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 (13:57:44) :
Pearl Street Boulder ia 1.05 miles entrance from the entrance of Boulder Canyon.
Old Town Ft. Collins is 3.92 Miles from Hughes Stadium and the foot hills.
See? I can cherry pick too! I was not disputing your analysis, just making an observation for those not familar with the area since I live in between the two cities.
The measurement station for Ft. Collins is not at the stadium, it’s on the main campus which is over 3 miles east of Hughes stadium stadium and the foothills.
Due to the proximity and the topology of the foothills (all are not created equal) the Boulder station will spend much more of the afternoon in the shade. However, as I stated, that should not affect the trends.
There are zero sunspots on my climate widget…does that mean we should be on the look out for zombies or something?
Bulldust (17:11:50) :
When I used to live in Denver they always referred to Boulder as 30 square miles surrounded by reality… has much changed?
I thought that was Canberra.
Do any of you ‘closed minded AGW proponents’ have more to offer than scripted responses based on perceived socioeconomic comprehension levels?
did i miss this earlier? royal society to be on the review panel?
10 March: Vancouver Sun: Reuters: U.K. academy to review UN climate change science
Britain’s science academy said on Wednesday it would take part in a review of U.N. climate science intended to restore trust after a 2007 report was found to have exaggerated evidence for global warming.
“I can confirm that we are one of the parties (on the review panel),” Bill Hartnett, a spokesman for The Royal Society, said..
(LOL: Pic Caption: Polar bear photographed in drifting and unconsolidated sea ice in Kane Basin, off Cape Clay, in northern Greenland. Photograph by: Nick Cobbing, AFP/Getty Images)
http://www.vancouversun.com/technology/academy+review+climate+change+science/2666267/story.html
11 March: ABC Australia: Independent body to review UN climate panel
He (Robbert Dijkgraaf) says the review will focus on what procedures were used.
“It will definitely not go over all the data, the vast amount of data in climate science,” he said
http://www.abc.net.au/news/stories/2010/03/11/2843268.htm
(the only mention found online that CALLS were made Wednesday for Pachauri to resign)
11 March: The Hindu:Narayan Lakshman : UN to hold independent review of IPCC: Ban
The IPCC Chairman, Rajendra Pachauri has also recently come under fire for such lapses. Amid calls for his resignation on Wednesday he said, “We have received some criticism. We are receptive and sensitive to that and we are doing something about it.”..
http://beta.thehindu.com/sci-tech/energy-and-environment/article236910.ece
OT….and tale of another city…..Barcelona, Spain.
March 8, 2010. Check out the hourly observations. At one point they had thundersnow!!
Thundersnow…the second week in March…in Barcelona!
http://www.wunderground.com/history/airport/LEBL/2010/3/8/DailyHistory.html?req_city=NA&req_state=NA&req_statename=NA
[Page down to the hourly observations to see the thundersnow report]
Chris
Norfolk, VA, USA
OK, last comment here for Steve Goddard, Tom Moriarity, superDBA, and TH (the locals).
I’ve lived in Boulder for 40+ years and I run past the Boulder CRS site on a regular basis. I know Fort Collins well and I maintain that the Boulder and Fort Collins sites are quite different in terms of solar exposure, winter snow accumulation, nearby “suburbanization”, summer humidity (due to evaporation from ditch irrigation, trees, etc.), and especially conversion of surrounding grass prairie to tract housing.
I think these factors are consistent with the trends in the raw data. They may/may not affect decadal trends in the data.
Joseph (09:59:58) asked ” If Fort Collins has been experiencing an increasingly greater amount of UHI than Boulder over time, I would expect the temperatures at those two sites to be diverging.
“Instead, judging from your third figure their temperatures appear to be converging, with the difference approaching zero. ”
Actually, the trends ARE diverging but the perception is based on an arbitrary zero-point.
The embedded caption on the third figure says “Boulder-FtCollins diff”. Comparison of the raw data plots indicates that the calculation was T-FortCollins minus T-Boulder. So the difference values start strongly negative (about -2.5 F) in the 1940’s (because the Fort Collins station was inherently cooler than the Boulder station due to local siting issues). Over time, the difference declined to the point that the stations are near-equal in the first decade of the 21st century.
Fort Collins warmed much faster than Boulder because the UHI effect in fast-growing Fort Collins was that much greater than in “eco-friendly” Boulder.
BTW, Boulder has grown slower than Fort Collins in terms of residents, BUT Boulder now experiences about 50,000 in/out-commuters/day due to residential-growth restrictions. Some carbon footprint.
“It’s a lovely place to live, but you wouldn’t want to work there”
So, what’ll it be? Dale’s Pale or Five-Barrel Pale Ale?
Having lived in both towns in the ’70s-’80s, I wouldn’t say they are geographically that similar. Boulder is where the mountains meet the plains, but Fort Collins is a true plains town, flat, with the mountains in the distance.
