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.
I ride my bicycle everywhere, day and night. On calm, clear nights there is often a 10-15 degree difference between a bike trail through a 20 meter wide greenbelt, and the surrounding neighborhoods with asphalt and brick.
Which is, of course, ridiculous. Using one site to adjust another has no relevance in reality.
And in Manila, it seems :^))
http://calsun.canoe.ca/News/gallery/earth/2008/10/28/7231861.html
Great visual. Not knowing how your equipment was set up, it did raise a question. Did you maintain a constant speed throughout the trip? For example, if you were driving slower in one area could heat from your car have raised the temperature?
REPLY: Relevant question. The Gill IR shield prevents a lot of this, I tried very hard to maintain 35-40 mph through the transsect, and that partly why I chose this time of night…all the stoplights go green on Virginia street at this late hour. The one time I did hit a red light due to cross traffic, I watched the sensor reading carefully while stopped, no change. – Anthony
Let me suggest that you make your first reference to UHI in each post be “Urban Heat Island (UHI),” so that people like me, who aren’t familiar with the term don’t have to do a search and scroll to find it. Good work in checking these things out.
re Steven Mosher
I interpret the graph you linked as showing that the UHI effect for Reno has indeed been adequately accounted for by NOAA’s homogenization process?????
That’s fascinating. When driving roughly that same route in mid winter, after there has been snow, I notice the snow cover is the inverse of this transect, more or less. This cannot be attributed solely to elevation, as the elevation change along the transect is not that great.
Jim, Mike, global warming is about the planet being warmer now than it was a certain time ago. Suppose Reno already had reached its current size & shape 50 years ago. Would the UHI effect have been the same as it is today? Probably very close. So would the UHI have affected the long-term trend? Hardly.
Now, what Anthony has done, is prove that Reno has a UHI, beyond a shadow of a doubt. The IPCC does not deny that, look at page 237 for AR4:
“Urban heat island effects are real but local, and have not biased the large-scale trends.”
So in order to prove the IPCC wrong, you have to prove that UHI’s have affected trends, not just that they are real, because the IPCC already agrees to this. In order to prove that the UHI has affected the trend, you need to either compare the current UHI-bubble to the bubble 50 years ago, or you have to proof that the trend in Reno is different from the trend in a nearby station outside the UHI-bubble. Otherwise you are arguing over something that everybody already agrees upon.
Having ridden a motorcycle for most of the last 40 years, i can attest to UHI firsthand. Colder in rural areas, and significantly colder in low lying rural areas.
Alan the Brit (05:45:20) :
So, common then somebody, just when is Solar Cycle 24 going to start in earnest?
Dr Hathaway & the Solar Prediction Panels & others seem to be having little more than wild stabs at it.
Made in March 2007:
http://www.leif.org/research/When%20is%20Minimum.pdf
SC24 so far:
http://www.leif.org/research/Region%20Days%20per%20Month.png
Not related to this post, I just wanted to call your attention to the following:
U of OK decertifies professor over Global Warming skepticism
A popular professor of environmental geology seems to be under attack by the University of Oklahoma because of his skepticism over global warming this month.
In October Dr. David Deming, a teacher for the U of OK for over a decade, was informed that his “general education” certification was being revoked for his class. This will result in many students passing over his class when they choose their classes in the future.
Too bad the wizards of smart at the climate center couldn’t do this and produce scientific data instead of gibberish that supports the hoax.
I notice that instead of measuring the UHI affect, the climate center try to estimate it. As others state, the actual measurements don’t support the estimate, nor does the math.
Sort of like the effeect of the sun is so small as to not be a factor. Wanna bet.
There are two different points at issue here:
1. UHI effects on temperature readings
2. The increase in the UHI effect over the last century.
Presumable UHI affected temperature readings a century ago also. If rural temperature readings increased 0.65 degrees over the last century, say from 14 to 14.65 C, and if urban readings increased 0.7 degrees over the last century, say from 16 to 16.7 C, then the 0.05 C adjustment would be correct. What would be needed to verify the adjustment one way or the other would be to get comparison tables of rural readings and urban readings for various regions extending over the century.
I suspect the increase in urban temperatures over rural temperatures over the last century has been a lot more that 0.05 C, but current readings of urban temperatures doesn’t settle the argument one way or the other.
Ric Werme (05:07:28) :
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.
Minor point but we had a discussion with a mechanic a few weeks ago. All or almost all cars have the sensor up just behind the grill so we see a rapid temp change as we drive thru different areas. The mirror is just the digital readout area, or in the Ford Fushion the readout is down by the a/c controls.
@ared (07:47:32) :
1) Anthony started http://www.surfacestation.org to determine if the data from the surface stations is even reliable. It is increasing looking like it is not and the bias is on the warming side do to poor siting.
2) UHI is not limited to big cities, as is supposed by many. Example: Cooperstown NY and Maryland NY are practically next to each other but Cooperstown shows a marked warming trend in the past 100 years, but Maryland shows a cooling trend for the same period. Both are considered rural stations. You can access the U.S. Historical Climatology Network (USHCN) Data Set and graph stations for yourself at http://www.co2science.org/data/ushcn/ushcn.php. However… I strongly suggest you bear in mind point #1 and visit http://www.surfacestation.org to check if the site has been surveyed and if a trend bias due to siting/operation was identified.
