cc: Peter Lemke , Martin Manning , Susan Solomon , ipcc-wg1@al.noaa.gov, k.briffa@uea.ac.uk date: Wed, 20 Apr 2005 09:07:27 -0600 from: Kevin Trenberth subject: Re: WG1 LA2 meeting - Overlap cluster A to: Phil Jones Hi Martin I agree with what Phil says, but I note that cluster B does not actually have chapter 6 as part of it. So the question is whether chapter 6 will be involved?. If so then we may well want to split into 2 parts. Last night I had a quick look at Chap 9 and I am concerned about redundancy and overlap and conflicts: they are doing some similar things with observations but maybe different obs, and coming to different conclusions e.g. wrt things like dimming. Kevin Phil Jones wrote: Dear All, In addition to Kevin's comments and from a quickish look through parts of Chapters 4, 6 and 9, here are a few suggestions. First for best use of time, I would suggest that Cluster B gets broken into two parts. Basically separating off the overlap with the paleo and instrumental record including borehole temperatures and glacier length changes from the sea ice/SST, snow/temperature. OHC/SST, salinity/precip and SLR etc. The latter can be dealt with by Chs 5, 3 and 4. The former is really for 6, 3 and 4. Issues for 3 and 6 are the interface of the instrumental and paleo records, particularly how the early 19th century is dealt with. This period of instrumental records is believed by many in the paleo community not to exist, but in Europe and a few other regions it exists back in good order to the late 18th century. The 19th century is, I believe, the key to resolving much of the discussion about the millennium. Much more should be made of this period when comparisons with long forced GCM runs are analyzed. Europe may be a small continent, but the 200-250 year 'perfect proxy' records (which have all seasons!) need to be studied more. As any conclusions relate to Ch 6, the main text should be there, with perhaps a box on the early instrumental period in Ch 3. Somewhat related to the above, Ch 4 has a section on the recent Oerlemans (2005) work - attached for reference. Mike Mann sent me a figure (see jpg) comparing this with most other reconstructions of parts of the millennium. It seems that this piece of work should be with all the others in Ch 6 and not Ch 4. When producing plots like this getting the right base level is crucial - not just for Oerlemans' series, but also for the boreholes. Also, the degree of smoothing and the y-scale used can easily determine the takeaway message. Chapter 9 has an interest in both these issues. Finally, there is one other issue. Do we want to consider having a web site (distributed?) where the data for some selected time series can be downloaded from - not just the smoothed/plotted series, but on the original timescale as well. This possibly comes back also to a consistent way of smoothing time series. Cheers Phil At 08:11 20/04/2005, Peter Lemke wrote: Dear Martin, I am also willing to co-chair the cluster B. (As always) Kevin has done a very good job in listing the most important issues. Therefore, I have nothing to add at the moment. I will think about this on the weekend. Best regards, Peter Kevin Trenberth schrieb: Hi Martin Yes I will do this. Firstly on cluster A: I/we have an issue which is: what about changes in radiative forcing from water vapor (or feedback if you prefer), it is of order 1 W m-2. So this relates to water vapor changes in chapter 3. Cluster B: Consistency in observed climate change: atmosphere, ocean, cryosphere. This may also extend to paleo, chapter 6. Issues: *Consistency of:* * sea ice with SST * snow cover with snowfall and temperature * glacier melting and permafrost changes vs temperatures * borehole temperatures, glacier changes and paleo record * overlap between paleo record and instrumental record * salinity vs precipitation * ocean heat content with SST and surface fluxes * sea level rise as an integrator: ocean expansion, melting of land ice, increased water storage on land, and changes in TOA radiation (presumably led by Chapter 5.) Issues consist of use of consistent temperature and precipitation records (don't use NCEP surface temperatures as in Ch 4 CQ). Points of contention: 1) consistency 2) overlap and redundancy 3) where to place integrated assessment? * sea level: Chapter 5 * snow, ice, temperature chapter 3 section 3.9 * paleo record vs instrumental chapter 6 * overall view including sea level chapter 3, in 3.9 * T increase (land, SST, subsurface ocean), snow retreat, sea ice retreat, thinning, freezing season shorter, glacier melt, sea level rise. * Precip changes, drought, salinity, ocean currents, P-E, snowfall. Please see the draft of 3.9. So in terms of the agenda, the main points are: 1) Ensuring consistency among variables across chapters 2) Agreement on which chapter and what person will handle what, and in particular, that 3.9 will have a look ahead aspect to the chapters that follow. The above points could all be briefly on the table with the focus on cross-chapter issues. Desirable to circulate draft section 3.9 (1 page). Peter may wish to add or change this? Regards Kevin Martin Manning wrote: Dear Kevin and Peter Please find attached our current program for the second Lead Author meeting on May 10 - 12. We will shortly be sending out some more details on the plans for the meeting and in particular would like to clarify what needs to be done in the Overlap Cluster meetings shown in the program on Wednesday 11th. This is to ask if you would be prepared to jointly co-chair the session on Overlap Cluster B dealing with "Consistency in covering observed climate change" and which will involve discussion among chapters 3, 4, 5, 9 and 11. The attached program lists, on the last page, overlap / consistency areas that have been mentioned in the ZOD. We would really be most grateful for your assistance in this, and if you agree, we would like to ask that you each to specify what in your view would be the 2 or 3 most important issues to resolve during the overlap cluster session. We will then use your input to draw up a specific agenda and circulate agendas for all overlap clusters to all CLAs prior to the meeting. We hope in this way that we can reach a shared understanding of the most important overlap and consistency issues and the corresponding key decisions that will have to be made in Beijing. I would be grateful if you could let me know whether you are able to help us with this by Wednesday 20th. Regards Martin -- *Recommended Email address: [1]mmanning@al.noaa.gov *** Please note that problems may occur with my @noaa.gov address Dr Martin R Manning, Director, IPCC WG I Support Unit NOAA Aeronomy Laboratory Phone: +1 303 497 4479 325 Broadway, DSRC R/AL8 Fax: +1 303 497 5628 Boulder, CO 80305, USA -- **************** Kevin E. Trenberth e-mail: [2]trenbert@ucar.edu Climate Analysis Section, NCAR [3]www.cgd.ucar.edu/cas/ P. O. Box 3000, (303) 497 1318 Boulder, CO 80307 (303) 497 1333 (fax) Street address: 1850 Table Mesa Drive, Boulder, CO 80303 -- **************************************************** Prof. Dr. Peter Lemke Alfred-Wegener-Institute for Polar and Marine Research Postfach 120161 27515 Bremerhaven GERMANY e-mail: [4]plemke@awi-bremerhaven.de Phone: ++49 (0)471 - 4831 - 1751/1750 FAX: ++49 (0)471 - 4831 - 1797 [5]http://www.awi-bremerhaven.de **************************************************** 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 [6]p.jones@uea.ac.uk NR4 7TJ UK ---------------------------------------------------------------------------- _______________________________________________________________________________ [cid:part1.06010200.08000003@ucar.edu] -- **************** Kevin E. Trenberth e-mail: [7]trenbert@ucar.edu Climate Analysis Section, NCAR [8]www.cgd.ucar.edu/cas/ P. O. Box 3000, (303) 497 1318 Boulder, CO 80307 (303) 497 1333 (fax) Street address: 1850 Table Mesa Drive, Boulder, CO 80303 Embedded Content: Re WG1 LA2 meeting - Overlap c.jpg: 00000001,429c633d,00000000,00000000