Hi Jonathan, Burkhardt et al
I'm not sure I like the idea of using change_in in this way. (Sorry I didn't
pick up the proposal idea in the earlier email ... Can someone explain to me
(possibly again) why this isn't a tendency of something due to advection? )
1) I don't like the chances of people working with data appreciating the
difference between intensive and extensive variables.
2) Limiting the use of change_in in this way is non-intuitive, again, while
we might want to define it that way, it may get used in other ways. Not now
perhaps, but ...
3) Whether or not the thing is intensive or extensive should
be independent of whether or not it is tendency otherwise we're complicating
our vocabulary. If there we need to introduce a new qualifier that would be
cleaner ...
Bryan
On Sunday 19 March 2006 16:29, Jonathan Gregory wrote:
> Dear Burkhardt
>
> > is there any news or any decision on the "change_in_" issue?
>
> No-one expressed any view.
>
> Having thought about it a bit more, I think change_in_ is OK if it has the
> same kind of uses as tendency_of. They are really the same except change_in
> is extensive in time and tendency_of is intensive. They have the same
> bounds in time. The units of tendency_of are X s-1 if change_in has units
> X. We must be clear that change_in should *not* be used to describe every
> possible kind of difference e.g. between locations or climates. It
> specifically means the change in a quantity as a function of time. Do you
> agree?
>
> Hence let us propose
> change_in_atmospheric_water_content_due_to_advection (kg m-2)
>
> Best wishes
>
> Jonathan
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--
Bryan Lawrence
Director of Environmental Archival and Associated Research
Head of the NCAS/British Atmospheric Data Centre
CCLRC, Rutherford Appleton Laboratory
Phone +44 1235 445012; Fax ... 5848; Web: home.badc.rl.ac.uk/lawrence
Received on Mon Mar 20 2006 - 01:19:35 GMT