3) We all agree that the IPCC acknowledges that UHI is a factor that needs to be backed out, but the disagreement is if the amount of adjustment by the IPCC reflects the true UHI/Siting Bias.
Ared, the trend (which is cooling as of today) is significantly less than the UHI of 3-4C,
So in fact, my guess is that earth has not warmed in 30 years or more.
And satellite records show that. Ground based temps are totally contaminated.
This comment doesn’t relate to this UHI article, but I find it interesting that the Wikipedia article on global cooling shows the W. Antarctica Peninsula warming dramatically during the 1965-75 period, during a period of global cooling. It makes one wonder what was driving such warming. Could it be that something else is operating there, maybe volcanic activity or something else?
Dee, I know all this. I’m just making the point that knowing the size of one UHI at one moment in time does not prove the IPCC wrong. You need to know how UHI develop over time and what effect many of them have on long-term global trends to say something usefull about whether 0,05 per century is wrong or not.
UHI London,
London experiences a phenomenon called the Urban Heat Island effect (UHI), which means the centre of London may be up to nine degrees warmer at night than the surrounding countryside.
http://www.london.gov.uk/mayor/environment/climate-change/london.jsp
UHI Hong kong,
After analyzing the data, PolyU researchers found that there was an average temperature difference of 7° to 8°C between urban and rural areas in a winter night, and the maximum difference could be as high as 12°C.
http://www.polyu.edu.hk/cpa/polyu/hotnews/details_e.php?year=all&news_id=1435
UHI at Beijing and Wuhan stations
Implications of temporal change in urban heat island intensity observed at Beijing and Wuhan stations
“In summary, temporal trends of annual and seasonal mean SAT for time periods of 1961~2000 and 1981~2000 at Beijing and Wuhan stations and their nearby rural stations are all significantly positive, and the annual and seasonal urban warming for the two periods for Beijing and Wuhan stations is also positive and significant. The annual urban warming at the city stations can account for about 65~80% of the overall warming in 1961~2000, and about 40~61% of the overall warming in 1981~2000.
http://www.agu.org/pubs/crossref/2007/2006GL027927.shtml
If 50% of the weather stations are urban, given these examples being the norm for that 50% the UHI effect must surely wipe out the majority of the reported warming, 0.05%, pull the other one.
Ared,
The biggest issue is credibility. The IPCC is supposed to be so expert on the subject of golbal warming that we must incur trillions in costs and consign the world’s poor to a future bereft of any chance of improvement (re: death, disease, starvation, etc) on the basis of their expertise.
The IPCC says that UHI effect is very small. The IPCC is wrong. This should jeopardize their credibility. Note also, the IPCC relies on a famous study for their view that the effect is small. When asked for access to the data used in the study, the author said that the dog ate his homework. Yet, the IPCC continues to rely on the eaten homework instead of the many, many observations of the UHI. One would hope that such reliance reflects on the IPCC’s lack of credibility.
If they can’t get the basics right, they ain’t experts. At least, not nearly expert enough to damn billions of people to lives of unnecessary misery, disease and death.
I wonder how many desk bound NCDC/GISS types ever engage in such field work as you regularly undertake.
One has to wonder how many of the stations in the USHCN are impacted by the UHI besides the obvious siting problems you’ve exposed at the surfacestations project.
And yet, despite all these problems, it seems the data provided by satellite is still being treated almost as a novelty. Turf battles can be so petty…
ALAN D. MCINTIRE (08:05:25) :
says, Presumable UHI affected temperature readings a century ago also.
Take a look Alan,
http://www.john-daly.com/stations/stations.htm
stan, the IPCC doesn’t say that the UHI effect is small. It says that after correcting for the effect, the impact on global trends is small.
And Anthony, I’m disappointed at your reply as it is obvious I’m not attacking your work, merely the unwarranted conclusions drawn from it by others, whom I specifically name in all but my first reply.
REPLY: Be disappointed all you like, it worries me not, but your version of “obvious” may not be the perception of others, nor can you expect them to glean that perception unless you clearly spell it out as to whom you are disagreeing with. The simple fact is that you haven’t done your homework on the UHI history of Reno, of which there is quite a bit. I’d kindly suggest that you read up on it. – Anthony
ared, look at the datat collected thus far at surfacestations.org. Closing in on half the stations in the US reveals a minimum of 5 deg. F bias. The remaining stations will have to have a strong negative bias to offset this, and that isn’t physically possible. This is the source of GISS temperatures, Hansen’s record of warming.
Ared,
As noted on this site recently, GISS says that the UHI in Manhattan is less now than it was 100 years ago. Does anyone really believe that? Manhattan?! (and not the one in Kansas)
As the various articles showing temperature histories of certain towns which have been cited here in the recent past show, there simply is no way that the UHI can be as small as the IPCC maintains. On the one hand, the Greens have screamed about the horrors of urban sprawl (all that concrete and asphalt!). But the IPCC tells us that it is minimal. BS.
The temperature records are garbage. The “adjustments” to temp data, the infilled data, the changes to past data, the poor siting that no one ever bothered to check, the “dog ate my homework” studies, the SWAGS, the secrets, the refusal to share data — it’s a massive, sloppy mess. As Steve Mc has pointed out, this garbage would get a stock promoter sued for fraud. No one could possibly get a new drug approved with science this sloppy. No one would even bother to try.
But we’re going to alter the course of world history on the basis of this crap!?!?