[CF-metadata] Land cover type

From: Jonathan Gregory <j.m.gregory>
Date: Wed, 19 Nov 2008 08:56:28 +0000

Dear Seth

You are right that a variable of area_type is the CF way to record that info.
This standard name replaced land_cover because area_type is more general. The
initial list of possible values of area_type is in the summary at the end of
ticket 17, point 3. They are
land sea sea_ice ice_free_sea land_ice snow cloud clear_sky vegetation bare_ground all_area_types
It also says "Additions to this table will be requested on the CF email list"
so you are welcome to do that. Types like broadleaf_trees, needleleaf_trees
and urban are the kind of thing that was anticipated as being needed.

I think there should be a list of possible area_types, like there is for
regions, on the standard name page. That is not there yet but I expect it will
be added.

If you want to specify a fraction for each grid cell, you could do this with
a data variable (area_type,lat,lon). The area_type dimension would have an
string-valued auxiliary coordinate variable to specify the area_type values.
(This is doing the job of a string-valued (Unidata) coordinate variable, but
netCDF-3 doesn't support string-valued coordinate variables.)

Best wishes

Jonathan
Received on Wed Nov 19 2008 - 01:56:28 GMT