Thursday, April 12, 2012


cc: "'michele'" <>, "'Maurizio Maugeri'" <>, "'Alexander Orlik'" <>, "'''Wolfgang Sch�ner' ''" <>
date: Tue Jun 3 11:00:09 2008
from: Phil Jones <>
subject: Re: WG: EI-news
to: "Reinhard Boehm" <>

Received OK this time and thanks. I had a look at the earlier spreadsheet last night.
Looking at the new spreadsheet it looks as though the adjustments look good
for the NW and NE regions. Basle and Geneva do not stand out as being different.
All three areas show the recent warmth, but the warm bump in extended summers
are comparable between the late 1940s/1950s and the 1790s/1800s, or the latter period
was just a few tenths warmer. It does look as though for S the 1940s/1950s were
clearly warmer than all earlier periods.
You will be aware of a few of the Italian series drifting away from the others in the
region. I guess these may involve Milano and Padova - it is difficult to tell with the
colouring of the lines. The same series drift away in the extended winter as well.
These Italian series don't drift away in the difference plots (extended summer minus
extended winter), so maybe it's a common problem.
In the difference series (summer minus winter) the change is occurring prior to about
1890. This is much later than the problem decade of the 1860s when a lot of changes
were occurring.
I think in any paper it would good to also look at these difference plots for CET and
De Bilt and maybe the Swedish series. I can send you the data to do this if you want.
Some plots are in the attached paper from 2003.
So, my suggestion would be to write up these adjustments. I assume you will need
to explain the Kremsmunster results as a start. I presume the numbers I will need for
the ALP-IMP WP9 paper are somewhere in this spreadsheet. I think all I'll need
are the averages for the three regions NW, NE and S, but I won't start on this again
until you've got an initial draft of your paper.
Maurizo's point about clouds will work, but the cloud data will not be good enough
to do this. Anders couldn't sort out the Swedish cloud data - even in the 20th century.
I don't think the cloud data - even if digitized - would be a help. There are so many
issues with observation times, and the fact that observers appeared to sometimes
base the observation on the time they looked and sometimes over the whole day.
The Swedish categories also reduced the further back in time.
I don't want to slow down the paper, so this is only a suggestion, but I think
the time series of rainday counts may be a better homogeneous proxy for cloudiness.
Cloud observations will be a waste of time!

At 08:36 03/06/2008, Reinhard Boehm wrote:


This yesterdays mail did not pass your file size limit. Therefore I try it once more,
now with an attached slim version of the xls-file. I hope this will reach you now.


Von: Reinhard Boehm [[1]]
Gesendet: Montag, 02. Juni 2008 11:04
An: 'Maurizio Maugeri'; 'Reinhard Boehm'; 'Phil Jones'; 'michele'
Betreff: AW: EI-news

Dear Maurizio, Michele and Phil,

Thank You Maurizio for your mail. To initiate further proceeding, I attach here a
completed file final-comp-HISTALP-ISAC.xls. It contains what Phil wanted (timeseries of
summer minus winterhalfyears) and I have added also hom minus ori timeseries. And all
already existing plots have been completed with the respective regional mean series (all
based on the 20-yrs smoothed version).

As I understood Maurizio argued to use the HISTALP version for further proceeding. Of
course this is also my preferred option, but I still think we should mention, that
independent homogenising activities in Italy produced a cooler EI-period, and maybe to
use this as a kind of uncertainty measure.

Whats your opinion?


Von: Maurizio Maugeri [[2]]
Gesendet: Mittwoch, 28. Mai 2008 11:41
An: Reinhard Boehm; 'Phil Jones'; 'michele'
Betreff: Re: EI-news

Dear Reinhard,

in the last months Michele and I spent a number of days on our early records with the
aim of producing a revised and improved version of our homogenisation. We really tried
to use all available information and we considered, beside the minimum and maximum
temperature records, also the wide metadata availability that we have for some of our
records. Moreover, after each new correction, we checked the homogenised records in
order to verify whether the applied correction caused a new inhomogeneity in the daily
temperature range records or it produced an anomalous picture of the yearly temperature
cycle. According to our experience, such checks turn out to be very useful in order to
avoid illegitimate corrections, which always constitute a remarkable risk in indirect
homogenisation methods, especially in time periods characterised by low data
availability and/or by a high number of inhomogeneities.

So, we are really confident that we did our best with our records, even though we
perfectly understand that the very low number of early records in our dataset is a
strong limitation which reduces our results significance. Actually the records we used
are not just Milano and Padova, but also Torino, Bologna, Genova (which is a very good
record), Mantova, Udine and Alessandria. Moreover, we think that our data yielded
interesting results that seem to be in good agreement with dendrochronological data,
glacial data, etc. and that is also in good agreement with other datasets like the Swiss
(partially) and Spanish ones.

Nevertheless, I perfecly agree with you: if the vast majority of sites are warm in the
EI period, we have to say that from the point of view of probability the warmer solution
is more likely. Sciences are based on data and the final word pertains to the data

So I agree with your proposal of applying the warm solution to the entire GAR, even
though I think it is important to mention clearly in the publication that, beside the
more likely warm solution, also a cold solution is possible though being less likely:
the conclusion could be that, even though the data lead us to the warm solution, the
question warm or cold for the early period is at present time still partially open.

So, in the future, it could be very interesting to plan (and to propose for EU funding)
a project aiming at reconsidering all EI European records with the aim of better
understanding if the warm solution is really the most correct one. Such a project could
also include other variables like e.g. cloud cover. Cloud cover can probably help to
better decide between the warm and cold solutions because, if the 1860s strong summer
warming showed by the cold solution is really present, that should be mirrored by a
clear signal in the cloud cover records. At the same time, also the pressure records
could be helpful (see e.g the EMULATE dataset and related projects).

