Tuesday, December 13, 2011


From: Eystein Jansen <eystein.jansen@geo.uib.no>
To: Keith Briffa <k.briffa@uea.ac.uk>, wg1-ar4-ch06@joss.ucar.edu
Subject: Re: [Wg1-ar4-ch06] IPCC last 2000 years data
Date: Mon, 11 Oct 2004 20:27:35 +0200

Hi Keith,
I can take a stab at the THC bit (not strong
evidence so far for linkages to
multidecadal/century scale changes, but cannot be
ruled out) the marine evidence from the North
Atlantic (14C chronological control), and some
aspects of tropical/high latitude linkages.

At 17:00 +0100 11-10-04, Keith Briffa wrote:
>Friends and authors ( especially Ricardo, Olga,
>Fortunat, David, Ramesh, Zhang, Dan, Eystein and
>Now back from travels (until Wednesday when off to Austria for a few days)
>I thought it best to suggest a break down for
>the writing of the data section for the last
>2000 years of the IPCC palaeoclimate chapter.
>Please see the outline produced at the meeting.
>We have 4 IPCC pages . I will write a short
>intro linking to the instrumental data with
>links to Chapters 3-5. I will coach this in a
>general introduction to this section that
>addresses the points listed in the initial notes
>( namely how we use the various high , and few
>low, resolution data to construct regional and
>large-scale temperature variability , and where
>possible, gain insight into hydrologic
>variability. I will say we use models to get
>insight into methodology and to explore regional
>coverage and seasonality issues and we use
>control and forced model runs to look at
>sensitivity and detection issues , but also use
>date to test model variability and sensitivity .
>I can first go at the NH (SH) Spaghetti diagram
>discussion and hopefully you will pick up the
>regional aspects of the temperature and
>precipitation (moisture) variability .
>Rather than me say - I would like you to come
>back with the major areas you will cover , but
>these may best be done in terms of
>climatologically meaningful regions - ie
>relating to the ENSO, NAM, PDO , AAO, monsoon
>areas - then we could fill in the remaining
>regions if significant non overlap in areas is
>apparent (Eurasia, non-monsoon china etc) . We
>do not want a list of every paper ever written ,
>but a selection of (the better) work that you
>feel has regional relevance (and some length
>presumably). THe other alternative is just to
>divide up the world to our own regions and then
>discuss the climate indices separately. This
>would likely be easier to do . Let me know what
>you think. Either way , we also should have a
>specific discussion of forcings at high
>resolution , and Fortunat, Valerie could cover
>solar and volcanic , perhaps Eystein discussing
>what evidence there is for THC change . The
>knotty issue of THC versus NAO and the link to
>model theories/models could go here - or
>perhaps later in the section ? Davis
>what say you about this? The same is true of
>ENSO links to terrestrial precipitation patterns
>and temperature?
>I don't like the idea of dealing wit quasi
>periodicities separately , but rather wit the
>regional discussions eg North American drought.
>The question of LIA , MWP will come up in the
>large scale average discussion but you can also
>address it in the regional discussions , but in
>a critical and quantitative way. I would like to
>see the evidence for extremmes/abrupt change
>from the regional syntheses and then see if we
>have enough to define and discuss the issue
>separately. Olga could you pick up on the
>glacial variations (perhaps with links to models
>So come back to me asap to let me know
>impressions and regional/variable focus you all
>wish to pick up. Ricardo will obviously do North
>South linkages as per the PEP1 transect , but
>what about along PEP2 and 3/ WE may have to pick
>this up in the light of the regional data. Can
>you also let me know if/who you might be asking
>to help with writing . Peck , I would still
>rather have Mike Mann in , so what is the story
>here - can I ask him? Suggestions for summary
>Figures still welcome - I would like to have a
>High lat , mid lat , low lat transect type
>figure for temperature , possibly along each PEP
>transect - with longest instrumental data . A
>forcing diagram is also a must - but could
>combine Holocene and "blow up " last 2000 years.
>Best wishes
>Professor Keith Briffa,
>Climatic Research Unit
>University of East Anglia
>Norwich, NR4 7TJ, U.K.
>Phone: +44-1603-593909
>Fax: +44-1603-507784
>Wg1-ar4-ch06 mailing list

Eystein Jansen
Bjerknes Centre for Climate Research and
Dep. of Earth Science, Univ. of Bergen
All�gaten 55
N-5007 Bergen
e-mail: eystein.jansen@geo.uib.no
Phone: +47-55-583491 - Home: +47-55-910661
Fax: +47-55-584330
The Bjerknes Training site offers 3-12 months fellowships to PhD students
More info at: www.bjerknes.uib.no/mcts

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