Many readers are familiar with the Central England Temperature Record (CET), now Frank Lansner investigates the Central Netherlands Temperature Record (CNT). Long, but enlightening. – Anthony
Guest post by Frank Lansner
Instead the KNMI has decided only to make available their “CNT”, the Central Netherland Temperature index.
KNMI do make two coastal temperature series available before 1951 (Vlissingen and De Kooy) and then some strongly adjusted temperature series (De Bilt and Maastricht). Finally the Northern Eelde Station that has not been adjusted has been made publically available, fortunately.
To make the “CNT”, KNMI use strongly adjusted versions of their temperature data, let’s start out with Maastricht:
Fig2
Before 1950 close to one full Kelvin of heat has been taken out of data. The strong dive in temperature 1950 has been removed.
Fig3.
Exactly the same occurs for the De Bilt station, the temperature dive in 1950 has been removed.
Fig4
Here the combined adjustments of Maastricht and De Bilt data. The “Central Netherlands Temperature” index is shown here too. It is almost identical to the adjusted De Bilt and Maastricht data.
Fig5.
The raw temperature data from Bruxelles station Uccle obviously confirms the raw versions of De Bilt and Maastricht. Perhaps slightly more urban heat warm trend can be spotted in the Uccle data. But check this:
Fig6.
It does seem that the other Bruxelles station “Bruxelles National” has less warm trend than the Uccle station, suggesting a little UHI in the Uccle dataset?
Fig7.
Let’s move on, the Luxemburg station is available from Crutem3, and the dive in temperature from the late 1940´ies to 1956 yet again is confirmed.
Imagine that KNMI was correct in their adjustments and just by coincidence we have De Bilt, Maastricht, Uccle and Luxemburg showing a HUGE freak error simultaneously in 1950.
Would it take a miracle at this point for KNMI to be correct?
Well, let’s move on.
Fig8.
From GHCN we have Frankfurt-Wiesbaden temperature data again the warmer pre-1950 data are confirmed. In addition the warm peak 1957-62 is stronger in central Germany.
In my previous article on this matter I analysed a row of German stations from raw GHCN V2, check link in the end of the article.
Fig9.
On the site “Tutiempo” you can normally find adjusted data but I checked out this “Ypenburg” station. It appears that in the period approx. 1936-55 there was an Airport in Den Haag called Ypenburg. Tutiempo for some reason holds just a little sequence of apparently raw data from Den Haag Airport:
Fig10.
The Ypenburg station is around 10 km from the coast. The “choice” of years available from Ypenburg is perfect: We have once again confirmed the large dive in temperatures 1949-1956 in Southern Holland.
How about Paris data? They must be available? For some reason NO raw temperature data is available before 1951 from all Northern France. But Paris then?
Fig11.
Obviously we should expect some UHI for a Paris station, but none the less, the Paris Orly data – (although not showing 1956) do confirm the warmer pre 1950 temperatures compared to the 1970-80 level. Also Paris do not support KNMI and their “CNT”.
Fig12.
When I first looked at Paris “raw” GHCN data I was surprised because the year 1949 showed a large temperature dive unlike the other stations in the area. However, the 1949-dive in GHCN Paris L Bourget was contradicted not only by all other stations in the area, but also by the other Paris dataset, Paris Orly, here taken from Tutiempo. Thus, all Northern French raw data are eliminated in GHCN before I 1951, and then the only dataset with a 1949 peak happens to have the data point lowered 2 K.
Fig13.
Before returning to the Netherlands, Finally one more German station from raw GHCN V2, Dresden (for more German and Czhech stations, see the link 2 in the end of the article).
Gemert:
Yet another Dutch temperature station seems to behave wrongly according to KNMI, and then the error happens to take place in 1950, so that KNMI have to lower the pre-1950 temperatures:
Fig14.
This is how KNMI illustrates the corrections done to the Gemert station. They compare to a reference dataset I believe is not public, but that is likely to resemble the CNT.
KNMI explains the changes to the Gemert station:
“
Gemert had a large break in October
1949, when the station was renovated. In the period 1906_
1949 the record shows a significant positive trend relative to
the reference stations Oudenbosch, De Bilt and Winterswijk.
This trend was likely to have been due to a gradual growth of
the vegetation at this station until the re-instalment in 1949
“
So, the increasing divergence 1906-1950 with (already adjusted!) De Bilt and more is due to plant growth, and the change 1949-50 is then due to re-instalment, KNMI says.
Fig 15.
Same scenario, this time its Uccle divergence from the KNMI “homogenized” De Bilt data set.
