From Cliff Mass, a study that demonstrates how adding a runway generated a hockey stick in temperature difference to surrounding stations. As I’ve been saying for years, the dynamic environment of the airport is the wrong place to measure “climate change”, and in this case, Cliff Mass shows why.
Last week the Seattle Times had a front page story about the Northwest becoming warmer and wetter based on recently updated climate statistics at Seattle-Tacoma Airport. But can we use one observing site to reliably determine region climate trends?
…
Between 2004 and 2008 there was a huge change at the airport, one of the largest construction/earth moving projects in the region in years–the building of a third runway. In this blog I will ask the question: did the construction of the third runway have an impact on summer temperatures reported from the airport? My conclusion and that of my colleague Mark Albright is: it sure looks like it.
But first a few pictures. Here is a picture of Sea-Tac before the third runway was installed. I have also indicated the position of the National Weather Service/FAA temperature sensors (their ASOS system) by a blue circle (just to the west of the second runway).
…
Here are two recent pictures of the current runway situation (with the blue circle showing the sensor position). Quite a change.
Did the runway change the summer climate at the airport? My colleague, Mark Albright, calculated the difference in summer temperatures (June, July, August) between Sea-Tac and an average of four nearby official reporting locations (Olympia, McMillan Reservoir near Tacoma, Kent, and Buckley).
Negative means that the neighbors are warmer than Sea-Tac, which you would expect since they are farther inland and generally south of Sea-Tac (which has some cooling influence from the Sound). You will see that Sea-Tac was generally cooler than those surrounding station (by roughly 1.5F) early in the period. And the slight shift in 2002 had little impact. But after construction began in 2004 (particularly in 2005 to 2006 when the heavy earth moving occurred) things changed: Sea-Tac temperatures warmed up by roughly 2F so it was the same or warmer than the surrounding, more inland, stations. I strongly suspect we are seeing the influence of the third runway.
…
Bottom line: It really looks that the third runway has significantly warmed summer temperatures at the airport. Thus, one must be really careful in assuming that any warming there is the result of some kind of greenhouse gas influence.
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Full story at Cliff Mass blog h/t to WUWT reader “Speed”
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“It is a well known fact that cities are warmer than the surrounding countryside because:
a) Tarmac is black and absorbs and then radiates away heat…”
Theoretically, this should produce a one-time jump in temperatures, and the long term trend thenceforth should be unaffected. In practice, growth in urban population and traffic will create a rising trend overlay. Also, the latter or any small temperature trend will be amplified by the presence of asphalt.
If one puts a couple of well-placed breaks the letters of the name of the graph (seatacheat) we get: seat-a-cheat.
Steven Mosher says:
July 17, 2011 at 12:44 pm
“What happens when you spatially average 5 sites,One which is 2F warmer than the average of the other 4? what happens to that 2F? well, its 20% or .4F.”
Math 101 FAIL.
Let’s try a theoretical example:
Site 1, let’s say Sea-Tac; 15F
Site 2: Anywhere; 12F
Site 3: Somewhere; 13F
Site 4: Everywhere; 14F
Site 5: Nowhere; 13F
Site 1 is 2F warmer than the average of the other 4. No matter how you try and twist the data there is no way it can be diluted to 0.4F The only place 20% can be dericved from is if all sites are added together, then the new average is 20% of the total, not Site 1 being 20% of the total. In this case that is 20% of 67F or 13.25F
Sorry but even here Site 1 is still 1.75F warmer than the new average, but the new average has been modified by the site that is being investigated. Another FAIL.
Having worked at YYZ for nearly 32 years, I’m surprised nobody has mentioned the effect of burning rubber on temp readings.
Don’t forget that many airports were originally called airfields.
These were flat rural or semi-rural fields with the grass, wheat, or corn flattened
to provide dirt “runways”.
With a couple of hangers and a few outbuildings added, that’s where the
temperature, wind direction and speed, and cloud cover and precipitation
measurements began for these facilities, with or without the use of
modern Stevenson screens.
