Dear Lars
I think you have to put the operations in the order they are carried out:
mean within years (to get monthly means), mean over years (to get climato-
logical monthly means), range (to get climatological annual range). However,
you can describe e.g. 30-year climatologies, as you would like, because
the final time dimension can be bigger than one. The climatological time
bounds for it will indicate the 30-year periods concerned.
This is a bit more complicated than the ticket as so far discussed because
of combining multiple time processing with climatological time processing.
The ticket went dormant because no-one had the impetus to conclude it. If
you comment on it now with your new needs, the discussion could resume.
Best wishes
Jonathan
----- Forwarded message from B?rring Lars <Lars.Barring at smhi.se> -----
> Date: Mon, 16 May 2016 08:39:58 +0000
> From: B?rring Lars <Lars.Barring at smhi.se>
> To: Jonathan Gregory <j.m.gregory at reading.ac.uk>, "cf-metadata at cgd.ucar.edu"
> <cf-metadata at cgd.ucar.edu>
> Subject: RE: [CF-metadata] climatological statistics --- climate indices
>
> Dear Jonathan,
>
> Indeed, this looks like good solution. And to follow this line of thoughts to its end; by shifting the order of the operations to
> time: mean within years (period: 1 month) time: range time: mean over years
> it should be possible to have one file containing a series of successive 30 year (say) averages of annual spans between monthly mean temperatures
>
> I note that ticket 82 has gone dormant since almost a year, there was not much discussion and the comments were largely positive. Any chance that it will be resurrected?
>
>
> Many thank you for you constructive input.
>
> Lars
>
>
> -----Original Message-----
> From: CF-metadata [mailto:cf-metadata-bounces at cgd.ucar.edu] On Behalf Of Jonathan Gregory
> Sent: den 13 maj 2016 17:23
> To: cf-metadata at cgd.ucar.edu
> Subject: Re: [CF-metadata] climatological statistics --- climate indices
>
> Dear Lars
>
> When you compute the third operation (the range over climatological months) you collapse the time axis to size 1, so it no longer indicates that it was months. It might previously have been days, 5-day periods, or anything else.
> I think this case could be dealt with by the proposed (but not agreed) con- vention for multiple processing of axes in cf-trac.llnl.gov/trac/ticket/82.
> Something like
>
> time: mean within years (period: 1 month) time: mean over years time: range
>
> might work.
>
> Best wishes
>
> Jonathan
>
> ----- Forwarded message from B?rring Lars <Lars.Barring at smhi.se> -----
>
> > Date: Fri, 13 May 2016 14:09:25 +0000
> > From: B?rring Lars <Lars.Barring at smhi.se>
> > To: Jonathan Gregory <j.m.gregory at reading.ac.uk>, "cf-metadata at cgd.ucar.edu"
> > <cf-metadata at cgd.ucar.edu>
> > Subject: RE: [CF-metadata] climatological statistics --- climate
> > indices
> >
> > Dear Jonathan,
> >
> > > > But how about common continentality indices based on the annual range of monthly mean temperatures?
> > > > Is there a "within months" such that the cell method for the basic element of the continentality index would be "time: mean within months time: range within years" ? Or is there another solution?
> >
> > > Climatological stats can be described for the annual cycle. The
> > > climatological monthly mean temperature would be "time: mean within
> > > years
> > > time: mean over years", and you would use the climatological time bounds to indicate the start and end of months (or other portions of the annual cycle).
> > > This would produce twelve climatological monthly values (for each location).
> > > Do you mean you then apply a third operation to compute the range of these twelve values?
> >
> > Yes, exactly.
> >
> > And, just to complete the picture, possibly even a to apply fourth operation to calculate a climatological average over e.g. 30 years. In practice, this is of course much simplified if one uses monthly mean temperature data as input because the operations that is actually performed would be described by the cell method "time: range within years time: mean over years". But this would be an incomplete description of the data.
> >
> > Kind regards,
> >
> > Lars
> >
> >
> >
>
> ----- End forwarded message -----
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----- End forwarded message -----
Received on Mon May 16 2016 - 09:49:00 BST
