KNMI has been measuring the wrong temperature for years
WUWT reader Mike writes with this little bombshell on one of the world’s leading meteorological agencies. It seems they can’t get their thermometer siting correct which resulted in a bias to the record. Hmmm. Where have we heard this before? The newspaper “AD” in the Netherlands has picked up the issue with two separate stories.Mike writes:
Dear Anthony,
I left this on the “tips” thread on WUWT, but since it is also relevant to surface stations, I felt you should hear of it directly. It probably deserves a whole story on WUWT.
As you probably already know, KNMI De Bilt is the only station in the Netherlands used for GISTEMP. The nearest long-term station is in a suburb of Brussels, hence is undoubtably UHI-polluted. De Bilt is the only long record stn in NL & within 150km in any direction would be a useful correction.
Two stories caught my eye in the Dutch papers today about a 0.5-degree error in the De Bilt record which was miraculously corrected this summer with a station move of 200 m without anyone being told of it. Here are the links to and my translations of the articles.
Mike’s translations of the newspaper stories are below, I’ve added relevant graphics. – Anthony
The instrument stood too close to a line of trees, due to which on average half a degree (Celsius) too high was measured.
After discovery of the fault the thermometer was moved to an open spot on the measurement field before last summer, the KNMI has confirmed. Due to the change the average measured temperature fell half a degree. This measurement should be reliable.
The mistake resulted in that the KNMI has announced more “official” summery and tropical days than there were in reality. According to the Institute, the defect has not or hardly influenced the scientific discussion on climate change, because researchers use the data from a large number of weather stations. SUZANNE DOCHTER
Above: GISS Temperature plot for De Bilt KNMI – notice the step function. Click for source data.
Here’s a picture and metadata for De Bilt, direct from KNMI. While I can’t be certain, this photo appears to be after the move:
Checking some nearby stations in GISS, click for source data:
The GISS plot for Maastricht Airport:
One whole data point? Why does GISS keep a station in the database with only one data point?
UPDATE: Well if GISS can’t find the data for Maastricht Airport, everybody else can, and damn quick:
See Weather Underground for current conditions.
And this website, tutiempo.net , has the complete climatic data set back to 1949.
http://www.tutiempo.net/en/Climate/Maastricht_Airport_Zuid_Limburg/63800.htm
Call out to GISS: Hey Gavin, as an American Taxpayer that funds your work, I request you take a moment from moderating realclimate.org and put some work into updating this record.
Here’s the next closest station, Essen, according to GISS a city of 7.5 million – doesn’t look much like the KNMI record:
2nd story —
KNMI has been deaf to criticism for years
WAGENINGEN – weather Institute KNMI has been deaf to years of criticism from competitor Meteo Consult of its temperature measurements in De Bilt
Weather specialists from the Wageningen-based Meteo Consult have been expressing their distrust for years, because the KNMI figures in De Bilt were always a bit warmer than in Cabau, 16 km away, where there is also a KNMI thermometer. The position of both places could, according to Meteo Consult, not explain the temperature difference of on average half a degree (Celsius). It was also not taken into account that De Bilt is located in a more built-up, and probably therefore warmer, surroundings than Cabau, near IJsselstein.
The meteorologists from Wageningen discovered this summer to their amazement that the temperature difference between both places in the KNMI figures had more or less disappeared. On enquiring of the De Bilt employees, it appeared that the thermometer had been moved. Since the intervention, the measurements from De Bilt show not 1/2°, but on average just 2 hundredths of a degree warmer than Cabauw, according to the spokesman of Meteo Consult.
This summer it appeared that the temperature difference was suddenly resolved. Again discussions blazed between the weather specialists and it was decided to closely compare the measurements between Bilt and Cabauw. “It was thus discovered that last summer in De Bilt was still 1/2 degree warmer and this year there was just a difference of 0.02 degree Celsius”, explained a spokesman of Meteo Consult.
The organisation decided to call the KNMI and heard that the “weather cabin” [translation: Stevenson Screen], in which the thermometer is located, had been moved. According to the KNMI the measuring instrument stood too close to a row of trees. Because the trees continued to get taller, the wind began to influence the temperature measurements too much. Now the “weather cabin” has been moved 200 m away, to a more open spot on the measurement field of De Bilt. KNMI employee Cees Molenaars cannot say how much influence the old placement of the thermometer has had on weather reports. “We must investigate that. We only regret is that we did not keep Meteo Consult and other parties informed of the movement.”
The thermometer of De Bilt is the official measurement used for determining heatwaves, cold waves, and summery days. To speak of a heatwave it must be at least 25°C released 5 days. Also it must be warm than 30° for 3 days. At 25° one can talk about a summery day.
With a cold wave, freezing temperatures must be measured for 5 adjoining days at De Bilt, with also 3 days with a hard frost. “The differences in minimum temperature between de Bilt and Cabauw were much smaller,” said the spokesman of Meteo Consult. “The chance that a cold wave is missed, is thus smaller.”
The thermometer in De Bilt has less influence on KNMI weather predictions. These are performed on the basis of the data of tens of measurement stations. Further, for scientific purposes, such as climate change research, the central Dutch temperature was brought to life long ago. For this, data from various stations is used [NOT TRUE — GISTEMP ONLY USES DE BILT!]. Meteo Consult are above all happy that the riddle has been solved. For fun they have also calculated what an extra half degree in De Bilt would have meant for this summer: 5 extra summery days and 2 tropical ones.
====================
Coincidentally, I’ve been conversing with Jos de Laat of KNMI, the Dutch Meteorological Institute who offered some scans of weather station siting specifications from the World Meteorological Institute (WMO)
he writes:
OK then, you can find the first part of the report here (~ 1 Mb):
http://www.knmi.nl/~laatdej/TMP/WMO488.pdf
Especially the beginning of part 3 is relevant, I guess. Because of document size considerations for now I only scanned up to paragraph 3.1.2.1.7 (after paragraph 3.1.2.1.7 the description of requirements for measuring on other locations like sea and the free troposphere starts).
Descriptions of sensor and siting requirements are also available online (see below) …
… but they are more formal and largely based on WMO report 488, which contains some interesting quotes that are not present in later reports. The online reports also refer to the report below, which unfortunately I was not able to locate either online nor in our library.
World Meteorological Organization, 1993a: Siting and Exposure of Meteorological Instruments (J. Ehinger). Instruments and Observing Methods Report No. 55, WMO/TD-No. 589, Geneva.
These specs are worth a read, because they show that quite a lot of thought and analysis went info choosing the specs.
As for the 100 feet cited by the NWS on this page: http://www.nws.noaa.gov/om/coop/standard.htm
I suspect its a round off of 30.48 m where 30 meters is the minimum distance to an artificial heat source cited for a Class 2 climate site as defined by the specs used in the Climate Reference Network (CRN) which has a French lineage, and likely traces back to WMO.
It seems that no matter where you look, meteorological agencies can’t follow siting specifications.
Steve McIntyre of Climate Audit has more on De Bilt and the adjustments that are being applied there:
http://www.climateaudit.org/?p=1650
the only station in the Netherlands used for GISTEMP
James Hansen is pathetic!
So a mere siting issue for a thermometer can give rise to a half degree error?
And what is the ‘runaway’ figure for global warming again?
0.6 degrees?
You obviously mean the DUTCH, not Danish Met Institute.
[Fixed, thanks. ~dbs, mod.]
Well, we all like WUWT to be precise and eloquent. So please, change “Danish” in the header for “Dutch”.
I read most amusing discussion on this subject on a Dutch/ Belgium weather forum. The meteorologist working for KNMI could’t explain why they moved the thermometer: the KNMI officially deny that the measurements were corrupted. The question why they changed the thermometer placement anyway remains unanswered to this day.
