cc: Alex Wright , Orson van de PLassche , Keith Briffa , jason.lowe@metoffice.gov.uk date: Wed, 28 Jun 2006 22:20:47 +0100 from: Jonathan Gregory subject: Re: Simulation data, missing 1900 trend? to: Tim Osborn Dear Tim and Alex > Little increase is simulated south of 60S This is generally the case in models, and we think in HadCM3 it is mainly because thermal expansivity is low at cold temperatures. > due to either (i) regional sulphate aerosol cooling; or > (ii) internal variations of the ocean circulation (ii) is more likely than (i) but it also depends on where the heat is taken up and stored in the ocean. > Such is the difficulty of interpreting *regional* sea level changes Yes. Given that regional changes from models tend to disagree, comparing any given place with the global mean is reasonable. However the local changes may give an indication of the multidecadal variability you might expect to see. Best wishes Jonathan