Re: convert grib to netcdf

From: David Brown <dbrown_at_nyahnyahspammersnyahnyah>
Date: Thu Nov 14 2013 - 11:23:14 MST

Hi Yonghui,
These are just warnings, so the output is probably okay. You definitely do not need to worry about the message about string types. It merely means that the string version of the time variable (which is not the actual coordinate variable -- only a supplementary convenience variable that helps make the time coordinate more decipherable for humans) must be converted to a 2d character array variable in order to fit into a supported NetCDF3 type. The other message suggests that there may be an error in the original GRIB file -- it has contradictory information concerning a grid that is specified using the pre-defined grid number 104 in the Grid Description Section (GDS). When this occurs, NCL lets the GDS information prevail because it is more likely to be correct. If you still have doubts about NCL's interpretation you can upload a sample file that produces this message and we can check to see whether NCL's behavior is correct in this instance.
 -dave

On Nov 12, 2013, at 4:11 PM, yonghuiw@ucar.edu wrote:

> Hi,
>
> I want to convert some data of grib to netcdf format so that I can use it
> for NCL plot. However, during the conversion. I got the following warning
>
> ncl_convert2nc gribfile_grid1_2006070100.grb
> Processing file: gribfile_grid1_2006070100.grb...
> Copyright (C) 1995-2013 - All Rights Reserved
> University Corporation for Atmospheric Research
> NCAR Command Language Version 6.1.2
> The use of this software is governed by a License Agreement.
> See http://www.ncl.ucar.edu/ for more details.
> warning:GribOpenFile: Grid Description Section not consistent with NCEP
> documention of grid 104; using GDS values for variables with this grid
> Classic model NetCDF does not support string types, converting
> initial_time0 to a character array
> Dimension 'ncl_strlen_0' will be added
>
> I use ncdump to view the variables of the converted netcdf file and it
> looks OK. However, I'm still
> wonder if the conversion is correct.
>
> Since the grib file is too large, I didn't upload it here.
>
> Best wishes,
>
> Yonghui
>
>
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Received on Thu Nov 14 11:23:23 2013

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