Wednesday, May 16, 2012

4311.txt

cc: <jan.esperatXYZxyz.ch>, "'David Frank'" <david.frankatXYZxyz.ch>, "'michele'" <m.brunettiatXYZxyzc.cnr.it>, "'Maurizio Maugeri'" <maurizio.maugeriatXYZxyzmi.it>, "'"'Wolfgang Sch�ner'"'" <wolfgang.schoener@zamg.ac.at>, "'Kurt Nicolussi'" <kurt.nicolussiatXYZxyzk.ac.at>, "'Michael Grabner'" <michael.grabneratXYZxyzu.ac.at>
date: Wed, 14 Feb 2007 18:08:11 +0100
from: "Reinhard Boehm" <Reinhard.BoehmatXYZxyzg.ac.at>
subject: AW: AW:
to: "'Phil Jones'" <p.jonesatXYZxyz.ac.uk>, "'Reinhard Boehm'" <Reinhard.BoehmatXYZxyzg.ac.at>

Phil,


Fine, Wolfgang and I have reserved Monday, 16^th April 2007 for early instrumental
discussion in Vienna. We hope to have then a "version 2 instrumental dataset" ready for use
and some comparisons with glaciers. Of course anybody else from the EI-group participating
at the EGU is welcome too.


Right now only some clarifications:

1) version 2 homogenising: We want to homogenise all early t-series, not only the
cold ones - but we intend to more likely use the cold ones as reference and less the
majority (as we did so far). We will then see what the results will be.

2) The mass balance modelling: We will use (and Wolfgang has already done so, but
with the "warm" early temperatures and with too negative MB-results in the early 19^th
century) HISTALP monthly temperatures, Dimitrios' 10'-precip - both adjusted to a finer
orography (necessary to better represent the glaciers). Using our (non linear tanh-)
relation between monthly mean temperature and the percentage of solid precipitation we then
calculate the real monthly amounts of snow- and of liquid precipitation at the glaciers
(for all months, not only for winter - summer snowfall have a strong influence via the
albedo, winter precip is not very effective, as we learned from our 25 years summer and
winter mass balancing in the Sonnblick region). .... at the end Wolfgang could reproduce
pretty well already measured mass balances of alpine glaciers in recent years - therefore
we assume that the (expected) positive mass balances based on the "cold" HISTALP version
should be kind of an independent argument in deciding between the warm and the cold version
of HISTALP summer temperatures.

Please note that the differentiation between solid and liquid precip is not trivial due to
the non-linearity of the precip[solid] (temp) function

3) Going the "number 2 homogenising"-path we do not directly include the
treering-evidence, but we hope at the end to come nearer to the early TR-evidence that with
the warm instrumental version.


Cheers


Reinhard and Wolfgang


___________________________________________________________________________________________

Von: Phil Jones [mailto:p.jones@uea.ac.uk]
Gesendet: Mittwoch, 14. Februar 2007 17:17
An: Reinhard Boehm
Cc: jan.esper@wsl.ch; 'David Frank'; 'michele'; 'Maurizio Maugeri'; "'Wolfgang Sch�ner'";
'Kurt Nicolussi'; 'Michael Grabner'
Betreff: Re: AW:


Reinhard,
Some thoughts. Obviously possibility 2 is the right way
to go scientifically. Have you considered developing an Alpine
series based just on the cooler stations (like Kremsmunster, Basle
and Geneva and one or two others? Then try this with the glacier
modelling. In the latter, there is likely to be much sensitivity to
snowfall amounts, so you could test what addition precip you might
need to get the glaciers at the right positions and right times, so
it is play-off between summer T and winter P. The latter could have
serious undercatch problems, which you've done your best to allow
for. I guess I'm saying can you determine what you need to do to
T and P to get agreement - sort of 2D surface.
I have many things on between now and the EGU, so I look forward to
discussing it more in Vienna. I'll only be there for the first two days. On
the Tuesday pm I'll be going out to dinner with the Hans Oeschger
medallist, and I have to run CL28 most of the day, so can we get together
on the Monday?
Cheers
Phil
At 12:51 13/02/2007, Reinhard Boehm wrote:

Phil,

As you proposed earlier, I also think we should first concentrate on the early instrumental
topic, produce an alternative version of early temperatures and then proceed with the WP-9
paper.

