[CF-metadata] "High cloud amount"

[V. Balaji]

I was trying to discover how to name a variable that's called "high
cloud amount", which is the cloud area fraction between two levels,
where "high" is defined as, say 450-150mb. The closest I get in the
table
http://www.cgd.ucar.edu/cgi-bin/eaton/CFStdNameTable/stdnameset?cloud,cloud

is the "cloud_area_fraction_in_atmosphere_layer" standard name, and I
can define it as a field of (T,Z,Y,X), with exactly one point in Z,
defined in the middle of the layer, and bounds defining its top and bottom.
So far, so good.

What happens when I also want to define "middle" and "low" cloud
amount? Do I define a single field with 3 Z levels?

Is it possible somehow to associate the words "high", "middle" and
"low" with the three layers? This is common parlance.

Something to think about over pudding tomorrow (or not).
-- 

V. Balaji                               Office:  +1-609-452-6516
Head, Modeling Systems Group, GFDL      Home:    +1-212-253-6662
Princeton University                    Email: v.balaji at noaa.gov