[CF-metadata] how to represent a "pft" dimension

From: Etienne Tourigny <etourigny.dev>
Date: Thu, 31 May 2012 09:36:22 -0300

Hi all,

I would like to know how one would specify a "pft" dimensionless
coordinate in order to be CF-compliant and supported by most software.

Here is an example which uses the "pft" dimension variable, with
axis='E' (for ensemble):

        double pft(pft) ;
                pft:long_name = "plant functional type" ;
                pft:units = "none" ;
                pft:axis = "E" ;

        double npp(time, pft, latitude, longitude) ;
                npp:long_name = "npp of carbon for each pft" ;
                npp:units = "kg m-2 year-1" ;
                npp:_FillValue = 8.99999982852418e+20 ;


GRADS accepts it, but cdo replaces the axis='E' with axis='Z',
presumably because it is not a CF/COARDS standard.

axis='Z' represents a vertical coordinate, and is supported by most
software. However, it does not fully represents the concept of pft
(because it is not formally a vertical axis).


thanks,
Etienne
Received on Thu May 31 2012 - 06:36:22 BST