cc: wigley@ncar.ucar.edu
date: Sun, 8 Nov 1998 21:01:03 -0700 (MST)
from: Tom Wigley <wigley@meeker.ucar.edu>
subject: Re: global land precip.
to: Mike Hulme <m.hulme@uea.ac.uk>

Mike,

Many thanks for the precip. data.  When I compared the mm(sd) column with
IPCC Fig. 3.11 (top panel) I found big differences in the individual
annual values (plus IPCC only goes to 1994).  Have you improved things?
IPCC says that there is a 1% increase overall, which is clearly garbage.
The apparent rend depends on the years before 1915:  surely these are less
reliable and represent poorer coverage?

By the way, what paper can I cite for these data?

Cheers,
Tom,

On Thu, 5 Nov 1998, Tom Wigley wrote:

> Mike,
> 
> I didn't get the attachment.  Can you try again please?
> 
> Thanx,
> Tom
> 
> On Thu, 5 Nov 1998, Mike Hulme wrote:
> 
> > Tom,
> > 
> > Attached is an output file from my regional precip. program.  This contains
> > annual precip. anomalies (wrt 1961-90) for global land areas derived from
> > my 1900-1996 gridded (on HadCM2 grid) precip. dataset.  
> > 
> > The first block of data are diagnostics for the 1496 boxes contributing.
> > 
> > The time series at the end of the file are for 1900-96 and show various
> > methods of calculating anomaly series for precip. (see Jones and Hulme
> > paper in IJC, 1996).
> > 
> > The one is prefer is column 5 mm(sd) which are mm anomalies from the
> > 1961-90 weighted mean of 989 mm.  Column 2 are the number of boxes
> > contributing each year.  Column 3 is the conventional standardised anomaly
> > index.
> > 
> > These data are equivalent to those shown in Figure 3.11 (top panel) in IPCC
> > 1996.  There are only three such series in existence to my knowledge -
> > mine, Dai et al. and the one from Karl/Peterson.  Dave Easterling showed
> > the latest version of their's at a recent meeting in Vienna so I know
> > he/Tom have one.  Dai has also published a version (JoC 1997), but this was
> > based on inferior data and used a different (less robust) method.
> > 
> > Regards,
> > 
> > Mike
> > 
> > 
> > 
> > 
> 
> 
>        **********************************************************
>        *Tom M.L. Wigley						*
>        *Senior Scientist 					*
>        *National Center for Atmospheric Research                *
>        *P.O. Box 3000				                *
>        *Boulder, CO 80307-3000					*
>        *USA                                                     *
>        *Phone: 303-497-2690                                     *
>        *Fax: 303-497-2699                                       *
>        *E-mail: wigley@ucar.edu                                 *
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> 
> 


       **********************************************************
       *Tom M.L. Wigley						*
       *Senior Scientist 					*
       *National Center for Atmospheric Research                *
       *P.O. Box 3000				                *
       *Boulder, CO 80307-3000					*
       *USA                                                     *
       *Phone: 303-497-2690                                     *
       *Fax: 303-497-2699                                       *
       *E-mail: wigley@ucar.edu                                 *
       **********************************************************