I’ve mentioned problems with airports as climate stations in the past, mostly that they are pockets of UHI that have grown with the 20th century aviation boom. A good example is Chicago O’Hare airport. I’ll bet that many of you don’t know that the ICAO ID for O’Hare, is KORD, and FAA uses ORD which is what you see on airline luggage destination tags. “ORD” has nothing to do with the name O’Hare, which came after the airport was established. It has everything to do with the name “Orchard Field” which is what the airport started out as, which at the time was far more rural than it was now. You can read about its early history here.
Here’s that same view today from Google Earth:
Look at O’Hare today, a sprawling megaplex of concrete and terminals surrounded by urbanization:
The weather station location above is designated by the orange pushpin. Here’s a closeup view:
Note that there’s two electronics equipment buildings nearby with industrial sized a/c exhaust vents. While not USHCN, NCDC metadata lists O’Hare as a Class “A” station, which means it does in fact record climate. Data from O’Hare can be used to adjust other stations with missing nearby data.
The point I’m making with all the photos is that airports are far from static, especially since airline deregulation in the 1980’s. The are just as dynamic as the cities they serve. We measure climate at a great many airports worldwide. E.M. Smith reports that the majority of the GHCN record is from airports.
Even NOAA meteorologists admit that airports aren’t necessarily the best place to measure climate. In a series of stories I did…
How not to measure temperature, part 88 – Honolulu’s Official Temperature ±2
..about the failure of the aviation weather station at Honolulu causing unparalleled record highs, the NOAA Meteorologist there had this to say:
“ASOS…placed for aviation purposes…not necessarily for climate purposes.”
The key issue here is “aviation purpose, not climate purposes”. The primary mission is to serve the airport. Climate is a secondary or even tertiary consideration. And that’s exactly what happened in the story from the Baltimore Sun below. The observer used FAA guidelines rather than NOAA guidelines to measure snow for the climate record. NOAA doesn’t like the record because he didn’t follow their procedures, so they toss it out.
However, when a new high temp record is set in Honolulu due to faulty equipment, NOAA thinks THAT’s alright to keep in the records:
NOAA: FUBAR high temp/climate records from faulty sensor to remain in place at Honolulu
A nearby station shows the error:
This is your Honolulu Temperature. This is your Honolulu Temperature on ASOS. Any questions?
Sat 20 Feb 2010
…
A contractor working for the Federal Aviation Administration at BWI Thurgood Marshall Airport, paid to measure the snow for the aviation industry’s needs, did not follow a separate protocol required by the National Weather Service and the National Climatic Data Center for valid climate data.
So while the contractor measured 28.8 inches of snow during that storm, the National Weather Service has thrown out the reading. Instead, climatologists will rank the storm as “only” 24.8 inches – a number that almost surely understates the “true” total.
Worse, for climatologists, it now appears the weather service’s rules for snow data had been ignored for years at BWI, throwing a cloud over the validity of snow totals as far back as 1998, when the FAA took the job over from the weather service.
Only BWI’s data are known to be affected, but the problem could be more widespread. That possibility has caught the attention of top officials at the FAA.
“We plan to meet with the National Weather Service next week to begin a discussion on making sure that we’re all on the same page in terms of measuring snow accumulations at our airports,” FAA spokesman Jim Peters said. “There will be a national discussion.”
In the meantime, the weather service’s Baltimore- Washington Forecast Office in Sterling, Va., is preparing to convene a committee of climatologists and other experts to review Baltimore’s snowfall records from the 2010 and 2003 storms, and perhaps back to 1998.
“I feel very strongly about historical records and getting the climate data correct,” said James E. Lee, the meteorologist-in-charge at Sterling. “Obviously, with the increased media attention and political attention to climate, it is really up to NOAA [the National Oceanic and Atmospheric Administration, of which the National Weather Service is an agency] to make sure … the climate record is a genuine one, and consistent to the best of our ability.”
The problem at BWI came to light Feb. 6, as snow accumulations reported at the airport passed 26 inches. They seemed poised to break the record set in February 2003 – the storm listed on Sterling’s Web site as Baltimore’s biggest.
But when reporters called asking about a new record, Lee said that because of measurement errors by an FAA contractor at BWI, the two-day storm total would be pegged at “only” 24.8 inches. He had discarded a 28.8-inch measurement from BWI because it was the sum of hourly measurements throughout the storm – a method invalid for climatological data.
