Dear Jonathan,
great! Sounds like we are on a good path then.
Concerning the "lumped" NOx and HOx you raise a valid point -- probably
mostly a matter of sloppiness in the jargon. It's a somewhat fuzzy divide:
NOx is probably rather clearly defined in most applications as NO+NO2, and
HOx is OH+HO2 (sometimes people add atomic oxygen as well if looking at the
upper atmosphere). Then we have NOy, which was defined originally based on a
specific measurement technology "everything that can be detected as NO after
passage through a heated gold converter" and practically means all oxidized
nitrogen componds with oxidation state of at least 1 (i.e. no N2O). Also you
have RO2 which is the organic counterpart of HO2, i.e. all kinds of organic
peroxy radicals. And here the mess fully unravels ;-) Although one would
probably agree to the naming of "total" for these groups. For the "lumped"
NMVOCs the situation is clearly less well defined and ultimately depends on
the investigator who put in a couple fo hours at some point to reduce a
mechanism of >10000 reactions to something managable in a CTM. Perhaps a
handful of people have performed pioneering work in this area and thus we
have a handful of fundamentally different lumping schemes.
Best regards,
Martin
-----Original Message-----
From: Jonathan Gregory [mailto:jonathan at met.reading.ac.uk] On Behalf Of
Jonathan Gregory
Sent: Thursday, September 25, 2008 4:53 PM
To: Schultz, Martin
Cc: cf-metadata at cgd.ucar.edu; Martin.Suttie at ecmwf.int
Subject: Re: [CF-metadata] CF: new names for atmospheric chemistry and
aerosols
Dear Martin
Thanks for your email. I am glad of this initiative to achieve a mapping
between GRIB2 and CF in this area.
I think the list of new species is not too large. You are right that we
don't generally try to look ahead too far, and we add things when they are
required.
However, it seems appropriate to me to include things which are very likely
to be needed in the near future, when they fit into an obvious framework.
I believe I understand the scientific difference between "lumped" and
"total".
The need to be vague for model comparison is also fine within the standard
name table; we give the same name to things that are intended to be
comparable. We already have "nox" in a standard name, for instance. What I
am not clear about is whether the word "lumped" would appear in a standard
name, if the "lumped"
group has a name anyway, such as hox and nox.
I think that the "template" names with X in should be included in the guide-
lines for constructions of standard names. This is similar idea to the
section in the guidelines on "Transformations". There are other non-chemical
templates of this kind which should likewise be shown in the guidelines. I
had an earlier exchange on this email list with Martina about the templates;
I think she and I agreed on some modifications to what she had originally
proposed, but no outstanding difficulties.
Best wishes
Jonathan
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Received on Thu Sep 25 2008 - 09:29:10 BST