We all saw tMax at De Bilt drop, the last half year. Now we know why.
Anthony! We live in the Netherlands, we are Dutch, not Danish
REPLY: Yes my bad, fixed, thank you. – Anthony
De Bilt is in Holland, so its Dutch not Danisch meteo institute!!!!!
Oops, should the headline read ‘Dutch’, Anthony? When I first read it I thought that all of those lovely danish arctic data were to be thrown into the garbage.
REPLY: Press refresh.
Dutch, not Danish! You better keep us Europeans apart, or we’ll assume you’re Mexican or Canadian 😉
Anyway, this is very interesting. I commented on the de Bilt station in the comment thread on Lucy’s Arctic article, questioning the quality of the data, and also that GISS actually adds a trend when “homogenizing” the data.
Anyway, one of the posters there commented “I’m 42 and I know the difference between recent years and the seventies/eighties. It is vast.”. Well, I’m 48 and know the difference too – especially the late seventies and late eighties had much colder winters than recent years. I think this claim is very revealing: Most of the researches, activist and politicians promoting the AGW theory are too young to have experienced the 30s and 40s – but they’re also old enough to have experienced the seventies or at least the eighties. So they have actually experienced “global warming”! But they don’t realize that this warming may be part of a natural cycle, and that many places in the world may have been just as warm, or very close to current values, in the 30s and 40s.
Therefore, it’s such a pity that there are so few stations left that actually cover the whole period from the beginning of the 20th century to today, and that so little care is taken to keep these records as continuous and good as possible.
Anyway, I have a hunch that we’re in for an extremely cold 2009/2010 winter. Maybe the Dutch may go skating on their canals again, like they did this January – for the first time in 12 years.
REPLY: PRESS REFRESH PLEASE
Yeah, it’s Dutch and Kopenhagen is the capital of Holland.
PRESS REFRESH PLEASE
Anthony: Hey, don’t shout, there were no comments yet when I started writing 🙂
If you don’t mind I’d like to repeat something I wrote in the “what hockey stick?” thread:
I tried to find stations with long records in Holland, and found De Bilt (near Utrecht) which shows the same result of homogenization as the arctic cities: The temperatures from 1881 to 2009 first shows a flat trend (-0.05C/century), but after homogenization there’s suddenly a +1C/century trend! For Milano, Italy, it’s even stranger – a -0.7C/century trend is turned into a +0.7/century trend. I.e. the homogenization performs the reverse of an UHI correction, despite the fact that Linate is an airport very close to a huge city!
Notice the part about Milano here. I’m starting to believe that the GISS data for Europe (and probably other parts of the world too) is even worse than what you have discovered in the US with the surfacestations project. And the CRU data we can’t even evaluate…
One interesting exercise one could do, is to have a look at the 2000-2008 versus 1921-1950 anomaly, with 250 km radius:
http://data.giss.nasa.gov/cgi-bin/gistemp/do_nmap.py?year_last=2009&month_last=08&sat=4&sst=0&type=anoms&mean_gen=08&year1=2000&year2=2008&base1=1921&base2=1950&radius=250&pol=reg
I think a lot of the red spots on that map will turn out to be due to really bad data…
REPLY: Not shouting, just trying to get everyone’s attention that keeps pointing out the error in the title. – Anthony
Espen (08:02:50) :
Regarding your point about having “actually experienced ‘global warming’!”
I find it really interesting that many of the ‘scientists’ have now taken to adding that there’s no way to account for the swift climatic change only from natural variability, and then proceed to allocate most of the warming to ‘man-man’, anthropogenic, or even “human induced” conditions.
It’s just another twist of terminology to cover their tracks, kind of like the official change of ‘global warming’ into ‘climate change’ when the surface temps refused to go along with their predictions. To me; the fact that they are adding ‘natural variability’ to their lexicon is a solid clue that most of them realize their golden-egg laying goose may eventually be cooked, ironically by a cooling climate!
correct population numbers:
De Bilt: 42,052
Maastricht: 118,355
Essen: 579,759
Uccle: 76,732
Don’t know where Gisstemp get their numbers… Oh, do they “correct” the data according to the population?
Joel Heinrich: GISS counts Essen as 7.5 millions. The reason is that Essen is in the middle of the Ruhr Area which can be considered one vast metropolitan area (they don’t do this to other similar areas, though, like Frankfurt am Main and surrounding cities, or Ludwigshafen/Mannheim/Heidelberg)
The step-down seen in the De Bilt record from the 50s through the mid-80s certainly can’t be attributed to proximity to then much-younger trees. Although it looks suspicious, similar cooling was experienced then throughout much of northern Europe, notwithstanding the contrary indication from UHI-affected Essen. It does, however, raise the issue of perhaps other unreported siting changes, which no “homogenization” procedure–least of all the GISS “knee-bend”–can adequately fix. Despite all of this, De Bilt is by no means the most egregiously unreliable record in that region.
What difference does this make when RC is making the daily claims that warming is continuing?
Just look at the recent comments there.
It’s an astounding display of very agressive manipulation by the most arrogant and condescending alarmists around.
IMO this battle must be waged here and in their faces.
Strange. My common sense would have said that if there is a line of trees shadowing the thermometer, this should read lower temperatures, not higher.
At least KNMI moved their sensor to comply with standards. Look at all the work Anthony and his helpers have done to show the deplorable state or the US surface stations and NOAA has done next to nothing to correct the numerous problems but found the time to attack Anthony. Hansen and NOAA or totally corrupt when it comes to AGW!
The drop in the 50’s is also because the station was moved away from a building. So pre 50’s should be lower. The early forthy’s had a lot of hars winters in a row. essen doesn’t look like the record of the bilt because the see influance is a lot larger in the bilt then essen. So you can’t compare those and say only 150km away. But then again KNMI are true AGW believers.
Another thing about the upward trend in the bilt from the 60′ till now. The knmi offcourse blamed AGW but they also noted that there was a lot of extra sunsine in the last years.
http://www.knmi.nl/klimatologie/maand_en_seizoensoverzichten/maand_260_grafiek.html
This link is form this month. You can see the second graph for sunshine.
Also, they changed from a pagode-hut to a Stevenson screen right at the jump in 1950. I’ve heard local specialists say the hut recorded T-max too high, also resulting in elevated T-avg.
Does anyone know how long the thermometer has been at this location? When they changed from Stevenson to digital dish (1993), or was the Stevenson at the same location? When did the difference between Cabauw and De Bilt build up?
Always the same line, no matter how many of these poorly sited, suspect stations turn up, they NEVER affect the overall accuracy of the system.
They say there is no change in the climate average because they use multiple stations. But these station are too suffering from bias.
KNMI is a miserable organisation and a slave of WMO and IPPC; therefore is good to know now how weak their temperature measurement procedures are. In the Netherlands you can better inform yourself about weather when you live in the south by KMI (Belgian weather forecast) or when you live in the north by the Northern German weather service. By the way, about 35 years ago, KNMI transferred a local weather station from the dike (near the sea) in Den Helder
(I lived there) to the local airport. Interesting to know if they realised/administrated then a possible sudden temperaure change.
Who needs GISS? Seems like a boat anchor attached to NASA, dragging down the parent institute’s credibility.
The question I would like answered is this: Is GISS really necessary and can it’s functions of meteorology be handled/absorbed by another Fed. institute with better credibility and accountability?
Or can GISS be salvaged with new management?
Budgets are tight, you know.
fipo 23-09-09 on Tips i want my name also mentioned 😉
peter vd berg (11:34:12) :
This link unfortunately only in dutch
http://www.elsevier.nl/web/Nieuws/Wetenschap/246638/KNMI-meet-jarenlang-foute-temperatuur.htm
shows that the dutch KNMI meteo has been measuring the wrong temperatures for years now.
