cc: Tim Osborn <t.osborn@uea.ac.uk>, mann@virginia.edu
date: Wed, 24 Jan 2001 17:55:53 -0500
from: "Michael E. Mann" <mann@virginia.edu>
subject: Re: verification results
to: Scott Rutherford <rutherfo@deschutes.gso.uri.edu>

Hi Scott,

Tapio is technically right, but on most proxy data a true estimate of
"observational error" will never be possible. Certain components of that
error (e.g., sample size in dendro estimates) are available, but this
will be very limited in general. I'm sure Tim can provide something along
the lines of the latter...

mike

At 05:27 PM 1/24/01 +0800, Scott Rutherford wrote:
>Dear Tim,
>
>After some reworking of the algorithm to better handle very sparse 
>data we finally have some results using your mxd data.
>
>You can see the plots at http://holocene.evsc.virginia.edu/~rutherfo/mxd.
>
>I ended up running tests using the 115 gridpoint series and using all 
>mxd records.  I also plotted the total NH mean, the land only NH 
>mean, then just a mean of 40-70 north.
>
>"xval" on the plots indicates the cross validation resolved variance 
>of the mean time series shown. "mult" is the total multivariate 
>resolved variance for all gridpoints over all time. (These are 
>actually normalized mean-squared errors, and we will probably be 
>switching to that terminology in the future.)  At the bottom of the 
>page is a link to the yearly maps.
>
>If you want any of the data files please let me know.
>
>I'm restarting the 400 year runs and will let you know as soon as we 
>have some results. I intend to run with both the 115 gridpoints and 
>the 387 individual records and see what the difference is.
>
>Can you give me an idea of the observational error on the mxd data? 
>I've been talking with Tapio Schneider about the errors and he seems 
>to think that scaling the different data types by the observational 
>error might improve the results.
>
>Regards,
>
>Scott
>-- 
>______________________________________________
>		       Scott Rutherford
>
>University of Virginia	University of Rhode Island
>Environmental Sciences	Graduate School of Oceanography
>Clark Hall			South Ferry Road
>Charlottesville, VA 22903 	Narragansett, RI 02882
>srutherford@virginia.edu	srutherford@gso.uri.edu
>phone: (804) 924-4669	(401) 874-6599
>fax: (804) 982-2137	(401) 874-6160
>
>
_______________________________________________________________________
                    Professor Michael E. Mann
           Department of Environmental Sciences, Clark Hall
                      University of Virginia
                     Charlottesville, VA 22903
_______________________________________________________________________
e-mail: mann@virginia.edu   Phone: (804) 924-7770   FAX: (804) 982-2137
         http://www.evsc.virginia.edu/faculty/people/mann.html              

