Re: regrid PCM displaced pole grid to regular grid

From: Dennis Shea (shea AT cgd.ucar.edu)
Date: Mon Nov 07 2005 - 14:03:48 MST


>
>As a new user to NCL, I'm wondering if someone can point me in the
>right direction in how to convert a netcdf file that's of PCM ocean
>data that has a displaced pole grid to a regular lat/lon grid?
>
>Thanks for any information you can provide.
>

http://www.ncl.ucar.edu/Applications/index.shtml

Click: POP ==> Lat/Lon

The basic structure is:

load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/popRemap.ncl"
begin
  diri = "/blah/blah/"
  fili = "PCM.nc"
  f = addfile(diri+fili,"r")
  x = f->Whatever
;************************************************
; convert PCM to a 1x1 degree grid
;************************************************
  xNew = PopLatLon( x ,"gx1v3","1x1d","bilin","da","010808")

  diro = "BLAH/BLAH/"
  filo = "PCM.1x1.nc"
  system("/bin/rm -f "+diro+filo)
  fout = addfile ) diri+filo , "c")
  fout->WHATEVER = xNew

end

The above can readily be expanded to loop over multiple files.

The real key is the 'weights' file. These are used
by NCL to remap. It may look like:

     map_gx1v3_to_1x1d_bilin_da_010808.nc [384x320]
     
These are produced externally ... not by NCL.
I am sure the weights file for the PCM grid you are using
is available.

If you want to interpolate vector quantities,
then you also need a file containing the
angles the PCM grid makes with latitude lines.

--

_______________________________________________ ncl-talk mailing list ncl-talk@ucar.edu http://mailman.ucar.edu/mailman/listinfo/ncl-talk



This archive was generated by hypermail 2b29 : Mon Nov 07 2005 - 16:39:36 MST