I have also read the answer by Michele from the Budapest meeting. I would suggest (for
the Italian group) to stop here with the data analysis. Michele and I are completely
aware of your records characteristics and the data you sent us are the same of the ones
we subjected to a number of analyses during last autumn. On the other hand, you are
perfectly aware of the characteristics of ours. So, I think that, after Phils comments,
its time to start writing, trying and presenting the chosen solution and thoroughly
discussing its possible limits.



----- Original Message -----
From: [3]Reinhard Boehm
To: [4]'Phil Jones'
Cc: [5]'Maurizio Maugeri' ; [6]'michele'
Sent: Wednesday, May 28, 2008 10:08 AM
Subject: AW: EI-news

Phil, Maurizio, Michele

Yes, the diverging seven Italian cold-series (those with the suffix ISAC) were
independently homogenised by Michele using Italian series only. All the other series
(also those seven ISAC-series) were homogenised by us, using our routine
HOCLIS-procedure). So there seems to be a break in the 1860s rather than a real
diverging climate signal north vs. south, and my point is, that I see no systematic
reason to EI-correct the vast majority of series in order to fit the majority to the
minority. The relation of the original series is something like 8 warm vs. 2 cold
series in subregion NW, 8 warm vs. 0 cold ones in NE and 3 warm ones (Torino,
Genova, Trieste) vs. 3 to 4 warm or partly warm (?) ones (Milano, Padova, Mantova?,
Bologna?) and several with unclear to very low quality (Verona and Trento).

So I think it makes no sense to adjust some 20 warm series to some 5 cold ones, if
there are no strong reasons from station history to do so. Therefore I see only two
remaining possibilities to deal with the problem:
1) adjust the 5 cold series to the majority (thats what we have already done)
2) to mention that there is also another solution based on Italian series only and
to use this as kind of an uncertainty band for the early period

As to the idea to produce AMJJAS minus ONDJFM plots: there are none so far, but they
can easily be done (but not earlier than this week because I have to leave in an
hour and have other things to be done this morning
We will also produce (lowpass filtered) HOM minus ORI plots. We have done so for non
filtered series, but there you dont see much because of all the highfrequent noise

Best regards

Von: Phil Jones [[7]]
Gesendet: Dienstag, 27. Mai 2008 17:08
An: Reinhard Boehm; 'michele'; 'Maurizio Maugeri'
Cc: 'Alexander Orlik'; "'''Wolfgang Sch�ner' ''"
Betreff: Re: EI-news

Thanks. I need to look at the file in some detail. A quick look
suggests to me that there are still problems with some series
as the plots for the 4 groups diverge prior to about 1860. They remain
quite tight except for one or two after this date.
Have you plots of AMJJAS minus ONDJFM?
Enjoy the dendro meeting.
At 14:45 27/05/2008, Reinhard Boehm wrote:

This is to inform you about the latest EI-news. We have gone through all our
longterm t-series once again and you see a summary of the result on the attached

On the first table sheet you see a comparison of all series for summer- and winter
half years (AMJJAS and ONDJFM). Those with the suffix ISAC are the seven series
which were sent by Michele and which, in the homogenised form (with Italian series
only, if I remember well) are considerably colder in the warm season. Michele had
just done once a comparison of the HISTALP-MEAN in Italy and the ISAC-mean. For a
better understanding the second sheet shows the three subregions.
In the attached file you get more information. You find the original and the
homogenised series, for all single 32 long-term sites. All are lowpass filtered and
without gaps and the originals are the outlier correctedoriginals, Alexander has
produced in the last months. They are all anomalies to a long common 150 years
period (1851-2000)

The result in one sentence: the vast majority of sites are warm in the EI, so from
the point of probability we think the decision is clear: the warmer solution is more

More in detail: It was (apart from the two strange series Verona and Trento) a game
between Milano, Padova, Geneva and Basel (cold) and all the rest (also including
some of the Italian sites, which are EI-warm). In my eyes the only real argument in
favour of this group of cold EI sites is that the two of the three longest (starting
in 1760) belong to them. But there are several (I think better) arguments for the
warm solution:
1) the splitting happens quite suddenly in the 1860s, exactly at a time when
in the Swiss weather service was founded and also in Italy there was a time of
change from less organised to better organised service (your words Maurizio). This
was not the case for southern Germany, Austria and Hungary. So the >Italian and
Swiss sites should be more suspected for breaks especially in this decade
2) after the 1860s there were no regional differences in neither of the
subperiods, therefore and also because of 1) it is extremely unlikely that we see a
real splitting into subregionally different climate evolutions with a cold South and
a warm north in the EI-period
3) we have also looked at the hom-ori series of each single site and we found
no systematic accumulation of breaks in the 1860s in the warm series subset

So for the moment we think it would be wise to use our solution for the entire GAR,
but to mention in the publication, we want to start writing now, the existing
difference between the warm and the cold solution and to use it as kind of
uncertainty measure (whats your opinion Phil?).
What would be the alternative: We should re-adjust more than 20 warm series based on
the result of only four cold series. This really is the alternative, because we
cannot describe it as a real subregional climate effect (as already argued).

I am looking forward to your comments

The rest of the week I am not at the ZAMG (EURODENDRO 2008)

But maybe we could draw some decisions next week?

Best regards


Prof. Phil Jones
Climatic Research Unit Telephone +44 (0) 1603 592090
School of Environmental Sciences Fax +44 (0) 1603 507784
University of East Anglia
Norwich Email

Prof. Phil Jones
Climatic Research Unit Telephone +44 (0) 1603 592090
School of Environmental Sciences Fax +44 (0) 1603 507784
University of East Anglia
Norwich Email

No comments:

Post a Comment