Wednesday, April 25, 2012

3481.txt

cc: Anders Moberg <andersatXYZxyzu.su.se>, "Deliang Chen" <deliang@gvc.gu.se>
date: Wed Jun 15 12:06:26 2005
from: Phil Jones <p.jonesatXYZxyz.ac.uk>
subject: Re: WP4 deliverables
to: alexatXYZxyz.gu.se

Dear Alex et al,
The reply from Adam indicates they are not going to do anything with the extremes in
the model runs, so we have a free run here.
I talked to Deliang on the phone this morning and we discussed possible pieces of
work over the next few months.
I tried to explain something to Deliang, but not very well, so I'm elaborating here.
The extreme software runs at present through station data and is based on the
1961-90 base period. You will need to modify this a little to cope with the model have
12 thirty day months and only 360 days in a year.
However, in order to show the model runs more clearly when comparing with
observations, I think you will need to do some experimentation with 1 or 2 of the
runs. There will eventually be 6 runs with natural forcing and 6 with natural plus
anthropogenic forcing. I presume that these 6 can be paired, so that one natural
run and one nat+anthro run start from the same initial conditions in 1869. If this is
the case then the 1961-90 base period should be used from one of these runs
and the extremes calculated (with the other pair using the same thresholds).
Which of the pair to use to calculate the thresholds is a difficult choice. I would
suggest you try the nat+anthro one first. This way the thresholds and counts should be
more similar to the real world than the nat only one. We can then plot time series
of differences between the pair of runs and see the anthro component more easily.
If Anders can't understand this once I've sent it I will try and elaborate.
Adam's point about the runs from 1949 makes some sense, but I would first see
how long it is going to take you to push the model data through the adapted software.
The long runs are more important. In order to avoid problems later, we should all
look at the output of the first pair in a little detail to make sure all is OK, before
moving on the the other members of the ensemble.
Cheers
Phil
At 08:06 15/06/2005, Alexander Walther wrote:

Hi Phil,
Yes, applying the extremes routine on the model runs is included in our plans. I'm
currently downloading the model runs. As soon as the data are "available" and readable
for me, I will run the routine. I think this could be done within the next four weeks. I
guess Deliang has promised anyway to present some results based on the GCM data.
So let's keep in touch on this. I think there is a need for some discussion (E.g. area
of interest to be extracted from the GCM, focus on certain indices etc.). I'm in contact
with Anders anyway. I think we'll find a suitable Agenda.
best regards westward
Alex
Phil Jones wrote:

Dear Adam and Alex,

Anders Moberg is in CRU this week and we are working on some of the WP4
deliverables. We are making good progress on D14 (observed changes in extremes
since the late 19th century). We've been thinking about D15 and D16. Anders will
email Jucundus, Paul and Alex about D15, but this is about D16 (assessment of the
likelihood of any anthropogenic influence in extremes).
The question to you, Adam, is the HC going to do any work on this deliverable
(D16)?
One possible aspect we can look at over the next few months is to compare the
time series of the indices across Europe from the model runs. The question to Alex is,
have you yet considered running the extremes software through the longer model
integrations. I think it is only worthwhile to use the runs that begin in 1869 and run
to
2001/2. From David Fereday's email of a week or so ago, roughly half of the
runs are there now, 3 of 6 all forcings and 4 of 6 natural runs. I've cc'd David to
check that natural runs include solar and volcanoes?
Hopefully whilst Anders is here you can give a few minutes thought to what
you might be doing on D16 over the next few months (up to the Paris meeting
in October).
Cheers
Phil
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
----------------------------------------------------------------------------

--
***************************
Alexander Walther
Earth Sciences Centre
G�teborg University
Box 460
S-405 60 G�teborg, Sweden
---------------------------
Fon: (+46)-31-7734849
Fax: (+46)-31-7731986
[1]http://www.gvc.gu.se/rcg
***************************

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
----------------------------------------------------------------------------

No comments:

Post a Comment