Subject: Re: Year 68 Virus
From: Andy Mai (mai@ucar.edu)
Date: Thu Sep 10 1998 - 16:17:39 MDT
On Thu, 10 Sep 1998, Kevin Werner wrote:
> Hello.
>
> I have been running the CCM at t31x15 with 18 levels. I am running the
> model on a SUN machine with multiple processors (although the result is
> invariant to the number of processors). The model has consistently crashed
> after 68 years and one month at timestep 1789568. I have encountered the
> same result with both versions 3.2 and 3.6. Is anyone aware of a solution
> to this problem? Or ideas on how to go about fixing it?
>
> Thanks,
> Kevin Werner
>
> o__ Kevin Werner INTERNET: werner@atmos.washington.edu
> _,>/'_ 685-8438 UUCP: uw-beaver!atmos.washington.edu!werner
> (_) \(_)......... WEB: http://www.atmos.washington.edu/~werner/
> Dept of Atmospheric Science, Box 351640, University of Washington
Ah, a fellow cyclist...
This is the same problem as Unix running out of dates in the year 2038.
Yes, I've had this problem, too, but it was a long time ago. It happens because
at some point in the model a calculation is done which involves the number of
seconds since the beginning of the run. So after 2**31-1 seconds =~ 68 years,
things go haywire. If someone else doesn't point out the relevant spot in
the code for you, send me another message and I'll try to locate it. BTW,
which version of CCM are we talking about here?
Andy Mai
303-497-1391
--- __o Andrew W. Mai
---- _`\<,_ National Center for Atmospheric Research
--- (*)/ (*) Boulder, CO 80307 USA mai@ucar.edu
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