So the Uccle increase in divergence 1906-1950 to the “homogenized” KNMI De Bilt data is also plant growth then? And also a re-instalment in 1949-50 in Bruxelles, perhaps?
But the increase in divergence is even faster 1880-1906 – So plants grew even faster before 1906?
Fig 16. From figure 5 of [1].
1) Its definitely possible that I misunderstand this figure, but as I understand, it shows the divergence between individual stations and then a reference trend based on data from Netherlands? If so, how come al stations show a positive divergence 1940-50? Should a valid reference not be made so that it resembled actual temperatures of Netherlands as much as possible?
2) The Maastricht and De Bilt stations only differ from this reference with around 0,15 K.
As the difference between raw Maastricht/De Bilt versus CNT is around 10 times as much, this suggests that this figure actually show divergence between a reference and already ADJUSTED temperature sets. I’m not sure what scientific value this has.
3) The Eelde divergence is shown lower than the De Kooy divergence. As we will see later, Eelde is roughly 0,5K warmer than for De Kooy before 1950.
So how come they can show De Kooy with a warmer divergence than Eelde?
Again it seems that several data sets have been adjusted before showing divergences in the above illustration.
One more note: The illustration do not show data points for Leeuwarden 1949-55?
Fig17.
Many Tutiempo temperature series I have been able to test against raw data appear to be warm adjusted. But the point here of mentioning Leeuwarden none the less is that we from Tutiempo learn that this data set do exist at least from 1949.
So, why did KNMI only use data from 1955 in their illustration?
Eelde:
Fig18.
In Northern Holland we also have the KNMI data for Eelde and it can be proven unadjusted against NACD V1. Eelde data resembles Leeuwarden data from Tutiempo, and thus the Tutiempo Leeuwarden dataset also appear unadjusted.
In comparison with the previously shown apparently raw datasets, this Northern region with the Eelde and Leeuwarden stations appears to have had a slightly colder period 1930-50 but still around 0,5-0,6 K warmer than the “CNT”.
Coastal temperature stations of the Netherlands.
Fig19
When examining data we know is raw (or have a reason to believe is raw), then only the coastal stations Vlissingen and De Kooy show similarity with the “CNT” temperature trend before 1950.
CNT appear to be the “Coastal Netherlands Temperatures” rather than the “Central Netherlands temperatures”.
Fig20.
We can now estimate coastal and Non-coastal temperature trends for Benelux based on coastal stations De Kooy and Vlissingen and non-coastal stations Uccle, Luxemburg Airport, Eelde, Maastricht and De Bilt. All are raw datasets. Obviously stations Uccle and Maastricht are likely to include some urban heat.
Fig21.
NE USA coastal and Non-coastal temperature trends. Somewhat similar to the Benelux data sets. (taken from link 3: From RUTI Coastal temperature stations.)
Closing comment:
Yes, here and there I cannot be 100% sure which stations are adjusted and which are not.
The issue here is that raw data from KNMI is not just freely available, that would be a lot easier. But since this is not the case, I find it better to try to give the best estimate possible.
Bonus info.
Fig22.
The distance ocean air influence over land is illustrated her for SW Jutland [4]. Most of the ocean effect disappears just around 5 km from the coast (depending on topography also). Therefore the poorest stations to use for land temperature estimation are the coastal stations. However, many hundred kilometres from the coast, still the coastal trends can dominate temperatures on hills and mountains, and sometimes valley stations just downstream from larger mountains.
Links:
