After reviewing over 1000 USHCN stations in the United States as part of my surfacestations.org project, I have often thought that I can’t find anymore surprises in the train wreck that is our surface observing network. Apparently I’m wrong.
Can you spot the problem between these two aerial photographs? Click for a larger image.
The answer is below.
This is another moment of serendipity, spawned by an interesting comment from physicist Dr. Robert Brown at Duke University, who was lamenting the differences in temperature in the Raleigh Durham area in this comment:
I continue to be struck by temperature differences in my very local sample space. For example, in Durham the NWS temperature is predicted to reach roughly 100F. Yesterday it was reported to have reached 101F. That’s warm for this time of year, although not unheard of, and last week it was cold, next week it will be cool to cold again. However, I subscribe to the Weather Underground service and keep a tab open on it all day, and it lists some 20-30 “local weather stations” belonging to citizens. In it I’ve noted a strange anomaly.
If you visit it right now:
http://classic.wunderground.com/cgi-bin/findweather/getForecast?query=27705
At the instant I’m typing this, the Durham (RDU Airport) temperature is reported to be 88 F. Since the NWS prediction is 99F (same page) and it is just after 1 pm, the NWS prediction seems a bit unlikely. However, if you scroll down to the list of area weather stations, a strange anomaly is revealed. First, only one weather station on the entire list reads 99F — Westglen, which is actually very near to my house. Westglen and my own household outside thermometer agree if and only if my thermometer is directly in the sun — true for part of the morning (mine isn’t a “weather station” — it is a radio thermometer just hanging on a rail of my deck 2 meters or so from the house, and it spends some part of the day with direct sun on its top).
I responded here at 2012/05/03 at 11:42 am, and as I responded, I thought I’d get a look at the RDU ASOS station, and I got a surprise in doing so:
@RGB, you may find this post interesting – airport ASOS stations have all sorts of issues, not the least of which is that after they fail and set new records, the records remain.
RDU is part of the climate record:
Strange that they felt a need to paint the asphalt near the ASOS station white:
http://maps.google.com/maps?hl=en&ll=35.89239,-78.782031&spn=0.000744,0.000873&t=h&z=21
Drag that view to kick it into 45 degree mode
Here it is before the painting:
WUWT?
WUWT indeed. Painting the asphalt white around the temperature sensor? It seems too bizarre to contemplate. Yet the closeup photographs don’t lie:
Here’s the Bing maps image from 2010 in closeup, with all the location instruments labeled:
And a further closeup from 2010, notice the dark cracks in the asphalt near the station:
…and here’s the Google Maps image from 2012, note the cracks are still there but it appears the asphalt near the station has been painted white:
Wow, can you say “albedo change”?
Here’s the two side by side along with the identifiers from NCDC’s MMS database:
This is the source of those ID numbers: https://mi3.ncdc.noaa.gov/mi3qry/identityGrid.cfm?setCookie=1&fid=14333
And here’s the GISTEMP selector page, showing they use the same station for their climate work: http://data.giss.nasa.gov/cgi-bin/gistemp/findstation.py?lat=35.87&lon=-78.78&datatype=gistemp&data_set=14
And here’s the graphs from GISS before (Raw) and after adjustments (Homogenized) overlaid. There’s that signature cooling of the past again:
Source:
http://data.giss.nasa.gov/cgi-bin/gistemp/gistemp_station.py?id=425723060000&data_set=14&num_neighbors=1 (homogenized)
Dr. Robert brown made a further reply of interest at 2012/05/03 at 1:12 pm
Hi Anthony,
I’m not sure why they painted it, but if you zoom out on the location and note the following (from the RDU History site, section on “the 80s”):
Terminal A opens to great fanfare in 1981.
Trans World Airlines begins service in 1984 as the sixth carrier to serve RDU passengers.
American Airlines begins service in 1985 as RDU’s seventh carrier.
RDU opened the 10,000 foot runway 5L-23R in 1986.