Today, you not only have the tarmac or concrete runways taking the
place of the dirt landing strips, but also the terminals, large hangers,
taxi areas added to the urban heat island effect.
Then one has to take a slightly wider view of the infrastructure
that’s been built up to support the activities at the “airport”… the
shipping company buildings, trucking terminals, state or interstate
highways leading to/from the “airport” etc. and then you
can worry about what influence prop wash and jet exhaust might have
on the ambient atmosphere near ground level inside an “airport”.
R.M.B on July 17th at 11:36 am, above:
“Airport temperatures are by definition the highest in the area, to use them for climate calculations is fraud.”
…pretty much says it all.
If the only information you’re studying is airport temperatures by
themselves or comparing them to/against the other readings in the area
their useful.
To batch airport temperature information in with region rural or
semi-urban readings for general climactic interpretation is to skew
the data to the warm side… and really poor methodology.
Cliff Mass could make the same report from almost any modern
airport.
Cliff Mass is highly competent and ethical. However, his grants in large part come from
NSF. When he says he believes in AGW, so what. Sod do I, but know that AGW is not a major driver of weather. If Mass disputed AGW, in effect he would be pissing in his rice bowl. Put his comments about AGW in context.
It is no surprise that the local AGW crowd and it’s mouthpiece, the Seattle Times, would run with this nonsense. I wonder what the readings at the Renton, Boeing Field, and Everett airports, in close proximity to SeaTac, were over the same time period?
From WonkyPedia. The airport was added to in 1959 to allow the use of jet engined aircraft. Will be interesting to compare the trend at the airport with nearby stations in light of this upgrade.
regards
I think the sensor should be moved to inside the main terminal where the temp is more stable and away from the nasty CO2 gas
Hot brakes…
Jantar.
The way averages are done in a regional average.
5 sites. they are all 10.
site 5 has 2F of positive bias.
What does that do to a regional average?
How do we ( cru, giss, etc ) calculate regional averages?
tada! something like what you see below
Truth, without the bias is 10.
with a 2F bias at one site????
site 1: 10, site 2: 10, site 3: 10, site 4: 10, site 5: 12
10+10+10+10+12 = 52
52 / 5 = 10.4
So if site 5 has 2F of Bias, when you average it with other the 2F of bias becomes…….
.4F of bias.
Then, of course, the 2F wasnt for the WHOLE YEAR. its 25% of the year.
so… damn, you are down to 1/100ths of F
WORSE YET. this is a step change. It doesnt impact the trend very much.
you go figure that math
The article stressed that the 30-year average for Seattle has gone up, now that the 1970s have been replaced by the 2000’s in the “climatic” average. Perhaps Mass could compute the annual average for Sea-Tac (NWS KSEA) for both 1970-1999 and 1980-2009 (or 1971-2000 etc depending on how NWS does it), all 12 months max/min average, and then do the same calculation for the average of the 4 comparison stations. The 2000’s are probably warmer than the cool 1970’s, so the later averages are probably higher. But Mass’s figures seem to show that the touted SeaTac rise overstates regional temperature change.
There’s about a 1.8 dF difference for half the 2000’s in Mass’s graph after the runway was added. If the difference was constant in the 1970s, the SeaTac 30-year average should look overstated by about 0.3dF or about 0.2 dC.
Then it would be interesting to go back and compare to the 1940’s or 50’s, which may have been warmer than the 70’s.
Why do I suspect that this issue will trigger a massively funded research project to determine whether or not airports are anthropogenic??
This doesn’t relate directly to sea-tac, but our local weather station is just south of the long runway at Cheyenne (CYS). We have had rain every day this week, heavy at times, and it is simply oppressive here today–hot and humid. Yet the official reading shows that RH was 36% this morning, declined to 27% at noon, and has, as of this post (7pm local), risen back to 39%. This is too dry to feel as sticky as it is all around the city, and especially around the city periphery. I’m a couple of miles beyond city limits to the east. I just pulled out my sling psychrometer and it shows 58% (wet bulb = 70F, dry bulb=82).