Even at 24.8 inches, Lee said, the storm total beat the previous two-day record of 24.4 inches, set at BWI during two days of the four-day 2003 event. “I’m convinced that was the most amount of snow Baltimore has seen [from a two-day storm] in recorded history.”
But Lee had to use the most conservative reading from the airport – a “snow depth” measurement of the total on the ground when the storm ended, after hours of compaction.
The FAA requires its observers to take hourly snow measurements and wipe the boards clean after each hour, adding the totals as they go. That provides pilots with better real-time information about changing conditions. But it virtually eliminates compaction and so inflates accumulation. Climatologists require measurements every six hours, striking a balance between the hourly and snow depth readings. Some airports maintain separate snow boards for the different protocols. But not BWI.
Richard Carlson, vice president of Pacific Weather Inc., said his company has experienced weather observers at 20 U.S. airports, including eight at BWI. Pacific has held the contract there since 2008.
“We follow the FAA manual … and that is the guide book on how these meteorological observations are to be taken,” Carlson said. “We had heard about the six-hour measuring thing, but … if you have high winds at all, this really is not going to work.”
…
Read the full article at the Baltimore Sun
Read Frank Roylance’s blog on MarylandWeather.com
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Allright, that’s it, the pint comment got me.
Downtown Brown, Lost Coast Brewery.
I feel better already.
Thanks to everyone who pointed out the typos. Family duty called this Sunday and I had to finish the article w/o doing a second proofreading pass.
I looked up the Environment Canada website to find out how snow is measured in Canada. The information at the website is very general so there is no indication of the locus of where the data is collected.
Usually, the snow amount or the depth of accumulated snow is measured using a snow ruler. The measurements are made at several points which appear representative of the immediate area, and then averaged.
Coincidentally, a similar article was published today in the Montreal Gazette:
http://www2.canada.com/montrealgazette/features/weatherwatch/story.html?id=d63549e6-65d7-4709-9df3-d71d9f701733
I also found another article on snowfall measurement from St. John, New Brunswick from Jan. 5, 2010.
http://telegraphjournal.canadaeast.com/rss/article/909791
As in the US, Environment Canada seems to rely on airport weather stations. However, there is no mention of waiting 6 hours to record the actual snow fall. I am not sure what exactly that achieves scientifically, especially if rain starts falling in the interim. Does it increase some version of accuracy?
I do know that what most people are interested in is the depth of the snow to be shovelled, and whether it is dense, wet snow or light, dry snow.
“Family duty called…”
A.K.A.
“The Canada vs USA hockey game for Gold is on…”
🙂
John M Reynolds
REPLY: I care for hockey about as much as I care for curling. Visiting relatives are more powerful than sports, and twice on Sundays. – Anthony
One more typo:
ICAO designation is KORD. FAA uses ORD.
REPLY: Yeah, that’s what I meant. Fixed. – Anthony
Anthony,
No need to apologize for typos. I seem to manage several with every comment – despite being a prof with a bit of spare time due to sabbatical – and I’m sure we all understand that this is the peril of written communication. What matters far more to all of us are the ideas you are sharing. We’re just glad to be able to contribute in a small way in catching your tiny goofs.
Anthony, this is hardly relevant to snow measurement but I came across some time ago that the NWS policy, at least in the Pacific, is to move WSOs to Airports.
Presentation here: http://www.faa.gov/news/conferences_events/2009_pacific_aviation/agenda_presentations/media/day3/PacAvDir%20May_09_2.ppt
So, not only are weather forecasts little but exercises in the art of guessing, but they can’t even measure the stuff of which weather is made. What else is new? As for the measure of snow, I think that metric by itself is meaningless without knowing the water content of the snow. After a season that’s been mostly nice dry powder that’s easy to shovel (just push it to the side of the drive), I just finished shoveling several inches of high water content snow; can’t push it — have to really shovel the stuff and toss the loads a few feet to clear the drive.
Once again we see the data as measured being adjusted after the fact. And again, what else is new?
vjones (14:18:44) :
Electronic wind sensor: No moving parts.
Sounds like an invitation to a disaster. When the instrument malfunctions, there’s no warning, just bad data.
Oh, and those electronics are foolproof. Seen them at FWS .
