[MITgcm-support] MITgcm 40km resolution Arctic simulation

[Jonny Williams]

Hi there

Regarding my previous email, I am trying to plot up the binary input files
to see if there are any obvious problems with the external forcing files as
these are certainly the underlying reasons for my crashes at the moment.
The modelling framework I currently use uses gridded NetCDF (and similar!)
so I am fairly unfamiliar with these binary files. Is there a simple way to
plot them in gnuplot or similar?

Many thanks!

Jonny


On 30 October 2013 15:32, Jonny Williams <Jonny.Williams at bristol.ac.uk>wrote:

> Hi again
>
> Good to know that my instructions may be of some use to others so thanks
> for that.
>
> I am now 'playing' with the model and have quickly discovered that the
> coupling period of the model with atmospheric variables is crucial to when
> the model crashes. Specifically the variables...
>
>    - precipperiod
>    - atempperiod
>    - aqhperiod
>    - swdownperiod
>    - lwdownperiod
>    - uwindperiod
>    - vwindperiod
>
> ... in the data.exf file (see here<http://mitgcm.org/viewvc/MITgcm/MITgcm_contrib/arctic/cs_36km/input/data.exf?view=markup> for
> web link).
>
> Thses are currently set to 21600s (6 hours) and sure enough the model
> crashes after the first coupling period.
>
> More precisely, the model does not actually crash but rather begin to give
> unphysical results, for example in the potential temperature output stream.
> I have attached 2 PNG files, one just before and one just after the first
> coupling period (40 minute time step). As you can see, the latter contained
> lots of small areas of NaNs which show up as blanks in the data. After
> this, the whole potential temperature field is NaN but the model itself
> does not actually crash and stop running.
>
> I am interested in running the model out for several months or more to get
> a good feeling for the circulation patterns which the model gives but at
> the moment I am unable to run it out past 6 hours without changing the
> coupling period which I'd rather not do if possible (I'd like to keep it
> close to the original).
>
> Does anyone have any experience with this type of numerical issue?
>
> Many thanks
>
> Jonny
>
>
>
>
>
> On 26 October 2013 00:56, Menemenlis, Dimitris (3248) <
> Dimitris.Menemenlis at jpl.nasa.gov> wrote:
>
>>  Hi Jonny.  Great that you got it to work.  And thanks for instructions.
>>  I have added them to
>> http://mitgcm.org/viewvc/MITgcm/MITgcm_contrib/arctic/cs_36km/readme.txt
>> for future reference and as a text file so they can more easily be
>> modified and change-tracked.
>>
>>  Cheers
>>
>>   Dimitris Menemenlis
>>
>>  On Oct 24, 2013, at 9:01 AM, Jonny Williams wrote:
>>
>>  Hi there
>>
>>  I have put a detailed guide on how to get the Arctic regional model
>> working here<http://www.paleo.bris.ac.uk/~ggjhtw/MITgcm_cs_36km_guide.pdf>.
>> Many thanks again to many of you for your help, particularly Dimitris,
>> Patrick and Renske.
>>
>>  Jonny
>>
>>
>>
>>
>
>
> --
> Dr Jonny Williams
> School of Geographical Sciences
> University of Bristol
> University Road
> BS8 1SS
>
> +44 (0)117 3318352
> jonny.williams at bristol.ac.uk
> bit.ly/jonnywilliams
>



-- 
Dr Jonny Williams
School of Geographical Sciences
University of Bristol
University Road
BS8 1SS

+44 (0)117 3318352
jonny.williams at bristol.ac.uk
bit.ly/jonnywilliams
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