[Mitgcm-support] Re: Calendar package for MITgcmUV

[mitgcm-support at dev.mitgcm.org]

Hi Jonni,

the calendar package allows you to jump between
model time (in seconds from a given start time) and
(1) real Gregorian time in date and time (YYYYMMDD and HHMMSS)
     with respect to your chosen start day and time (i.e. you
     don't have to worry about 30 vs. 31 day months, leap years etc.,
     the calendar does it all for you)
or
(2) an idealized model calendar consisting of 360 days
     and 12 months of 30 days each.

As you see there are 2 things to chose, and you do the selection
at runtime using the data.cal file:
* specify TheCalendar = 'gregorian' if you want (1)
   or      TheCalendar = 'model' if you want (2)
* specify your absolute reference start time, e.g.
           startDate_1=19920503,
           startDate_2=063000,
   for a start on 03-May-1992 at 6:30

The calendar package can be very helpful when working
with realistic (e.g. daily NCEP or ECMWF) forcing.

There is a verification experiment called global_with_exf
which has cal in action together with the exf package.
 From the given forcing timings in data.exf (with respect
to the selection in data.cal)
it computes the corresponding records to retreive the
current forcing fields.

Cheers
-Patrick



Jonni.Lehtiranta at fimr.fi wrote:
> 
> Greetings!
> 
> I've been playing around with MITgcm and the calendar package, but fail 
> to grasp
> the whole idea. I think I compiled it right (with the 
> barotropic_gyre_in_a_box tutorial
> example). Copying the code in section (3) of pkg/cal/README proved 
> troublesome,
> but the code compiled when I removed the trailing spaces from the lines not
> beginning with an I.
> 
> Still, I fail to modify this tutorial in any such way that would show 
> the cal package in
> action. What effects should be there? What does the data.cal input matter?
> 
> Also, I know it's not your thing, but I've had hard time trying to 
> figure out anything
> from the MITgcm documentation.. Like for example, the input file formats 
> (I figured
> something by reading the gendata.m scripts =). How is time handled in 
> input?
> 
>  -Jonni Lehtiranta


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