date: Tue, 03 Aug 2004 07:55:09 -0600 from: Tom Wigley subject: question etc. to: Sarah Raper Sarah, In a paper by Robert Nicholls he says "the 9-88cm range in the IPCC TAR does not include the additional uncertainties from changes in terrestrial water storage". True -- but for the AR4? Any idea? Did you see Gregory's comments on our volcano paper? Thanx for the notes from Paris. Some comments ... (1) I pointed out the DT2x vs Qaer thing years ago when I reviewed the first Had2 paper claiming a good 20th century fit. It is pretty obvious, but often ignored. I believe James Murphy put in a sentence to cover this in the above-mentioned paper -- but I still judge the modellers (including Jerry Meehl and others at NCAR)as being dishonest here. (2) 1% runs. Collins' number is irrelevant -- but there are uncerts in Q2x that we could look at. (3) Re Myles, what is the 'Allen, Raper Mitchell' policy piece? (4) I first estimated XKLO from the seasonal cycle. On this basis it cannot be too high. We could put in a finite land heat capacity. I do not think the numbers have to be 'realistic', whatever that means. It is just a tuning parameter that has to be balanced in a statistically sensible way against RLO. (5) We will need to make an effort to include every AOGCM and avoid upsetting anyone. (6) No problem re convergence of AOGCM DT2x. We didn't use AOGCMs in our Science paper -- and the reason (I hope) that you stuck to 1.7-4.2 in the TAR was because this was a fair estimate of the range based on other evidence. At the high DT2x end the sensitivity to sensitivity is less. It is the 'full evidence' range that must be covered. (It not, the AR4 will be strongly criticized.) To base a DT2x range on AOGCM results alone would be crazy. (7) We really need to push for forcing information. ---------- We have a lot to discuss when I visit soon. It is possible that Eirik will come to Norwich then too -- altho he will stay with James and Camilla. Tom.