Using NetCDF files

["Jerry Davison" <davison@xxxxxxxxxxxxxxxxxxxx>]

Hi Ferret users -

Agbeli Ameko recently asked --

>
>    Hi Ferreters, I would like to know how does one go about
> converting a NETCDF file into something readable by ferret?
>

It turns out that NetCDF is not, by itself, a sufficiently well-defined
standard.  For NetCDF files to be intelligible they have to conform to a known
NetCDF "profile".  Ferret works with files conforming to the COARDS profile --
it's online at

 ftp://ftp.unidata.ucar.edu/pub/netcdf/Conventions/COARDS

and also at

 http://ferret.wrc.noaa.gov/noaa_coop/coop_cdf_profile.html


Ferret may fail to successfully read files not conforming to that standard; in
particular

* gridded, multi-dimensional fields that are not encoded as multi-dimensional
in NetCDF, but are instead encoded as single dimensioned variable n-tuples (X,
Y, VALUE in separate variables for example)

* data with permuted axis ordering (eg, Y X T order)

cannot now be read (though reverse-ordered axes are handled correctly).  You
can use "ncdump -c" to examine the file to see its internal structure.  Ferret
is able to reformat the files in many cases.

Please let us know if you have problems reading NetCDF files.  We may be able
to suggest a way to resolve the problem you're having.

	Regards,

	Jerry Davison





-- 
davison@noaapmel.gov