Guest post by John Goetz
As noted in the previous post, GISS has released their monthly global temperature summary for June, 2009. This month’s whopping anomaly of 0.63C is once again much higher than that of RSS, UAH, and even NOAA, which is the source of the GISS temperature data. Not only is the anomaly higher than the other metrics, but it is trending in the opposite direction.
Temperature data from 1079 stations worldwide contributed to the analysis, 134 of them being located in the 50 US states. Data from essentially the same few stations have been used for the past twenty-four months. Many, many hundreds of stations that have historically been included in the record and still collect data today continue to be ignored by GISS in global temperature calculations.
Once again, the bulk of temperatures comprising the present-day worldwide GISS average come from airports – in this case 554 airports, according to the NOAA metadata from the V2 station inventory. In the US, the ratio of airports to total stations continues to run very high, with 121 out of the 134 reporting stations being located at airports.
Why worry about airports? Aside from recent posts on this site documenting problems with airport ASOS equipment in the US, WUWT has also documented a number of equipment siting problems, notably the typical close proximity of the equipment to a tarmac heat sink. Airports can introduce a mini-UHI effect where one would otherwise not be found.
The NOAA metadata is not entirely accurate, and several stations located at airports are not noted as such. Some examples include Londrina and Brasilia in Brazil, Ely / Yelland in Nevada, and Broome in Austrailia. Those stations were easy to find because they had “airport” (or some variant) in the station name. A check of coordinates using Google Earth confirmed the airport locations.
Let’s examine the metadata a little further, shall we?
NOAA says that 345 of the stations it passes on to GISS are rural and presumably free of UHI influence. Fifteen of those stations are located in the US. However, only 201 of those rural stations are not located at an airport, and therefore presumably free of UHI effects (including tarmac heat sinks). In the US, only one of the fifteen stations is listed as both rural, and not located at an airport: Ely / Yelland in Nevada.
Doh!!! As noted above, that station is located at an airport – confirmed not just by Google Earth, but also by NOAA’s NCDC website as well! This means that all of the US temperatures – including those for Alaska and Hawaii – were collected from either an airport (the bulk of the data) or an urban location.
As for the rest of the world, some of the stations listed as being rural and not at an airport have metadata indicating they are located in an area of “dim” or “bright” lights. Filtering those out, we find a total of 128 stations that are rural, not at an airport, and “dark”.
Why are “dark” stations important? Recall that GISS uses dark stations to adjust for UHI in the urban stations. With only 128 dark stations available, none being in the US, it would seem this is an impossible task.
Fortunately, GISS adjustment rules allow old data to be used in adjusting new data. The older “non-reporting” rural weather stations continue to adjust reporting urban stations, even though the most recent two years of overlap is missing.
Thankfully, the algorithms are robust enough to calculate adjustments to the 100th of a degree even when data is missing.
Thank you for explaining the nature of the data. I was eyeballing it after looking at a lot of employment data and thought it might be picking-up construction work, but now that you point out it is airport data that makes sense why it didn’t pan out. I decided to eyeball some aggregate flight volume data and there is a peak in 2007 in both the heat anomaly and flight volume, then a decrease in both the following year. Unfortunately, the raw data looks expensive like $700 from OAG.
http://www.oag.com/graphics/4th+quarter+global+flight+volumes+10yr+view.jpg
An interesting study would be to look at record high max temps versus record low max temps, and record low min temps versus record high min temps as a function of airport placement. If Airport sites are over represented in the high records, that would be evidence of a temp sensor site bias. A case in point, the temp sensor at the Pendleton Airport is probably on record as the site of record highs while the sensors placed at the same elevation but away from the airport in this high plateau area will record the record low at that elevation. The NOAA sensor at Meacham, Oregon is in an area all its own. I swear that place really is an Arctic island that just got misplaced in the continental shuffle and neglected to adjust its climate accordingly.