They’d placed their equipment next to a row of trees and only found out when they moved their equipment and suddenly there was a temperature drop of about 0.5 Celsius on average.
Later comparisons with other weatherstations showed that this fault had been creeping in due to the row of trees growing and retaining heat more.
This just in: ReallywrongClimate has declared that this mistake “doesn’t matter”…..
Meteo Consult (The other, privately funded) meteorological institute in the Netherlands originally came up with the story (can be found here, in Dutch though):
http://www.weer.nl/nl/home/weer/weer_in_het_nieuws/weernieuws/archive/2009/september/ch/ce28e4a799/article/knmi_verplaatst_thermometer_stilletjes.html
because a lot of us were puzzled, to say the least, that EHDB had been more in line with the stations in the southeast of the Netherlands on hot days than what should be expected. And we were just as puzzled when EHDB was not this summer.
Turns out that the staff had undertaken research because they had noticed that effect as well (turned out to be +0.28C on average, and up to +0.5-+0.7C during hot days), and quietly moved their thermometer to a site that complied with WMO standards. Another side effect of this move is that the average night time temperatures nowadays are warmer than they used to be, because the old, more sheltered location gave an average deviation of -0.48C. All together, the old location was on average -0.15C colder than the new one, that complies with WMO standards.
The only thing that KNMI messed up with in this entire episode is that they did not sent out a press report concerning this move, allowing the tabloid media in the Netherlands to make their own story off of it.
Clint Hotvedt,
Bsc student Earth Sciences,
VU Amsterdam.
Is anybody else noticing a theme lately where otherwise “alarmist” institutions (I’m looking at you BBC, Guardian), are publishing articles that convey a sense of “Maybe it’s not as bad as we thought”.
Don’t get me wrong, there’s still an awful lot of cant being published, but I’m noticing a definite amelioration. I wonder if they’re starting to reposition themselves in light of new realities.
Do these people and organizations that take care of these weather stations ever make ‘mistakes’ that end up with a negative bias?
If that photo shows how one of their sites looks, is this the old met. site which is very close to the KNMI premises?
52.099119° 5.176728°
If so, as usual, these professionals never give accurate co-ordinate information.
Anthony,
This proves a lot of people are carefully reading your site.
I think it is wonderful you have a large and attentive audience.
There is a price: people want errors fixed.
And you fix them, unlike other sites.
I forgive you for confusing Dutch with Danes.
But will I find it in my heart to forgive if you were to confuse Colorado with Texas? Or worse, California?
LOL
In my World Weather Records book 1941-1950, under the station notes for DeBilt temperature it says “in order to reduce means of 1/3(8+14+19hr) to means of 24 hours, the following corrections should be applied:” then it lists corrections of from -0.3C for Dec. and Jan. to -1.8C for June. Then it says that “these corrections are based on the means of the period 1901-1930.” I have often wondered if all these corrections from when records were in hard copy were correctly accounted for when the records were put on line. The temperature drop for the year was -1.1C after the adjustment–it seems odd the adjustment happened the same time as the big drop in the graph above.
I sent the Met Office a questioning email last week, they have just posted this article on their climate change section. Perhaps a tipping point has been reached but not in the way you might think!!
A Pause in Arctic’s melting trend — Met Office response
23 September 2009
Met Office response to American research which has found that the Arctic sea-ice melt has not been as profound as in the last two years:
“The extent of Arctic sea ice has been decreasing since the late 1970s. In 2007 it decreased dramatically in a single year, reaching an all-time low. At the time it was widely reported that this was caused by man-made climate change and that the rate of decline of summer sea ice was increasing.
“Subsequent analysis has shown that this minimum was due, in part, to unusual weather patterns. Arctic weather systems are highly variable year on year and the prevailing winds can enhance, or oppose, the southward flow of ice into the Atlantic. Consequently, the sea ice has not declined every year, but has shown considerable variability.
“The high variability has made it difficult to attribute the observed trend to man-made emissions of greenhouse gases, although there is now enough data to detect a human signal in the 30-year trend. The trend and observed variability, including the minimum extent observed in 2007, is consistent with climate modelling from the Met Office.
“The climate model shows that ice invariably recovers from extreme events and that the long-term trend of reduction is robust, with the first ice-free summer between 2060 and 2080. However, about half of the climate models involved in the IPCC fourth assessment report, show that ice declines in steps — failing to recover from extreme years. The observed temporary recovery from the 2007 minimum in 2008 and 2009 indicates that the Arctic ice has not yet reached a tipping point, if such exists. We expect Arctic ice to continue to decline in line with increasing global temperatures. If the rate of global temperature rise increases then so will the rate of Arctic sea-ice decline.”
Americans + Geography = total mess.
Unfortunately both KNMI and Meteo Consult enjoy their ride on the AGW gravy train spewing AGW propaganda en mass.
I had the same problem, except wind was described as the problem and not shadow. One possibility is that blocking the wind was allowing the still air to warm more than the surrounding air. There are probably other identifiable effects but the known effects should have been taken into account when the siting rules were created.
No, they don’t. Anything that comes out which does not support the current meme of AGW gets “adjusted” before publication.
“The only thing that KNMI messed up with in this entire episode is that they did not sent out a press report concerning this move, allowing the tabloid media in the Netherlands to make their own story off of it.”
Is this the same KNMI that allowed the tabloid media to vent their warming hysteria?
There is lots of talk about how bad GISS is, and how it negatively affects NASA reputation and that change is needed. I think that the folks at GISS and their liberal masters are getting exactly what they want. They have control of the data, and a “connection” to NASA that gives them an aura of respectability. The desired outcome of the product that GISS produces is “PROOF” of AGW. This is not a scientific operation, it is a political one. The fact the GISS is in NASA has no bearing on what GISS is doing. Their goal is not rocket science. The goal is to further the political agenda of the Left.
isn’t this all moot?
I thought that the correction algorithms are so reliable that we are phasing out actual measurements because we don’t really need them anymore.
Anthony,
Not sure I quite get your point with the comparison to Essen. I resized and overlayed the Essen graph onto DeBilt, and they actually do show good agreement.
Graphic here.
http://www.prclaser.com/images/debiltvsessen.jpg
Are you trying to make the point that the more recent high temps have caused Giss to adjust down the past temps at DeBilt??
George Tobin (11:56:16) :
I thought that the correction algorithms are so reliable that we are phasing out actual measurements because we don’t really need them anymore.
—-
No, no, no.
You have it all backwards.
The MODELS are so good that we don’t need to collect observational data. It is obvious that if there is any discrepancy between the models and reality, that there must be something wrong with the instruments.
Robert M. (11:46:07) :
Fine. I’m sure the argument can be made to increase NASA’s budget at the expense of a disposable institution.
You heard the President: We are going to seek out those institutions that aren’t working and eliminate them.
I’m much rather see NASA have what they need for space stuff.
My favorite quote of the month!!!!
Heck, out here, they don’t look at instruments OR out the window for weather forecasts… it seems they just try to guess based on historical averages. Which would be why yesterday’s record high (by 3C !!!) was a total shock to those whose job it is to guess…. er, forecast.
And hey, everyone knows that 30 years is “enough” for historical averages, right?
I just found a copy of “World Weather Records” online at archive dot org–sorry I don’t know how to make links but you can find it by googling. The fact that the temperature shoots up again about 1990 really looks fishy; like corrections were applied incorrectly then later corrected? If you would like to see the publications history and provenance of “World Weather Records” google global change master directory DSI-9644 –it’s eye opening. When these records were put online or digitized, I expect it was done by some poor little GS-2 who may not have any idea what a correction meant or how it was done.
