Western Europe Rural temperature trend
RUTI: Western Europe Rural Temperature Trend
(Update 6/7 2011, see end of article)
- Searching for the long rural stations in Europe. Are almost all rural temperature data limited so much, that we in reality are building temperature data mostly on urban data?
To what extend are temperature indexes from Hadcrut, Giss, GHCN etc based on rural data?
After making the writing articles like “RUTI South Africa” and “RUTI Turkey” etc. where all rural datasets have been ut down to just the period 1960-90, I got the impression that the share of long rural stations is perhaps more limited than most believe?
Lets check it out for Europe.
A “long temperature series” would be a station from where we have most years 1900 till 2010 included.
Fig1. In fact, we can loosen this definition somewhat, because the interesting part is to examine the warm peak 1925-1940 with the warm peak of the most recent years 1995-2010:
Fig2. We can loosen our demands further: We only need to see 10 of the 15 years for both periods 1925-40 and 1995-2010, since this will often give a fair chance to compare the 2 warm peaks:
Fig3. In general I am looking for stations representing the bulk of the European land mass, not extreme locations like icy mountain tops (see RUTI Alps) or smaller Islands (to a high degree representing Marine Air Temperature trends).
We can expand our definition further: If a temperature station is near a city but clearly outside a city (perhaps 1 mile from urban area) we can accept the station too.
So lets see what long rural temperature series we have available from GHCN:
Fig4. Blue starts: Temperature stations fulfilling criteria’s for “long rural temperature series” as defined above. Green stars: Stations almost fulfilling demands except we have more than 10 years in the period 1925-1949 in stead of the shorter period 1925-40. Red stars: Stations fulfilling demands except location is on mountain top (see RUTI Alps).
Great Britain + Ireland : Plenty stations meet the above criteria’s for long rural temperature series, see RUTI Great Britain.
Orange areas on map above: Countries without long rural temperature series meeting criteria’s, at least in area shown.
The number of rural stations generally in GHCN is irrelevant. For example in Turkey there are around 100 rural stations but non of these are used outside the interval 1960-90 (See RUTI Turkey). So although almost half the Turkish GHCN stations are rural, not a single Turkish rural temperature station has any effect on the long trends, the trends that matters.
So to answer my original question:
"To what extend are temperature indexes from Hadcrut, Giss, GHCN etc based on rural data?"
I would have to say: Very little.
This was the main point of this article, but lets move on and check out the European long rural temperature stations of Europe as pointed out above:
Fig5: 4 Western European long rural temperature series. I don’t have to mention the obvious similarity between these data series when no urban influences, marine stations or mountain peak stations are used.
Could the similarity be a coincidence? I wont answer that question since my answer is no better than any readers answer. I think what all could agree is: GHCN Should release all data, urban and rural series for France, Germany, Poland, Italy… all the world. If this does not happen, people might suspect that trends like the above are what GHCN is holding back from the public.
Fig6. Finally NASA´s GISS uses 1200 km radius around their stations when mapping temperature trends. I tried to apply this on the 4 long rural temperature stations in the above area of Western Europe. If NASA/GISS are correct, and it is recommendable to use 1200 km radius for temperature stations, then it might not be such a coincidence that the temperature trends showed some similarity.
But obviously, to conclude much more we need all temperature data released.
For Italy, I found this near rural couple, both from Catania:
And check out their combined temperature series:
And then lets add the combined (averaged) Catania to the other rural western Europe data series:
Kevin Trenberth to Michael Mann, Oct 12, 2009:
The fact is that we can’t account for the lack of warming at the moment and it is a travesty that we can’t. The CERES data published in the August BAMS 09 supplement on 2008 shows there should be even more warming: but the data are surely wrong. Our observing system is inadequate.
Kevin Trenberth to Tom Wigley, Oct 14, 2009
How come you do not agree with a statement that says we are no where close to knowing where
energy is going or whether clouds are changing to make the planet brighter. We are not
close to balancing the energy budget. The fact that we can not account for what is
happening in the climate system makes any consideration of geoengineering quite hopeless as
we will never be able to tell if it is successful or not! It is a travesty!
“I know that most men, including those at ease with problems of the greatest complexity, can seldom accept even the simplest and most obvious truth if it be such as would oblige them to admit the falsity of conclusions which they have delighted in explaining to colleagues, which they have proudly taught to others, and which they have woven, thread by thread, into the fabric of their lives.”
“We have 25 or so years invested in the work. Why should I make the data available to you, when your aim is to try and find something wrong with it.” -
Phil Jones to Michael Mann Feb 21, 2005:
The IPCC comes in for a lot of stick.
Leave it to you to delete as appropriate !
PS I'm getting hassled by a couple of people to release the CRU station temperature data.
Don't any of you three tell anybody that the UK has a Freedom of Information Act !
Tom Wigley to Phil Jones Sep 27, 2009:
If you look at the attached plot you will see that the
land also shows the 1940s blip (as I'm sure you know).
So, if we could reduce the ocean blip by, say, 0.15 degC,
then this would be significant for the global mean — but
we'd still have to explain the land blip.
I've chosen 0.15 here deliberately. This still leaves an
ocean blip, and i think one needs to have some form of
ocean blip to explain the land blip (via either some common
forcing, or ocean forcing land, or vice versa, or all of
these). When you look at other blips, the land blips are
1.5 to 2 times (roughly) the ocean blips — higher sensitivity
plus thermal inertia effects. My 0.15 adjustment leaves things
consistent with this, so you can see where I am coming from.
Removing ENSO does not affect this.
It would be good to remove at least part of the 1940s blip,
but we are still left with "why the blip".
Let me go further. If you look at NH vs SH and the aerosol
effect (qualitatively or with MAGICC) then with a reduced
ocean blip we get continuous warming in the SH, and a cooling
in the NH — just as one would expect with mainly NH aerosols.
The other interesting thing is (as Foukal et al. note — from
MAGICC) that the 1910-40 warming cannot be solar. The Sun can
get at most 10% of this with Wang et al solar, less with Foukal
solar. So this may well be NADW, as Sarah and I noted in 1987
(and also Schlesinger later). A reduced SST blip in the 1940s
makes the 1910-40 warming larger than the SH (which it
currently is not) — but not really enough.
So ... why was the SH so cold around 1910? Another SST problem?
(SH/NH data also attached.)
This stuff is in a report I am writing for EPRI, so I'd
appreciate any comments you (and Ben) might have.
Tim Osborn to Michael Mann and Ian Macadam , Oct 5, 1999:
Dear Mike and Ian
Keith has asked me to send you a timeseries for the IPCC multi-proxy
reconstruction figure, to replace the one you currently have. The data are
attached to this e-mail. They go from 1402 to 1995, although we usually
stop the series in 1960 because of the recent non-temperature signal that
is superimposed on the tree-ring data that we use. I haven't put a 40-yr
smoothing through them - I thought it best if you were to do this to ensure
the same filter was used for all curves.
> For the record, I do believe that the proxy data do show unusually
>warm conditions in recent decades. I am not sure that this unusual warming
>is so clear in the summer responsive data. I believe that the recent warmth
>was probably matched about 1000 years ago. I do not believe that global
>mean annual temperatures have simply cooled progressively over thousands of
>years as Mike appears to and I contend that that there is strong evidence
>for major changes in climate over the Holocene (not Milankovich) that
>require explanation and that could represent part of the current or future
>background variability of our climate. I think the Venice meeting will be
>a good place to air these isssues.