By Steven Goddard and Anthony Watts
Fort Collins, Colorado is most famous for Balloon Boy, and Boulder, Colorado is most famous for Jon Benet and Ward Churchill.
Both are hotbeds of Climate Science, with familiar names like Roger Pielke (Jr. and Sr.) Walt Meier, William Gray, Kevin Trenberth and Mark Sereeze. Both are of similar size (Boulder 91,000 and Fort Collins 130,000) and located in very similar geographical environments along the Front Range – about 50 miles apart. The big difference is that Fort Collins has tripled in size over the last 40 years, and Boulder has grown much more slowly. Fort Collins population is shown in blue and Boulder in red below.
Sources:
http://en.wikipedia.org/wiki/Fort_Collins,_Colorado
http://en.wikipedia.org/wiki/Boulder,_Colorado
Until the mid-1960s, NCDC temperatures in the two cities tracked each other quite closely, as you can see below. Again, Fort Collins in blue, and Boulder in red – with Fort Collins temperatures shifted upwards by two degrees to normalize the left side of the graph. Since 1965, temperatures in Fort Collins have risen much more quickly than Boulder, paralleling the relative increase in population.
Source: NCDC Boulder Temperatures NCDC Fort Collins Temperatures
The graph below shows the absolute difference between Fort Collins temperatures and Boulder temperatures since 1930. There is some sort of discontinuity around 1940, but the UHI imprint is clearly visible in the Fort Collins record. The Colorado State Climatologist, Nolan Doesken manages the Fort Collins Weather station. He has told me that it has never moved or changed instrumentation. and that he believes the increase in temperature is due to UHI effects.
Roger Pielke Sr. further commented:
“the Fort Collins site did have the introduction of the CSU Transit Center a few years ago, although this is well after the upturn in temperature differences between Boulder and Fort Collins started to increase.”
From the promotional photo on the CSU website, the Fort Collins USHCN weather station (below) seems reasonably sited.
However when you look at the Google Earth street view, you realize that it is surrounded by concrete, asphalt, nearby parking, and a building just 7.5 meters away (By the GE ruler tool). It would rate a CRN4 by the surfacestations rating. It also appears to have been modified since the promo photo was taken as there is a new fence with shrubbery and wood chips surrounding it.
Besides the pressure of CSU expansion, Fort Collins has seen an increase of about two degrees since 1970, corresponding to a population increase of 90,000. This is probably a little higher than Dr. Spencer’s estimates for UHI.
The Boulder weather station is similarly sited since the concrete path is just under 10 meters away.
It is at the campus of NOAA’s and NIST’s headquarters in Boulder. Anthony Watts visited the station in 2007 and took photos for the surfacestations project. Like Fort Collins, it gets similar expansion pressure due to nearby construction as seen in this aerial photo.
Here are the temperature records fro these two USHCN stations:
NCDC Fort Collins Temperatures
There is some UHI effect visible in the Boulder record below, but much less than Fort Collins.
Conclusion:
We have two weather stations in similarly sited urban environments. Until 1965 they tracked each other very closely. Since then, Fort Collins has seen a relative increase in temperature which tracks the relative increase in population. UHI is clearly not dead.
Steve Goddard (22:15:21)
I delivered mail one summer in Fort Collins (1975), substituting for carriers on vacation. The whole city is flat. Only rural delivery went uphill. The city will have grown since then, but that’s how it was in 1975.
Here is the same graph as in Figure W1, but using the corrected data:
Figure W3. Ft. Collins minus Boulder temperatures and gaussian average (left scale) and Populations (right scale). Darker blue line is the linear trend of the temperature differences. Data prior to January 1942 have been decreased by 0.6°C, per the analysis detailed above.
By the way, people are always complaining that skeptics’ analyses do not get investigated here in the same way as AGW supporters’ analyses. Next time someone says that, point them here. This is a scientific site, and anyone’s claims are up for critical examination. That’s the beauty of the site, it is science at its finest. Kudos to Anthony Watts for fostering the true scientific spirit.
Steve, Willis:
There is a problem with the underlying data for Boulder, CO if you look the data up with the flags turned on in the USCHN site Steve got the plots from.
From 7/1895 thru 4/1897 there is an E flag
From 7/1910 thru 8/1910 there is an E flag
From 9/1910 thru 11/1911 there is an X flag
From 12/1911 thru 2/1912 there is an E flag
From 3/1912 thru 4/1912 there is an X flag
From 6/1936 thru 6/1939 there is an X flag
From 11/1956 thru 7/1958 there is an X flag
From 5/1970 thru 1/1971 there is an X flag
according to NCDC that means:
Thats a whole lot of Filnet for Boulder. On the other hand Ft. Collins has no flags in it’s data history. So you have to ask is the deviation really in the record or in the Filnet program?
If you can find 50 – 100 pairs like this in different geographies, then you will get your definite answer on UHI.
Don’t know how easy that is.
A real research proposal, perhaps??
