[ncl-talk] Problem GRIB2 file

HAVENER, KEVIN F GS-12 USAF ACC 14 WS/WXED kevin.havener at us.af.mil
Tue May 12 04:38:17 MDT 2015


I am trying to ncl_convert2nc a grib2 file downloaded from the National Ice Center http://www.natice.noaa.gov/ims/grib2_v3_p1.html.  I either get this error:

    Processing file: NIC.IMS_ice_v3_201504900_1km.GRIB2...
     Copyright (C) 1995-2014 - All Rights Reserved
     University Corporation for Atmospheric Research
     NCAR Command Language Version 6.2.0
     The use of this software is governed by a License Agreement.
     See http://www.ncl.ucar.edu/ for more details.
    fatal:systemfunc: cannot create child process:[errno=12]
    fatal:["Execute.c":8567]:Execute: Error occurred at or near line 270 in file /tmp/tmp12209-55379965.ncl

Or this error:

    Processing file: NIC.IMS_ice_v3_201504900_1km.GRIB2...
     Copyright (C) 1995-2014 - All Rights Reserved
     University Corporation for Atmospheric Research
     NCAR Command Language Version 6.2.0
     The use of this software is governed by a License Agreement.
     See http://www.ncl.ucar.edu/ for more details.
ncendef: ncid 65536: NetCDF: One or more variable sizes violate format constraints
fatal:NetCDF: Operation not allowed in define mode: error attempting to write variable (ICEC_P31_GST0) to file (/home/havenerk/NIC.IMS_ice_v3_201504900_1km.nc)
fatal:["Execute.c":8567]:Execute: Error occurred at or near line 628 in file /tmp/tmp16245-5537a2e1.ncl
ncclose: ncid 65536: NetCDF: One or more variable sizes violate format constraints

Pay no attention to the NCL versions.  I thought the first might be related to being able to write in a directory, but I got the same on 6.3.0, where I knew that wouldn't be a problem.  The second error only occurred under 6.2.0 after I eliminated the potential permission problem by moving the process to my home directory.  Only the first error occurs under my own personal laptop 6.3.0.  

It is a 1km resolution file on a polar stereographic grid.  I suspected the file size/resolution might be a problem, so I downloaded a 4km version of the same file.  Turns out it is different--has 3 variables in it instead of 1, so is actually larger.  Aside from not having the right local table for two of the parameters, the ice cover (only parameter in the 1km version) converted to netcdf properly.  So maybe still a resolution issue?

Any idea what is going on here?  Hopeless case, bad grib2,or user error?

Kevin Havener 

Here is an ncl_filedump of the file:

ncl_filedump NIC.IMS_ice_v3_201504900_1km.GRIB2
 Copyright (C) 1995-2014 - All Rights Reserved
 University Corporation for Atmospheric Research
 NCAR Command Language Version 6.2.0
 The use of this software is governed by a License Agreement.
 See http://www.ncl.ucar.edu/ for more details.

Variable: f
Type: file
filename:       NIC.IMS_ice_v3_201504900_1km
path:   NIC.IMS_ice_v3_201504900_1km.GRIB2
   file global attributes:
   dimensions:
      ygrid_0 = 24576
      xgrid_0 = 24576
   variables:
      float ICEC_P31_GST0 ( ygrid_0, xgrid_0 )
         center :       US NOAA/NESDIS 
         production_status :    Operational products
         long_name :    Ice cover
         units :        Proportion
         _FillValue :   1e+20
         coordinates :  gridlat_0 gridlon_0
         grid_type :    Polar stereographic can be south or north
         parameter_discipline_and_category :    Oceanographic products, Ice
         parameter_template_discipline_category_number :        ( 31, 10, 2, 0 )
         forecast_time :        0
         forecast_time_units :  hours
         initial_time : 02/17/2015 (00:00)

      float gridrot_0 ( ygrid_0, xgrid_0 )
         long_name :    vector rotation angle
         GridType :     Polar Sterographic Projection (North or South)
         units :        radians
         formula_u :    Ugrid = cos(rot)*Uearth - sin(rot)*Vearth
         formula_v :    Vgrid = sin(rot)*Uearth + cos(rot)*Vearth
         note1 :        u and v components of vector quantities are resolved relative to earth
         note2 :        apply formulas to derive u and v components relative to grid

      float gridlat_0 ( ygrid_0, xgrid_0 )
         corners :      ( -21.4961, -21.2433, -20.98764, -21.2433 )
         long_name :    latitude
         grid_type :    Polar Sterographic Projection (North or South)
         units :        degrees_north
         Dy :    1
         Dx :    1
         Lov :  280
         Lo1 :  235
         La1 :  -21.4961

      float gridlon_0 ( ygrid_0, xgrid_0 )
         corners :      ( -125, -35.27276, 55, 145.2728 )
         long_name :    longitude
         grid_type :    Polar Sterographic Projection (North or South)
         units :        degrees_east
         Dy :    1
         Dx :    1
         Lov :  280
         Lo1 :  235
         La1 :  -21.4961



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