NCL: ACCESS (Australian Community Climate and Earth-System Simulator) Data

The ACCESS (Australian Community Climate and Earth-System Simulator) weather model is based on the UK Meteorological Office's Unified Model. There are various configurations (domains) of the ACCESS model: Global (G), Regional (R), City (C) and Tropical Cyclone (TC).

ACCESS data products are available in GRIB-2 (grb2) and/or netCDF-4 (nc4) format. The nc4 files contain additional information not available via the grib formatted file. For example:

     // global attributes:
                     :Conventions = "CF-1.5" ;
                     :source = "Australian Bureau of Meteorology" ;
                     :modl_vrsn = "ACCESS-G" ;

NCL's ncl_filedump can be used to examine the contents of either file format.

As a side point, the default behavior of NCL for a grib formatted file with one time step, is to not explicitly include a time dimension. NCL can be forced to explicitly include the time dimension.

On the command line use:

    %>  ncl_filedump -itime foo.grb2

Within an NCL script, the setfileoption procedure can be used (See Example 2). 

        setfileoption("grb","SingleElementDimensions","Initial_time")