The Federal Aviation Administration (FAA) Air Traffic Control Tower opens in May 1987.
American Airlines opens its north-south hub operation at RDU in the new Terminal C in June 1987, greatly increasing the size of RDU’s operations with a new terminal including a new apron and runway. American brought RDU its first international flights to Bermuda, Cancun and Paris Orly.
I started school at Duke in 1973. At the time the airport was a single terminal and serviced maybe two or three airlines with infrequent flights. Cary was still a sleepy little town outside of Raleigh, and so was Morrisville. Most of highway US-70 was still forested between Durham and Raleigh. There was just one runway, and it was a small one, so the planes that came and went from RDU were similarly small.
In the 1980s, as you can see, they opened two new terminals! Terminal A was four or five times the size of the original terminal (which became Terminal B and is still there and still functioning, although for some reason they’ve closed Terminal A and are ready to tear it down). If you back off on the overhead map you post you can easily see the relative sizes — Terminal B is at the east corner of Terminal Blvd, with A running southwest of it and C the BIG terminal — bigger than A and B combined — due west of the two on the other side of the Terminal Blvd U. The old runways are still there on the Southeast side. The “new” runway — built in the early 1980′s and completed in 1986 — is clearly visible west of Terminal C.
Note that it is huge. As they say, 10,000 feet long. It may have even been built that long partly so that RDU could land a B-52 — in the late 70s a friend of mine was a B-52 pilot located in Goldsboro and he said that RDU wasn’t likely to be a nuclear target because its runway was too small to land a B-52, and somebody in SAC may have decided to nudge it somehow for strategic reasons. Then look at where they located the weather station — right there at the end of the big runway, with the entire airport complex to the south and a big expanse of hot asphalt runway a hundred meters or so away.
And there are so many better places! Probably the best place is the southeast corner of the complex, over next to the William B Umstead State Park, in that patch of ground past the National Guard. But even where they built it, they could have gone across the street and put it in the open patch in the woods a quarter mile or more away from the actual runway and it would have been better.
Now, look back at the GISTEMP record for the site. That peak in the early 90s was sure impressive (although check out 1890! WUWT too!) but it strangely enough happened just after they built a huge new runway and started landing a lot more, and bigger, planes at RDU. Did I mention that from 1987 to 1996, RDU was the US North-South hub for American Airlines, so basically every flight up or down the east coast ran through RDU? Or that they began international service with flights to e.g. London, Paris, Bermuda in that time frame? It was probably the single busiest stretch of air traffic in the entire record — flight numbers have gone down since (the cold war ended abruptly, no more need for big runways for B-52s and:-) they shut down the hub.
Even with a half a degree jump from the “are we starting the next ice age” hysteria of the early 60s — an event that they failed to “erase” from the RDU record, at least — what fraction of the jump was due to the steady blanket of CO_2 and water being dumped every five minutes all day long as jumbo jets were burning huge volumes of gasoline taking off literally over the top of the weather station? What fraction of it is due to the warming of air as it passes over the hot summer asphalt of at least one square mile of almost unbroken buildings and asphalt that lies due south of it, beginning a mere 100 or so meters away? What fraction of it is from the further CO_2 enhancement from the eight lanes of jammed rush hour traffic that uses the roads that bracket the airport on three out of four sides now? Only one of those roads was even there in the 60′s, and what is now I-40 was a lightly travelled four lane highway in the 70s (I once drove a friend from Duke to the airport in 10 minutes flat to catch a flight — try that now!)
And with all of that, we see less than 1.5 C warming from the coldest part of the record (your choice 1890s or 1960s). And
for any linear trend fit, even given the warming in the very late 90s, is visibly going to be what, 0.01, across over 100 years.
