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[GEMPAK #PKR-554453]: .gem to .nc

Pete-

The netCDF-Java library doesn't go the other way, unfortunately.

What's the source of the netCDF files?  There is dcreanal which converts NARR 
reanalysis netCDF files to GEMPAK.  Otherwise, I don't know of a generic netCDF 
to GEMPAK.  One problem is that mapping netCDF variable names to GEMPAK 
variable names is not just straightfoward.

Can you upload the netCDF file and the resulting GEMPAK files to:

http://motherlode.ucar.edu/repository/alias/idvupload

and I'll take a look to see if anything jumps out at me?

Thanks.

Don

> Ok, and this time with the attachment :)
> 
> From my previous email:
> 
> Don,
> 
> Does the java netcdf interface go the other way as well, i.e. read a
> netcdf file and create a gempak file? If not, do you know of anything
> that will do that?
> 
> I found a program cdfconvert, I think from the Canadian meteorological
> society, that does this, but for some reason the gempak files that are
> created from this are skewed. Seems like they should be simple enough,
> using a 2.5 deg CED grid for both the netcdf grid and the gempak grid,
> but it looks skewed. I've attached an image plotted from gempak showing
> the skew. The data points look in the right place at the SW and NE
> corners of the grid, but the NW and SE points are wrong.
> 
> Thanks,
> 
> Pete
> 
> Unidata GEMPAK Support wrote:
> > Hi Sharon-
> >
> > The easiest way might be to use the netcdf-Java library if you have Java on 
> > your system.  The full library is available at:
> >
> > ftp://ftp.unidata.ucar.edu/pub/netcdf-java/v4.1/netcdfAll-4.1.jar
> >
> > Download that and then run:
> >
> > java -Xmx512m -classpath netcdfAll-4.1.jar;.
> > ucar.nc2.iosp.gempak.GempakGridServiceProvider GEM_FILE.gem NETCDF_FILE.nc
> >
> > where GEM_FILE.gem is the name of the GEMPAK grid file and NETCDF_FILE.nc 
> > is whatever you want the output called.  This only works for grid files.
> >
> > Don Murray
> >
> >
> >> I am writing to find out if you know of a convenient way to convert
> >> "gem" files to "nc" (or another format that could be read by MATLAB).
> >> So far the options I have come up with are:
> >>
> >> - to use the gdlist program and do a significant amount of post-processing
> >>
> >> - use the gdgrib program (so far that is not working and I am getting an
> >> error about the coordinate system being rotated) - then convert the grib
> >> files to netcdf
> >>
> >> - write a Fortran program to do it
> >>
> >> Do you have any suggestions?
> >>
> >> They would be greatly appreciated
> >>
> >> Thank you!!
> >>
> >> Sincerely,
> >> Sharon Jaffe
> >> address@hidden
> >>
> >>
> >
> >
> > Ticket Details
> > ===================
> > Ticket ID: PKR-554453
> > Department: Support GEMPAK
> > Priority: Normal
> > Status: Closed
> >
> 
> 
> --
> Pete Pokrandt - Systems Programmer
> UW-Madison Dept of Atmospheric and Oceanic Sciences
> 608-262-3086  - address@hidden
> 
> 
> 


Ticket Details
===================
Ticket ID: PKR-554453
Department: Support GEMPAK
Priority: High
Status: Open