1 The creation of a Central Netherlands Temperature, KNMI:
www.knmi.nl/publications/fulltexts/CNT.pdf
2 NW Europe and De Bilt (more details on German stations from raw GHCN V2)
http://hidethedecline.eu/pages/ruti/europe/nw-europe-and-de-bilt.php
3 More on Coastal temperatures.
http://hidethedecline.eu/pages/ruti/coastal-temperature-stations.php
4
http://img.kb.dk/tidsskriftdk/pdf/gto/gto_0047-PDF/gto_0047_69738.pdf
If you have the time, please cut and paste the below temperature data while they are online…
http://www.tutiempo.net/en/Climate/Brize_Norton/36490.htm
http://www.tutiempo.net/en/Climate/Prestwick_Airport/31350.htm
http://www.tutiempo.net/en/Climate/Bremen/102240.htm
http://www.tutiempo.net/en/Climate/Hamburg-Fuhlsbuettel/101470.htm
http://www.tutiempo.net/en/Climate/Hannover/103380.htm
http://www.tutiempo.net/en/Climate/Nuernberg/107630.htm
http://www.tutiempo.net/en/Climate/Koeln_Bonn/105130.htm
http://www.tutiempo.net/en/Climate/Paris-Orly/71490.htm
http://www.tutiempo.net/en/Climate/Szczecin/122050.htm
http://www.tutiempo.net/en/Climate/Gdansk-Rebiechowo/121500.htm
http://www.tutiempo.net/en/Climate/Gdansk-Rebiechowo/121500.htm
http://www.tutiempo.net/en/Climate/Koebenhavn_Kastrup/61800.htm
http://www.tutiempo.net/en/Climate/Bruselas_Bruxelles_National/64510.htm
http://www.tutiempo.net/en/Climate/Leeuwarden/62700.htm
http://www.tutiempo.net/en/Climate/YPENBURG_NAFB/62000.htm
http://www.tutiempo.net/en/Climate/Guernsey_Airport/38940.htm
PLEASE GIVE ME A TIP IF YOU HAVE KNOWLEDGE ON
RAW TEMPERATURE DATA IN WRITINGS ANYWHERE IN THE WORLD
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I think an analysis of my hometown (village) up in the Jura mountains would be interesting for the population of the world, will you do it? The name of the place : Le Lac des Rouges Truites, France. It is as good a proxy as your little province of the Netherlands.
Temperature data, like fine shellfish, are best enjoyed raw.
Frank….excellent work…and a lot of it
1930’s-40’s….American dust bowl
This is all good and great. But at other times remember the layman. We need concise arguments to defeat the warmists when they can convince most of the public in just 10 words: “it’s hot… and look what CO2 did to Venus!”
We got to get it down to just a few words.
Don’t bring a treatise or dissertation when 30 words would be better. Indeed, in some cases, the very (long) length of skeptic arguments can be used against it. Why do the skeptics need so many words? What are they hiding? I can’t make heads or tails of what they’re saying…. look at Venus.
There are subsidiary points (credibility & deceptions & ideological motivations of the warmists, sea & ice levels etc) that should be attacked separately, but we have 2 main debunking points to keep in mind, to kind of refer back to sometimes when “digressing” into extended verbiage. 1. There’s nothing wrong with the climate. It’s that simple. The fabricated hockey stick has been debunked; there is nothing at all unusual about temps, or the rates of recent temp change.
And 2. CO2 has nothing, or effectively nothing, to do with the climate. Yes, and if you doubt this, consider that it turns out (surprise) that there is NO empirical evidence that CO2 effects temps on a climate level. None. At best we have an ambiguous and arguably dubious theoretical model. And, further, here’s an excerpt that can give us cover on the CO2 question: [Mit Professor] Lindzen says: “Claims… that man’s activity have contributed to warming are trivially true but essentially meaningless.” Piers Corbyn, in a comment, takes it further: “Observational evidence gives the possibility that the net effect of CO2 increases on World temperatures may not be ‘only trivial’ but in fact miniscule, zero, or even negative due to errors in some of the science some claim or – I would suggest – hitherto not understood feed-back and competing processes…”
And 99% of the public doesn’t even know what is presented in the following video, that the ipcc deceived the public in claiming the causal correlation between temps & CO2. See algor repeat this key ipcc deception, and help spread the word to the public at large about this must see ~ 3 minute video:
Hmmmm…..
I thought the Dutch were chocolate experts, but for KNMI – Koninklijk Nederlands Meteorologisch Instituut, it looks like ‘fudge’ may be their true calling.
MtK
read the papers on uccle.
also you cannot compare raw absolute temperatures unless you correct for altitude differences and latitude differences in stations since both latitude and altitude explain a majority of the variance in temperature between stations. WRT coastal stations you must stake care there as well since the predominant effect is a narrowing of the standard deviation at least up to 50km from the ocean. beyond that range the sd increases.. generally speaking.
There used to be a commentator named R. R. Kampen (IIRC) on WUWT who worked for the Dutch Metoffice. Maybe his email can be dug out and maybe he would comment on this?
Eric Simpson says:
May 17, 2012 at 6:55 pm
We got to get it down to just a few words.
Don’t bring a treatise or dissertation when 30 words would be better.
=========================================================
Here we go. The idea, that back/trapped radiation can significantly warm the surface was debunked by professor R.W.Wood in 1909: http://www.wmconnolley.org.uk/sci/wood_rw.1909.html .
