Dear Mithat,
 
A GCM could simulate accurate climate in a global scale, however it could 
simulate the worst one in a region (and the opposite). You have to compare
current (observed) climate with 1xCO2 GCM outputs in order to decide which GCM
outputs are most appropriate for your region of interest. The 1xCO2 outputs
from the GCMs should be compared with averaged database of observed climate,
not with site-specific climatic data. Expecting that a GCM grid box as large as
8o x 10o (for example) can represent climate at any particular point would be
unreasonable.
At least three GCMs should be used for creating 2xCO2 regional climate change
scenarios. Using one GCM scenario can create the impression of a prediction,
and using two GCMs shows only minor variance among scenarios.
 
I hope the above information would be helpful for you.
 
Best regards
Vesselin Alexandrov
 
 
> Dear Dssaters
>
> I'm wondering what is the most accurate of GCM's on climate change
> predictions (CCCM, UKMO, GISS, GFDL etc.), which output can be used in
> Dssat simulations.
>
> I very much appreciate, comments, and opinions of Dssaters working on this
> issue
>
>
> Thanks in advance
>
> Mithat Mema
> Unidad de Economia Agraria
> Carretera Montaņana, 176
> 50006 Zaragoza
> Spain
>
>
 
 
 
++++++++++++++++++++++++++++++++++++++++++++++++++++++
+               Vesselin Alexandrov, PhD             +
+                 Assistant Professor                +
+              Department of Meteorology             +
+   National Institute of Meteorology & Hydrology    +
+ 66 Tzarigradsko chaussee Av., 1784 Sofia, Bulgaria +
+         Tel. (+359-2) 975-39-86/444(ext.)          +
+         Fax: (+359-2) 88-44-94 or 88-30-93         +
+         E-mail: [log in to unmask]       +
++++++++++++++++++++++++++++++++++++++++++++++++++++++