that are not urbanised. Or, to quote IPCC AR4 WG1 Chap 4:
“Urban heat island effects are real but local, and have
not biased the large-scale trends. A number of recent studies
indicate that effects of urbanisation and land use change on
the land-based temperature record are negligible (0.006ºC per
decade) as far as hemispheric- and continental-scale averages
are concerned because the very real but local effects are
avoided or accounted for in the data sets used.
Bye for now.
JP.
REPLY: “massively diluted”…still bollocks. Why? check the station distribution. Your argument assumes there are more stations in the oceans and the poles, i.e. a more evn distribution…but the reality is far different. In fact, there has been a sustained loss of stations at high latitudes in the past 20 years.
– Anthony
John Phillip, It is not the land area of the UHI effect that is important, it is that the temperature probe sits in the middle of it. Even moving from a 100′ clear area to within 10′ of a rural house because the data cable is restricted in length causes UHI. Look at the surfacestation.org data showing a bias from the almost 50% of US sites investigated of +1.95 C. This does have an effect not accounted for by the IPCC.
[…] UHI is real, in Reno at least A couple of days ago there was a guest post from Russ Steele citing a California study “Feeling the Heat” […] […]
Today’s (31Oct08) “The Advertiser” newspaper (South Australian daily paper) there is an article titled “Temperatures changing face of Adelaide” stating:
“Adelaide is 1.5C hotter today than it was almost 100 years ago. This is altering the coastline and climate, new research shows.”
“The metropolitan urban jungle is trapping the day’s warmth after sunset more than before.
The heat radiates at night and keeps temperatures higher than if the heat could dissipate into the atmosphere.”
“University of Adelaide researchers have found this heat is drawing the afternoon sea breeze into land more quickly than in previous decades making sea breezes stronger”
“The breezes affect the size of waves in Gulf St Vincent. That affects the movement of sand and sediment along the gulf, causing beach erosion.”
The research was undertaken by Civil, Environmental and Mining Engineering honours students.
If, according to the IPCC, UHI effects are negligible and local:
* this research appears to show that UHI has added at least 1C to Adelaide’s average temperature which is around the same increase attributed to CO2
* how ‘local’ is ‘local’ – the effects of the Adelaide UHI cover St Vincent Gulf which is 90 miles long and 45 miles wide?
* Adelaide is a coastal city in South Australia with a population of approx 1 million. What effect do much larger cities have on weather patterns and climate that is blamed on CO2?
Anthony thanks for doing this great work. Don’t let the nonsense from some of these people discourage you. Some on here are trying to be to analytical/negative in regard to your study, while inferring things from it that you have not implied. The large UHI effect is so obvious that you must simply be a fool for not believing it. Here in Central California on calm clear nights in both summer and winter temperatures in rural areas are routinely 5-11 degress cooler than urban areas like Fresno and Bakersfield.
I know this from first hand temp readings with 2 Nimbus NTL thermometers with an accuracy of .02 degrees that I had up several years ago while living in the country 15 miles from Fresno. I had several thermometers up at the same time just to verify each other as I didn’t believe them at first. Also one can easily look at the NWS Hanford Regional Temperature Roundup to see the UHI effect for themselves.
It’s so upsetting that some try to be so smart and in doing so miss the obvious. Some just don’t know how to objectively take a step back and look at the big picture. Some are just to prideful, which clouds their judgement. Sorry for the rant, just wanted to present my thoughts. Thank You again for your work Anthony.
Your argument assumes there are more stations in the oceans and the poles, i.e. a more even distribution-but the reality is far different. In fact, there has been a sustained loss of stations at high latitudes in the past 20 years.
No I do not make that that assumption. In GISTEMP, for example, the contribution of each grid cell to the global mean is identical (after weighting for latitude band) regardless of the number of stations within it. So the contribution of a cell with relatively dense station coverage (eg Reno, presumably) and that of a grid cell with fewer cells (e.g.in rapidly-warming Siberia) to the global mean is identical.
I always thought ‘Bollocks’ was a British coinage. Interesting to see it is used over the pond.
REPLY: Still bollocks. Even with such cell weighting, the majority of stations are still being impacted by ubanization though city scale UHI as well as microsite urbanization issues, thus UHI is contributing to the signal on a broad scale, and .05 doesn’t begin to cover it.
I can say with certainty, that the overwhelming majority of stations we’ve studied so far are affected with urbanization issues, either on a city scale and/or microsite scale. only 4% of stations surveyed are truly pristine.
As surfacestations.org has shown, even remote stations can suffer from localized urban effects. So while IPCC, Hansen, Parker and other armchair data jockeys claim they have it under control, the simple fact is they have absolutely no idea of the magnitude of the local effects nor have they even lifted a finger to study the issue. They just dismiss it with a wave of the hand.
Parker’s ridiculous “cool parks” statement demonstrates his complete lack of understanding of the measurement system and it’s problems, thus rendering his conclusions moot. – Anthony
typo
‘fewer cells’ should read ‘fewer stations.’
Apologies.
My take is that truly rural stations tend to show either no trend, or a cooling trend over the las 100 years, while those closer to urban areas show mostly a warming trend. Then adjustments occur, for no logical reason, on those rural stations, making the trend change based on other stations up to 1500km distant. Completely ludicrous. It tells me that even if UHI isn’t a major factor in the surface record, GW aint global.