Interesting article illustrating how a faulty station can play havoc with the records.
As I don’t like the concept of ‘global temperatures I tend to use national temperature data sets-the older the better. The Dutch ones go back (sporadically) about as far as CET.
I thought it would be an interesting exercise to try and smooth out the short term temperature trends that will make someone in their 30’s today say-‘it’s got warmer in my lifetime’- a point which their great grandparents might disagree with, having lived through the 1920’s and 30’s
Consequently I decided to see what temperature a person living a three score year and ten life span in England would experience (using CET to 1660)
This table is based on the average annual mean temperature enjoyed by the ‘British Everyman’ through each year of each decade. This assumed he was born at the start of a decade and died the last year of the decade seventy years later. These are the calculations;
Someone born in Britain in 1660 and living to 70- Average annual temp 8.87c
Someone born in 1670 and living to 70 Average annual temp 8.98
1680 9.01
1690 9.05
1700 9.19
1710 9.21
1720 9.17
1730 9.14
1740 9.04
1750 9.03
1760 9.08
1770 9.10
1780 9.07
1790 9.12
1800 9.15
1810 9.13
1820 9.14
1830 9.12
1840 9.10
1850 9.14 (Start of the famously reliable Hadley global temperatures)
1860 9.17
1870 9.21
1880 9.30 Official end of the Little Ice Age-Start of GISS
1890 9.39
1900 9.40
1910 9.46
1920 9.497
1930 9.60
1940 9.70 (projected to 2009)
1950 9.76 Extrapolating current trends (our favourite phrase)
1960 9.79 Using advanced modelling techniques to create a robust scenario.
I called the people born in the period from 1660 to 1880 ‘LIA Everyman’ in as much the person lived part or all of their lives during the little ice age. Those born born from 1890 to the present day I have termed ‘UHI Everyman’ for obvious reasons. No adjustments have been made to correct UHI, poor siting, change of instruments etc.
The depths of the LIA can be clearly seen, but what I find interesting is that temperatures have risen only some 0.6 degree C since the warmest period of the LIA, which does not suggest a runaway climate change scenario to me.
(The slightly cooler average temperatures in the LIA are primarily due to colder winters – summers were pretty similar)
Of course, were it possible, it would be most interesting to extrapolate this back to the MWP and Roman optimums, as it would put todays very modest rises into a proper perspective.
My main point is whether anyone else living in a country with long records-Holland, Denmark, Sweden etc, would care to compile a similar chart on the same basis, that smooths out the short term noise.
tonyb
Is our RR Kampen not a Dutch meteorologist? Where is he when he is needed? Can he be prodded to come out of the woods?
(I just hope he does not work at KNMI)
a reader 12 47 19
Here is the explanation for the temperature increase since 1990-it is to do with the impossibility of constructing a meaningful global temperature
Link 1 Wikipedia’s explanation of global temperature with a colour globe showing location of weather stations world wide.
http://en.wikipedia.org/wiki/File:GHCN_Temperature_Stations.png
Link 2 Even better explanation with graphs
http://www.appinsys.com/GlobalWarming/GW_Part2_GlobalTempMeasure.htm
Link 3 This piece is taken from link 2 and is a blink chart illustrating station change
http://climate.geog.udel.edu/~climate/html_pages/air_ts2.html
(go to first item- ‘stations locations’ and click) You will get a media player animation illustrating the ever changing location and number of weather stations from 1950. Look for the startling changes since 1990.
These are primarily due to vast numbers of ‘cold’ stations being withdrawn in Russia following the end of the approriately named cold war.
tonyb
In Norway I have noticed some places that the area under the white boxes where they measure temperature is “environmentaly” a disaster area with very little green, but instead loads of brown.
Strange?
MattN,
Mistakes never matter to RC or members of the ‘Team’. Even the “hockey stick” mistake is now deemed unimportant and it is time’to move on’.
They are on a mission and mistakes don’t alter that.
OT: It has been confirmed,
COLDEST SEPTEMBER TEMPERATURE ON GREENLAND: -46.0 C
http://vejret.tv2.dk/article.php/id-25292765.html
OT: Greenpeace is at it again, someone needs to shut down this terror ring.
http://www.pittsburghlive.com/x/valleynewsdispatch/s_644707.html
Urederra (09:05:17) :
The instrument stood too close to a line of trees, due to which on average half a degree (Celsius) too high was measured
Strange. My common sense would have said that if there is a line of trees shadowing the thermometer, this should read lower temperatures, not higher.
That would be a natural conclusion if the trees shade the instruments for some time during the day. If, however, the trees are on the north side of the instrument package, they could, presumably, reflect sunlight onto the instruments. The explanation put forward by AnonyMoose is also plausible and valid.
The temperature drop after moving the instruments should give one pause in claiming “global warming” at this site.
http://heliogenic.blogspot.com/2009/09/eu-ets-kaput.html
Cold greendland warm west europe. But the NAO can change in a month.
19.955M
Mark (10:35:29) :
Do these people and organizations that take care of these weather stations ever make ‘mistakes’ that end up with a negative bias?
What a great question! I’m not aware of a single documented case myself, but there might be one out there, lurking, somewhere… Anyone?
They managed to find Normandy.
“Do they ever make mistakes that end up with a negative bias?”
Not often.
It is easier to make an “honest mistake” that adds an upward bias. For example, urban sprawl only engulfs a sensor that was previously in the country, the reverse doesn’t happen. Green spaces get converted into black-top parking areas and highway, the reverse seldom happens. Air conditioning gets added and is seldom removed.
Secondly, and more sadly, data sanitization is dependent on the observers. People expecting an up-trend will soon find a way to fix a down-trend sensor.
The temperature record from De Bilt is one of the longest continuous records in the world and is often praised for its usability in climate studies. Sadly it appears that the data available from GISS, also used by Anthony, is faulty. There are at least two issues: both the raw and homogenized GHCN data deviates strongly from the official KNMI measurements (both uncorrected and homogenized), which have been available for decades. Second, GHCN claims to have De Bilt measurements before 1897, the year that measurements started there. Before 1897 measurements were taken in Utrecht, Haarlem and Zwanenburg (near Amsterdam). These series were combined by KNMI into one homogenized record for the central part of Netherlands, starting in 1706. The GHCN series deviates from that homogenized series as well. Notably, though the differences disappear almost entirely after 1951. This is the year that KNMI starting use a better type of radiation shield and lowered the sensor from 2.2 meters to the current 1.5 meters (WMO standard).
I have made NASA/GISS aware of the issues with the De Bilt series in the GHCN and pointed them to the proper data source for updating/replacing the record of De Bilt in the GHCN database. For those interested, I made an intercomparison of the De Bilt series from GHCN raw (blue), GHCN homogenized (red) and KNMI homogenized (green): http://benlanka.tweakdsl.nl/climate/comparison.jpg
Ben Lankamp
Meteorologist from The Netherlands
If moving a thermometer a couple hundred meters can chop a half degree off “global warming”, maybe we ought to move ’em all! 🙂
Best,
Frank
the only place with a negative bias could be a themometer in tjernobyl
for a birdseye view of the trees on the side of the observation field see:
http://www.bing.com/maps/default.aspx?v=2&FORM=LMLTCC&cp=spgv8xhdy769&style=b&lvl=1&tilt=-90&dir=0&alt=-1000&phx=0&phy=0&phscl=1&scene=11657685&encType=1
[i]Strange. My common sense would have said that if there is a line of trees shadowing the thermometer, this should read lower temperatures, not higher.[/i]
This is a common feature in Holland we call the “garden effect”: narrow gardens with 6 ft walls between them generate microclimates with significantly higher temperatures then the official readings give and gave the effect its name. This only works if the north side of the compound is sheltered from cooling northerlies. It seems that the KNMI suffered from “garden effect”, an effect that any amateur takes into account and tries to avoid (if possible) when setting up a weather station.
anybody interested in homogenised de bilt (my homogenisation!) relative to rural hohempeissenberg
http://members.casema.nl/errenwijlens/co2/europe.htm
So they have been measuring Double Dutch? Maybe they should have chopped down the offending trees and done some ring analysis to correct the past and future temperature records 🙂
Oh wait… yes this is Holland we are talking about… they don’t even cut the grass on the road verges anymore, let alone cut down trees. Silly me.
jeroen (15:53:10) :
I think it had a massive spike a while back 😉
Hans Erren: Judging from the map it looks like a very good site. Much better than nearly all the US sites.