If you look at personal weather centers located just a tiny bit further away from concrete in that general vicinity, they generally record temperatures around 1C cooler than RDU. It was almost cow pasture and forest back in the 1960s, after all. And there goes all of the land-use based warming, along with it.
rgb
Couldn’t have said it better myself. I put a call into the MIC at the RDU NOAA Weather Service Forecast Office to inquire about why the surface albedo around the ASOS turned GISS climate monitoring station has changed dramatically, and if he was aware of it. No reply yet, but I’ll add an update if I hear anything from him.
Won’t the white paint make for better measurements? –AGF
I would question how much of albedo that is. Some white paints appear black in infrared.
@agfosterjr
It isn’t about making it better, it is about consistency of the observations…things like this can induce step changes in the data, which are often unaccounted for.
And, over time, that white paint will get dirty, and turn darker again, introducing a trend bias.
Keeping any weather station site surroundings identical over time is the best practice.
Cooler, maybe, but *better*? I don’t think so. You want the albedo around a climate monitoring station to be as close to the natural terrain as possible. An airport weather station is not designed for climate monitoring. It is designed for monitoring conditions at the runway so planes can be configured with the right operating parameters. They need to know how hot it is, for example, to get an idea of stall speed or at what speed to rotate up off the runway. For that sort of thing you WANT a station as close to the runway as possible. If it is reporting a temperature that is too cool, it could possibly lead to an accident by causing an aircraft to rotate too soon or approach too slowly.
The Google Earth image I get today — dated 7/5/2010 — shows even more white area with no marks, breaks, or any thing else. Very strange.
Yes Anthony, I’m puzzled by the claim that anomalies in the temp record are just as good or better than the actual temp measurements for determining trends. Does anyone know what math is used to justify this? They must be taking the first derivative of the measurements but changes in surrounding station conditions would surely effect the temp derivative calculation.
My friend Doug G. was flying home to Philly from RDU on the last flilght of the day back when it was a small and unpopulated place. He checked in at 5:00 PM, checked the time against his ticket and strolled to the boarding gate for his 6:00 PM flight. The plane was pulling out as he reached the gate.
Surprised, he went back to the check-in counter and asked, “Why did my plane leave an hour early?” and pointed to the large clock in the lobby which read 5:10.
She replied in a chiding Southern drawl, “Eveahbody knows that clock is an hour slow!”
Apparently it is not only the clock that is behind the times in RDU.
Gene @2:24
Albedo from albus for white. The white of an egg from albumen, and so on. IR would seem not to be an issue.
Anthony Watts says:
May 3, 2012 at 2:26 pm
[…]
Keeping any weather station site surroundings identical over time is the best practice.
Is that even possible, in 99.99% of cases?
False and erroneous information becoming part of the official record is also common in census tracts. I sometimes do genealogical research and discover errors fairly frequently. Also happend in death certificates too, when the deceased has lied about their age.
To crosspatch,
As a retired naval aviator who has flown into RDU many times, I agree with you. Airport weather stations are not placed to monitor climate change. They are there to measure the present conditions near the runway. It would be interesting to see if there was a step change in the temperature when the pavement was painted. My guess is that there is no statistical significance in any difference.
The real question is why would you put black asphalt around your temperature sensor in the first place?
Weather stations at airports are designed to provide weather useful for air movements in and out of the airport , and that is all. The idea you can take their values and spread them far wider simply makes non sense , especially when you consider that airports are in no way typical of their local areas. For instance they can be the only tarmac for miles around or the only big open area in a crowded city .
Using them makes about as much sense as using weather stations at steel mills and they being surprised that trend to read a bit high . Frankly there used not becasue there a good idea nor that that they meet the standards required but becasue their available, their a free resource and one whose maintenance is the airports problem . There a cheap but rubbish way of collecting weather data for wider areas .
More likely crushed limestone, not paint.
REPLY: I thought about that…but the cracks in the asphalt are clearly visible, they likely would have been covered over. – Anthony
RE the 10,000 ft runway.
