Hi Jonathan,

As you can tell, I'm still getting to grips with CF. Thanks for the explanation 
and revised example. I can apply the same principle to specifying the depth of 
our soil temperature measurements, so that's another question answered.

> You probably saw John Graybeal's posting

The link given by John is blocked here (not sure why), however it was easy 
enough to navigate to the list from the ORR home page (http://mmisw.org/).

Regards,

Dan


-----Original Message-----
From: CF-metadata [mailto:cf-metadata-boun...@cgd.ucar.edu] On Behalf Of 
Jonathan Gregory
Sent: 12 September 2014 13:49
To: cf-metadata@cgd.ucar.edu
Subject: [CF-metadata] New standard name: 
number_of_days_with_surface_temperature_below_threshold

Dear Dan

> I found the list on the CF web site here:
> http://cfconventions.org/Data/cf-standard-names/docs/area-type-table.html

You probably saw John Graybeal's posting that he has put the up-to-date
list at http://mmisw.org/ont/cf/areatype.

> The only references to area_type in the CF conventions doc (v1.6) appear to 
> be in section 7.3.3 Statistics applying to portions of cells. However our 
> data are point values (obtained by interpolating point observations) so we 
> are not defining bounds for the spatial coordinates and therefore do not have 
> a cell method for 'area'. Is it still possible to use area_type as a 
> coordinate variable in this situation?

Yes. It has a special role in that section, but it is always permissible to
attach coordinate variables to quantities to describe the data variable, and
the area_type is often needed for such a purpose.

> x=180
> y=290
> time=UNLIMITED
> ntypes=1
> maxlen=20
> 
> lat(y,x)
> lon(y,x)
> 
> surface_type(ntypes,maxlen)
> surface_type:standard_name="area_type"
> surface_type="grass"
> 
> surface_temperature(time,ntypes,y,x)
> surface_temperature:coordinates = "lat lon surface_type"
> surface_temperature:cell_methods = "time: minimum within days   time: mean 
> over days"

> Personally I'm not that keen on having to add a dimension

You don't have to add a dimension. You can use a scalar coord var, thus:

> x=180
> y=290
> time=UNLIMITED
> maxlen=20
> 
> lat(y,x)
> lon(y,x)
> 
> surface_type(maxlen)
> surface_type:standard_name="area_type"
> surface_type="grass"
> 
> surface_temperature(time,y,x)
> surface_temperature:coordinates = "lat lon surface_type"
> surface_temperature:cell_methods = "time: minimum within days   time: mean 
> over days"

This might be a good subject for the FAQ because it has come up before.

Best wishes

Jonathan
_______________________________________________
CF-metadata mailing list
CF-metadata@cgd.ucar.edu
http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
_______________________________________________
CF-metadata mailing list
CF-metadata@cgd.ucar.edu
http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata

Reply via email to