Of course it is well known that a small site change even from one “good” location to another can result in large differences. But it is an eye-opener that a site move so small in relation to trees so distant should result in such a large step change.
It certainly makes one wonder how well documented these changes are and what the margin of error is regarding the adjustments. Homogenization doesn’t fix the problem, though, it just spreads it around and makes it harder to detect.
Murray Carpenter (11:16:12)
forgive the blunt question, but who the heck would pay any attention to the Met Office? They don’t know what on earth is happening at the present,at least if the present consists of between 2007 and 2009, but can predict exactly what will happen in 2080?
This is the same sort of Alice in Wonderland answer they reply to my questions, and its not in my nature to be vituperative about a scientific organisation’s response, so I just don’t question them anymore
To feel cooler, I often sit under a tree that adjoins my patio, but does this report mean that if I sat in the sun under an umbrella and far from some trees I would feel even cooler? (By the way, does “umbra” means shadowed or shaded? I think “ella” is a diminutive, meaning a “a little”, so does an “umbrella” provide a “little shade”?)
Anyhow, can anyone explain to me why nearby trees that are providing a little shade near a sensor would cause temperature readings higher than normal? Pardon my ignorance, but is this because of heat generated by decaying vegetation that often is found under trees unless it has been raked up and removed? Or is there another reason?
This raises an interesting issue about slowly growing time-span biases in temperature measurements. If there are trees growing near the thermometers over a period of years, does this compound the growing bias over time caused by the heat island that also is growing near the sensor — e.g., more asphalt parking lots are paved (sparing the nearby trees), more people are moving into bigger buildings that must add more heat-generating air-conditioning condensers, wider paved roads are built for better access by more traffic to the bigger buildings, etc?
So do trees growing within the growing urban heat island create a sort of temperature bias double-whammy?
evanmjones (16:35:12)
Homogenization doesn’t fix the problem, though, it just spreads it around and makes it harder to detect.
So we fix the problems, spread it, nobody knows.
It seems that James Hansen at GISS is breaking some sort of law by tampering with temperature data.
RealClimate says this change of location is nothing? This opinion of theirs tells more about they themselves than they know.
REPLY: AFAIK they have not commented on it. That was sarcasm from an earlier commenter. – A
Espen (08:16:22) : I tried to find stations with long records in Holland, and found De Bilt (near Utrecht) which shows the same result of homogenization as the arctic cities: The temperatures from 1881 to 2009 first shows a flat trend (-0.05C/century), but after homogenization there’s suddenly a +1C/century trend! For Milano, Italy, it’s even stranger – a -0.7C/century trend is turned into a +0.7/century trend. I.e. the homogenization performs the reverse of an UHI correction, despite the fact that Linate is an airport very close to a huge city!
Notice the part about Milano here. I’m starting to believe that the GISS data for Europe (and probably other parts of the world too) is even worse than what you have discovered in the US with the surfacestations project. And the CRU data we can’t even evaluate…
This is a direct result of the processing done in the PApars.f program using “reference stations” up to 1000 km away. Many of these are in the mountains and in particular Hohenpeissenberg is the longest lived station in the area. This means it is applied first for “UHI” correction. One Small Problem: It is on the edge of the Alps and rather cold and GIStemp has what I think is a “bug” in the processing so that the first station applies a bias (rather than correcting it out). The end result is that anything within 1000 km of Hohenpeissenberg ends up with a bogus UHI correction. A second effect comes from other cold high mountain stations also making the UHI go the wrong way. GIStemp claims not to do this, but the result of running the code and reading the code says otherwise. Details at:
http://chiefio.wordpress.com/2009/08/30/gistemp-a-slice-of-pisa/
The end point conclusion is rather simple: GIStemp is fatally flawed and produces a useless temperature series.
Given that HadCRUT is the “dogs lunch”…
We’re left with not much of a foundation for the AGW fantasy.
The reports about the “on average half a degree error” are erroneous themselves.
Newspapers are not to be relied upon, at least not with regard to scientific data, because in general news-reporters are often more interested in writing juicy stories than to present objective balanced information. This certainly applies here.
It seems that the “journalists” based themselves upon an article of Meteo Consult which speculated about the alleged measurement errors of the KNMI at De Bilt. That article compared data from De Bilt with a location at Cabauw about 16 km away from De Bilt, comparing data over the period 15 May – 15 September in 2008 and 2009.
It seems that numbers were selectively taken from that article and were misinterpreted along the way. Meteo Consult found out that the average maximum temperatures in the summer of 2008 were 0.53 degree higher for De Bilt compared with Cabauw, while the difference was only 0.02 degree in 2009. So I guess this is where that “half a degree error” comes from.
But what the newspaper articles don’t report is that Meteo Consult also found out that the average minimum temperature at De Bilt was actually 0.36 degrees lower in 2008 and 0.22 degrees lower in 2009 compared with Cabauw! That finding probably wasn’t helpful for a juicy story.
So you see, the reports about the “on average half a degree error” are based upon misinterpreted selectively chosen data from speculations. However, it is true that the station at De Bilt was moved to a better location. I will lookup some real data and post it in my next message.
rbateman (09:49:54) : Who needs GISS? Seems like a boat anchor attached to NASA, dragging down the parent institute’s credibility. The question I would like answered is this: Is GISS really necessary and can it’s functions of meteorology be handled/absorbed by another Fed. institute with better credibility and accountability?
Having gone through all of GIStemp I can tell you that the only part I would keep is the “glue together the Antarctic data sets and GHCN” bit early in STEP0.
There are 6 steps numbered from 0 through 5. Step 4 just updates the Hadley SST anomaly box file. Step 5 merges this with the GIStemp land data. Given that Hadley data are now “the dogs lunch” I see no reason to keep STEP4_5 (it is a composite step).
STEP3 does a boxing / gridding process. It takes temperatures that it has fabricated (via a variety of oddball processes) and smears them around over an area up to 1200 km in radius. This, unfortunately, does not do what the AGW advocates assert in that it does not suppress one bad thermometer from having influence. In fact, one bad thermometer can warm an area about 1/2 the size of the continental USA (and does so).
See the impact of Diego Garcia, for example:
http://chiefio.wordpress.com/2009/09/08/gistemp-islands-in-the-sun/
So STEP3 is bogus just because all it does is take broken temperatures (largely based on airports) and smear them over far larger areas than they would otherwise screw up.
OK, what about STEP2? As seen in the “slice of pisa” link above, it takes temperatures from cold places and uses it to give an upside down UHI correction to places like PISA. It does not achieve it’s stated goal in that the anomaly phase in it does not suppress the real impact of actual cold places on the temperature series. The anomaly code does not work as advertised.
So jettison STEP2.