Augusta GA’s runway is also 10,000 and it is still a small airport. The reason is so it could accommodate C-5 Galaxy’s and other large military airlift planes. Augusta is home to Ft Gordon and close to Ft Stewart. Savannah (home to Ft Stewart) also has 10,000 ft runways.
Ft Bragg is closer to Fayetteville – another 10,000 ft runway airport, but I believe it is still close enough to Raleigh Durham to be useful as an alternate field.
Jay;
As noted above, climate monitoring is the poor second cousin at airports. They want to keep the planes from crashing, period. Which means: “What is the air over the runways doing?” Which is of little or no use metroclimatologically.
Something looks ‘funny’….. the building to the right is a correspondingly brighter ‘white’ also.
Is this a ‘false contrast’ issue with the photo…. or did they paint the building and ‘have a little paint left over’ so they painted the parking lot also??!!!
Having spent over 32 years working at YYZ, I’d like effects of burnt rubber to be explained.
Can be a major stink if the wind is blowing the “wrong” way.
Guys, you do not seam to realise the possible consequences of this story: the AGW proponents might suggest everything be painted white to mitigate “the global warming”. The ultimate solution! Poor black people, though… (lol)
I lived in Raleigh and/or Durham for over a decade. The readings from RDU were ALWAYS rediculous. Easily 3-5 F higher than any other reporting station. They set the all time high one summer of 105F, found all the grass had died around the station and refused to make any correction to the record.
Seems to me ASOS and GISS have cross purposes. An ASOS needs to report important factors like density altitude where the field temperature is important, that is the temperature the aircraft actually encounter. You need that sort of information to calculate whether you can get off the ground before you reach the end of the runway.
I just went back to double check what other people said, and I’m repeating some ideas a bit, but in a different way. Add us all up, and it may be clearer.
@John F. Hultquist
I am familiar with the meaning of ‘albedo’, but I appreciate the reinforcement. The point here is that it is unlikely that the airport authorities chose to do this for the visual effect. Thermometers “see” in a much wider spectrum than we do, so it is not entirely incorrect to think of albedo in a broader sense, and that is indeed how many people use the word:
http://scienceworld.wolfram.com/physics/Albedo.html
So you should not be shocked when you hear an expression like “radar albedo”; it is no less sane than “black body” or “white noise”. They are expressions of how we perceive things — whether directly or mediated by instruments.
As some of us have guessed, the purpose of that white-looking stuff could be to make the thermometer readings correlate more closely with the density altitude at the runway. I would think that adjusting the temperature computationally might be an easier fix, but perhaps a lot of exposed asphalt in the vicinity of the thermometer, distributed in a non-uniform manner, makes it more random and faster-changing than the actual air density above the runway. If it really works, we should simply admire the hack. They certainly did not do that as a means to study climate.
Here’s an interesting source of data on “cool paints”. They have a higher albedo (if you pardon the expression) than commonly used paints, even though they are not white.
http://www.basf.es/ecp1/Spain/es/function/conversions:/publish/upload/02_Products_Industries/02_Solutions/paint_cool.pdf
I would guess you are right. From a flight operations standpoint the difference wouldn’t be enough to make any difference. From a climate monitoring standpoint, 1 degree of change is huge when we are talking about 1.5 degrees of global warming over 150 years.
Of course it reached 99°F at RDU on May 3, 2012. Just ask any tax-paid climatologist with authority and creditials. I know all surrounding stations report 81°F to 88°F but that is not the point. The official temperature is 99°F and is now carved in stone. That is how it is done so live with it. And don’t off trying to upset the apple cart, it just won’t work, too many tax dollars are resting on these high temperatures. OK’s Will Roger and Wiley Post airports do the same all of the time, sorry you just noticed your local problem. The only thing that matters is anomalies and accurate temperatures are meaningless, haven’t you noticed yet?
Anthony,
We need our own network.
Is that one of those things that’s easier said than done?