Smokey (12:13:19) :
I certainly thought it was fun.
removing trees! shame! and it sure would have made a BIG difference.
Anthony I hear you Might??? be coming to Aus. Please do:-) we’d love to hear you speak, I am trying to find info re places round where I live to maybe arrange a venue.
Hansen out here spewing lies sure needs Rebuttal!
Scott Covert (13:23:05) :
Steve,
That is very funny and insightful. May I have your permission to use this illustration?
Finally, some real benefit from acne.
Well, there is another benefit. It proves you are not a eunuch.
Tom_R (13:40:17) :
When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge of it is of a meager and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced it to the stage of science.
— Sir William Thompson, Lord Kelvin (1824-1907)
It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts.
— Dr Watson, the author, addressing Doyle, the author, in “A Scandal in Bohemia”
Steve Goddard (14:03:39) :
You mean you didn’t select the sites because of Balloon Boy and Ward Churchill?
Colorado certainly seems to have more than its fair share of wackiness. Maybe not to the same extent as California, but in the same league. My friends and family are always commenting on how many strange coincidences and stories are right here, in the front range.
For example, why did the Islamic wannabe terrorist set up operations here in Denver, getting a job as, of all things, a shuttle bus driver at Denver International Airport? Was there something about our city or air or water convincing him this would be a good place to purchase women’s hair products for hydrogen peroxide? http://articles.latimes.com/2009/sep/25/nation/na-terror-plot25
And Balloon Boy?
What’s the deal with the Columbine Massacre and the more recent repeat?
I don’t know, but it is strange.
I still love Colorado. In particular, I really do like Boulder and Ft. Collins. Nice places both, but have suffered from the growth.
But Steve, really liked the article. Good job.
Also, Dillon probably wouldn’t be a good place for long term temp studies. The original town is now under water from the dam. That might have affected the temperatures.
George E. Smith (14:33:37) :
George,
You’re right. It works both ways. I’ve personally met people I strongly disagree with and really liked the person. I’ve also experienced the reverse.
It should always be the position/opinion attacked, not the person. Sometimes the person we disagree with is simply misinformed. Sometimes they are partially correct. And, quite simply, sometimes we are wrong.
Always make sure that crow your cooking up for somebody is well seasoned. You might have to eat some of it.
Comletely off topic (always nice to have a lighter side), where did Mork live?
Steve Goddard
Re the stable USA states since the 1930’s.
I have forwarded a paper to Anthony abut a study of six Australian sites, widely scattered around the country.
I found that some have constant or slowly increasing temperatures, some others quite rapid warming.
The differece is in the monthly maximums – the minimums clump together quite closely.
Some records go back to the 1850’s.
My conclusion is that each location has its own long enduring micro climate.
You can get ant global temperature index you want by carefully selecting sites to suite your expectations – alarmist or denialist, or luke warmist in between.
I would like to see an analysis of the growth profile of the many stations dropped from the global indexes in the 1990’s – were they growing too slowly and so were considered to be not “fit for purpose”?
Oh dear – there I go again.
I meant to type “you can get ANY global temperature index to want …..”
Ants in pants have no place in this discussion.
Wren (23:06:00) :
But how do you know for sure the low’s rising to meet the highs is a signature of UHI anyway?
Because when I look at these sites, I make sure I look at the data, all of it, in one big picture:
http://www.robertb.darkhorizons.org/TempGr/Med_AshAv.GIF
Steve told me “It has been cold in Colorado in recent years. This winter in particular seems endless, after a non-summer in 2009. Winter started the second week in October.”
The time of year most affected by UHI is also the time of year where the Sun angle is the highest and the area of buildings have the greatest daily exposure to direct sunlight. You need to do yearly graphs to demonstrate and test this. And make sure you plot daily highs and lows.
boballab (01:53:44) :
Boulder(50848) is missing B-91’s from 1947 on back, according to the noaa site http://www7.ncdc.noaa.gov/IPS/coop/coop.html that serves them up.
Ft. Collins(53005) has a good set of them.
You can try hitting noaa up for the missing Boulder(50848) B-91’s.
tommoriarty (22:11:49) : I agree with you, it is obvious to me that if you cut off heat, the sun, earlier in one spot than in another, it can not become as warm as the spot that is not cut off. I don’t understand why this is so difficult to convey!? The difference between Boulder and Ft. Collins is clear to me as well, don’t know what Mr. Goddard is so hung up on.
concerning
Steve Goddard (23:12:22) :
Steve Goddard (22:44:17) :
Steve,
I commend you on the important comments you have made on a variety global warming issues.
One the the most useful aspects of WUWT is the discussion of the effects of temperature sensor placement. It in in this spirit that I offer my comments about the difference between the Boulder and Fort Collins placement.
I have added more annotation to my Fort Collins image. It shows the elevation at various points moving west from the Fort Collins temperature sensor placement site. Readers can see it here.