The UHI discussion would be enhanced if it was possible to extract the most relevant satellite records conveniently.
Since they aren’t calibrated, it would be another set of apples-to-oranges. But. When you’re comparing trends it would be quite handy to have some concept of how the gridcell was trending.
Not that is matters much, but Theo Goodwin (10:54:41) : said that both cities are on top of plateaus and in the foothills of mountains. But in actuality, both are in valleys adjacent to the foothills; Boulder in the Boulder Valley and Ft. Collins in the Poudre Valley (although the Boulder Valley is more dramatic, especially entering Boulder from the South on Hwy 93, where the motto is “Pray for me I drive 93”).
And yes Coors is in Golden and the Solar Energy Research Institute has become NREL. Both cities are special places but Boulder holds the edge, partly due to it being the home of the Golden Buffaloes, a few Nobel Prize winners (not saying much) and several astronauts, as well as the Bustop Ballet.
While it is true that Pearl Street in Boulder has a pedestrian mall, one can still drive a park in downtown Boulder.
Boulder certainly is a liberal bastion, many love Gore and Hansen here.
How quickly things remain the same – this heat island stuff was discussed in this 1969 publication:
http://tinyurl.com/yc2bmr8
The poor CO2 molecule was already on the most wanted list by then.
harrywr2 (18:17:22) :
I see. So UHI doesn’t work in the rest of the world. Only in the USA.
Very sound observation there, air tight.
(sarc/off)
R. Gates (16:34:40) :
If you are correct that Arctic ice is in a shrinking trend why would it be important? Your implication is that it is because of pollution?
If it is you need to provide proof of this.
But if you look at the graphs it is quite clear that Arctic ice is in a growing trend for 3 years running. This cannot be denied.
OT but just filing this here for interest.
American’s concerns about global warming drop.
http://www.gallup.com/poll/126560/Americans-Global-Warming-Concerns-Continue-Drop.aspx
via national review online
Steve Goddard (14:03:39) :
steven mosher (13:28:19) :
Thanks for the links. Those sites are interesting, but are up in the mountains and mostly on the other side of the Continental Divide. Boulder and Ft. Collins are very similar college/climate science towns with well maintained long-term records, which is why I chose them.
**************************
Think the point would be to compare the TRENDS of the two rural sites
with the trends of these two that you have selected. of course the weather will be different.
Oops sorry latitude (13:36) – I scanned the page but missed it.
Bah
Phil M (10:02:28) :
Okay, what am I missing:
– In 1970 Ft. Collins had less population than Boulder.
– In 1970 Ft. Collins had higher temperature than Boulder; and the the trends had already diverged.
Shouldn’t we conclude that something other than UHI was causing warming?
===
And what happened to the lows after the 1990’s? Both places just stopped getting as cold as they used to get.
Wren (20:44:25):
We already know that it’s natural climate variability. The planet has been warming, in fits and starts, since the LIA. CO2 has nothing verifiable to do with it. If you disagree, provide solid evidence.
The wide array of ideas and concepts put forth by the long list of commenters above in their efforts to explain or further question aspects of the comparative data about these two Colorado communities, dramatically demonstates the near endless factors that influence very local climates. In my town and I suspect in both of the communities in the study, there are a variety of microclimates. The diffrerences from spot to spot and in response to localized changes such as the growth of a nearby cluster of trees or building of a bridge are small, but in fact they are large enough to significantly skew the long term tempereature trends when we are working with tenths of a degree or even a degree and half or so.
A man who was the State Climatologist of Kansas had a theory that the dust bowl was the result of the burning of the prairie grass and plowing of the prairie as early settlers tried to turn range land into farm land. They changed the albedo of the land from the dark of prairie grass to the pale light tan of poor soil and conventive storms no longer formed and a drought followed; the dust bowl of the 1930s. He says that this was followed by the drilling of artesian wells and irrigation again changing the albedo and the rain returned. I do not vouch for his theory, but I point out how out that he illustrates in his theory how our activities can alter the climate. I cannot say what was taking place in and round these two cities through the years that altered the comparative increase in temperatures.
Now that we have thousands and thousands of thermometers on line all over the United States, I think we have the resourse to begin to do more studies of localized effects.
But, all of this underlines the difficulty in producing a meaningful scientific record from the occassional temperature readings that we have historically relied upon. Instead, I strongly think we should look a the bigger picture of temperatures as produced by the new satellites where we seen through average of the multitude of local effects blended together in a full atmosphere scan and where we break lose of from just surface temperature data in our average and consider the full depth of the atmosphere. This is briefly explored in my recent interview with John Christy, Ph.D. who with Roy Spencer has done the studies of full atmospheric temperatures from satellite data. I will post that full interview soon on my webpage.