Does this seem reasonable to anyone out there? Is the airport being warmer and drier a reasonable observation? Can anyone quantify the plus-minus on a sling psychrometer?
I know it has been 6 years since I left Everett, and I dont have a date on the picture up there, but I seem to remember quite a bit less snow on Rainier when I left. Just sayin’….
For England through the 20th century up until the 80s, GISS use 50 or so stations comprising of a mixture of rural, urban and a small number of airports. Then through the 80s up until the 00’s, these bottleneck into 9 or 10 airport stations (some of the station names don’t reflect this). I was looking into this a few months ago and was surprised to find that all stations currently used by GISS in England are located at airports. There is no valid reason for doing this (unless, I imagine, you are mining for an enhanced warming trend), as many of the airport records don’t even begin until the 80s. I wanted to see how this reduction in the number and nature of stations correlated with the difference between GISS and other datasets through the late C20th warming period, but got sidetracked by work, and can’t remember the exact numbers.. If anyone with more statistical skill than me is interested however, it might be a worthwhile investigation. I can try to find the information I collated.
Roger Sowell says:
July 17, 2011 at 10:58 am
To expound on an OT comment – a friend of mine was flying into a Connecticut airport, I think on the way to some airshow and had a conversation with the tower that went something like:
Tower: Clear to land runway X (okay, not sure exactly what it was called).
Wes: Please repeat runway.
Tower: Clear to land runway X.
Wes: Do you have a visual on me?
Tower: Sorry, clear to land runway 24. (Or something with a sensible compass heading, I don’t recall which airport, otherwise I would have read one from Google maps.
Being a CT airport, a lot of traffic was corporate jets and helicopters. Helicopters were parked along a taxiway. Wes was flying a biplane and was so slow that the tower flight controller assumed he was flying a helicopter!
Aside to the pilots here – sorry for however badly I messed that up…. Actually, it might have not been a biplane, but it was old, slow, and obviously not the usual fare.
Steven Mosher says:
July 17, 2011 at 12:44 pm
How about the fact that this airport proves that whoever monitors that data station has no standards whatsoever? Do you have some reason to believe that the people who monitor other data stations are any better? Who is ultimately responsible for all data stations? To whom can we complain about their standards? And, oh yes, are there any standards? What are they? Is there no standard that says “Surrounding a station with asphalt that is used by jetliners requires moving the station.”
If our temperature reporting regime is a Keystone Kop operation at best, then it has to be rebuilt by responsible people who behave transparently. Otherwise, all the surface temperature data is trash. I believe it is trash.
I really don’t care about statistical magic. I care about holding people responsible for mismanagement? Do you?
When you surround a station by adding a new runway or taxiway on one side of it, the change in temperature reading would not be from the new asphalt alone. The added traffic on one side of the station would also have an impact and that traffic increases incrementally, not in a step wise fashion.
http://wattsupwiththat.com/2011/05/11/the-long-awaited-surfacestations-paper/#comment-658282
Mosher 5/11 13:28
how MUCH of the .8C is due to changes we have made to the atmosphere?
….
So one way to get the debate you want is to put your numbers down.
1. UHI ( ~.1c)
2. NV ( ~.3c)
3. GHG (.4c)
or any such thing, subject to some constraints.
Back on May 11, you challenged some of us to put down there estimate for how much of the total warming is do the “changes we made in the atmosphere”, lumping all that into GHG (Green house gasses) as opposed to NV (Natural Variablility), and UHI (Urban Heat Island).
You challenged us and some of put down values or ranges. Where is yours? Whas the 0.1, 0.3, 0.4 your estimate or only an example?
I do not believe it is fair to look at UHI alone.
In addition to UHI issues at city scale, there are real surfacestation historical biases that the sufacestations.org project is all about.
So there are at least 4 elements:
UHI,
SSHB (surface station historical bias),
NV (Natural variability), and
GHG.
The Sea-Tac anecdote is real data about SSHB. It shows station biases are real factors, independent of UHI effects.