STEP0 takes the antarctic data, GHCN data, a “special” copy of Hohenpeissenberg data and glues them all together. Unfortunately, it also mucks around with an strange “unadjusting UHI” step as it does this merger and it has a slightly broken F to C conversion that warms 1/100 of the records by 1/10 C each. Easy fix: Use the GHCN “adjusted” records and forget about the GIStemp UHI farce. This also eliminates the F to C problem and gets rid of the strange “unofsetterizing” and merging process.
http://chiefio.wordpress.com/2009/07/30/gistemp-f-to-c-convert-issues/
So we are left with Hohenpeissenberg. Take a look at the data, if clean, let it in, if not, use the GHCN record.
And finally there is STEP1. This step uses stations from up to 1000 km away (or maybe it was 1200 km… GIStemp keeps changing the radius it likes to use from STEP to STEP. Cherry picking is so messy…) to re-imagine the temperature series by fabricating data where there are none. While it looks like it MIGHT be OK, it also looks like it does not contribute much to the process. Through STEP1 the temperature series are warmed by about 1/2 C (in addition to any bogus temperatures recorded in the first place).
http://chiefio.wordpress.com/2009/08/12/gistemp-step1-data-change-profile/
I see no reason to add 1/2 C to the data series while fabricating data that do not exist. So I’d toss it too.
That leaves the simple process of:
Get NOAA GHCN Adjusted data, merge Antarctica. Done.
I would then look at the long lived thermometers (not bothering to re-imagine data that do not exist) and simply ask them what to they say. What they say is that there is no warming:
http://chiefio.wordpress.com/2009/08/13/gistemp-quartiles-of-age-bolus-of-heat/
So at the end of about 3/4 of a year of work dragging my brain through GIStemp code, my conclusion is that the world would be better off tossing it in the dust bin and using the straight GHCN data plus Antarctic.
Anyone who supports the use of GIStemp has not analyzed what it does.
It sucks to be caught with your weather station pants down!
Here is some real data on the measurements site in De Bilt:
==============
Source: http://www.knmi.nl/publications/showAbstract.php?id=426
Parallel air temperature measurements at the KNMI-terrain in De Bilt (the Netherlands) May 2003 – April 2005
November 2004
by T. Brandsma (KNMI),
Abstract
From May 2003 through April 2005 a field experiment is being carried out
at the terrain of KNMI in De Bilt. The objectives of the experiments are to
study the representativeness of the current operational air temperature
measurements site and to explore the possibility of using present-day parallel
measurements to correct for inhomogeneities, caused by changes in the
surroundings and a relocation of the thermometer screen in 1951. At five
locations, including the operational location, temperature and wind speed
are measured at a height of 1.5 m every minute, using identical instruments.
The temperature differences between the sites are studied in connection
with wind speed differences and operationally measured weather variables.
The experiment is part of the KNMI-program ‘Hisklim’ (HIStorical
CLIMate). The measurements can be followed real time at the KNMIintranet
site http://info.knmi.nl/ks/hisklim/Parallelmetingen/.
The present interim report presents the results of the first phase of the experiment
(May 2003–April 2004). The report is meant to serve as a basis
for deciding upon the optimal future location of the current operational
temperature site. A Final report will be published at the end of the experiment.
Full text (pdf: 5 MB): http://www.knmi.nl/publications/fulltexts/hisklim7.pdf
==============
Source: http://www.knmi.nl/publications/showAbstract.php?id=5759
Understanding of inter-site temperature differences at the KNMI terrain in De Bilt (the Netherlands)
2008
by T. Brandsma (KNMI),
Abstract
From May 2003 through June 2005 a field experiment was carried out at the KNMI terrain in De Bilt. At five sites, including the operational site, temperature and wind speed were measured at a height of 1.5 m every minute, using identical instruments. The temperature differences between the sites have been studied in connection with the wind speed differences and operationally measured weather variables. During the experiment (in October 2004) a renovation of the nature area just west of the operational temperature screen took place. The renovation introduced an inhomogeneity in the temperature time series at the operational site. The inter-site temperature differences are largest in summer and smallest in winter. Except for the most enclosed site, these temperature differences have opposite signs for daily maximum and minimum temperatures. As could be expected, the magnitudes of the differences strongly depend on the weather conditions. The understanding of these dependencies is an important condition for improving the homogenization of daily temperature series.
TonyB (12:57:20) :
These are primarily due to vast numbers of ‘cold’ stations being withdrawn in Russia following the end of the approriately named cold war.
I trust that you are not implying that removal of cold stations will increase the rise in temperature?
Only anomalies are used in global averages (there is no other possibility) so of course the absolute temperature of individual stations does not affect the average.
Good one! LOL
Don’t forget that this works both ways. Those born in recent decades are likely to see a return to a more 70’s like climate over the coming decades.
If the cyclic nature (at least in this locale) is real, it would cause a lot of problems for places like the UK where AGW has been accepted more readily for the reasons you outline. Planning and taxing for a ‘Mediterranean’ climate while snow frequently brings our infrastructure to a grinding halt.
Meanwhile in Finland the Finnish Meteorologial Institute finds that due to UHI the night temperatures can be up to nine (9) degrees higher than in neighbouring urban areas.
This affects Helsinki metropolitan area in particular.
http://translate.google.fi/translate?prev=hp&hl=fi&js=y&u=http%3A%2F%2Fwww.fmi.fi%2Fuutiset%2Findex.html%3FId%3D1253684912.html&sl=fi&tl=en&history_state0=
3×2: If the cyclic nature (at least in this locale) is real, it would cause a lot of problems for places like the UK where AGW has been accepted more readily for the reasons you outline.
The optimistic olive (indeed – but in Cornwall, I think) and wine farmers may have to move to Tuscany to fulfill their dreams – after all 😉
@ E.M.Smith
http://chiefio.wordpress.com/
So at the end of about 3/4 of a year of work dragging my brain through GIStemp code, my conclusion is that the world would be better off tossing it in the dust bin and using the straight GHCN data plus Antarctic.
Anyone who supports the use of GIStemp has not analyzed what it does.
Very few people have analyzed the GIStemp code, but you have, and we are in your debt. WUWT is fortunate to have people like you who dig into the details of the science and separate the slag from the AGW output.
It must be frustrating for the ‘professionals’ to put together a scientific paper or process, then have WUWT ‘amateurs’ go through them and not only point out the errors, but then reverse engineer their secret methods and generate the results they should have gotten.
Again, Danke. (is that Dutch or Danish?)
When iused to drive to work from a village 10 miles outside Munich Airport to the airport my car thermometer always jumped at least 1 degree c no matter what time of year or time of day.All that tarmac and concrete holding on to heat.Airport heat island,how many weather stations do airports have, that might find their readings ending up in climate data..
@Mike McMillan
Danke is German, ‘Dank je wel’ is Dutch
“De Bilt were always a bit warmer than in Cabau, 16 km away, where there is also a KNMI thermometer.”
In reality, the distance is about 36 km.
In reality, the difference over time has varied from zero to 0.5° C (which is minimal in all respects). It is statistically not possible to determine whether the hut had been displaced or not.
In reality, the difference of +0.5° C is on average maximum temperature, not on average temperature. The difference between min and max in the Bilt is a little larger than in Cabauw simply because de Bilt lies on sandy ground whereas Cabauw is mud. The difference of average max has varied between zero and a degree since the start of Cabauw in 1986 and may be attributed to said sandy underground and of course weather.
In reality, the average daily temperature on the new location was found to be 0.15° C higher, though this difference has no significance.
The ‘step function’, that is the sudden warming as of 1988, is real, no artefact. It is shown by all Dutch stations. It is reflected in e.g. the fact that skating on canals was possible 9 out of 10 winters prior to 1988, 4 out of 10 between 1988 and 2000, 2 out of ten this century.
