[Go-essp-tech] drs, cmor, realms, and atomic datasets and components

[Bryan Lawrence]

Hi Folks (probably Luca, Bob primarily)

I'm about to ask some questions, but in order to be very accurate, I need some definitions:

An atomic dataset defines a variable from a single model run. The breakdown of components
in a CMIP5 DRS compliant dataset look like ...
<activity>/<institute>/<model>/<experiment>/<frequency>/<modeling
realm>/<variable>/<ensemble member>/<version>/[<endpoint>],

I believe CMOR is writing directory hierarchies that look like that. For now I'm interested in <modelling_realm> which is a tag that comes from the *primary* realm associated with a variable in the CMOR tables.

In terms of cataloguing, from Luca's comments, I *think* ESG was planning on aggregating these up so that a dataset in their catalogue looks like the agregation of all variables in a given modelling realm (for a given ensemble member and version), and the idea was that one browse between datasets and their modelling realms. 

This is because metafor (and curator) also have the concept of modelling realms, and these are the "top level" components within the model. 

I think there was an assumption that these two uses of modelling_realm were the same. As of today they're not quite. I'll get back to that.

CMOR also has the concept of secondary realms, that is, one can tag a variable with more than one realm.

So the first of my questions:
1) Is ESG using those secondary realms at all in the catalogue (or planning to do so)?
2) Do they make it to the catalogue via ESG publisher?
3) Is ESG providing wget scripts to get all the data in one of their aggregated datasets?
4) Is ESG providing a way of getting wget scripts for the individual atomic datasets within an aggregated dataset?

Getting back to the difference between modelling realms as seen by CMOR and metafor/curator.

5) Does it matter if there is a slight difference between them. (At the moment curator/metafor has aerosols within atmospheric chemistry, CMOR has them as distinct primary realms). Either CMOR could change or Metafor could change or neither could change, but the balance of choosing between these options depends on the answers to the five questions above, since both CMOR and metafor/curator have valid reasons for the way they have done things).

thanks
Bryan














-- 
Bryan Lawrence
Director of Environmental Archival and Associated Research
(NCAS/British Atmospheric Data Centre and NCEO/NERC NEODC)
STFC, Rutherford Appleton Laboratory
Phone +44 1235 445012; Fax ... 5848; 
Web: home.badc.rl.ac.uk/lawrence