[Go-essp-tech] Searching for gridspec files

[Kyle Olivo]

Hi Jennifer,

I can offer some assistance with respect to GFDL's gridspec files. The angles were published for the supergrid, which is twice the resolution of the actual grid.

The points in the supergrid corresponding to the actual grid are: nxp={2,4,...360}, nyp={2,4,6,…200}.

Sorry this information wasn't recorded anywhere. We'll likely republish these files on the actual grid in the near future.

Thanks,
Kyle

On Jul 23, 2012, at 1:39 PM, Jennifer Adams wrote:

> Hi, Everyone -- 
> I have downloaded the transix and transiy variables for the historical experiment (realm=seaIce,frequency=mon,MIP=OImon) for the following models:
> 
> CMCC.CMCC-CM/
> CMCC.CMCC-CMS/
> CNRM-CERFACS.CNRM-CM5/
> CSIRO-BOM.ACCESS1-0/
> CSIRO-BOM.ACCESS1-3/
> CSIRO-QCCCE.CSIRO-Mk3-6-0/
> INM.inmcm4/
> IPSL.IPSL-CM5A-LR/
> IPSL.IPSL-CM5A-MR/
> IPSL.IPSL-CM5B-LR/
> MIROC.MIROC4h/
> MIROC.MIROC5/
> MIROC.MIROC-ESM/
> MIROC.MIROC-ESM-CHEM/
> MPI-M.MPI-ESM-LR/
> MPI-M.MPI-ESM-MR/
> MPI-M.MPI-ESM-P/
> MRI.MRI-CGCM3/
> NASA-GISS.GISS-E2-H/
> NASA-GISS.GISS-E2-R/
> NASA-GISS.GISS-E2-R-CC/
> NCC.NorESM1-M/
> NCC.NorESM1-ME/
> NOAA-GFDL.GFDL-CM3/
> NOAA-GFDL.GFDL-ESM2G/
> NOAA-GFDL.GFDL-ESM2M/
> 
> The vector components transix and transiy are grid relative, and in order to display them properly, I need to rotate them to earth-relative coordinates. On page 10 of the document titled "CMIP5 Model Output Requirements: File Contents and Format, Data Structure and Metadata" , it says:  "… for grids other than Cartesian latitude-longitude grids, a file recording all the grid configuration information called for by gridpsec must be created for each modeling realm…" The name of this gridspec file is provided in the global attribute named associated_files in all data files. Unfortunately, as far as I can tell by searching with P2P, the gridspec files have not been published by any institute except GFDL. 
> 
> I have grabbed all the GFDL gridspec files that are available via ESGF. Here is the relevant output from ncdump on one that matches my data, "gridspec_seaIce_fx_GFDL-CM3_historical_r0i0p0.nc" :
> 
> dimensions:
>         nxp = 721 ;
>         nyp = 401 ;
> variables:
>         double angle_dx(nyp, nxp) ;
>                 angle_dx:standard_name = "grid_vertex_x_angle_WRT_geographic_east" ;
>                 angle_dx:units = "degrees_east" ;
> 
> There is the variable I desire, angle_dx, but it is on a 721x401 grid. 
> The native grid of the data file transix_OImon_GFDL-CM3_historical_r1i1p1_186001-186412.nc is 360x200. 
> I cannot use the angle_dx variable in this gridspec file because it doesn't match the data. 
> 
> Here are my questions: Do accurate gridspec files exist? How can I acquire them? 
> 
> --Jennifer
> 
> 
> 
> 
> 
> --
> Jennifer M. Adams
> IGES/COLA
> 4041 Powder Mill Road, Suite 302
> Calverton, MD 20705
> jma at cola.iges.org
> 
> 
> 
> _______________________________________________
> GO-ESSP-TECH mailing list
> GO-ESSP-TECH at ucar.edu
> http://mailman.ucar.edu/mailman/listinfo/go-essp-tech

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.ucar.edu/pipermail/go-essp-tech/attachments/20120724/76c852df/attachment.html