⇐ ⇒

[CF-metadata] [CF Metadata] Question about ancillary variables/formula terms variables

From: Karl Taylor <taylor13>
Date: Mon, 21 Dec 2015 13:59:33 -0800

Hi David,

I can't think of anyone needing these constructs, although there are
cases when both the "parent" and ancillary or formula_terms variable
might *both* have a scalar dimension.

Karl

On 12/21/15 7:41 AM, David Hassell wrote:
> Hello,
>
> I was wondering if anyone has ever had use for an ancillary variable
> (or data variable pointed to from a formula_terms attribute), having a
> size 1 dimension which the "parent" field does *not* have. The
> convention do not say anything about this.
>
> For example:
>
> dimensions:
> t = 1;
> x = 96;
> y = 73;
>
> variables:
> float q(x, y) ;
> q:standard_name = "specific_humidity" ;
> q:units = "g/g" ;
> q:ancillary_variables = "q_error_limit" ;
>
> float q_error_limit(t, x, y)
> q_error_limit:standard_name = "specific_humidity standard_error" ;
> q_error_limit:units = "g/g" ;
>
>
> Similary for a scalar coordinate variable, which is logically
> equivalent to the size 1 dimension case (this time shown on a formula
> terms variable):
>
> dimensions:
> x = 96;
> y = 73;
> z = 19;
>
> variables:
> float q(z, x, y) ;
> q:standard_name = "specific_humidity" ;
> q:units = "g/g" ;
>
> float z(z):
> z:standard_name = "atmosphere_hybrid_height_coordinate";
> z.formula_terms = "a: var1 b: var2 orog: var3"
>
> float var3(x, y):
> time:coordinates = "time";
>
> float time:
> time:standard_name = "time";
> time:units = "days since 2000-12-1";
>
>
> Thanks for your help,
>
> All the best,
>
> David
>
>
> --
> David Hassell
> National Centre for Atmospheric Science (NCAS)
> Department of Meteorology, University of Reading,
> Earley Gate, PO Box 243,
> Reading RG6 6BB, U.K.
>
> Tel : +44 118 3785613
> E-mail: d.c.hassell at reading.ac.uk
> _______________________________________________
> CF-metadata mailing list
> CF-metadata at cgd.ucar.edu
> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
Received on Mon Dec 21 2015 - 14:59:33 GMT

This archive was generated by hypermail 2.3.0 : Tue Sep 13 2022 - 23:02:42 BST

⇐ ⇒