WOW simply WOW, ASOS temp sensors are at best +- 2 degrees F! You’d do as well to use the temperature for a bank sign!
what’s up with all the grammar and spell checking? you would think that some folks have nothing else to do than pick nits
” the National Weather Service has thrown out the reading”
“throwing a cloud over the validity of snow totals as far back as 1998, when the FAA took the job over from the weather service.”
Hogwash
This is as valid as their fixed temp stations.
Did the FAA take over all of the airport stations? or just ORD?
“hottest decade”
Of course snowfall is highly variable. So is rainfall, cloud cover, humidity, temperature, wind speed and direction, . This was given as the reason meteorologists use pressure for their charts as it is the most consistent meteorological variable least affected by micro siting issues.
That’s what we were taught on meteorologist course at the Australian BoM in 1971.
Actually the ORD stands for Orchard Douglas. It was a Douglas site for building airplanes. The original site for WX measurements in Chicago was Midway, MDW. When they changed to ORD the temperature was a couple of degrees cooler so I bet they adjusted it to make up for the difference.
My Father said when he first went to Midway it was in the middle of a cornfield. I flew B-727s into Midway and you could see the televisions in the buildings from the runway, no change in the temperature caused by this difference i am sure!
There was a accident at Midway many years ago in a storm. The tower could not see the airplane so they asked where the airplane was. The answer was,” If the street signs are correct we are at 55th and Cicero.”
peterk (14:50:44) :
It’s called peer-review.
I find the constant nitpicking of very minor and insignificant points in Anthony’s spelling and grammar very tiresome and juvenile.
The import of his and his guest writer’s posts are very clear and the writing is concise and fully understandable.
A very appreciated quality from this layman.
WUWT is a fast moving blog with immense amounts of fast moving and free flowing information being constantly placed before us often on an hour by hour basis and this from just one unpaid man with limited resources and with small number of dedicated unpaid volunteers as backups and contributors, not a vast empire staffed by hundreds.
WUWT is not a highly edited textbook where a close editorial scrutiny is required to ensure precise accuracy that is without reproach so please lay off the nitpicking scrutiny for insignificant spelling, punctuation and grammatical errors that some here seem to love to indulge in.
Value WUWT for it’s marvelous, up to date and open access to a whole range of climate, weather and science based items and for the freedom and quality of the contributions of it’s many highly qualified science and professionally based commenters just as the rest of us do.
There is a shockingly high proportion of airports in the GHCN data. You can visualise it here:
http://www.climateapplications.com/GISSMaps/stationairportcodes.asp (takes time to load – hit ‘NO’ a few times if it stalls).
So how do they handle all those surface stations that are not properly sited? Toss out the measurements?
Failure to capitalize; failure to punctuate.
20 Quatloos per item in the tip jar …
(We’re not Peter Perfect are we?)
.
.
…………………Al is back. He’s decided to publish one page of wishwashy ‘scientific’ rebuttal and 2 pages of nonsense he made up while looking out of the window on his Gulfstream VII flight back from the Apple convention. There is progress however: He’s decided not to mention CO2.
Yes. Drop the spell check issues unless it comes out Chinese. It’s amazing what you can blame on a typo but as there is no agenda here, no need to worry.
I miss Manuel already. His Iron sun and all that(what ever that is-still can’t figure out what the hell he’s barking on about!). Can I petition for a month long ban instead of life time. I’m sure he’ll behave in the future. It’s just to see a fellow realist get a smack down here at WUWT.
REPLY: I dunno. I warned him about it many times. He just kept trying to sneak in stuff and I got tired of his thread bombing. I will say this for him he was courteous. – Anthony
………………..paul jackson (14:47:07) :
WOW simply WOW, ASOS temp sensors are at best +- 2 degrees F! You’d do as well to use the temperature for a bank sign
PAUL: You can go over to WUWT 2007/3 there is an excellent article from a guy called Lon on accuracy of thermometers.
Measuring snow depth is subjective. The Canadian way described earlier is an accepted practice. The more important factor is water content which I am assuming they measured correctly. Snowfall depth can vary greatly over short distances. So can rainfall. I’m sure its happend where those observers were standing in sunshine watching a thunderstorm at the end of the runway.
It is clear the government cannot be trusted with science. Like academia, it has been taken over by left-wing crackpots.