Wednesday, May 16, 2012

4310.txt

cc: wg1-ar4-ch06atXYZxyzs.ucar.edu
date: Tue, 8 Nov 2005 15:06:53 -0700
from: Jonathan Overpeck <jtoatXYZxyzrizona.edu>
subject: Re: [Wg1-ar4-ch06] FOD X-chapter issues and LA3
to: Fortunat Joos <joosatXYZxyzmate.unibe.ch>

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Hi Fortunat - we are saddened that you can't come
to the LA3, particularly given your broad
perspectives and links with the TS and SPM. Maybe
something will happen to ease your other burdens
and you can reconsider. If not, we'll work hard
with the preparation you can send us in advance
of the meeting - proposed responses to reviewer
comments on parts of the chapter that you played
a major role in.

Also, it would be good to get your help with the
issues you raise below (thanks very much for the
list!). In particular...

1) will you send us (Eystein and Peck) the data
for the GHC that we should ask Chap 2 to use?
We'll also need the complete references (missing
in FOD chap 6, as it turned out - can you send in
endnote form?). We will engage w/ them, and
suggest perhaps a plot that zooms in on the last
2000 years, and refs our fig for the Holocene.
Can't have too much of this, and we discussed w/
Susan a while back.

2) "simple formulations to estimate LGM GHGs
forcing from ice core GHGs concentrations . These
have not been revised by chap 2 up to now." Can
you work w/ chapter 2 on this, or ????

3) good point too regarding "I believe that the
ocean c-cycle sectin in chap. 7 needs a major
rewrite." How do you recommend this get done? Are
you the CA (chap 7) to do the job, or???

4) we agree on the ocean acidification issue in
chap 6, to the extent we have room. I don't think
the paper(s) exist that will make this easy
(e.g., on pre-Quaternary CO2 and calcification
impacts - slow changes in CO2 shouldn't impact as
much as fast changes, right? So maybe we could
add something in our pre-Q box if there is useful
information. OR into your section as another
subsection/question? You want to do this job? Is
there a CA candidate we could invite who might be
a big help?

5) you suggest a good idea: "I suggest that we
include also a table or at least some text
describing the rates of change and magnitudes
over different past period in the main text and
have bullets in the executive summary on this in
the SOD to back up the TS and the SPM. This is a
bit complicated by the time resolution of the ice
core and the life time of the GHGs which is
especially short for methane (20yrs). Dominique
and I need to work on rates of change in GHGs to
see what we can say with which level of
uncertainty, perhaps in collaboration with Renato
Spahni who has an model describing the
attenuation of atmosperic signals by the bubble
close-off process in ice cores. We will probably
also have a look what we can say in terms of GHG
evolution earlier than 650 ka BP."

Can you and Dom do it in time to show in New
Zealand? Is there a way to make a figure that is
more compelling that the table? That could be an
award winner. ?????

6) It has been the plan to showcase the EPICA
results instead of long Vostok in the figure, no?
The question is... can we make the proposed new
figure in time for vetting before New Zealand?
Can you provide it, or is this another job for
our man in Grenoble?

Fortunat - thanks for helping with all this. We'd
still love to see you in New Zealand, so if you
change your mind, I'm sure we can arrange good
wine and coffee!

Thanks, Peck and Eystein.