Do all stations have this effect? No. But it is equally ridiculous to suggest that this is a one-off and no other station suffers this bias. JJB MKI’s post above would indicate that potentially the effect of SSHB might be increasing over time as the number of stations is reduced over time and concentrated around airports with growth in traffic (another sampling bias — you cannot collect data at airports that are closed.)
Then, of course, the 2F wasnt for the WHOLE YEAR. its 25% of the year.
so… damn, you are down to 1/100ths of F
You did mean a tenth of a degree, didn’t you?
And while you point out that the data in incomplete,
you get 2 deg F for 3 months of the year,
you make the assumption that the rest of the year it is zero. There is no basis for that. Do not assume zero where null (missing) is appropriate.
The key point of the observation is that for at least part of the calendar year, the SSHB at SeaTac is NOT ZERO, not Less than zero, and significantly positive enough to warrent caution in future studies.
And while we are at it, let’s separate out UHI effects at city scale from SSHB at line of sight scale.
Kevin Kilty says:
July 17, 2011 at 6:16 pm
… our local weather station is just south of the long runway at Cheyenne (CYS). … it is simply oppressive here today–hot and humid. Yet the official reading shows that RH was 36% this morning, declined to 27% at noon, and has, as of this post (7pm local), risen back to 39%. This is too dry to feel as sticky as it is all around the city, and especially around the city periphery. I’m a couple of miles beyond city limits to the east. I just pulled out my sling psychrometer and it shows 58% (wet bulb = 70F, dry bulb=82).
New England meteorologists do a good job of ignoring relative humidity and focus on dew points. even in Houston, the relative humidity is quite low on an afternoon with the temperature above 100°F.
Dewpoints above 60°F are annoying to people with scandinavian genes, above 70°F it’s getting oppresive, and above 80°F it’s time to get out of the sweat box.
According to http://www.wunderground.com/cgi-bin/findweather/hdfForecast?query=kcys , CYS currently has a dew point of 60°F, likely humid for Wyoming. Nearby non-commercial stations report values like 58°F to 62°F, so I’d say KCYS is probably right.
According to http://www.4wx.com/wxcalc/wetbulb.php , 82/70 dry/wet at sea level is dew point 64, RH 55%. At 6000 feet elevation, let’s call it 24″ Hg, that give a dew point of 65, RH 57%.
Humid if you aren’t used to it. Delightful if you’re from Houston. One handy thing about the dew point is that it’s often close to the low temp the next night. Once air temp drops to the dew point, dew formation releases a lot of heat, slowing down the temperature fall.
Currently at KHOU (midnight or so) 83 °F, 73°F dew point.
For our study Cliff Mass and I used the DS 3220 monthly data set available from NCDC. The 4 comparison sites used are the four coop/ASOS sites with a complete record from 1996-2010 and located within a radius of about 45 miles of SeaTac Airport. We started at 1996 so as to restrict the airport data to the ASOS era. Both Olympia and SeaTac ASOS installations became operational during early summer 1996.
-mark albright
U of Washington
pat says:
Remember the differential at the Honolulu International Airport that has 2 meteorological stations a mere half mile apart? One near the a runway, the other on natural surface, properly situated. Half a degree differential at noon, with nighttime temperatures even more disparate. Guess which one is used by NOAA?
This also makes a complete nonsense of “homogenization” of data gathered from sites with hundreds of kilometres between them.
It also needs to be remembered that meteorological stations at airports are there to provide relevent information to pilots rather than weather forcasters or climate “scientists”.
Steven Mosher said, “There are some obvious questions one should raise about any analysis.
The months reported are 25% of the year. In that time you see a 2F jump.
What about the other months? Well, we dont know because the report has no data sources.”
The Cliff Mass post was in response to a story in the Seattle Times, not a complete and detailed climatological study. It was designed to educate the public about a potential problem and to call into question a story in the main stream media.
Perhaps it would be more effective if you posted your criticism at Cliff’s blog. It’s more likely to be read by Cliff and his audience than a comment here.
With regard to anecdotes, in medicine it was always said that one case = “in my experience”, two cases = “in my extensive experience” and three cases = “in my personal series”