Concerning the early temperatures I (and also you I suppose?) received a number of treering
series from David Frank which should be useful to at least have a good basis from this
kind of summer data. I myself am just having a look in my spare-time on hourly temperature
comparisons of the two Kremsm�nster sites - leading at the end to much more information on
possible biases. This will be useful as an argument for a "colder alternative" for early
instrumental temperature series. I still have not made up my mind on how to proceed then:
There are two possibilities:
1) simply adjust all early series in the same way (like I did in the example I sent
some time ago) - this would be easier and would lead to homogeneous results
2) try to re-homogenize the whole early temperature series station by station, using
the "colder stations" like Basle, Geneva, Kremsm�nster, and one or two Italian sites as
reference.
The second alternative would be "scientifically more correct" but I am not sure whether
there will get a solution leading to a satisfying state in terms of homogeneity tests and
fit as well to the treering series.

In any case I do not plan to completely withdraw the "summer-warm solution" we have now, I
only want to add another alternative (could be called a TR-version) which will somehow
stand for a rather summer-cold early period. The two together will then span a range within
which real climate should be supposed to be.
At last Wolfgang and I will try to produce some glacier mass balance series for the early
period calculated with the HISTALP temp and precip series - here we believe that the
summer-cold version will produce results nearer to the glacier evidence we have (with
positive mass balances for most of the early 19^th century - necessary to explain the
massive advances in the 1810s and 1840s). We have already tried it for the uncorrected
early temperatures, it did not work, so the final conclusion will be in favour of colder
early instrumental summer temperatures I suppose.

Anyway, it would be fine to discuss this at the occasion of your stay in Vienna at the EGU
Since then we should have all the calculations done and can decide on what to finally write
in which paper...

Cheers

Reinhard

P.S. I send this for information also to the treering group and the others concerned
___________________________________________________________________________________________

Von: Phil Jones [[1]mailto:p.jones@uea.ac.uk]
Gesendet: Dienstag, 13. Februar 2007 11:31
An: Reinhard Boehm
Betreff: Re:

Reinhard,
Not sure where we are on the paper from WP-9. I've been too busy
with IPCC up the end of last week. I have quite a bit of travel during
March, so may not be able to make much progress. We need to try
and come to some sort of agreement on how to proceed.
I will be in Vienna for the first 2 days of the EGU meeting.
Cheers
Phil
At 14:08 10/01/2007, you wrote:
Dear early instrumentalists,

I pass on two things to the "plenum" in charge of the early instrumental adjustment:

1) David and I agreed yesterday on a 2 weeks "moratorium" until the next and definite
resolutions about adjusting the early instrumental temperature series. The TR-group is
going to use this time to agree upon which TR-series (or which sample of different
TR-reconstructions) should be used best as the "warm-season TR-reference". This may be a
single reco, a mean of some recos or (best) a mean plus error bars. I am going to use the
time to produce some more information on our Kremsm�nster comparison (taking into account
Phil's question about the way of calculating the means).

2) Some of You have already got a preliminary version of a Diploma thesis on the
early instrumental problem. Johann Hiebl has sent us today the definite version he
submitted yesterday (already containing the pre-reviews of Anders Moberg, Wolfgang Sch�ner
and myself). I think it is, for a diploma thesis, a quite "mature" piece of work which is
closely related to our topic and may be well usable for our little paper. Please use it
confidentially for the time being, because it has not been formally approved yet. I would
like to draw your attention to the chapter dealing with the ERIK-model run of the GKSS
guys. Do you think this to be adviseble for our purposes too? It would be kind of an
independent information, but I am somewhat sceptical whether we should use such a
"reconstruction". Anyway I ask Phil if the colleagues from the Hadley centre can also
contribute such a model run and his opinion on it.

Best regards

Reinhard
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 p.jonesatXYZxyz.ac.uk
NR4 7TJ
UK
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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 p.jonesatXYZxyz.ac.uk
NR4 7TJ
UK
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