Dear @johnwilkin 

Thanks for your comment. I think `zlev` and `sigma` both have to be dimensioned 
by `nlayer`, since they're formula terms of a coordinate variable of that 
dimension. That's also implied by the text, since the same `k` is used to index 
both of them. However, for any `k`, only one of them is used. The reason for 
putting missing data in the other is so that the data-reader or program can 
easily tell which way round (top down or bottom up) the levels have been 
arranged along the dimension.

If `nsigma=0`, the vertical coordinate is purely depth; if `nsigma=nlayer`, the 
vertical coordinate is sigma. In either case you wouldn't use sigma_over_z, 
would you?

Best wishes

Jonathan

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://urldefense.us/v3/__https://github.com/cf-convention/cf-conventions/issues/314*issuecomment-824219000__;Iw!!G2kpM7uM-TzIFchu!hOOWFsF0r8K5ReMHQTzeKFUv-s1eAL_TM4U8g1d8her_vmmGg1vaahzvj7Zm4LrSoOZFRQPnTIg$
 
This list forwards relevant notifications from Github.  It is distinct from 
[email protected], although if you do nothing, a subscription to the 
UCAR list will result in a subscription to this list.
To unsubscribe from this list only, send a message to 
[email protected].

Reply via email to