July 2006, the hottest month ‘ever’ (shall we guess: about 4.000 years?) was real. I can’t stand that kind of Spanish heat and lost 10% of my bodyweight in those weeks.
Essen is a city of about 540.000 inhabitants but situated in the so called “Ruhrgebiet” an industrial area since the 19th century with a very high density of population. There are many cities quite close to each other like Essen, Dortmund, Duisburg, Bochum, Oberhausen. In former times this area was famous for coal mines, steel (Krupp) and heavy industry.
Re: Mike McMillan (00:27:02) :
“Again, Danke. (is that Dutch or Danish?)” – Neither, that’s German. Danish: Tak. Dutch: Dank.
Nice, these reactions from KNMI employes. And indeed, they have a lot to defend, in the first place their unassailable position in the dutch mainstream media concerning the holy AGW belief. In the second place of course their wages and funding as provided by the dutch ministry for economic affairs. KNMI nowadays is nothing else than a red-green propaganda institute collaborating with the government to oppres and indoctrinate the country in a stalinistic way.
@Mike McMillan.. Danke is German!
Anyway here is all the official DATA for De Bilt (maastricht and others are also there)
http://www.mscha.org/knmi/summer.cgi?station=260&sort=year&month=-1&columns=more
the average annual temp in the netherlands is 9.8 C (
here is the report from the parralel measurement before the move
it states that the old location is on average -0.15C colder !
http://www.knmi.nl/publications/fulltexts/hisklim7.pdf
Joel Heinrich : Uccle is part of Brussels. Brussels is formed of 19 borough like Paris 20 “arrondissements”, so the population of Uccle should not be considered as 76K but well at 1 million for Brussels
rtgr (02:58:24) :
Anyway here is all the official DATA for De Bilt (maastricht and others are also there)
http://www.mscha.org/knmi/summer.cgi?station=260&sort=year&month=-1&columns=more
What kind of adjustments have been applied to these temperatures?
They are very different from the unadjusted GISS data:
http://data.giss.nasa.gov/cgi-bin/gistemp/gistemp_station.py?id=633062600000&data_set=0&num_neighbors=1
and has even more trend than the adjusted GISS Data:
http://data.giss.nasa.gov/cgi-bin/gistemp/gistemp_station.py?id=633062600003&data_set=2&num_neighbors=1
At times when I consider the AGW argument, I feel as though I stepped through the looking glass.
Alice laughed, “There’s no use trying,” she said, “one can’t believe
impossible things.”
“I daresay you haven’t had much practice,” said the Queen. “When
I was your age, I always did it for half-an-hour a day. Why,
sometimes I’ve believed as many as six impossible things before
breakfast.”
In these discussions, humor, sarcasm, and irony have to be INDENTIFIED. The pro-AGW arguments become so tortured that they are parodies of themselves. So, ridiculing them has to be identified as ridicule so it won’t be taken as a serious comment.
By the way, I am guessing that:
Re: Mike McMillan (00:27:02) :
“Again, Danke. (is that Dutch or Danish?)”
is a subtle attempt at “engineer humor”. To imply that a German word is either Dutch or Danish is vaguely insulting to all parties. Sort of like saying Texas and California are the same. (I was working with a Dutchman and I mistakenly spelled his last name Von… instead of Van…. He promptly explained the enormity of my crime against the Dutch
People.)
Anthony,
Please keep up the good work. We need you!
Regards,
Steamboat Jack
RR Kampen: July 2006, the hottest month ‘ever’ (shall we guess: about 4.000 years?) was real.
4000 years? Come on! It may be the hottest month for 100 years in the Netherlands, but there are close contenders. And since June and August were not so hot, the summer 2006 wasn’t that extraordinary.
According to GISS data for de Bilt (I’m using the homogenized data now), the following are the 11 hottest June-July-August periods:
1947
1911
1935
1976
2003
1933
1939
1941
1983
2006
And according to the even more “homogenized” (i.e. upwards trended…) dutch data posted above, 1947 also had higher max temp than 2006.
So please, don’t conclude anything about climate from one hot summer month…
Re: Espen (06:16:07) :
“4000 years?”
That is the calculated return time for a July with such a great anomaly.
“Come on! It may be the hottest month for 100 years in the Netherlands, but there are close contenders.”
For July 2006 there are simply none. Temperaturerecord back to 1706, with some small interludes back to 1634, nothing like it.
“And since June and August were not so hot, the summer 2006 wasn’t that extraordinary.”
June 2006 was 13th warmest since 1901. August on the other hand was a degree cooler than the norm 1971-2000.
Summer 2006 became number three hottest, after 1947 and 2003.
“According to GISS data for de Bilt (I’m using the homogenized data now), the following are the 11 hottest June-July-August periods:
1947
1911
1935
1976
2003
1933
1939
1941
1983
2006”
According to our data (also with GISS, which has three different records by de Bilt) the 11 hottest summers were:
1947
2003
2006
1976
1983
1995
1994
1997
1992
1911
1975.
The only normal summer of ‘this century’, the year doesn’t even belong to it, is 2000.
The coolest summer this century ranks 39th since 1901.
“And according to the even more “homogenized” (i.e. upwards trended…) dutch data posted above, 1947 also had higher max temp than 2006.”
No, the highest absolute maxtemp and the July average were both above 1947. The pair June – July as well.
“So please, don’t conclude anything about climate from one hot summer month…”
I didn’t, read my post and please don’t put contentions in my mouth. I just said July 2006 was vastly extremely hot and this heat was real. Needed no thermometer to confirm that. If I wanted to show climate change, I would not take one month but a lot of numbers. The result is clear, though.
http://nlweer.com/img/17sep2006.PNG
I drink Homogenized milk
I wrote: “And according to the even more “homogenized” (i.e. upwards trended…) dutch data posted above, 1947 also had higher max temp than 2006.”
RR Kampen responded: “No, the highest absolute maxtemp and the July average were both above 1947. The pair June – July as well.”
Let me clarify: When I wrote “dutch data above”, I meant:
http://www.mscha.org/knmi/summer.cgi?station=260&sort=year&month=-1&columns=more
– which shows a max of 36.8 for 1947 and 35.7 for 2006.
Do I understand correctly:
RR Kampen IS a emloyee of KNMI?
And there are THREE different set of records by KNMI at GISS? Why?
And summer 1947 WAS warmer in Holland than anything recent?
Re: Espen (05:21:43) ,,What kind of adjustments have been applied to these temperatures?”
No adjustments were applied to the official (non-homogenized) KNMI record. The GHCN contains outdated or plain wrong records of De Bilt, of which I have already notified NOAA through the proper channels. Hopefully an update will be made to the GHCN soon.
When I checked the temperature-data from De Bilt I found that the climate changes more during the night than during the day.
For the period 1901 – 1920 the mnimumtemperature was 5,0 degress C.
Between 2001 – 2008 average minima were 7,3 degrees C.
Minimumtemperatures have increased by 2,3 degrees Celsius.
The maximumtemperature increased from 13,3 to 14,7 degrees Celsius.
A smaller increase of 1,4 degrees.
When I asked a question about UHI-effect on the minimumtemperatuur, the KNMI replied that the effect was probably not significant. The difference between day- and nighttemperature can also be caused by other factors.
The data are summarized in: http://img200.imageshack.us/img200/1009/1250846805333.gif
Ben Lankamp (08:10:50) :
“No adjustments were applied to the official (non-homogenized) KNMI record. The GHCN contains outdated or plain wrong records of De Bilt, of which I have already notified NOAA through the proper channels. Hopefully an update will be made to the GHCN soon.”