And, that brings up, one more point. I just posted my full interview with our host Anthony Watts inwhich he gives his full powerpoint presentation on surfacestations.org. It is viewable at
http://www.kusi.com/weather/colemanscorner/87131742.html
Sorry about rambling on, so.
Smokey (20:56:11) :
Wren (20:44:25):
Shouldn’t we conclude that something other than UHI was causing warming?
We already know that it’s natural climate variability. The planet has been warming, in fits and starts, since the LIA. CO2 has nothing verifiable to do with it. If you disagree, provide solid evidence.
—-
You are addressing me with your response to Phils M’s comment. Wouldn’t it make more sense to address me with a response to my comment?
Here again is my comment:
And what happened to the lows after the 1990’s? Both places just stopped getting as cold as they used to get.
Any thoughts?
If UHI is the accumulated heat from the sun on asphalt and buildings, and one site is cut off from the sun even an hour earlier than the other, that site cannot warm as much with all else being equal. I am not saying they are equal, but Boulder has a higher population density than Denver according to Wiki. I lived on the front range from 1972-92 outside of Masonville, and have to disagree with you Steve about the mountain shadows falling on these respective cities.
These Google Earth shots each have a 5 mile horizontal line for relative comparison:
Boulder: http://i44.tinypic.com/212ze6x.jpg
Ft. Collins: http://i40.tinypic.com/2112hbo.jpg
There are conventions established for describing trends in financial circles. Stocks (and bonds, and commodities, etc.) are considered to move in trends of varying length, conventionally called long-term (or major), mid-term (or intermediate), and short-term (or minor). (There are even super-cycles of multi-decadal length (supposedly), and ultra-short intra-day trends.) These trends aren’t the same as statistically significant trends. They are just established by observing a pattern of higher highs and higher lows, for a rising trend, for instance, or a rising moving average trendline. (Such averages may be short, intermediate, or long-term, depending on the number of periods in their average.)
It’s therefore possible to be both in a bearish trend AND a bullish trend concurrently, if the bearish trend is a countervailing “correction” within a longer-term bullish trend, or the bullish trend is a short-term rally within a longer-term bear market. (There were six such false rallies after 1929 until the real turnaround in 1932.)
Obviously, this is the situation with Arctic ice extent: we have a long-term decline and a short-term increase. If someone says the long-term trend is down, he’s correct. But if he says the ice extent “is” declining, he’s wrong, because at present it is rising, and an unqualified “is” implies the most recent trend.
Similarly, if someone says the ice extent “is now” rising, or “is recovering,” or even “is trending upward,” he’s correct, because that’s what it is doing currently. But if he says that “the trend is up,” that’s not correct, because saying “the trend” without qualification implies the “major” or long-term trend, which has actually been declining.
So when one side corrects the other, it shouldn’t say that the other side is wrong, just that its claim lacks the qualifier that is necessary to provide context.
The current year-to-year trend is up over the past two years, so R. Gates was making an overstatement to claim that the year-to-year trend is down. That implies that skeptics are basing their claim on a period that is shorter than a year or two, which isn’t so. He should have said something like, “the five-year moving average trend is down, despite the recent uptick (or blip).”
The hijackers at Lucia’s blog have proven UHI is not a problem. Just ask them.
MikeC (17:04:15) quotes me as follows…
Tom Moriarty (14:34:58) :
“The Boulder site is only a mile east of the mountains, with nothing but open space between them. In fact it is only about a mile from the Flatirons (a prominent rocky feature that rises 1500 feet about the temperature site) and less than two miles from the summit of Green Mountian, which rises 2500 feet above the temperature site.
Best Regards,
Tom Moriarty
Colorado”
Mike C. then replies…
“Tom, this is ridiculous and a strawman argument. The question here is not in how they ARE different, but what is the difference in their CHANGE.”
My Response…
Mike C., I am not making a “straw man argument.” I am not disputing the diverging temperatures between Fort Collins and Boulder. I am simply pointing out the important (for this discussion) fact that the two sites are quite different.
Steve Goddard says in the first paragraph of the article that both sites are “located in very similar geographical environments along the Front Range.” I think that statement misses some important differences.
Compare the following two annotated images, on the same scale, from Google Earth.
Boulder
Fort Collins</b
The bottom line is that the Boulder site is MUCH closer to higher mountains, and has less (none) developed land between it and the mountains. My guess is that the highly developed four miles between the Fort Collins site and the Horsetooth Resevoir to the west were much less developed 10, 20, or 40 years ago. This point, in fact, lends support to idea that the temperature divergence between the two sites is due to an increasing UHI affect in Fort Collins.
Best Regards,
Tom Moriarty
ClimateSanity
jonrgrover (15:37:22) :
Perhaps we need to place most of our surface stations in large graveyards because they don’t change as much year to year.
=========
Probably a good idea, except for the way the stations look. I like the idea of stations in National and State Parks.