date: Tue, 10 Nov 2009 08:47:42 -0700 from: Tom Wigley subject: Re: CC Essay to: Phil Jones Ah ha --- thanks. Tom. ++++++++++++ Phil Jones wrote: > > Tom, > This was related to whether the CC Essay should say anything about > global T estimated from Reanalyses. > I did send you a paper while ago about ERA-INTERIM from 1989-2008. > The extended reanalysis (by Gil Compo) is from 1891-2005. It uses > only SST and surface pressure as input. > Bottom line is this extended reanalysis (20CRv2) gets about the same > trend as HadCRUT3 for the 105 year period. The model gets the SSTs, but > also changes in forcing due to CO2, volcanoes and the sun. It uses the > SST that NCEP got. So it isn't using the newer SST dataset that Jim > Hurrell et al talked about. It is, though, the extended reanalysis that > Jim talked about at the end of his paper in J. Climate in 2008 - > attached this. > > Cheers > Phil > > > At 14:29 10/11/2009, you wrote: >> Phil, >> >> I can't remember what this is in response to. >> Can you remind me? >> >> Tom. >> >> ++++++++++++++++++++++ >> >> Phil Jones wrote: >>> >>>> Tom, >>> I've got some info back from Gil Compo. I can't pass on though, >>> but I can summarize. >>> I've given him loads of suggestions to track down some of the >>> differences. As large-zonal-band time series none are that large, but >>> he needs to look at maps. >>> On trends though for 50S to 70N (for land) his extended reanalyses >>> are very similar to HadCRUT3 and to GISS. For some reason he's yet to >>> use the NCDC series. >>> Correlations between his series (20CRv2) and HadCRUT3 for this >>> large domain is 0.85 and for GISS it is 0.81. GISS/HadCRUT3 >>> correlate (all over 1891-2005) to 0.98. The correlation reduce to >>> 0.69, 0.60 and 0.95 if you detrend them. They'd also drop a little >>> further (by about 0.02) if you looked at 20-70N. Correlations would >>> be improved if you could drop the 1890s. >>> Despite always being pressure only they give better agreement from >>> the 1960s onwards. I suspect this is just down to more input surface >>> pressure data then. >>> The odd periods are the 1920s and the period from 1940-60. For the >>> latter if the SSTs were adjusted they would look much better. The >>> 1900s, 1910s for some reason look amazingly good. >>> It looks as though there won't be a paper to refer before we have >>> to submit the CC piece. I've asked him to plot land minus ocean when >>> he has some time. >>> 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 >>> ---------------------------------------------------------------------------- >>> >> > > 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 > ---------------------------------------------------------------------------- >