[MITgcm-support] about 510*510*6*50 cubed sphere example

[Dimitris Menemenlis]

Hi Liuyu, a few more comments to add to the very helpful reply by Christoph
Voelker.

> 1.  Where can I find the needed data, noted by file 'job_altix92_54t' : \ln
> -sf /nobackup2/menemenl/cube/run_template/* . \ln -sf
> pickup_seaice.0000131976.data.cube8 pickup_seaice.0000000216.data \ln -sf
> pickup.0000131976.data.cube8 pickup.0000000216.data

Do you have access to NASA Ames computers?  If not, I will ask for permission to
bring the run_template files to a public server at MIT.  What about the
"ncep_rgau" forcing files?  Do you have those files already?

> 2.  What are the horizontal resolution  and  the longitude & latitude range
> of these 54 tiles, How can I plot the images of output files(after normal
> run)?

Horizontal grid spacing is approximately 18-km.  There are output files XC.data,
YC.data, etc., which specify the longitude and latitude of the output.  Output
format is direct access IEEE big-endian binary, typically real*4 (but sometimes
real*8).  Two-D fields are 510x6x510.  3D fields are 510x6x510x50.  There's a
couple of matlab routines in MITgcm_contrib/high_res_cube/input for simple
plotting of the 32x6x32 cube.  If you change 32 to 510, it should work for
hi-res cube.  More matlab routines for cube sphere are at
MITgcm/utils/matlab/cs_grid

> 3. Which file need to be modified if I want to use less than 54 cpu(such as 10 cpu)?

As Christoph said, you'd have to have a ton of memory and superfast CPUs to want
to run on anything less than 54 CPUs.  The way to reduce number of CPUs is to
modify the file SIZE.h.  The parameter that determines number of CPUs is nPx.
You can decrease that value by increasing nSx, as long as nSx*nPx remains
unchanged.  For example for 27 you would set nPx=27, nSx=2.  Then recompile and
link the code, i.e., "make -j".

Cheers, Dimitris

-- 
Dimitris Menemenlis <menemenlis at jpl.nasa.gov>
Jet Propulsion Lab, California Institute of Technology
MS 300-323, 4800 Oak Grove Dr, Pasadena CA 91109-8099
tel: 818-354-1656;  fax: 818-393-6720