This has nothing to do with changing the temperatures. This is stealth geo-engineering. The Earth is heating up and all the Arctic ice is melting so to reflect more sunlight and keep the Earth just right we need to paint Texas white. Now that would cause a huge updraft and mess up the weather in Texas so we’ll do the same area distributed over a very large geographical area. All airport parking lots and soon most building rooftops will be white. This will keep us from overheating. It is so obvious I don’t know why you all can’t figure it out. Big Brother is watching out for you and taking care of you. Now pay your carbon tax or we’ll paint it all black and let you fry in hell.
/sarc
“From a climate monitoring standpoint, 1 degree of change is huge when we are talking about 1.5 degrees of global warming over 150 years.”
Which slould be all one needs to know to realize the folly of “the science” using these stations for climate modeling data.
I always get an icky sensation when reading the expression “the science”. It’s used in such a way as to imply some sort of exclusive credibility to the practitioners which is unlike any other branch of science. One which cannot be questioned by non practitioners. Is there another branch of science which can be referred to simply as “the science” and be immediately identified by a large percentage of the population?
That small patch of white pavement 2 meters below the box may even make readings hotter, not cooler. The asphalt itself gets cooler indeed if painted white, but the air above it, I don’t think so. There’s always some wind in open areas, so hot air from the runways gets blown that way as often as not. The planes themselves using the facility generate lots of turbulence. On the other hand, short wave radiation reflected from the white surface surely does some warming job on the underside of the box.
Anyway, one would need actual experiments to settle the issue.
use the history feature on google earth.
The white in the 7/6/2010 image is a google white out
Where have the shadows of the tower gone where they cross the paint?
Anthony: Catching step changes in weather station data makes you a real Menne.
Berényi Péter says:
May 3, 2012 at 4:47 pm
There you go with that talk of actual field experiments again. Don’t you know climate scienceTM doesn’t need any of that stuff!!! (with the redundant /SARC )
Has anyone ever compared the temperatures measured at US Airports say from Sept 12-14 2001, vs. non-airport stations for the same time period. And how the delta might compare to a just a few days before. Since, no planes flew during this period, one might be able to find an effect that planes landing and taking off have on measurements.
I remember somebody trying to measure if the com trails cooled temps by using this time period.
You could publish a paper and possible relate temp trends to airport traffic.
Hmmm….temps have leveled out since 2001, perhaps less airline traffic due to economy and 9/11 caused artifical cooling trend in airports weather stations. Or,it was an evil plot by Usama to send the world into an iceage so he could take over. 🙂
We all know this airport temp thing is a red herring, uhi is insignificant, Steve Mosher has told us so many, many times (thought I’d save you the bother Steve..heh!).
Ok…sarc off…..
Suggest Dr Brown revisits Chefio’s big spread on this. The movement of temp stations to airports/grass airports to tarmac airports is jaw dropping when it dawns on you.
Hence a land based temp rise that is not reflected by the sattalite readings. And likewise a failure in developing world land temps to keep up with the gallop (ie not enough temp stations at big tarmac airports).
Its as obvious as the nose on your face…and makes you say..”what global warming….0.2C maybe in 40years?” WUWT?
This is a perfect example in support of the point I was making in a thread at CA “Berkley ‘Very Rural’ Data” Jan 1, 2012 arguing against S. Mosher on his (and Berkley’s?) definition of rural.
As I countered with an example of a Bougier Gravity Terrain Correction process it is the combination of size and distance of the corruption of an instrument reading that matter in estimating the correction to the reading. Here in the the change in the Raleigh-Durham station won’t make a blip on Mosher’s 1 km pixel, but who can honestly approve of the change when stable temperature records are what we seek?
Is there something akin to MDLs for these stations? “MDL” refers to two things in relation labs. One is “Method Detection Limit”. That refers to, well, the built in limits of the procdure. It would be like having a 4 power scope on your rifle. No matter how carefully you aimed, what you saw in the scope would never be magnified more than 4 times its size.
