[cam-users] A problem with CAM2.0.1 restart run

[Ravi S Nanjundiah]

Hi,

 Is it possible that different number of processors are being used for the
two runs? Then is it likely that order of summation in Gaussian quadrature
is different leading to different results?

Regards,
Ravi Nanjundiah

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
|Ravi S Nanjundiah         | email: ravi@caos.iisc.ernet.in             |
|Assoc Professor           | phone: +91-80-293-3072                     |
|Centre for Atmos & Oc Sci,|        +91-80-293-2505                     |
|Indian Institute of Sci,  | fax:   +91-80-360-0865                     | 
|Bangalore 560012 India.   | http://caos.iisc.ernet.in/faculty/ravi.html|   
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 
> On Wed, 10 Sep 2003, [gb2312] y ww wrote:
> 
> > I running CAM2.0.1 on Linux and the problem is as follows:
> >  An initial run of one day was restarted , while another initial run with
> > the same datasets was running without any interuption. I had expected that
> > results of the two cases would be exactly the same. But the difference of
> > monthly averaged precipitation (PRECL+PRECC) turned out to be as much as 12
> > mm/day after one year of model time. I am confused. Did I do anything
> > wrong? Or is it a bug of CAM2.0.1?
> > Could anyone offer some advice?
> 
> Can't say for sure that you did anything wrong.  But your expectation of
> identical results is correct.  Any other result is indicative of a problem.
> 
> I just tried a test run of CAM2.0.1 on Linux using pgf90.  With 2 MPI tasks,
> all defaults from "configure" except setting the resolution to T5, gave
> identical results after 1 and 2 months where one run was restarted after 1
> day while the other ran straight through as an initial run.
> 
> Jim Rosinski
> 
> _______________________________________________
> cam-users mailing list
> cam-users@ucar.edu
> http://mailman.ucar.edu/mailman/listinfo/cam-users
>