Dear Christiane,
Thank you for continuing to move this discussion forward. I think the
removal of "as_such" from the names and the addition of information to
the
definitions is a big improvement.
>
> The remaining issues concern:
>
> ============================
>
> 1) emission fluxes
>
> >>atmosphere_emission means a source within the atmosphere, e.g. from
the
> >>surface or from an air plane.
> >
> > Ah, OK. Why is the surface included? You have separate surface
fluxes.
> >
>
> The updated names are atmosphere_emission_mass_flux_of_X, there is no
> surface. I have added a comment:
> Integrate 3D emission field vertically to 2d field.
>
OK, so I understand atmosphere_emission to mean emission into the
atmosphere
from any source, regardless of whether that source is physically located
at
the earth's surface or higher in the atmosphere. Would it be clearer to
rearrange the names to
emission_mass_flux_into_atmosphere_of_X? I think that would help to
avoid
confusion as to the location of the source. As you pointed out in a
much
earlier posting (31st October 2006) we could always introduce names for
emission purely from the surface if they are required at a later date -
we
could then use mass_flux_into_atmosphere_of_X_due_to_surface_emission.
> >
> >>atmosphere_production means production within the atmosphere, this
> >>includes direct sources and chemical production from precursors.
> >
> > So production = emission (from sources) + chemical net production
> > It seems to me potentially confusing to have production in these two
> different
> > senses on the left and right of the equation. What about saying
> "addition" on
> > the left e.g. NOx is added to the atmosphere by emission from
aircraft
> and by
> > chemical production. The opposite of "addition" might be "removal",
> which
> > comes about by deposition and chemical destruction. Do we also need
to
> > distinguish gross and net addition?
> >
> I agree that production is not the best term here. Could we use
> atmosphere_source and atmosphere_removal?
>
As with the emission names, I wonder whether using something like
"atmosphere_source" would lead to confusion about the location of the
source. I suggest something like
mass_flux_into_atmosphere_of_X_due_to_emission_and_chemical_net_producti
on
and, if an opposite name were required,
mass_flux_from_atmosphere_of_X_due_to_deposition_and_chemical_net_destru
ction.
Admittedly these names are longer but they are also self-explanatory.
> > I see. Is reemission included in emission? This might be a source of
> confusion.
> >
> re-emission is not included in emission, and as it occurs only for a
few
> species, I do not think that it is necessary to add.
> >
>
I have no objection to the term re-emission as long as we are clear
about
the definition. To be consistent with my earlier suggestions I would
rearrange these names to something like
re_emission_mass_flux_into_atmosphere_of_X.
> ============================
>
> 2) optical depth or thickness
> Ok, convinced: I changed it to thickness.
>
>
> ============================
>
> 3) X_optical_thickness or optical_thickness_due_to_X
>
> (depth changed to thickness)
>
> > Perhaps, as with named surfaces, it might be acceptable (if not too
> > complicated) to say X_optical_depth if X is one word (since that is
> convenient
> > and what people usually say e.g. for cloud and aerosol), and
> > optical_depth_due_to_X if X is several words (to make it easier to
> understand).
> >
> (Please help me: Which named surfaces? is this linked to surface in
> emission variables?)
I suspect that Jonathan was referring to named surfaces such as
"tropopause"
or "canopy" as well as just the earth's surface. I think this was
simply a
comment on how best to order the words in the name, depending on whether
X
is one word or several.
>
> So we come back to
> atmosphere_optical_thickness_due_to_X. I agree that this is easier to
> understand. I would like to add 'atmosphere' because it could also be
> e.g. in the ocean. I have changed the table accordingly. See
> http://wiki.esipfed.org/index.php/CF_Standard_Names_-
> _Proposed_names_for_TF_HTAP
I think the proposed names look fine.
>
> X) something additional: particulate_organic_matter_dry_aerosol
> Expressed as mass of particulate organic matter.
> I have added a comment asking for the scale factor to obtain carbon
mass
> (particulate organic matter = Factor * particulate organic carbon)
> "If possible, indicate scale factor to obtain carbon mass."
> Different factors are used by the modelers, and it is of advantage to
> know what is assumed for scaling OC and OM. OK?
>
I understand the usefulness of a scale factor in interpreting the
different
masses, however, I feel that a request to include the scale factor
doesn't
really belong in the definition of a name. Also, I am not clear where
the
value of the scale factor would actually be specified. From your
description it sounds as though, for a particular model, it would have
the
same value at every point in time and space. Could it be calculated
from
the ratio of particulate organic matter to particulate organic carbon or
would a model typically output only one of those fields? If it could be
calculated in that manner, we could include an appropriate comment in
the
definition of the names and we needn't actually request that the scale
factor be specified separately.
------
Alison Pamment Tel: +44 1235 778065
NCAS/British Atmospheric Data Centre Fax: +44 1235 445858
Rutherford Appleton Laboratory Email: J.A.Pamment at rl.ac.uk
Chilton, Didcot, OX11 0QX, U.K.
Received on Mon Jan 15 2007 - 05:03:30 GMT