>Dear Chapter 6 team,
>
>Unfortunately, I am not able to make it to New Zealand. Coming back from
>Boulder, I have to take my share of teaching here at the University. IPCC work
>is continuing on a number of issues. Namely, contribution to the TS and SPM
>writing process, scenario calculations with the
>Bern Carbon Cycle-Climate Model
>for chapter 10; we will shortly become new mitigation scenarios from chap. 3
>for evaluations. I will aim to go through the comments of the chap 6 section
>that I have written and propose solutions before Christchurch.
>
>I have read and commented on the whole chapter
>2, the majority of chap. 10, the
>carbon cycle part of chap 7 and the BGC part of chap 5. A few issues to watch
>are:
>
>- Chap 2:
>Solar forcing. The present split between chap 2
>and 6 looks quite reasonable to
>me.
>
>GHG forcing: chap 2 uses a very limited set of ice core data for CO2, CH4, and
>N2O over the last millennium to produce question 2.1 figure 1 that shows the
>evolution of GHGs over the last 2000 year. I suggest that chap 2 uses the same
>data as chap 6 to produce such a figure or simply refers to our figure showing
>the changes in GHGs over the Holocene.
>
>- simple formulations to estimate LGM GHGs forcing from ice core GHGs
>concentrations . These have not been revised by chap 2 up to now.
>
>- Chap 7
>chap 7 has text linking back to the box on glacial-interglacial CO2 changes.
>This looks fine at the moment.
>
>- chap 7 has text on various carbon cycle mechanisms and the ocean section
>argues that the impact of ocean biology changes
>on atm. CO2 is largely unknown.
>This conflicts with what we say in chapter 6 and
>with the story of the ice core
>data. I believe that the ocean c-cycle sectin in
>chap. 7 needs a major rewrite.
>
>- Ocean acidification: An issue not well covered
>in TAR is ocean acidification.
>Ocean acidification is an important issue. For example, it poses a threat to
>the marine foodchain and the projected shoaling
>of the lysocline threatens cold
>water corals. There are some paleo studies on the issue, e.g., Pelejeros,
>Science, 2005 using corals. There may also be
>some useful information available
>from the very deep past about possilbe mass
>extinction of calcyfiying organisms.
>Currently, ocean acidification is dealt with in
>chap 7 from a process view point
>and in chapter 5 looking at current observation.
>I expect chapter 10 to include
>a discussion and results on acidification in the SOD. I think we also should
>take up the issue in chap 6 from a paleo perspective.
>
>As far as the chapter presentation in Beijing is concerned, I guess most is
>covered by the available text and figures.
>
>Additional points that are not yet well covered are:
>
>- A table in the ZOD of the Technical Summary gives the rate of change in RF
>for the major GHGs. The recent acceleration in
>GHG forcing is quite impressive.
>The TS also make some statements for how far back recent GHGs changes were
>unprecedented in terms of magnitude and rate. Such statements were prominently
>included in the SPM of the TAR and the TAR
>synthesis report. I think the FOD is
>too silent on rate of changes for GHGs. I suggest that we include also a table
>or at least some text describing the rates of change and magnitudes over
>different past period in the main text and have bullets in the executive
>summary on this in the SOD to back up the TS and the SPM. This is a bit
>complicated by the time resolution of the ice core and the life time of the
>GHGs which is especially short for methane (20yrs). Dominique and I need to
>work on rates of change in GHGs to see what we can say with which level of
>uncertainty, perhaps in collaboration with Renato Spahni who has an model
>describing the attenuation of atmosperic signals
>by the bubble close-off process
>in ice cores. We will probably also have a look
>what we can say in terms of GHG
>evolution earlier than 650 ka BP.
>
>- The new EPICA results should be included.
>
>
>With best wishes,
>
>Fortunat
>
>Quoting Eystein Jansen <Eystein.Jansen@geo.uib.no>:
>
>>
>> Dear Chapter 6 Lead Authors:
>>
>> As many of you have just finished reading and
>> commenting on the FOD, we will use this
>> opportunity to ask you to think ahead to LA3 in
>> Christchurch. The primary focus of the meeting
>> will be on the comments received to our own
>> chapter, but there will be a number of x-chapter
>> issues and consistency issues we need to solve
>> for the SOD.
>> In order to have an effective meeting, we need to
>> identify what the key issues we have concerning
>> Ch 6 vs the other chapters.
>> We would be grateful if you could send us your
>> views on this within a week. Thus we can collate
>> these and prepare ourselves and the other CLAs
>> for the meeting.
>>
>> One more thing we would invite you to come back
>> to us with is the following: As you remember
>> there was in Beijing a plenary session in which
> > some of the chapters presented their perspective
>> on the newxt IPCC-report. In Christchurch it is
>> our turn. Thus if you have views on what we
>> should say, what we should present, nice
>> illustrations etc., please send them so we can
>> prepare.
>>
>> Looking forward to hear from you.
>>
>> Best wishes,
>> peck and Eystein
>> --
>> ______________________________________________________________
>> Eystein Jansen
>> Professor/Director
>> Bjerknes Centre for Climate Research and
>> Dep. of Earth Science, Univ. of Bergen
>> All�gaten 55
>> N-5007 Bergen
>> NORWAY
>> e-mail: eystein.jansenatXYZxyz.uib.no
>> Phone: +47-55-583491 - Home: +47-55-910661
>> Fax: +47-55-584330
>>
>> _______________________________________________
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>>
>
>
>--
>e-mail: joos@climate.unibe.ch;
>
>Until November 23
> National Centre for Atmospheric Research, Terrestrial Sciences, CGD
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>
> home address:
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>
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--
Jonathan T. Overpeck
Director, Institute for the Study of Planet Earth
Professor, Department of Geosciences
Professor, Department of Atmospheric Sciences

Mail and Fedex Address:

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