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.
Anthony,
This experiment could be expanded – in a fashion similar to surface stations.org. Volunteers collecting transects such as yours across multiple cities of many different sizes at different times of year, etc. You might be able to collect a large enough data set to quantify the UHI effect is such a way that a reasonable UHI correction could be made according to city size & station location within that city. At the very least, it would provide a large data set to prove the UHI effect is real (& commonly large).
An observation I have made here in Denver is that the UHI effect appears to be larger on drier days – which might imply that it is not only a radiative effect but also a moisture effect – with all the “urban irrigation”, there is also a latent heat component with the additional urban moisture.
Somethings to consider anyway….
Anthony’s data seem to a non-scientist the basis of pure science. Anthony, your being there and recording the difference in temperature from a rural to an urban setting is the real thing, IMHO. Experientially, everyone knows that we get hotter when we drive from a beautiful, rural area to the equally, but differently, fascinating city. What I think scientists ought to add to our knowledge of climate change is now much help UHIs will add to global warming. UHIs might be a much larger contribution than CO2 to global warming, of which we might need a great deal in the near future as we move into global cooling. Just sayin’.
I have also heard the “more forests now” statement but don’t now how to check it. Many residential areas have a lot more trees than the land did when it was farm fields. People also don’t seem to realize that practically the entire Eastern forest died when the chestnut blight hit in the early 1900’s. Chestnut was the dominant tree in the Eastern US much like redwoods in the West. The forest we have today is not only more extensive, it is made up of completely different tree species.
To be a little more specific about the science we might need in the future — there are mega-urban areas, and metropolitan urban areas, and urban areas, and cities, and towns, etc. What percentage of the land mass of the globe are these developed areas compared to the land mass of undeveloped areas, and what percentage of increased temperature does each add to their section of the earth (there are probably more specific questions that can be asked). Then we can find out what the developed areas, in their specificity, add to global warming. If the conclusion is that they are significant “pollutants” in terms of global warming, then we can ban developed areas from the earth. On the other hand, if we find that they help to keep the earth warm and happy, perhaps we can keep them.
Bottom line. We need the best science regarding temperature we can get. We do not have it as yet, as Anthony has clearly shown in his experiment.
Jon Jewett (19:09:48) :
‘I believe that there are more forests now than in 1900 (in the US anyway). ‘
I forget the study, as it was aprox. 10yrs ago, but for New England, you are absolutely correct. The study mentioned that 200yrs ago, New England was basically clear-cut farmland, and that there are MANY more trees here now than there were 200 yrs ago.
Jim
This satellite pic of the earth at night clearly shows mans impact and coverage as far as urbanization.
http://www.cobybeck.com/illconsidered/images/earthlights.jpg
And if we are to believe this website over half of the worlds forests have disappeared.
http://www.globalchange.umich.edu/globalchange2/current/lectures/deforest/deforest.html
The site states almost half of the forests have disappeared in the USA but do mention recovery in some areas.
But if UHI’s are contributing to actual global warming it must be on a small scale or we would not be experiencing the current cooling.
What a demo, there is no way GISS can correct accurately for this kind of clear effect. How is the sensor mounted in the car?
I continued my posts on Tamino’s ARMA analysis here
http://noconsensus.wordpress.com/2008/10/30/dont-get-fooled-againagain/
REPLY: see the update photo showing the mount – Anthony
Evan,
I wasn’t aware of the rumours, but last time I checked I wasn’t you.
However, I hear that you can switch identities, friends, political philosophies and birthplaces at the last minute – if you are running for president of the USA.
coby (12:43:24) :
Perhaps it’s just the scale, but the green line is so flat, you could argue that there is no warming, at least in Reno.
Or if you are voting in Ohio! #B^1
And I’m not kidding. That’s actually a rumor! Or that you are actually Steve McIntyre. Or that we are the fevered alter-egos of Andrew Orlowski, courtesy of El Reg.
Andrew, I’ve met.
But as no one has ever seen us both in the same room, maybe I really AM you!
How many stations would we have left, if we restricted the test to only those that were “in fact” well sited according to the defined standard?
Would the number be enough to allow for a reasonable test?
Perhaps the test can’t be run as there is insufficient quality data?
