cc: "Allan, Rob" date: Wed, 28 Mar 2007 13:13:33 +0100 from: philip.brohan@metoffice.gov.uk subject: Re: WW2 marine data to: Phil Jones Phil We've got quite a lot of evidence we need to look again at bias adjustments for the mid-20th century: I've been doing some systematic model-obs comparisons, and John Kennedy has been looking at the differences between SSTs from ships from different countries. What we haven't yet done is sat down and derived some new adjustments and uncertainties. I've put a preliminary look at the new obs from the WW2 logs on the web (http://brohan.org/hadobs/digitised_obs/docs/) there are some interesting indications of biases in SST and night air temperature. We're still short of obs for the Pacific though. Clive's done some good work in the archives, and I'm hoping that collaborating with him and the historians from Exeter we can have a serious crack at making instrumental temperature series back past 1800. I'm still keen on a 'climate of the 19th century' project - as well as digitising more observations, we could use GCM runs and proxies to help bias adjust the early instrumental observations, and make a credible time-series back through the Tambora period - that would give us a wider range in instrumental temperatures, and so help to calibrate longer proxy reconstructions. But so far this is just an idea. Cheers, Philip On Wed, 2007-03-28 at 11:48 +0100, Phil Jones wrote: > > Philip, > Just had a coffee with Clive Wilkinson. He was telling me > of the progress with the WW2 logs and his finds for WW1 as > well. I suggested he also look into log books during the > late 1870s as the RN were then doing SST and we then had > a Valpariso Fleet. > On the WW2 logs, hopefully these may resolve the > issue Daithi Stone talked to me about regarding the D&A > figure from WG1 SPM (the one with the continents and the > world oceans on). He was a little concerned about the obs > for the global oceans popping out of the model swathe around > 1940, as it doesn't do this for the continents. > I guess if there are significant more obs in the E Eq Pacific > this issue could be nailed down. May relate to whether the > obs are bucket/intake and need adjustment or not. > > I told Clive, I'd be happy to be involved in Exeter Uni. > initiatives re their Inst for Maritime History. > > Cheers > Phil > > > > > 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 p.jones@uea.ac.uk > NR4 7TJ > UK > ---------------------------------------------------------------------------- -- Philip Brohan, Palaeoclimate Scientist Met Office Hadley Centre for Climate Prediction and Research Tel: +44 (0)1392 884574 Fax: +44 (0)1392 885681