[MITgcm-support] Forcing files in data.dic (biogeochemistry)

[Manfredi Manizza]

Hi Jonny,

yes, you are correct that namelist below works fine for the verification
experiment where you run the 2.8 by 2.8 global
setup with dimensions 28 by 64 by 12 of input filles for sea-ice cover
and for windspeed

For your (coarse-res ?) Arctic set-up, you will read wind speed  via the
EXF package  directly from re-analyzed products (NCEP, ECMWF, JRA-25)

For the fraction of sea- ice (or sea ice cover) you will pass to the
biogeochemical routine the variable that is computed
by the sea-ice model that its is coupled in your run to the ocean
physical model.

In this case you do not have to generate any input files with specificy
dimensions becuase in the data.exf file you should have
all details needed to interpolate on the fly your forcing accordingly to
your Arctic domain. 

Debugging tip :

Just make sure that in the dic package the sea-ice coverage is correctly
read in order to compute the gas transfer velocity
and the amount of irradiance use to compute the Net Community Production
that has to be masked at the surface
by the sea-ice fraction. Running 2-3 time steps with printout linese of
the variables always helps
to figure out that all works OK and the two parts of the code talk to
each other.

I hope this helps.

Manfredi


On 07/30/2014 07:45 AM, Jonny Williams wrote:
> Hi there
>
> I am currently trying to incorporate the GCHEM, PTRACERS and DIC
> packages into my setup of the MITgcm. I already have it successfully
> working in regional model using the OBCS and EXF forcing packages.
>
> in the ~/MITgcm/verification/tutorial_global_oce_biogeo example, the
> data.dic file calls for the following files in the DIC_FORCING namelist
>
> &DIC_FORCING
>   DIC_iceFile='fice.bin',
>   DIC_windFile='tren_speed.bin',
>   DIC_silicaFile='sillev1.bin',
>  &
>
> What I cannot work out however is what size these files should be in
> my setup. From trial and error, I think the ice and wind files are
> monthly climatologies (longitude x latitude x 12 months) and the
> sillev1 file (silica data file, according to the manual
> <http://mitgcm.org/public/r2_manual/latest/online_documents/manual.pdf>)
> is of the form longitude x latitude x 15 levels. 
>
> Does anyone know what size they should be? Should they have the same
> number of elements as the underlying grid, or is it staggered?
>
> This raises a more generic issue in that clearly the binary input
> files are not self-describing (like, say, NetCDF) and so having to
> reverse-engineer what size forcing and boundary condition files should
> is not uncommon for me.
>
> I may well be going about this in the wrong way so any suggestions
> about how to avoid this situation in future would be appreciated :)
>
> Many thanks, as always
>
> Jonny
>
> -- 
> Dr Jonny Williams
> School of Geographical Sciences
> University of Bristol
> University Road
> BS8 1SS
>
> +44 (0)117 3318352 <tel:%2B44%20%280%29117%203318352>
> jonny.williams at bristol.ac.uk <mailto:jonny.williams at bristol.ac.uk>
> bit.ly/jonnywilliams <http://bit.ly/jonnywilliams>
>
>
> _______________________________________________
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> MITgcm-support at mitgcm.org
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-- 
Dr. Manfredi Manizza
Geosciences Research Division
Scripps Institution of Oceanography
University of California San Diego
9500 Gilman Drive La Jolla, CA 92093-0244
email : mmanizza at ucsd.edu
tel   : +1-858-534-7094
web   : http://bluemoon.ucsd.edu/mmanizza/

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