cc: "Keith Briffa" date: Wed Jun 1 13:32:56 2005 from: Tim Osborn subject: IPCC AR4 model runs of last 1000 years to: "Pascale Braconnot" Dear Pascale, As you know, Keith Briffa (with some input from me) is preparing a section on the climate of the last 2000 years for the next draft of the IPCC Paleoclimate chapter. We are including some model simulations and forcings from experiments of the last 1000 years, and have begun to produce a figure - see the attached early version (note that labelling is wrong etc. so don't use it). Keith said I should ask you about including suitable simulations from your group in this IPCC figure. Please let me know if you would like to contribute data for this figure. If the answer is yes, then I would need a single simulation. We cannot include ensemble members or multiple runs with different forcings, simply because the figure would become too complicated (I know though these ranges are important in comparing models with each other and with paleo data, but we cannot include many tens of curves and/or ranges). I would need the following information/data (see also attached table/refs): (1) Model name and reference (and, if multiple simulations are described by the reference, then some indication of what data you are sending - e.g. ensemble mean from the XX experiment). (2) Global-mean forcings, specifying separately: (a) volcanic (b) solar (c) anthropogenic forcing (GHGs, aerosols, ozone etc.) and if possible include here pre-industrial GHG forcing if you included such variations in your experiment. (3) NH-mean temperature (optionally include NH-land temperature and full global-mean temperature, in case the IPCC authors decided that some other figure panel is needed) from one simulation or an ensemble mean. I hope that you agree to contribute some data to this IPCC figure, and that this data request is not too time consuming! Best wishes Tim