[CF-metadata] Proposal for better handling vector quantities in CF

From: Jonathan Gregory <j.m.gregory>
Date: Fri, 25 Nov 2011 17:52:42 +0000

Dear Thomas

Thanks for your posting about vectors. This issue has come up before. It has
previously been suggested that different components should be in the same
data variable, with a dimension for component, but I prefer your solution,
because the components might have different units (e.g. in the case of modulus
and direction), and they might be on different horizontal grids (e.g. for
an Arakawa C-grid), which makes it undesirable or impossible to store them in
a single data variable. Furthermore, your solution is more flexible since it
allows you to have several different decompositions in the same file, as you
say. It is also backwards-compatible; the variables containing components are
described exactly as before, and we have the extra umbrella variable showing
some associations between them, which should not cause a problem to any
existing software.

We would need more standard names, as you say, and these could be proposed as
required. The new standard names would be permitted only with the umbrella
variables, or with ancillaries of the umbrella variables.

Best wishes

Jonathan
Received on Fri Nov 25 2011 - 10:52:42 GMT