The record in http://www.mscha.org/knmi/summer.cgi?station=260&sort=year&month=-1&columns=more does not contain the step change in 1951 which is obvious in the GISS record. And this step change is discussed in http://www.knmi.nl/publications/fulltexts/hisklim7.pdf
To me it looks like the unadjusted GISS record is unadjusted for the 1951 step change because of the station relocation, while the record in http://www.mscha.org/knmi/summer.cgi?station=260&sort=year&month=-1&columns=more is indeed adjusted.
Do you have a direct link to the non-homogenized record you mention above?
…but what if the step change in 1951 was real?
Uccle actually shows a very similar step change! – but on the other hand, Uccle seems to have gotten an additional station in 1951 too, so they may have introduced a similar error. However, right on the other side of the canal lies Gorleston, which ALSO had a big temperature drop in 1951:
http://data.giss.nasa.gov/cgi-bin/gistemp/gistemp_station.py?id=651034960010&data_set=0&num_neighbors=1
The 1950 step is a well known WMO artifact
Below is the reported well documented move in De Bilt:
http://members.casema.nl/errenwijlens/co2/debiltlocations.jpg
Compare adjustments to GHCN data by GIS, van Engelen & Nellesein (KNMI) and myself.
http://members.casema.nl/errenwijlens/co2/debilthomogenisations.gif
http://members.casema.nl/errenwijlens/co2/homogen.htm
and this interactive google map
http://maps.google.com/maps/ms?ie=UTF8&hl=en&msa=0&msid=108455475154621623933.0000011301001df084755&ll=52.100488,5.177125&spn=0.002755,0.007081&t=h&z=17&om=1
Hans Erren: Thank you for the links! If the 50/51 step is a well known WMO artifact, I’m surprised that it’s not removed in the homogenized GISS records.
Regarding the UHI adjustments in the article you refer to, I’m surprised that one uses remote Fichtelberg to adjust dutch data – the climate of Fichtelberg in Sachsen is obviously very different from the dutch climate, so don’t you introduce a lot of noise that way?
I would have thought that the US and Western Europe would be where the best measurements of Temperature are made. Not so good, as we now know.
I wonder what Anthony would find if he had the time to look at European WX-stations. And I prefer not to think about what he might find in some other places.
Darwin, at the North centre of the Australia coast, is a bit important when examining El Ninos. The land temperature at Darwin over about 100 years can be found on the Internet and on Bureau of Meteorology products, as adjusted by various parties.
Here is one version (I have applied minor in fills to missing data here and there, not significant in showing the picture, but not reproducible for detailed maths).
Given that all of the data originate from one source (the earliest being labelled BOM CD 1993, it was not a CD but a dowload) it is fair amazing how much variation there is. Plotted are annual averages from daily records.
If you wanted to correlate a climate property with temperature, which curve would you select and why?
http://i260.photobucket.com/albums/ii14/sherro_2008/DARWIN_SPAGHETTI_2.jpg?t=1253928389
to Clint Hotvedt
[snip]
Moving the sensor out from under the trees and into an open area would not have made the night time temperatures warmer. The trees, like concrete and building walls, would be a heat souce at night and would have warmed the night time readings. That’s why there is a urban heat island effect. You obviously need to stay in school much longer.
Giss Data not homogenise shows much the same as the series 1,2,3,4 from 1882 – 2009
The homogenised is only from 1963 – 2009 but again follows 1,2,3,4 (1963 to 1970 are similar temps to 2000 to 2005)
So where have you obtained series 5?
In the Smithsonian Miscellaneous Collections Volume 79 page 559 with corrections on page n43, there are records for Utrecht-DeBilt going from 1849-1900. Later volumes contain the more recent records. I expect records like these may be the “outdated” or incorrect records, or the source of the multiple versions.
Could one of the knowledgeable commenters from the Netherlands explain how records from that long ago are determined to be outdated or incorrect? I think this question ties in with requests for raw data recently done at Climate Audit, as I believe GISS and its predecessor agencies as well as Hadley Center all used these Smithsonian Collections as their first resources when building their climate history records.
Anthony,
Several people here have pointed out the errors in the newspaper articles. So for the sake of presenting balanced and objective information, it would be fair to update your post and make clear that the two newspaper articles you quoted are erroneous.
At the very least it should be noted that there is no basis for the statement that there was a “on average half a degree error” at De Bilt. This statement apparently was made up by a reporter who wanted to write a juicy story, and then other reporters eagerly copied it without checking it out themselves.
REPLY: Actually I have something better – the internal report prepared by De bilt that shows the results of a running field experiment on this issue, which I’ll publish soon. – Anthony
Espen (14:40:12) :
The climate in Western Europe is remarkably similar as this graph shows from observation points 1400 km apart
http://members.casema.nl/errenwijlens/co2/europe.htm
I also used these stations to identify the inhomogeneity in the Hohenheim temperature data
http://www.climateaudit.org/?p=7134#comment-357111
So yes Fichtelberg can be used as a homogeneitytest. Of course if stations are remote, small inhomogeneities can disappear in the noise.
a reader (05:59:18) :
I obtained the long GHCN series from the GISS website, before James Hansen decided to truncate all records at 1880
Full record is still available at KNMI
http://www.knmi.nl/klimatologie/daggegevens/antieke_wrn/labrijn_ea.zip
A van Engelen and Nellestijn, JW, 1996, Monthly, seasonal and annual means of air temperature in tenths of centigrades in De Bilt, Netherlands, 1706-1995. KNMI report from the Climatological Services Branch
this maps shows the sites that are used to make the series
http://maps.google.com/maps/ms?ie=UTF8&hl=en&msa=0&msid=108455475154621623933.0000011301001df084755
Original source:
A. Labrijn, 1945, Het klimaat van Nederland gedurende de laatste twee en een halve eeuw, Mededelingen en Verhandelingen nr. 49, KNMI publ. 102. (PhD dissertation Utrecht University)
Espen (12:17:30):
Data is available from KNMI in comma-separated format: http://www.knmi.nl/klimatologie/maandgegevens/datafiles/mndgeg_260_tg.txt
Notification from KNMI with regard to this record: due to possible relocations and changes in observation methodes these records of monthly values are not homogenic.
There is no step change around 1950 in this record, so possibly the 1950 relocation, which Hans already described, is the -only- thing corrected for in the record above. For the rest it is non-homogenized data (according to KNMI). The official homogenized version of the De Bilt record can be found here:
http://climexp.knmi.nl/data/temp_De_Bilt_hom.dat
Source: A.P. van Ulden, The Construction of a Central Netherlands Temperature, KNMI-WR 2009-03, available online: http://www.knmi.nl/publicaties/fulltexts/CNT.pdf
Re: Alexej Buergin (12:56:09) :
Is our RR Kampen not a Dutch meteorologist? Where is he when he is needed? Can he be prodded to come out of the woods?
(I just hope he does not work at KNMI)
and
Alexej Buergin (07:59:42) :
Do I understand correctly:
RR Kampen IS a emloyee of KNMI?
And there are THREE different set of records by KNMI at GISS? Why?
And summer 1947 WAS warmer in Holland than anything recent?
—
I am no employee of KNMI or any other weather/climate institute, although in 2006 I was close to a job of operational meteorologist at WeatherNews. But I’m into software quality assurance for a company not at all related to weather/climate. Nevertheless I’m ‘into weather and climate’ since I was 11, 31 years ago, have some years university on this subject until I went into mathematics to study (‘chaotic’) dynamic systems, am an active participant in the Dutch meteorological community.
For the sets of de Bilt records at GISS, see explanations by Ben Lankamp.
1947 is still the hottest summer in the Dutch record, though individual summer months July and August carry high records of very recent years.