Hi Martin, et al.,
Overall I see no major problems :-)
A few minor thoughts:
In part 1: If chemical formulas are to be used in some documentation
then I think they need to be capitalized appropriately to avoid possible
ambiguity: eg, OCS/OCs, and HF/Hf.
In part 2: Do you mean 'moles' rather than 'molecules' at the end of
the preamble?
In part 3: The first quantity (tendency_of_nitrous_oxide_mole_burden)
seems to be missing a region qualification.
How do you define 'middle atmosphere'? Is the middle world/lowermost
stratosphere included?
Also, how should a model report its data when it only has a partial
stratosphere (eg a model top at 3 mbar)?
Good luck with CCMVal :-),
Philip
On Mon, 21 Jan 2008, Martin Juckes wrote:
> Attached is a list of around 150 proposed standard names needed for the CCMVal
> project.
>
> CCMVal is the Chemistry Climate Model Validation exercise
> (http://www.pa.op.dlr.de/CCMVal/).
>
> The coupled chemistry-climate model data for the validation will be hosted by
> BADC, and the intention is that it should be CF compliant netcdf. In order to
> achieve this we need standard names fro around 150 quantities not yet covered
> in the standard name table. The proposed new names are listed in the attached
> word document, split into 4 tables.
>
> There has been some preliminary discussion, with the most controversy caused
> by the `age_of_stratospheric_air'.
>
> A couple of key quotes from the discussion between Darryn Waugh and Jonathan
> Gregory are given below. No real agreement was reached, so the decision is up
> to other members of the list.
>
> QUOTE from Darryn Waugh
> The age of stratospheric air is the time since last contact with the
> troposphere (just as age in the ocean is time since contact with atmosphere).
> There is a distribution of ages (i.e. not a single travel time) but we are
> concerned here with the mean of the times, hence the need for "mean age".
> It is not a residence time, and the use of "mean" is crucial.
>
> The term "mean age" is extensively used in stratospheric, oceanic, and
> groundwater communities (with "of water" added for latter two), so I think
> this counts as interdisciplinary, and again I am lost at the resistance to
> it.
> END QUOTE
> QUOTE from Jonathan Gregory
> I agree that "mean" is needed, but I think that in CF metadata it belongs in
> the cell_methods rather than in the standard_name.
> END QUOTE
>
> There was also substantial discussion between Jonathan and myself about the
> use of "_burden" to indicate a whole atmosphere integral. Jonathan favoured
> something of the form "area_integral_of......_content", but conceded that the
> area integral of a vertical integral was not the most natural of
> formulations. The term "burden" is widely used in the scientific literature
> with the meaning intended here.
>
> The original list from the CCMVal community included a number of annual loss
> variables, but these have been replaced with tendencies, the intention being
> to use the cell_methods attributes to express annual losses as summed
> tendencies.
>
> The gravity wave terms also caused some comment. E.g.
> upward_flux_of_eastward_momentum_due_to_nonorographic_eastward_gravity_waves
>
> eastward_momentum indicates the component of the momentum which is being
> transported, eastward_gravity_waves indicates the class of gravity waves
> included, with eastward referring to the phase speed of the waves. There is
> thus no obvious redundancy here, though there is a tendency in the specialist
> community to do away with one "eastward" when referring to this quantity,
> since gravity waves with eastward phase speeds only carry eastward momentum.
> I have submitted the longer version, as this level of knowledge should
> probably not be expected of standad name interpreters.
>
> Names such as the "dynamic_tropopause_potential_temperature" introduce the
> problem that the precise definition of the dynamic tropopause is not fixed.
> The intention is to use an attribute in the file to give a reasonably precise
> definition. The method will be used for "..middle_atmosphere_ ..._burden",
> which requires a specification of the definition used for "middle atmosphere".
> After discussion with Jonathan it was decided, however, that there was no need
> to get the method for doing this into CF at this time.
>
> sincerely,
> Martin Juckes
>
>
> -------------------------------------------------------
>
------------------------------------------------------------------------
Dr Philip Cameron-Smith Energy & Environment Directorate
pjc at llnl.gov Lawrence Livermore National Laboratory
+1 925 4236634 7000 East Avenue, Livermore, CA94550, USA
------------------------------------------------------------------------
Received on Wed Jan 23 2008 - 18:47:44 GMT
