[MITgcm-support] cubed grid cell volumes

[Menemenlis, Dimitris (3248)]

Hi Juan, I copy answer to mitgcm_support, since this may be helpful to others,
and also so that others can correct me if I am wrong - as I often am :-(

Regarding grid cell volume, you are pretty close, except that because we use z*,
ETAN (equivalent to ssh when there is no sea ice) is distributed across the full depth.
I think the correct tracer grid cell volume is: dV = RAC * DRF * hFacC * ( 1 + ETAN / Depth )
But note that UVELMASS and VVELMASS already include the "1+ETAN/Depth" factor.

Regarding web site, please try again and let me know if it works.
Sometimes it is down for repairs or other causes but right now I can access fine.
Same files are also available on regular http and ftp servers (as opposed to opendap).
http://ecco2.jpl.nasa.gov/data1/cube/cube92/lat_lon/quart_90S_90N/matlab/
ftp://ecco2.jpl.nasa.gov/data1/cube/cube92/lat_lon/quart_90S_90N/matlab/

Dimitris Menemenlis

On Sep 3, 2013, at 10:16 PM, Juan A. Saenz wrote:

> Dear Dimitris,
> 
> I have a couple of questions that I am hoping you would be able to help me with.
> 
> I am trying to look at the files used to interpolate from cube92 to lat lon available here, but there seems to be a problem:
> 
> http://ecco2.jpl.nasa.gov/opendap/data1/cube/cube92/lat_lon/quart_90S_90N/matlab/
> 
> 
> Also, I am want to get the grid cell volumes associated to the T, S data for the ECCO2 cube92 runs.
> Is the volume of fluid with T, S at on a grid calculated simply as
> 
> for interior cells: dV = RAC*DRF*hFacC ,
> for surface cells: dV = RAC*(DRF+ssh)*hFacC ,
> 
> where ssh is the sea surface height and the rest are variables using the files in this directory
> 
> ftp://ecco2.jpl.nasa.gov/data1/cube/cube92/grid
> 
> Thanks in advance for your help,
> Juan
> 
> -- 
> -------------------------------------
> Juan A. Saenz
> Postdoctoral Fellow
> Geophysical Fluid Dynamics
> Research School of Earth Sciences
> Australian National University
> http://people.rses.anu.edu.au/saenz_j