Dear @JonathanGregory, Thanks for your comments.
> I think that "unlike" implies it's somehow inconsistent ... Agreed. With your new text, that last paragraph becomes In CF-netCDF a domain topology can only be provided for a domain defined by a UGRID mesh topology variable. In this case, the connectivity array is supplied by a UGRID connectivity variable, such as a "face_face_connectivity" variable. **The information represented by the symmetrical connectivity array of the domain topology construct in the CF data model is stored in a different but equivalent way in UGRID. The trailing dimension of a UGRID connectivity variable's data records, for each cell, the indices of the other cells to which it is connected (padded with missing data if a cell has fewer connections than some others).** > What role do the edge coordinates have in the domain which refers to the > faces? That sounds like the right question, and I think the answer is "none", which clarifies for me that [my initial concern about "round-tripping"](https://urldefense.us/v3/__https://github.com/cf-convention/cf-conventions/issues/153*issuecomment-887768641__;Iw!!G2kpM7uM-TzIFchu!npi0cAUkgsn2Aau2vThp0Uhvt3R2ZkQ5Duq3d1Q2HjJBF0MPtxOnQg8tCC3OtvWiMdmZzePrWEk$ ) is not actually relevant, here. How a software implementation decides, when writing multiple fields to a file, to avoid the duplication and proliferation of domain-related netCDF variables is up to it, as it always has been. All the best, David -- 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/153*issuecomment-889263224__;Iw!!G2kpM7uM-TzIFchu!npi0cAUkgsn2Aau2vThp0Uhvt3R2ZkQ5Duq3d1Q2HjJBF0MPtxOnQg8tCC3OtvWiMdmZi84W30Y$ 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].
