[MITgcm-support] 'repeatPeriod' in data.exf

[Suneet Dwivedi]

Hi Martin,

Thanks for your reply. Your suggestion is helpful. However, if i follow what
you suggested for 60 years of simulation, for example, then for 8 air/sea
forcing fields i will have to create 480 (60*8) yearly forcing files, which
is possible, but cumbersome. An alternative that I could think of may be to
run the model for somewhat shorter duration and restart from there...., for
example, running the model for 15 years at a time and restart from there
again for 15 years and so on.....Thus rather than splitting forcing fields
into years, one may split time window.

I guess in this case, i should set repeatPeriod = 0 in data.exf, if i am
using continuous in time daily forcing fields for 15 years. But I am not
sure how to set namelist parameters in input/data while restarting from
pickup files. What i could gather from looking at verification directory
examples and mitgcm manual is that it is possible to restart the model from
pickup files by setting nIter0 equal to number as suffix in pickup file, but
i am not sure how to set data.cal in this case. Probably, I should not
include data.cal in my input directory when I am restarting. Is this right?
Any suggestions....

Thanks again,
Suneet

On Tue, Jun 22, 2010 at 8:19 AM, Martin Losch <Martin.Losch at awi.de> wrote:

> Suneet,
>
> you can split you forcing fields into years. They have to follow this
> naming convention:
> forcingFile_year, where "year" is a 2 or 4-digit year (e.g. myatemp_1996,
> myatemp_1997, etc).
>
> In data.exf set:
>  useExfYearlyFields= .TRUE.,
>  twoDigitYear      = .FALSE.,
>
> and
> atempfile = myatemp,
> etc. If you want to use a Gregorian calendar the data.cal should look like
> this:
>  &CAL_NML
>  TheCalendar='gregorian',
> # here you insert your start date, of course
>  startDate_1=19920101,
>  startDate_2=000000,
> # this makes the model interpret output "freqs" (e.g. dumpFreq) close to 1
> month (say 2592000.) as a "real" month, the same for a year.
>  calendarDumps = .TRUE.,
>  &
>
> There are a few examples in the MITgcm_contrib area (arctic, high_res_cube)
>
> Martin
>
>
> On Jun 22, 2010, at 1:38 AM, Suneet Dwivedi wrote:
>
> > Hi Everybody,
> >
> > Could anyone of you please tell me what is the exact meaning of parameter
> 'repeatPeriod' in exf package/data.exf?
> >
> > I wish to perform a long run of 50-55 years with daily air/sea forcing
> values over Indian Ocean. Matlab is unable to store and process such a long
> matrix of dimension [250 150 20000] ~ O(1e+10) with 64 bit precision. An
> alternative way to do this may be to use climatological daily forcing values
> (averaged over all available years) of dimension [250 150 366] and use the
> climatological values for each year of simulation. In this case, i need to
> know the variable that does this in MITgcm. I wonder 'repeatPeriod' does
> this. Am I right? For example, if i set 'repeatPeriod' to something like
> 31622400.0 (for 1 year), will I be able to use same values of forcing on
> same days of each year after completing one year of simulation? Please
> suggest.
> >
> > Thanks,
> > Suneet
> >
> > _______________________________________________
> > MITgcm-support mailing list
> > MITgcm-support at mitgcm.org
> > http://mitgcm.org/mailman/listinfo/mitgcm-support
>
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