The other is “Minimum Detection Limit”. This can differ from lab to lab. Using the rifle scope again, if the scope is out alignment then the closest the crosshairs may be able to get to the target is, say, 3 inches at 100 yards.
Our lab scale is accurate to something like 0.0001 mg. But that’s not our Minimum Detection Limit for total suspended solids. To determine that for TSS, we ran the same sample something like 30 times. (I don’t remember the actual number of times.) After running the test and comparing the results, it was determined that for our lab 0.05 mg/l was our MDL. In other words, we could not be resonably certain that any lower result was accurate. Slight differences in the filter paper, maybe a piece of machinery setting up subtle vibrations that affected the scale, etc. etc., could all effect the accuracy of our results in our lab.
Are there MDLs or could something like them be set up for these stations? Maybe a test at regular intervals not just to check the equipment but also to determine to what degree (no pun intended) their readings can be trusted?
(OK, the pun was intended.8-)
“”””” Gene says:
May 3, 2012 at 4:02 pm
@John F. Hultquist
I am familiar with the meaning of ‘albedo’, but I appreciate the reinforcement. The point here is that it is unlikely that the airport authorities chose to do this for the visual effect. Thermometers “see” in a much wider spectrum than we do, so it is not entirely incorrect to think of albedo in a broader sense, and that is indeed how many people use the word: “””””
As it relates to planet earth, “albedo” is specifically the solar spectrum average reflectance of the planet; so the LWIR reflectance of xyz or white paint is quite irrelevent.
If you mean TOTAL reflectance, then say so; don’t use “albedo” as if it is any ersatz reflectance in the audio frequency range, or whatever.
wayne says:
May 3, 2012 at 4:16 pm
Of course it reached 99°F at RDU on May 3, 2012…..
____________________________
RDU had a high of 91 °F.
I live an hour directly south of RDU (Old Chestnut Crossing, Moncure
Elevation 415 ft) and the high today was 91 °F. It is a rural area. The airport 2 miles down a dirt road (Raleigh Executive Jetport @ Sandford NC Elevation 246 ft) was also 91 °F. It is a very small airport in a cow pasture. We see small private aircraft out of that airport.
However I agree with Dr. Robert Brown, we are generally cooler than RDU. That is IF you look at the actual temperatures. The “Official Temperature” recorded at the end of the day is usually 2 to 3°F high than we actually see during the day from the Moncure station. Since I am out side a lot and come in to cool off, I check the weather often during the day. Therefore I think all those 91°F have already been “adjusted”
Right now @ 9:40 pm (about an hour after sunset.
Old Chestnut Crossing, Moncure = 70.7 °F – rural station.
Nearby Airports
City …………. Temp. ….. Conditions
Sanford………72 °F ………… Clear
Chapel Hill… 71.6 °F ……… Clear
RDU Airport.. 84.1 °F.. Mostly Cloudy
Burlington……73.7 °F ……… Clear
(I got up to the minute info from each station)
Information from: http://www.wunderground.com/US/NC/Moncure.html
I contacted the General Manager of WRAL (Raleigh NC), provided a link to this post, and encouraged him and the entire weather team to review the material. I’ll post any response I receive.
If you visit the Bing site (http://binged.it/JWBPfP) in bird’s eye view and zoom/rotate/scan the scene you can also see there has been flooding and a break-out about 75′ away, and that plowed field it is in shows obvious signs of greening/plowing cycles.
This is an example of a weather station ideally placed for aircraft operations but next to useless for weather trending.
ASOS has been co-opted for climate, it was never designed for that. See what this NOAA employee says about a malfunctioning airport station at the end of this TV interview:
Well, that explains the discrepancy. NOAA uses the Bradley Gravy Train Correction process. It works a little differently.
dp, what you are seeing in the pictures is the markings in the field is from tractors cutting and bailing hay or tactors with wide Bush Hog {tm} mowers. No plowing there, but good eye. That was the first thing that caught my eye also. I used to live in High Point for 18 years and loved every minute of it.