By the way Frank, I emailed the Unisys site and attempted to educate on standard metrics for warm vs cool colors. Red is warmer than gray when it comes to standard definitions for color warmth but on the new color scheme at Unisys SST, red is used to show just a bit of warming while gray is used to show a lot of warming. The “warmest” color on their new design is…wait for it…BLUE.
OT but has anyone looked at the headline picture and thought “What happens next”?
Pamela-Meacham’s site is where the long gone FAA(really CAA) Flight Service
station was.-there used to be an Airport there too.I knew an old FSS fellow back in the 1970’s who was one of the last to “man” that FSS.-He likened it to his days at Solydatna Ak.-execpt Solydatna-not sure of the spelling-was warmer.
Meaham’s got a long string of records-at least into the 1930’s but finding it all
would be a challenge.As I recall 1948 is the oldest in the NOAA data…
For the old Meacham stuff, that’s easy DC.
http://www.wrcc.dri.edu/cgi-bin/cliMAIN.pl?or5396
And here
http://www4.ncdc.noaa.gov/cgi-win/wwcgi.dll?WWDI~StnSrch
Maybe this one will work. Type in Meacham, OR in the search field.
http://www.ncdc.noaa.gov/oa/climate/stationlocator.html
Claude Harvey (10:07:57) :
Has anyone else noticed the AMSU-A satellite readings lately?
Steven Hill (12:41:21) :
Looks like July is heating up.
Agreed. Go to http://discover.itsc.uah.edu/amsutemps/execute.csh?amsutemps and set the graph for ch05. There is a dramatic warming in the last two weeks. Is there an equipment issue, or is this the effect of the return of El Nino?
Roy Spencer: If you’re reading this: What’s up with that?
Rereke Whakaaro (22:46:24) :
Warning: non-scientist alert!
Several lifetimes ago, I spent some time in the air force, mainly in hot and uncomfortable places (and in the tropics too). At that time, the air force always mounted the airfield weather station at the top of a wooden tower, about twenty feet above ground level – presumably to remove bias caused by ground temperature.
All of the pictures I have seen recently that show civilian weather stations show them close to the ground.
———–
The observing stations were generally placed a bit higher that ground level to observe field conditions better. Every one I ever saw had thermometers and sling psychrometers in an instrument shelter that was properly placed close by and properly maintained. The observer was also usually equipped with a calibrated recording thermograph and often with special visibility sensors, both vertical and horizontal, some along the runways.
But much more was reported than temperatures, and at minimum every hour. That observer had the authority to close the field done whenever he observed conditions below minimums. Temperature was not one of those conditions. These folks were concerned with safe aircraft operations — not climate.
A B-29 crashed on take-off at Ladd Field, Alaska (I think in 1946) with the measured temperature at TO time (actually accident time) of -57F. He had his turbos compressing that dense air at full blower and blew the heads right off several cylinders at an inopportune moment.
If you zoom in the station is just around the corner where the Airport road leaves the Murchison downs road.
The BoMs metadata puts it 2 kilometers south of there. Unless the Google Earth’s GPS locations are wrong which doesn’t seem to be the case.
>>>In Perth we call the sea breeze the Freemantle Doctor.
Indeed you do.
But if the met stations are all coastal, then one might be forgiven for thinking that the midday temperature in Western Oz never gets above 30oc – whereas it can climb to 47oc as you know (I had 47oc last time I was there).
Thus these coastal monitoring stations are completely misleading and largely useless, in that they measure sea temperature and not land temperature. How many others are similarly poorly sited?
FWIW, GIStemp also uses airports to represent pristine “rural” stations in the STEP that “corrects” for Urban Heat Island effect:
http://chiefio.wordpress.com/2009/08/23/gistemp-fixes-uhi-using-airports-as-rural/
So not only are the bulk of the thermometers at airports, but 500+ of the “rural” stations used to “correct” for UHI are at airports.
Among the “gems” I found on the list were the Marine Corp Air Station at Quantico, yes, THAT Quantico and the main commercial air port at Lihue Kauai, Hawaii with over 100,000 flights a year…
So we correct for UHI at airports using airports via the Reference Station Method… Uh Huh…