Hi all,
I haven't followed this discussion closely either I'm afraid but I do
remember a conversation I had with a few people at a geospatial data
workshop a while ago. I think we had agreed between us that
"ensemble" was *not* a meaningful dimension, because there is no
concept of direction along an ensemble axis and no meaningful way to
subset along this axis. Ensemble members are likely to be stored in
different NetCDF files (I think) and therefore an ensemble dimension
would have to be aggregated across files.
Having said this, I can see some advantages in the concept of an
ensemble dimension from a data modelling point of view but it doesn't
seem to translate into a practical use in data storage or data
extraction. I would say that a standard attribute identifying the
ensemble member in a file was more appropriate, but I haven't thought
about this issue as much as others clearly have.
Just my $0.02.
Jon
On 2/26/07, John Caron <caron at unidata.ucar.edu> wrote:
> Without following some of the details of this discussion very closely, my feeling is that when you have a set of data arrays, say an ensemble forecast from the same model, that have exactly the same coordinate system, metadata, etc then an ensemble dimension is reasonable.
>
> If its coming from different models, it seems unlikely that the meaning of the data is close enough to justify putting the data in the same array. They should be different variables, possibly different datasets.
>
> Thats just a first thought from an abstract data model POV. There could be other practical reasons why you dont want to combine them (like existing apps that cant handle another dimension).
> _______________________________________________
> CF-metadata mailing list
> CF-metadata at cgd.ucar.edu
> http://www.cgd.ucar.edu/mailman/listinfo/cf-metadata
>
--
--------------------------------------------------------------
Dr Jon Blower Tel: +44 118 378 5213 (direct line)
Technical Director Tel: +44 118 378 8741 (ESSC)
Reading e-Science Centre Fax: +44 118 378 6413
ESSC Email: jdb at mail.nerc-essc.ac.uk
University of Reading
3 Earley Gate
Reading RG6 6AL, UK
--------------------------------------------------------------
Received on Mon Feb 26 2007 - 11:32:26 GMT