Maybe not. Only 13 % of the 500+ observed stations are CRN1 or 2 rated. Only 4% are CRN1. And some of those have seen urban areas grow around them, so they’re not a constant.
However, La Dochy did a study of California stations
LaDochy, Medina, Patzert. 2007. Recent California climate variability: spatial and temporal patterns in temperature trends. Climate Research, 33
ABSTRACT: With mounting evidence that global warming is taking place, the cause of this warming has come under vigorous scrutiny. Recent studies have lead to a debate over what contributes the most to regional temperature changes. We investigated air temperature patterns in California from 1950 to 2000. Statistical analyses were used to test the significance of temperature trends in California subregions in an attempt to clarify the spatial and temporal patterns of the occurrence and intensities of warming. Most regions showed a stronger increase in minimum temperatures than with mean and maximum temperatures. Areas of intensive urbanization showed the largest positive trends, while rural, non-agricultural regions showed the least warming. Strong correlations between temperatures and Pacific sea surface temperatures (SSTs) particularly Pacific Decadal Oscillation (PDO) values, also account for temperature variability throughout the state. The analysis of 331 state weather stations associated a number of factors with temperature trends, including urbanization, population, Pacific oceanic conditions and elevation. Using climatic division mean temperature trends, the state had an average warming of 0.99°C (1.79°F) over the 1950–2000 period, or 0.20°C (0.36°F) decade–1. Southern California had the highest rates of warming, while the NE Interior Basins division experienced cooling. Large urban sites showed rates over twice those for the state, for the mean maximum temperatures, and over 5 times the state’s mean rate for the minimum temperatures. In comparison, irrigated cropland sites warmed about 0.13°C decade–1 annually, but near 0.40°C for summer and fall minima. Offshore Pacific SSTs warmed 0.09°C decade–1 for the study period.
http://www.int-res.com/abstracts/cr/v33/n2/p159-169/
This study, however, does not specifically take into account microsite violations, so we have a hanging vairable in play.
Vote early and vote often!
I’ve met Andrew as well, and I am sure he is not me. I have received e-mails from you which I did not send, so I am quite certain that you are not me. And St. Steve McIntyre’s statistical analysis typically go completely over my head, so I am 100% certain I am not him.
Didn’t one of the presidential candidates say this in his book?
“I chose my friends carefully. The more politically active black students. The foreign students. The Chicanos. The Marxist professors and structural feminists.”
No friends who cling to guns and religion? Or capitalists? Or military people? Or Americans who are proud of their country? Or people who have ever had a real job?
Evan and Steve,
Obviously – Neither of you are each other – now that should clear it right up…
That’s only a theory.
Hey Evan – thanks for that – interesting.
Steve, just read your last post, especially the part in italics… hmmm very worrisome – in fact I’m alarmed. (no really – I am).
This is bad for Australia too.
Graeme,
“I chose my friends carefully” Wright, Ayers, Rezko, Farrakhan, Jackson ….. ?
Here’s the flip side:
Ross R. McKitrick, Patrick J. Michaels , JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, DECEMBER 2007, Quantifying the influence of anthropogenic surface processes and inhomogeneities on gridded global climate data
http://www.agu.org/pubs/crossref/2007/2007JD008465.shtml
Abstract
Local land surface modification and variations in data quality affect temperature trends in surface-measured data. Such effects are considered extraneous for the purpose of measuring climate change, and providers of climate data must develop adjustments to filter them out. If done correctly, temperature trends in climate data should be uncorrelated with socioeconomic variables that determine these extraneous factors. This hypothesis can be tested, which is the main aim of this paper. Using a new database for all available land-based grid cells around the world we test the null hypothesis that the spatial pattern of temperature trends in a widely used gridded climate data set is independent of socioeconomic determinants of surface processes and data inhomogeneities. The hypothesis is strongly rejected (P = 7.1 × 10−14), indicating that extraneous (nonclimatic) signals contaminate gridded climate data. The patterns of contamination are detectable in both rich and poor countries and are relatively stronger in countries where real income is growing. We apply a battery of model specification tests to rule out spurious correlations and endogeneity bias. We conclude that the data contamination likely leads to an overstatement of actual trends over land. Using the regression model to filter the extraneous, nonclimatic effects reduces the estimated 1980–2002 global average temperature trend over land by about half.