Anne (15:42:32) :
Ric Werme (05:07:28) :
That ranks a high 2nd on my list of culprits. The road is asphalt, widened from 4 lanes several years ago. Traffic does move at or above the speed limit now. That, combined with solar warming during the afternoon is likely significant.
I haven’t noticed a similar effect on cloudy days – then again, I haven’t looked, I should, though there is something to be said for watching traffic, not thermometers.
Anne and I are talking about Nashua NH at 1730 and a sensor in a external rearview mirror (black housing), not Reno at night with good equipment.
One could discover UHI contamination in 100% of the US surface stations [ Though this seems improbable ] and all this would demonstrate would be that 2% of the globe is affected by urbanisation. . Everyone acknowledges the reality and the scale of UHI, and that there are localised temperature gradients of several degrees in urban areas compared to surrounding countryside, and indeed all datasets attempt to correct for this , but one cannot just wave away the fact that there can be no such effect in the oceans, in Antarctica, in Greenland, in Central Australia and hence the overall impact on the global long term trend from urbanisation is insignificant.
REPLY: “Seems improbable”, but the fact is that even stations in the absolute middle of nowhere are affected by microsite biases that are not accounted for. The fact is that rural vs urban categorizations have been shown to be wholly unrepresentative of the measurement environment around the thermometer. For example, here’s a “rural” station, which is badly polluted.
Miami, AZ USHCN station shown here
And there are plenty more where that came from.
The rural -vs- urban assignment is essentially useless for determining potential bias impact on the thermometer. Where large scale UHI might not be can easily be replaced or even be greater in bias by local site issues. Just moving the thermometer to an improper setting can dwarf UHI effects.
And, none of theses studies by Hansen, Jones, Parker, et al even touch on it. The are absolutely clueless about the measurement environment because they never look at the experiment in progress themselves. Any scientist that doesn’t look at where the data is gathered and assure themselves of it’s integrity, relying on the face value of the data aloine is not truly a scientist in my book.
As for that 2% well, we see the problem elsewhere too, as the US system is supposedly the best. Do you really think that the same sorts of problems I’ve documented only exist in the USA? Seems improbable that would be true. Human folly is universal. – Anthony
AnneI have done some quick calculations on how much heat a car dumps, and it is not negligable.
Crossing Westminster Bridge yesterday after the famous snow… the pavement was divided by a clear line down the middle, bone dry roadside, dripping wet riverside. Mind you, there could be a “fan” effect as well as warming from cars.
John Philip:
“Everyone acknowledges the reality and the scale of UHI…”
Half right, John.
The problem is the scale. The UN/IPCC incorrectly minimizes the effect of the UHI influence. The UHI effect is present, and that effect is much greater than the UN/IPCC assumes in its computer modeling.
If the UN/IPCC were honest about the effect of the UHI adjustment, the scientific community would see that the only credible measurements are those that rigorously adjust for external influences, preferably by siting surface stations well away from urban heat sources.
Anne (15:42:32) :
REPLY: Anne, nice try, but no. I’m not measuring the waste heat of the car in front of me. I purposely chose that time of night because there was so little traffic, and I was careful to avoid any cars ahead.
Anthony, perhaps you didn’t notice, I was answering Ric Werme, not commenting on your article. I was well aware that you drove at night.
Sorry if this has been listed before-found a NASA news release about urban heat-in 2000 they said that urbanisation created “vast heat islands” and “This could be demonstrating a profound urban heat island effect”
”
Lynn Chandler
Goddard Space Flight Center, Greenbelt, Md.
(Feb. 21, 2000
RELEASE NO: 00-23
URBAN SPRAWL REDUCES ANNUAL PHOTOSYNTHETIC PRODUCTION
A study of the impact of urbanization and industrialization over the past seven years using satellites shows that annual photosynthetic productivity can be reduced by as much as 20 days in some areas where urbanization is intense, not unlike turning the lights off in a greenhouse during the growing season.
The study also reveals that urbanization may be creating vast heat islands that can actually lengthen the growing season, but do not improve the productivity of the land..
NASA Goddard Space Flight Center (Greenbelt, Md.) researcher Dr. Marc L. Imhoff presents his findings during a news media briefing at the 2000 American Association for the Advancement of Science (AAAS) Annual Meeting
According to Imhoff’s research, urbanization and industrialization have resulted in the development of mega-cities and urban and suburban sprawl. The environment is altered as a result of replacing land cover with roads, housing, and commercial and industrial structures…
..A most interesting finding according to Imhoff was that urbanization seems to elongate the growing season, yet still reduces the overall productivity of the land. “…. “This could be demonstrating a profound urban heat island effect and have implications in climate change, especially in the northern Hemisphere where urban development is most intense.”
For supporting images: http://svs.gsfc.nasa.gov/search/Keywords/URBAN.html
This text derived from http://www.gsfc.nasa.gov/news-release/releases/2000/00-23.htm
Nasa put out a news release in 2000 about “vast” and “profound” urban warming/heat islands from Marc Imhoff.
It describes longer growing season but less productivity.
Havent found a retraction! Is it still current thinking in certain corners of NASA?
http://earthobservatory.nasa.gov/Newsroom/NasaNews/2000/200002211661.html
[…] Read more here Consider then UHI, and my recent measurement of a temperature transect from Reno, NV […]
[…] Here is what a surface temperature transect of Reno looks like, I did this one myself: […]