From	Caspar Ammann	Date	Thu, 29 Jun 2006 06:43:40 -0600
To	Christoph Kull
CC	Tim Osborn, Keith Briffa
Subject	Re: climate reconstruction challenge
Hi Christoph, sounds excellent. 20th is a good target with three weeks left. Let me launch one full round to solicit comments and ideas, and then I can send you what we have to build the web site. I'll check with Mike about having him fold this into the report. Cheers Caspar Christoph Kull wrote: > Dear Caspar and Tim, > Thanks for putting this issue forward!! > PAGES/CLIVAR may help communicating this challenge to the community. > > We will be able to setup the website with the data sets and the call etc.: > - let me know what you need! It would be best for us to have first a simple > "word document with the structure, headings and text. We will then produce a > "hidden site" that can be updated and finalized before it will go public > online. > > We will be able to announce the challenge to the community via the > Newsletter and e-news: > - we need a respective experiment description. > - the next Newsletter is going to be published by end of July. Can you > provide me this information by the 20th? This would also fit with the > planned announcement in the workshop report for EOS...Mike will draft this > report. > I suggest to directly contact him for an incorporation of this call. > > All the best, thanks a lot and greetings from Bern, > Christoph > > > On 23.06.2006 19:23, "Caspar Ammann" wrote: > > >> Hi Tim, >> >> just back from the various trips and meetings, most recently >> Breckenridge and the CCSM workshop until yesterday. This coincided with >> the release of the NRC report... >> >> Thanks Tim for getting in touch with Simon and Eduardo. And I would >> think it would be excellent if you would be on the reconstruction side >> of things here. We really need to make sure that all the reconstruction >> groups (the ones that show up in the spaghetti-graph) also provide >> reconstructions for the Challenge. By the way, Mike Mann is fine with >> the participation of the german group in this as he has spoken now >> favorably on the project. >> >> I think the separation you point at is absolutely crucial. So, as I >> indicated in Wengen, I would suggest that we could organize a small >> group of modelers to define the concepts of the experiments, and then >> make these happen completely disconnected from standard data-centers. A >> Pseudo-Proxy group should then develop concepts of how to generate >> pseudo-proxy series and tell the modelers where they need what data. But >> what they do is not communicated to the modelers. Based >> >> The underlying concept as well as the technical procedure of how we >> approach the pseudo-proxies should be made public, so that everybody >> knows what we are dealing with. We could do this under the PAGES-CLIVAR >> intersection umbrella to better ensure that the groups are held separate >> and to give this a more official touch. Below a quick draft, we should >> iterate on this and then contact people for the various groups. >> >> So long and have a good trip to Norway, >> Caspar >> >> >> >> >> Here a very quick and simple structural draft we can work from: (all >> comments welcome, no hesitations to shoot hard!) >> >> >> Primary Goals: >> >> - cross-verification of various emulations of same reconstruction >> technique using same input data >> - comparison of skill at various time scales of different techniques if >> fed with identical pseudo-proxy data >> - sensitivities of hemispheric estimates to noise, network density >> - identify skill of resolving regional climate anomalies >> - isolate forced from unforced signal >> - identify questionable, non-consistent proxies >> - modelers try to identify climate parameters and noise structure over >> calibration period from pseudo-proxies >> >> >> Number of experiments: >> >> - available published runs >> - available unpublished, or available reordered runs >> - CORE EXPERIMENTS OF CHALLENGE: 1-3 brand new experiments >> ^one experiment should look technically realistic: trend in >> calibration, and relatively reasonable past (very different phasing) >> ^one experiment should have no trend in calibration at all, but >> quite accentuated variations before >> ^...one could have relatively realistic structure but contains a >> large landuse component (we could actually do some science