From	Eystein Jansen	Date	Mon, 11 Oct 2004 20:27:35 +0200
To	Keith Briffa, wg1-ar4-ch06@joss.ucar.edu
Subject	Re: [Wg1-ar4-ch06] IPCC last 2000 years data
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. Eystein At 17:00 +0100 11-10-04, Keith Briffa wrote: >Friends and authors ( especially Ricardo, Olga, >Fortunat, David, Ramesh, Zhang, Dan, Eystein and >Valerie) >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 6.4.3.2 ? 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 >also?) > >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 >Keith > >-- >Professor Keith Briffa, >Climatic Research Unit >University of East Anglia >Norwich, NR4 7TJ, U.K. > >Phone: +44-1603-593909 >Fax: +44-1603-507784 > >http://www.cru.uea.ac.uk/cru/people/briffa/ >_______________________________________________ >Wg1-ar4-ch06 mailing list >Wg1-ar4-ch06@joss.ucar.edu >http://www.joss.ucar.edu/mailman/listinfo/wg1-ar4-ch06 -- ______________________________________________________________ Eystein Jansen Professor/Director Bjerknes Centre for Climate Research and Dep. of Earth Science, Univ. of Bergen Allégaten 55 N-5007 Bergen NORWAY 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 ----------------------------------------------------------------------------