Dear @davidhassell and @johnwilkin Thanks for your comments, and for the new diagram, John. Omitting the bounds is a problem for many types of vertical coordinate variable, not just this one. Bounds can be provided for both `sigma` and `zlev` in the usual way; the CF convention has a special provision for bounds of formula terms, since they are often needed.
It seems like we agree then. Unless you say otherwise, I'll revise the text to reduce or remove the explicit mention of which way up the coordinates are and the choice of base for `k`, and to require the missing data. I think that means we should make `nsigma` optional in `formula_terms`, and add a conformance rule to state that, if it is supplied, it must equal the number of entries of `zlev` which have missing data, and also that at each level either `sigma` or `zlev` must be missing, but not both or neither. 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-825651792__;Iw!!G2kpM7uM-TzIFchu!k6e2yRtpx5VksqFJ4QVW0SHviiTUbuFS4sofIzvmT-XrHd7JkFOqHt_pZeoAtmLQUdMPO_hR1b4$ 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].