This is they reason, why older people were not taught the “greenhouse effect” at schools, although the hypothesis is 150 years old.
watching everyone rugged up at the tennis in Rome, this doesn’t surprise me:
18 May: UK Telegraph: Britain colder than Arctic and Antarctic with just two weeks until summer
Britain is colder than winter as the country faces a late spring washout weekend – as it emerged parts of the Arctic and Antarctic are warmer than Britain.
http://www.telegraph.co.uk/topics/weather/9272469/Britain-colder-than-Arctic-and-Antarctic-with-just-two-weeks-until-summer.html
I had to pay $50 US to get the RAW DATA for the Chanhassen MN station. I’m still P-O’d over this. My grandparents paid for it, my parents paid for it, I paid for it.
I don’t have the time to “tilt at windmills”. If I did, I’d be suing the NOAA under FOI to get all the RAW DATA MADE PUBLIC.
How damned (sorry, you can edit it if you want…remember Gone with the Wind, it’s a vulgarity..that’s all!) hard is it to put out this data? Well, Chanhassen MN was 1.8 MB. The 1400 some stations in the USA would be about 2 GB. Heck, I’ll pay for the THUMB DRIVE myself…
WHAT A SCAM! What proof that NOAA is HIDING INFORMATION THEY DON’T WANT US TO HAVE!
Max
Mosh
Regarless of the latitude, longitude and altitude, the long-term trend in raw temperature for each of the different stations should be similar. The long-term trend for each station should also be similar to that of the regional temperature index. The combined effect of altitude and latitude is to warm or cool the entire temperature history of one site relative to another. The first difference between two sites (or between one site and the regional index) should be approximately constant over time unless there is some other factor such as UHI, which would give as gradual change rather than an abrupt one. We do not see that in the sites discussed above.
In the case of the stations and index under discussion by Frank Lasner there is a common change point around 1950. The past seems to have been made colder by an abrupt adjustment to the older part of the data. The reason for this needs to be explained.
In the early 1950s, the East Flevoland Polder was drained, 56,000 hectares of water became land.
De Bilt, for example, became twice as far inland as previously. Any summer – winter divergence at that time?
Mosher says:
Steve, that’s only if you want to compare or combine absolute temperatures. The raw data is fine for observing changes in temperature over time, like the big 1950 temperature drop that Frank is focused on. Its presence in pretty much all raw temperature records (except a few that are highly moderated by proximity to the ocean) show that it really happened and should be represented in the combined record.
Bzzzt!
Recommend one subject to study: IR Spectroscopy.
Please note which molecules this involves.
Then report back.
(Also note we are dealing with different rates of cooling as opposed to this idea you expressed about ‘significantly warm …’)
Thank you in advance.
.
_Jim says:
May 17, 2012 at 9:43 pm
Bzzzt!
Recommend one subject to study: IR Spectroscopy.
Please note which molecules this involves. … …
=================================================
No valid arguments, I am not surprised.
Mosher is right. You cannot just combine the records. You must do them like BEST, slice and dice them so that the absolute temperatures are never seen, much less trusted. You just find the slopes you like, then when an inconvenient drop in temperature occurs you whip out the scalpel, break the record, shift and suture. You just cannot use the absolute temperatures. (That would be too easy!) You can only trust the slopes (that you don’t want to cut) /sarc
In all seriousness, there is a missing plot in this fine(!) document. There are a bunch of wiggles with various adjustments. Let’s see a plot that just combines the adjustments. It ought to be a set of overlapping step functions of different plateaus and smooth slopes. From what we’ve seen, many of them change right at 1950. I like to hear a good reason for that.
Well done, Mr. Lansner!
@Harold Ambler. “Temperature data, like fine shellfish, are best enjoyed raw.” Love that comment. So appropriate, already a classic!
@Greg House. “Here we go. The idea, that back/trapped radiation can significantly warm the surface was debunked by professor R.W.Wood in 1909: http://www.wmconnolley.org.uk/sci/wood_rw.1909.html.”
Great, though that particular passage per your link could use some cleaning up, modern rewording. In ads or presentations, we note a basic point, and give references to extensive rebuttal-resistant support for the claims. And what you reference in the link is a point of support that we keep in the arsenal, that we refer to, in making a foundational point: that at best all we have supporting CO2 as a significant greenhouse gas is an arguable and tentative theoretical model, NO evidence.
Your point illustrates the scientific uncertainty with the theoretical model, the obvious lack of consensus, if you will. Others suggest CO2 only has an effect below 200ppm. There is also the issue of the missing tropospheric heat signature, and of the missing heat generally (it’s not at the bottom of the ocean!). As with your link, many contend that while CO2 has demonstrable effects in closed systems, the trace gas has no effect in the wide open atmospheric system. When the theoretical model is so uncertain and arguable, the (lack of) evidence must trump the sketchy model. Especially, I hasten to add, when the radical cap & trade type schemes that the leftists advocate call for up to 83% mandated CO2 cuts (this passed in the U.S. House in 2009), and would in effect take a wrecking ball to civilization as we know it.