Note that in the first three miles the elevation changes by only 150 feet. The rise up the Hogback to the reservoir is only another 270 feet in the next mile (This is the area shown in the image you provided at time 23:12:22). This is a total of about 420 feet in four miles.
Now look at the Boulder image again. Please note that the elevation change going west from the sensor site is over 1700 feet in less than a mile and a half, and over 2500 feet in less than two miles!
Now, I am agreeing with you (for the third time) that the divergence in temperatures between the two sites is likely due to the UHI effect. The broad flat expanse between the Fort Collins site and the mountains probably was developed in the last 40 years. The folks in Boulder have not been inclined to develop the much smaller, steeper area between the Boulder sensor site and the Flatirons.
Here is where I disagree with you: Your statement, made in the original article, that the two sites are “located in very similar geographical environments along the Front Range,” is not really accurate in the spirit of WUWT’s attention to site placement detail, as my images show.
I am genuinely looking forward to your further insights.
Best Regards,
Tom Moriarty
OK, first things first… you guys need to cut all the talk about topography and hiking, biking etc… YOU’RE MAKING ME FEEL TOO DAMN OLD!
Topography, elevation, and etc are all irrelevant because the mountain ranges have not changed over the last 100 years. What is there and has not changed in the past 100 years is not going to make a difference
change change CHANGE CHANGE change CHANGE
What has changed in the past 100 years is what is relevant.
Willis, you smoothed out the temperature graph too much, the yearly graph in the original post is fine.
Willis, sorry, I forgot to add that Dr Roy’s population hypothesis is fine because more population eventually leads to more roads, houses, buildings etc… in this case, the changes are still UHI, just proximity to the station. Of course, add an ac unit or bbq and you have even more of the same.
A little OT, but here is a plot of raw, TOB-adjusted, and total-adjusted temperatures for Boulder:
http://img24.imageshack.us/img24/4475/050848.gif
There was a big adjustment between roughly 1950 and 1970, but all three plots show a very small positive temperature trend. Actually, if you were to “fill in” some points in the raw plot, the trend would decrease slightly.
Anyway, back to the topic: from a UHI perspective, a flat trend in Boulder (little development to the west) and a rising trend in Ft. Collins (much more development to the west) makes sense since the prevailing wind at night (absent larger synoptic forcing) is from the west. From a “comparing the TRENDS” perspective, these two sites are very similar. All of the details about how far each site is from the foothills, etc. can be used to explain why the ABSOLUTE temperatures are different, but absent anything else, the climatic TRENDS should be very similar. Ft. Collins is affected by all of the same weather systems that Boulder is.
Tom,
I agree with you that Fort Collins and Boulder are not identical. The sensor in Boulder is closer to the mountains. The foothills in Boulder are generally taller than in Fort Collins, which creates the impression that you are closer to the mountains.
My disagreement comes more as an avid cyclist who knows that once you hit the western edge of town in both cities, you have some serious climbing to do up over the hogback or up into the canyons. I also have found the climate to be nearly identical in both cities, except that Boulder tends to be a little warmer – as seen in the graphs.
I have a thermometer on my bicycle and the temperature in downtown Fort Collins is usually at least two degrees warmer than it is two miles away in the south, north or east.
Note that Horsetooth reservoir is in the mountains, and that the football stadium is right at the base of the mountains.
http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=80525&sll=37.0625,-95.677068&sspn=54.928982,95.712891&ie=UTF8&hq=&hnear=Fort+Collins,+Larimer,+Colorado+80525&t=p&ll=40.561352,-105.151005&spn=0.02605,0.046735&z=15
And the similarity of the geographic settings between the two cities
http://maps.google.com/maps?f=d&source=s_d&saddr=Boulder,+CO&daddr=City+Park,+Fort+Collins,+CO&hl=en&geocode=FYqUYgId7rK5-SnTr40nTo1rhzFYgBugfDs5yA%3BFVBKawId6Te8-SmdX-EHFUpphzEOX8AtiVxTfg&mra=ls&sll=40.303618,-105.166626&sspn=0.836792,1.495514&ie=UTF8&ll=40.33503,-105.516815&spn=0.836402,1.495514&t=p&z=10
The article leaves out one very important factor. Boulder did not have an official climate station until 1990. Before that the Boulder record is from many different non-standard locations including the rooftop of the firehouse for many years. There is lots of missing data, including entire months. As a result we know there is a significant warm, dry bias in the pre 1990 data. The article is trying to make interpretations that simply cannot be made due to big inconsistencies in the pre-1990 data at Boulder.
All I knew Boulder for was Mork and Mindy:
Jack Simmons,
I agree that Colorado has a disproportionate share of whackos, including another school shooting in Littleton two weeks ago. It also has the highest rate of teen drug use in the country. I was in Boulder once on National Marijuana Day, and there were literally ten thousand stoned students walking from campus towards Pearl Street after a rally. Looked like a scene from Shaun of The Dead.
Apparently a lot of people take that “Rocky Mountain High” thing a little too literally.