[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: GRIB NetCDF

This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.

  • Subject: Re: GRIB NetCDF
  • Date: Thu, 20 Dec 2007 10:58:20 -0700
> ------=_Part_23287_9946808.1198172159721
> Content-Type: text/plain; charset=ISO-8859-1
> Content-Transfer-Encoding: 7bit
> Content-Disposition: inline
> 
> Hi Russ,
> 
> Have a quick question:  We need to decode GRIB 1 & 2 files to netCDF CF and
> found these converters:
> http://www.unidata.ucar.edu/downloads/decoders/index.jsp
> http://www.ncl.ucar.edu/prev_releases.shtml#4.3.0
> 
> Which one should we use? Thanks in advance

I would recommend against using the first one, gribtonc, because it
doesn't handle all GRIB1 or GRIB2 inputs (just those that were
encountered on the NOAAPORT stream), and it has to be modified and
recompiled whenever the GRIB tables on which it depends are modified.

I don't know much about the NCL converter, ncl_convert2nc, but it looks
like it's maintained more actively than gribtonc, which has been
deprecated.

Note that converting GRIB files to netCDF files can result in a large
growth in file size, since netCDF-3 doesn't support compression.  We're
just getting around to benchmarking use of netCDF-4 and comparing with
GRIB files and will have results to report at the upcoming AMS meeting.
 
> Just a question to Ben: The data we refer to is the NWS Air Quality
> Forecast<http://www.weather.gov/aq/>model which is available as GRIB
> on the FTP site for
> ozone<ftp://tgftp.nws.noaa.gov/SL.us008001/ST.opnl/DF.gr2/DC.ndgd/AR.conus/>a
> nd
> PM <ftp://ftp.emc.ncep.noaa.gov/mmb/aq/5x_grib/> . Conceivably someone
> already made a THREEDS  front end. Or - Is Unidata be interested adding it
> to the motherlode and serving it as WCS?
> 
> 
> Rudy