Gail, gee, did I leave the /sarc off? I though every one here knew me well enough. I was just also agreeing with Robert, on the absolute side there is a definite problem. On the relative aspect maybe both ways, case by case. But wasn’t RDU warmer by about ten degrees? Maybe it’s just a hot spot, I don’t know the geography there at all. Here I watch NOAA predicted and then official temperature and it is always higher. I haven’t seen one day in the last three or four years back i can remember that they actually underestimated the temperature as reported by all of the surrounding areas. That would be a real “event” to me. But the surround area stations are not “prime” stations and are basically ignored at the national level. Maybe that is why Oklahoma climatology shows a flat trend for OK for the last 115 years and in the global record they swear a hefty increase. But that very question is what has been hashed around here for at least the last three years and I see no change in the agencies, no corrections, no admission, no “we’ll take care of that” or “we will look into that”. Zip.
I’m tired of it. Thank goodness Anthony and everyone else here just keep plunking. Hat’s off to all for keeping the pressure on.
It’s in preparation for the global cooling thats coming. They are going to slowly change the colour over the years to black!
With all that white paint I see warming in the pipeline.
Imagine that as a matter of policy they moved all these airport based stations away from the runways! I reckon they’d be predicting the next ice-age in no time.
Heathrow airport, the busiest in Europe, has the same problem. A good 2Celsius warmer than anywhere else on the west of London in the Summer. The Met Office know full well this is the case as they predicted it would be the first place to break temp records in the heat wave of 2002.
Jay says:
May 3, 2012 at 3:09 pm
The real question is why would you put black asphalt around your temperature sensor in the first place?
The ashphalt was put there so that the ground engineering crews working on the other equipment like the ILS have somewhere to park their trucks otherwise the place turns into a bog. They would probably know that the automated weather station was there – but not be too concerned about leaving their truck idling alongside it during a cold night while they work there.
It looks like it might be a tarp or liner. Maybe something used to repair the cracks in the asphalt.
We all know that the data is for the Airport – NOT for Global temperature monitoring.
What is the fix, and how will it be implemented?
I have a ton of things to do today, so I probably won’t respond as often as I’d like — exams to grade, businesses to start up…;-)
Remarks:
a) I’m not actually quite as psychotic with italics as Anthony’s repost indicates — I suspect an artifact of quoting quotes of quotes or something. Bear with me. However one or two are my fault as I sometimes forget the trailing \ in the closing of . And we still don’t have e.g. a Goodreads-like interface that permits you to edit your own posts at any point. Ah well, GR doesn’t allow embedded latex which is probably more important, but sigh indeed.
b) If the white paint is around the anemometer, perhaps is was put there to try to minimize local updraft conditions. Grass (especially moist/green grass) is cooler than pavement in the sun, as anybody who goes around barefoot in the summertime appreciates. Even as a kid I learned to walk with my feet carefully on the white stripe of a pedestrian crossing when I was walking to the park to swim or fish without shoes — the blacktop is scorching, literally, while the white lines are just warm. Grass is cooler than both, without exception.
Differentially heated air expands, its density lowers, and it is displaced by denser cooler air. Putting the anemometer in the middle of a patch of asphalt surrounded by grass almost guarantees that the air there is constantly being uplifted and replaced with air swirling in from the cooler grass surrounding. I’ll wager one can photograph it happening. On a still day, it might be enough to actually get a non-zero reading for wind speed when in fact there is no wind at all! A kind of “solar updraft tower”, hold the actual tower. This updraft also pulls air across the thermometer, located a short distance away, OR because the asphalt is located a few meters away from the thermometer — not even 40 or 50 meters but less than 10, if the wind is blowing lightly out of the northeast it simply puts the thermometer in the spiralling updraft of pavement heated air.
