In the case of 'raw' output from numerical models, it probably makes sense to use the end-point of the time interval rather than the mid-point. That's the moment for which the model stores the data, whether they're instantaneous values (intensive variables) or time-averages over the previous timestep (extensive variables).
If you used the mid-point of the interval for extensive variables, they wouldn't have the same time coordinates as the intensive variables, which would be very confusing. Using the end-point keeps everything aligned. --Seth On Thu, 12 Nov 2009 14:41:26 +0000 (UTC) Thomas Lavergne <[email protected]> wrote: >Dear Jonathan, > >----- "Jonathan Gregory" <[email protected]> wrote: >> Dear Thomas >> >> I'm not saying the coordinate *must* be the mid-point. If there's a >> good reason >> for it being something else, then you could choose it to be so. I was >> suggesting that we could recommend it should be the mid-point if there >> is >> no strong basis for making another choice. We could also say that it >> must not >> be outside the bounds. > >I agree with your recommendation. > >But I was also trying to gain support on "which axis value should I choose for >my variable" and your answer does not help :-). > >I have rather little basis for making the choice of the end time for >representing an accumulated quantity but, at least, CF does not forbid it. I >guess I have to seek agreement inside my scientific community and that it is >not CF's role to decide upon that. > >Are there people interested in taking the discussion further? We seek the >answer to the question: "In which cases would another choice (other than >mid-point) be relevant?". > >Thomas > > >> >> You are right, it cannot be missing data. That would break some >> applications, >> anyway. >> >> Cheers >> >> Jonathan >> _______________________________________________ >> CF-metadata mailing list >> [email protected] >> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata >_______________________________________________ >CF-metadata mailing list >[email protected] >http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