Received 26 January 2007; accepted 8 November 2007; published 14 December 2007.
Evan, Steve,
Thanks.
Of course there is UHI in Reno… NCDC used Reno as the example on the USHCN V2 roll out… they clearly admit it
Graeme Rodaughan (21:42:31) :
I’m offended – with one exception that I’ve nearly completely forgotten about no one has accused me of being someone else. Therefore, I wish to categorically state that I am not the poster who goes by the name Lucy Skywalker. Just because we’ve both written web pages that are good introductions to this sorry field doesn’t mean that they’re both mine. Or hers. But they are ours.
Hey, the clouds outside are breaking up, thank you Graeme. Speaking of which, that was a pretty weird storm here in the east a couple days ago. Odd wind patterns, no lake effect, at least at first, while it was snowing in upstate New York and Philly suburbs (away from the dreaded UHI), Boston was warmer than Atlanta but eventually cooled down on a cold south wind. Gonna be an interesting next few years.
One thing strikes me. The IPCC claims that UHI is almost negligible and cites some studies that are almost laughably weak. I’m sure Anthony wouldn’t claim his test to be a rigorous scientific test. And yet, almost certainly, if those tests could be done world-wide as a fully funded scientific experiment they would confirm what Anthony – and many others – had found.
So the obvious question is this: why aren’t the scientists doing this? By making repeated, accurate measurements along routes that pass across urban areas then a very accurate picture of the strength of UHI should emerge. It would be persuasive because it was based on real measurements. To put it bluntly: how difficult can it be to grab a thermometer and actually measure the temperatures?
I would like to know if this has been done already. And if not, why not? It seems so obvious.
Another poster suggested that this could be a new campaign that complements the surface stations campaign. I think that’s an excellent idea.
Chris
REPLY: The idea to make a campaign out of this has been on my mind for some time, I just need (ahem) the right vehicle. Mainly, something that is affordable. I think I may have a solution that would allow this to be done for under $100 per city. – Anthony
Mike C.
We understand they “admit it”…we also understand that IPCC “admitted it”.
The problem is that based on close examination of the “science” involved, or lack thereof, many (me included) believe that the impact of UHI on the overall picture has been underestimated. Some believe this is simply based on poor science, others believe it’s a deliberate manipulation of the data to make it fit a projection/prediction.
This could easily be put to rest IMHO if the two sides would engage in an open debate about the experiments and the results, but frankly, it seems to me that the AGW camp is completely unwilling to do so.
Jim (who would REALLY like to SEE that debate…)
Has it occurred to anyone in the BBC that this 4’C differential urban to rural is the same ‘catastrophic’ warming that they claim will occur longterm? You’d think commuters would have noticed by now – its clearly nothing we can live with!
I believe this graphic was posted on this site a while back. It seems relevant [note Reno on the map], so here it is again: click
This is a great little illustration of how out to lunch people are when considering scientific information. People still buy the “hockey stick” after numerous debunkings. Yet despite believing that the world is getting warmer from people driving cars and emitting CO2, they refuse to believe that one local area could be warmer from people driving cars and emitting heat. Therein lies the reason this debate is so screwed.
One note on DOE for Anthony. Many of the areas in and around the Sierras, are well known for extensive microclimates. Someone inclined to take pot shots at your conclusions may raise this point. You may want to consider setting a control for your experiment to combat such claims. Something like taking temperature measurements as you drive concentric circles around Reno (that is outside the UHI affected perimeter) might work. This will help to establish whether or not there are any macroscale or microscale temperature gradients present that may be influencing the appearance of UHI. Given your skill with statistics, once you made such a determination, I think you have the tools to determine the scope of any observed microclimate impact on your results based on their size and location in relation to your UHI-indicating measurements. Obviously if you see a gradient from outside the city flowing seamlessly into the observed UHI gradient, this may just be the effect of microclimates. But if you universally see the heat gradient pointing into the city at all points along the circumference, then UHI becomes the only logical explanation.
Just some food for thought. God know’s there’s enough BAD science being done, and where it’s put us. Now that you’ve started, why not make this as thorough and rock solid as possible, given it’s potential to shake the foundations of the AGW argument. Great stuff as always!