Painting it white mitigates these effects, locally. It probably results in local ground surface temps that are much closer to the dry, dead grass that is still a terrible surface (albedo and natural cooling wise) compared to a location in the actual shade, actual green grassland, and near to actual forested land nearby, such as the suggested site near the national guard hangar. But it is at best an approximate fix.
The interesting question is what about thermal updrafts on the entire bloody airport nearby — a square mile of low albedo concrete and asphalt? I’ll wager it generates a thermal updraft you could ride a glider up on, almost every day. And again, when the wind is from anywhere to the south or east, that thermal simply flows right over the weather station.
There is actually an interesting study here waiting to happen. The data needed is freely available in e.g. Wunderground’s network of contributing personal weather stations. One can apply fairly simple criteria to eliminate stations like Westglen that produce consistently spurious results, one can use Google Maps (or whatever) to examine surrounding land use if not the actual siting of the station (which will often be visible!). One can then use a variety of statistical methods to create a moderately accurate picture of “true” surface temps and site anomalies, I think. I can only imagine such a study would be highly illuminating in the UHI/land use discussion, as well as the problem of anomalies in the GISS stations.
But the really humorous thing is subtracting from that 1890 peak in the RDU record. Otherwise it would still pretty much be the record.
rgb
Just looks like a whitewash to me : > )
Digital distortion?
Look at the runways in the same google maps images. They are white with a black streak from the tires. That’s not real either.
The caps on my chimneys are dark gray. They appear white on satellite images in some cases.
Very likely the digital processing software paints or fills areas. Kind of like how you might fill boxes on a temperature grid with adjacent boxes when data is bad or missing.
The Raleigh/Ralei plot shows the homogenized data systematically below the raw data before 1920 and systematically above the raw data after. Now that’s how you get a temperature rise over the last hundred years.
Interesting information about the site including images here…
http://weather.gladstonefamily.net/site/KRDU
I thought I was the only one who noticed this. I prefer some of WU maps. They give me the info I want much quicker and simpler than Accuweather.com. But the other day, they had my home city temp hitting 100, while Accuweather had it at around 88 with the heat index. That is slightly warm for this time of year, but not unusual. Accuweather was right, WU was wrong, but this is not the first time their temp forecast has been ginned up. Maybe there is Global Warming and maybe there isn’t, but it’s easy to see why WU thinks there is. When all you have is a hammer ….
rgbatduke: ” I’ll wager it generates a thermal updraft you could ride a glider up on, almost every day.”
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Or you can watch the hawks ride the thermals above 20 acres of asphalt surrounded by fields–like where I work. –AGF
Wouldnt an aircraft also heat the airfield as it takes off , there is a tremendous amount of superheated air shooting out of the engines as it burns gallons of aviation fuel . A cloud of ex exhaust gas drifting around a thermometer must increase the reading – just as it would if it were situated downwind from a burning bonfire .It would be interesting to know how much fuel is actually burnt on a take off landing and taxiing etc .
Airports are hot places. Between the runways, the jet exhaust, and the carpark tarmac (not to mention the terminal roofs, sidings, and air conditioner vents) they are significant heat islands. Oh, and the vegetation (that tends to cool things via transpiration) are either tightly mowed or killed off all together.
Airplanes can only fly in a given density of air. Density drops with heat. The concept used is called “density altitude”. Over a hot runway, what is the ‘equivalent’ altitude and can you fly that that high? ( It can move your effective altitude hundreds or thousands of feet). Get that calculation wrong, airplanes can’t take off (and crash) or land too fast (and crash).
So there is a fundamental requirement that airport thermometers record an accurate temperature at the runway (which is typically a warm place) and if they err, it ought to err to the side of too hot (avoiding crashes). This is antithetical to use for “climate science”.
Over time airports grow, often dramatically. At present, over 90% of GHCN thermometers are at airports. In 1880 not so much…
IMHO, that is enough to account for ALL measured “global warming” and then some.