date: Fri Aug  7 09:05:16 2009
from: Phil Jones <p.jones@uea.ac.uk>
subject: Re: geoeng
to: Tom Wigley <wigley@ucar.edu>, Ben Santer <santer1@llnl.gov>

    Tom, Ben
      The best precip dataset to use is from GPCC.
    [1]http://gpcc.dwd.de
    Then find the window about GPCC products, which are all gauge-only based products.
    GPCC rarely write anything up, which annoys Kevin, Aiguo and others. GPCC
    also can't release the raw precip totals.
    VASClimO 51-00 is best as the gauges are mostly the same for the whole 50-year
    period.
    In a paper almost accepted in JGR where we are comparing ERA-INTERIM (for 1989-2008)
    we used v.4 of the Full Data Reanalysis.
    I've attached the paper recently resubmitted - don't pass on! Kevin and Aiguo were 2 of
   the 3
    reviewers. They both wanted the PREC/L dataset added in. It was - in Fig 12 and a Table.
    Figures 10-12 are the precip ones. These are continental precip averages, so not global
   land
    and no ocean estimates.
    Trenberth and Dai (2007) is where the figure in this Science Perspectives
    piece comes from (paper attached). It seems to be after SOI subtraction!

    This SOI extraction is probably better done regionally than as one domain (global land).
    SOI will cause excess rain in some areas and deficits in others at the same time.
    Will read the paper over the weekend.
    Cheers
    Phil


   At 02:54 07/08/2009, Tom Wigley wrote:

     Ben, Phil,
     I think this paper is rubbish. Please comment.
     Phil -- how well do we know the drop in precip after Pinatubo?
     What would be the best time series data to use.
     By the way, when one uses comined mitigation and geoeng, the
     effect on global precip is the opposite. (Pls ignore this
     when commenting on the attached.)
     Tom.

   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
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