Inclusion of ScenarioMIP extension experiments

[matthew-mizielinski]

In the ScenarioMIP GMD paper there are three extension experiments to ssp585, ssp534-over and ssp126 (see table 2 in GMD paper). The CVs include options on the end year (2100 or 2300, see here for example, but neither the data request nor ES-Doc include this information.

Is it straightforward, and safe for current users of the data request, to introduce alternative end dates/nyears for these experiments?

An alternative would be to separate the extensions into distinct experiments (as used in the historical extension historical-ext, and in the ScenarioMIP paper), which would allow restricting data volumes more straightforwardly, but would require a change to the CVs to maintain consistency and a coherent change in ES-Doc.

[taylor13]

I don't think we should add new experiments at this point. If only 1 end-date is allowed, then I would specify the later of the two. A modeling group can, of course, elect to only to part of the experiment (ending at the earlier date).
The reason that historical-ext was defined was to distinguish the portion of the run where forcing is likely to be less uniform across models (because there are no "standard" forcing datasets for the -ext portion).

[martinjuckes]

I believe it is safe for modeling groups to extend these experiments. I'm not sure if prePare checks the date associated with data submitted, but any check would be done on the basis of the CVs,

[taylor13]

No, I don't think PrePARE checks this.