here...) >> >> >> >> Pseudo-Proxies and "instrumental-data": >> >> - provide CRU-equivallent instrumental data (incl. some noise) that is >> degrading in time >> - provide annually resolved network of pseudo proxies ((we could even >> provide a small set of ~5 very low resolution records with some >> additional uncertainty in time)) >> - 2 networks: one "high" resolution (100 records), one "low" resolution >> (20), though only one network available for any single model experiment >> to avoid "knowledge-tuning", or through time separation: first 500-years >> only low-red, then second 500-years with both. >> - pseudo-proxies vary in representation in climate (temperature, precip, >> combination), time (annual, seasonal) and space (grid-point, small region) >> >> >> >> Organization of three separate and isolated groups, and first steps: >> >> - Modeler group to decide on concept of target climates, forcing series. >> Provide only network information to Proxy-Group (People? Ammann, Zorita, >> Tett, Schmidt, Graham, Cobb, Goosse...). >> - Pseudo-proxy group to decide on selection of networks, and >> representation of individual proxies to mimic somewhat real world >> situation, but develop significant noise (blue-white-red) concepts, >> non-stationarity, and potential "human disturbance" (People? Brohan, >> Schweingruber, Wolff, Thompson, Overpeck/Cole, Huybers, Anderson, ...). >> - Reconstruction group getting ready for input file structures: netCDF >> for "instrumental", ascii-raw series for pseudo-proxy series. Decide >> common metrics and reconstruction targets given theoretical pseudo-proxy >> network information. (People: everybody else) >> >> >> >> Direct science from this: (important!) >> >> - Forced versus internal variations in climate simulations (Modelers) >> - Review and catalog of pseudo-proxy generation: Noise and stationarity >> in climate proxy records, problems with potential human/land use >> influence (Proxy Group) >> - Detection methods and systematic uncertainty estimates (Reconstruction >> Group) >> >> >> >> >> >> >> >> Tim Osborn wrote: >> >>> Hi Caspar and Christoph, >>> >>> I just wanted to let you know that: >>> >>> (1) I have emailed Simon Tett (for HadCM3) and Eduardo Zorita (for >>> ECHO-G Erik-I, not sure about Erik-II) to ask if they would be >>> prepared for surface temperature fields to be made available from >>> their model runs and placed on a pseudo-proxy website for use in >>> pseudo-proxy studies. I'll let you know their response. >>> >>> (2) In Wengen I suggested that Philip Brohan, a colleague of Simon >>> Tett, might be interested in creating pseduo-proxies from the output >>> of Caspar's secret model simulation, because of Philip's interest in >>> statistical error models (e.g. in the error model he just published of >>> the instrumental temperature record, HadCRUT3). I have emailed Philip >>> to ask him if he would be interested. Again, I'll let you know his >>> response. >>> >>> With regard to the "climate reconstruction challenge", Keith and I >>> were wondering how it is going to be run. Obviously some kind of >>> organising group would be useful to ensure it is designed to be as >>> scientifically useful an experiment as possible. Yet there needs to >>> be a clear distinction between provided experimental design advice >>> (and things like convening EGU sessions) and having too much knowledge >>> of the setup that would prevent such people from taking part in the >>> challenge. Keith and I would be interested in the former, but would >>> also like to keep our distance and take part in the challenge. I'm >>> not sure that it was clear in Wengen exactly who is to organise this all. >>> >>> Cheers >>> >>> Tim >>> >>> Dr Timothy J Osborn, Academic Fellow >>> Climatic Research Unit >>> School of Environmental Sciences, University of East Anglia >>> Norwich NR4 7TJ, UK >>> >>> e-mail: t.osborn@uea.ac.uk >>> phone: +44 1603 592089 >>> fax: +44 1603 507784 >>> web: http://www.cru.uea.ac.uk/~timo/ >>> sunclock: http://www.cru.uea.ac.uk/~timo/sunclock.htm >>> >>> **Norwich -- City for Science: >>> **Hosting the BA Festival 2-9 September 2006 >>> >>> >>> > > -- Caspar M. Ammann National Center for Atmospheric Research Climate and Global Dynamics Division - Paleoclimatology 1850 Table Mesa Drive Boulder, CO 80307-3000 email: ammann@ucar.edu tel: 303-497-1705 fax: 303-497-1348