Hi Philip,
I see. There does seem to be a conflict here. The "mole_fraction" prefix
is always used to mean ratio to air (medium), it doesn't really address
what we're looking for - a species/species ratio, as you point out.
I found there is a Transformation prefix "ratio_of_X_to_Y", where
apparently X and Y are to be replaced by other standard_names. Following
that slavishly would give something like
"ratio_of_moles_of_nitrate_to_moles_of_phosphate_in_sea_water". It's a
mouthful, but I suppose that would be the alternative to defining a new
prefix. ("mole_ratio_of_X_to_Y" would be a new Transformation?) Does the
length really matter? Since the N/P ratio is a fairly singular case - or
is it? -, it may not be justifiable to define a new prefix. Maybe just
as well to use an existing prefix for this particular quantity.
It's really up to you (all) to you to decide this. I'll be happy with
any definition.
Cheers, Bruce
Philip Cameronsmith wrote:
>
> Hi Bruce,
>
> In the atmosphere CF has used 'mole_fraction_' to designate mole/mole
> quantities.
>
> Hence, perhaps we should use
> MOLE_FRACTION_of_nitrate_to_phosphate_in_sea_water here?
>
> The counter argument is that, in every existing CF std name I could find,
> mol_fraction_ is always the mole ratio of the species to air.
>
> Hence, I think the question boils down to: Do we want to create a new
> prefix (ie 'mole_ratio_') for ratios of species to species (as opposed
> to the ratio of species to medium)?
>
> Best wishes,
>
> Philip
>
>
> On Tue, 12 May 2009, Bruce Hackett wrote:
>
>> Hi,
>> I was too quick in my last msg, sorry. Got to thinking about the n/p
>> ratio and checked it out with the people who programmed it. It is the
>> ratio of mole concentrations that we are calculating and putting into
>> netCDF files. That's what we suggest establishing a standard_name for.
>> Our motivation is that marine biologists use the N/P ratio,
>> calculated in this way. (They also seem to prefer expressing oxygen
>> concentration in ml/l, by the way.)
>>
>> Should we change the proposed name to
>> "mole_ratio_of_nitrate_to_phosphate_in_sea_water"?
>>
>> Cheers, Bruce
>>
>> ----- "Philip J. Cameronsmith1" <cameronsmith1 at llnl.gov> wrote:
>>
>>> On Mon, 11 May 2009, olivier lauret wrote:
>>>
>>> >> 2) ?ratio_of_nitrate_to_phosphate_in_sea_water?
>>> >> >> Does this refer name to the mass or volume or mole ratio?
>>> > > I guess it doesn?t really matter, because of the ratio (mass ratio
>>> is equal to volume ratio
>>> > anyway)?
>>>
>>> Hi,
>>>
>>> I'm not sure what volume_ratio means in the ocean, but surely
>>> mass_ratio and mole_ratio will be different?
>>>
>>> Best wishes,
>>>
>>> Philip
>>
>> --
>> ------------------------------------------------------------------------
>> Bruce Hackett Senior Scientist
>> Norwegian Meteorological Institute (met.no), R & D Dept.
>> P.O. Box 43 - Blindern e-mail: Bruce.Hackett at met.no
>> N-0313 Oslo Phone: +47 22 96 33 39
>> NORWAY Fax: +47 22 96 33 80
>> Mob: +47 48 048 958
>> ------------------------------------------------------------------------
>> _______________________________________________
>> CF-metadata mailing list
>> CF-metadata at cgd.ucar.edu
>> http:// mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
>
> ------------------------------------------------------------------------
> Dr Philip Cameron-Smith Atmospheric, Earth, and Energy Division
> pjc at llnl.gov Lawrence Livermore National Laboratory
> +1 925 4236634 7000 East Avenue, Livermore, CA94550, USA
> ------------------------------------------------------------------------
--
------------------------------------------------------------------------
Bruce Hackett Senior Scientist
Norwegian Meteorological Institute (met.no), R & D Div.
P.O. Box 43 - Blindern e-mail: Bruce.Hackett at met.no
N-0313 Oslo Phone: +47 22 96 33 39
NORWAY Fax: +47 22 96 33 80
Mob: +47 48 048 958
URL: http://met.no/english/r_and_d_activities/people/bruceh.html
------------------------------------------------------------------------
Received on Wed May 13 2009 - 01:10:28 BST