My contention, and this is consistent with the ultra-trace nature of this gas, is that much more weighty factors such as variation in the sun and ocean and atmosphere overwhelm any conceivable minimal effect of CO2. My analogy: imagine a big high school basketball gym / auditorium in freezing winter weather, with all its big doors kept wide open. And then take a tiny 800w bathroom heater, and run it continually inside the gym. Sure, the tiny heater, just like trace gas CO2, heats a little bit. But the little heater is overwhelmed by other factors, by the size and scope of the frigid environs surrounding the gym. It’s not going to change the temperature in the open auditorium by even the slightest.
I think that the leftist politicos and econuts drummed up the whole theory to meet their specification. And since its inception, the theory has been supported by untold billions or trillions of $, and by an unquestioning MSM. Just as your link tells it… in the past, CO2 was dismissed as an ineffectual greenhouse gas. Why the change all of a sudden only when the leftist enviros came to the scene??
Steven Mosher says:
May 17, 2012 at 7:13 pm
read the papers on uccle.
also you cannot compare raw absolute temperatures unless you correct for altitude differences and latitude differences
Most of Holland is not more than around 30m above sea level. The country spans 2 degrees of latitude.
Re Mosher
Perhaps not this time. Holland isn’t well known for it’s mountainous terrain. De Bilt altitude is around 5m, Maastricht 65m. I don’t think that justifies cooling them by 1K. Keeping some employees in De Bilt warm and well fed might.
Why are coastal temperatures lower than inland temperatures in the earlier period, but not in the modern period? Air pollution from coal powered ships and coal warmed homes etc causing more coastal fogs in the earlier period? Another recent study in Holland showed improved visibility over the 1980-2000 period, allowing greater insolation at the surface.
There is another way to check the weather station data as follows:
The minimum meteorological surface air temperatures in this region should track the Atlantic Ocean temperatures quite closely. The prevailing weather systems approach from the Atlantic Ocean. I checked in my data collection and there was a decrease in the Atlantic Multi-decadal Oscillation (AMO) from 0.407 C in Oct. 1955 to -0.243 C in June 1956. This is a drop of 0.65 C that is consistent with the measure weather station data. I am using the NOAA ‘long’ AMO data set. It may be better to use a local ocean temperature from another database.
I have used the Pacific Decadal Oscillation to check the California climate record and the AMO to check the UK climate record. I just used a 5 year rolling average with a linear fit to the data over the same period of record. The difference in slope (with care) provides an indication of the local urban heat island effect. It can also indicate other station anomalies. There are further details in an older post: http://hidethedecline.eu/pages/posts/what-surface-temperature-is-your-model-really-predicting-190.php
The difference in temperature between the minimum and maximum temperatures is an indication of the local solar heating effects. The monthly averages of the min. and delta temperatures can be quite revealing. The can show the ocean influence for example.
There is another way to check the weather station data as follows:
The minimum meteorological surface air temperatures in this region should track the Atlantic Ocean temperatures quite closely. The prevailing weather systems approach from the Atlantic Ocean. I checked in my data collection and there was a decrease in the Atlantic Multi-decadal Oscillation (AMO) from +0.407 C in Oct. 1955 to -0.243 C in June 1956. This is a drop of 0.65 C that is consistent with the measured weather station data. I am using the NOAA ‘long’ AMO data set. It may be better to use a local ocean temperature from another database.
I have used the Pacific Decadal Oscillation to check the California climate record and the AMO to check the UK climate record. I just used a 5 year rolling average with a linear fit to the data over the same period of record. The difference in slope (with care) provides an indication of the local urban heat island effect. It can also indicate other station anomalies. There are further details in an older post: http://hidethedecline.eu/pages/posts/what-surface-temperature-is-your-model-really-predicting-190.php
The difference in temperature between the minimum and maximum temperatures is an indication of the local solar heating effects. The monthly averages of the min. and delta temperatures can be quite revealing. This can show the ocean influence for example.
Max Hugoson says:
May 17, 2012 at 7:38 pm
Please email me the Chanhassen data as I would like to see if there is a solar signal in it.
david.archibald at westnet.com.au
In the atmosphere, IR-active molecules contribute more to dumping heat from the top than trapping it at the bottom.
It’s all in the timing, Mosh; same old same old: lower the early readings, boost the later ones. If it’s too blatant, lose the early ones.