cc: Keith Briffa date: Wed, 22 Mar 2006 13:49:57 +0000 from: Tim Osborn subject: Re: EXTREMELY URGENT: SO&P report to: philip.brohan@metoffice.gov.uk Hi Philip, thanks for this input to the soap report. Cheers Tim At 10:37 14/03/2006, you wrote: >Hi Tim. > > Another victory for EU bureaucracy. Here's what you asked for from us - >let me know if you need anything else. > >We didn't encounter any unexpected difficulties, or change our plans. > >We've one extra non-peer reviewed report: >Hadley Centre GMR milestone report III.A.3, "Evaluating simulated >climate variability and climate response to forcings using the paleo >reconstructions", September 2005. >This will form part of Deliverable 14. > >We've worked on 2 workpackages > >Workpackage 4: > >We have presented some preliminary results of >intercomparison between simulations and instrumental temperatures. We >have taken account of observational uncertainty as well as chaotic >climate variability in this analysis. We found that simulated Southern >Hemisphere temperatures during the mid and early 20\th century were too >warm compared to observations. An optimal detection analysis >showed some discrepancy between simulation and HadCRUT3 though mainly >in the response to natural forcings rather than in the response to >well-mixed greenhouse gases. > >We have analysed the statistical methods used to reconstruct past >temperatures from proxy data and shown that there are still considerable >uncertainties in reconstructing past climate and to reduce these will >require good estimates of proxy uncertainties. Even so, we have done >comparisons between simulated and reconstructed temperatures, and our >preliminary results suggest that HadCM3 has less multi-decadal >variability than any of the paleo-reconstructions have. This could be >because HadCM3 lacks sufficient internal or chaotic multi-decadal >variability, that the forcing used is too small on multi-decadal >timescales or that HadCM3 is not sufficiently sensitive to the forcing >applied. > >Workpackage 5 > >We have completed the calculations and analysis of sea level changes >based on the simulations of the last 500 years carried out using the >HadCM3 AOGCM with anthropogenic and natural (solar and volcanic) >forcings. Simulated contributions to global-mean sea-level rise during >recent decades due to thermal expansion (the largest term) and to mass >loss from glaciers and ice caps agree within uncertainties with >observational estimates of these terms, but their sum falls short of the >observed rate of sea level rise. This discrepancy has been found in >previous studies; a completely satisfactory explanation of 20th-century >sea-level rise is lacking. The model suggests that the apparent onset of >sea level rise and glacier retreat during the first part of the 19th >century was due to natural forcing. The rate of sea level rise was >larger during the 20th century than during the previous centuries >because of anthropogenic forcing, but decreasing natural forcing during >the second half of the 20th century tended to offset the anthropogenic >acceleration in the rate. Volcanic eruptions cause rapid falls in sea >level, followed by recovery over several decades. The model shows >substantially less decadal variability in sea level and its thermal >expansion component than 20th-century observations indicate, either >because it does not generate sufficient ocean internal variability, or >because the observational analyses overestimate the variability. > >Regards, > > Philip > >On Fri, 2006-03-10 at 10:56, Tim Osborn wrote: > > Dear all, > > > > we have had a very bad message from the CEC project officer who now > > deals with SO&P (Riccardo Casale, who took over from Hans > > Brelen). See the exchange of emails below. > > > > The result is that a written scientific and management report is > > required after all for the 3rd year of SO&P even though a final > > report is also due in just a few months. > > > > Not only that, but he requires it by 16 March -- next Thursday! > > >---------- CUT -------------- > >-- >Philip Brohan, Climate Scientist >Met Office Hadley Centre for Climate Prediction and Research >Tel: +44 (0)1392 884574 Fax: +44 (0)1392 885681 >Global climate data sets are available from http://www.hadobs.org Dr Timothy J Osborn 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