CF Standard Names - Construction of Atmospheric Chemistry and Aerosol Terms
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This page provides the basis for the construction of CF standard names for atmospheric chemistry and aerosols.
The concepts described here have been developed since May 2006 for the definition of the 207 standard names that are accepted by the CF community as of October 2008.
The construction of CF standard names for aerosols and chemicals originated in the work of the PRISM project (Peter van Velthoven) see PRISM Standard Name Tables, latest Version, V 1.3. They have then been further developed on this wiki page and within the CF-mailing list. Important contributions come from the participating model intercomparison projects listed on the entry page.
The CF web site provides general Guidelines for Construction of CF Standard Names. The CF standard names for aerosols and chemicals are composed of certain standard phrases and forms, following these guidelines. The concept is explained below in section 2.
At the moment, many new proposals for standard names for aerosols and chemicals are under discussion by the CF mailing list. Therefore, we (Christiane Textor with input from Martin Schultz, Heinke Hoeck, and Martina Stockhause) try to summarize the current status of work here, in order to highlight the principles and concepts we have developed so far.
A large quantity of new standard names for chemical species, or for other topics, might be necessary in the future. This potential need has triggered a discussion on more general approaches to standard name construction (Thread "a different (but perhaps unoriginal) approach to standard name construction" launched by Karl Taylor.)
Four main ideas for the construction of new standard names for chemical species have been discussed so far:
- Definition of each chemically related standard name explicitly in the CF standard name list, and discussion of each of these names individually (current approach).
- Definition of groups of standard names (see below) with the individual chemical species or aerosol type given as a scalar coordinate. Names for individual species would not appear any more as CF standard names. Unphysical names would not occur, but the names would not be as human-understandable any more.
- Definition of groups of standard names (see below). Automated generation of explicit standard names based on these groups. Submit and accept all possible names, even if some of them might not have a physical meaning.
- Definition of groups of standard names (see below). Automated generation of explicit standard names based on these groups. Experts (possibly from the AC&C model intercomparisons) review these possible names and eliminate unphysical combinations before submission to and acceptance by the CF community.
Please note that the discussions of the aerosol and chemisty names in CF should be continued on the CF mailing list, and not on this wiki. The wiki is only used here to summarize the state of such names in CF. The descriptions below could help to converge to the most efficient strategy. (Please note, that Modifications of existing CF standard names are suggested, if they do not fit in the general concepts explained below.)
LIST OF ACCEPTED STANDARD NAMES FOR AEROSOLS AND CHEMICALS
The list of standard names for aerosol ad chemicals accepted by October 29 2008 can be found here.
CONSTRUCTION OF STANDARD NAMES FOR AEROSOLS AND CHEMICALS
Certain phrases and forms are used:
- chemical species and aerosols: describe the species
- physical quantity (generic names): describe the property of the species, and determine the unit of the variable
- processes: are used in derivatives of variables (e.g. fluxes): tendency_of_.... due_to_<process> and give the change of the species' property due to a certain process
- medium: indicates the local medium or layer within which the variable applies
These phrases and forms are combined to obtain the standard names, like for example <physical_quantity>_of_X_in_<medium tendency_of_<physical_quantity>_of_X_in_<medium>_due_to_<process> The combination of these phrases and names results in groups of Standard_Names that are given below. However, not all combinations are possible or reasonable. There are some odd names that do not fit in the general concepts. Modifications are suggested for these names in order to allow for the automatic creation of individual names from groups of CF standard names.
Phrases and forms
Chemical species and aerosols
These can be chemical species with a defined molar mass (molecules, salts, etc.) or components that do not have a defined molar mass (aerosol, biological species)
Goto to the list of chemical species and aerosols as of 29 October 2008.
tendency_of_<Z>_due_to_<process> (with Z=physical quantity of component, in units of per s)
(Please note, that a discussion on the units might be necessary.)
<no process=total changes>
or atmosphere used as a prefix (suggested to be changed)
Please note that 'atmosphere' denotes all phases in the atmosphere and includes for example in_air, in_cloud, in_precipiation, etc.
in_air means in the gas phase, a definition if this includes also water vapor (dry_air or wet_air?) would be needed.
Groups of Standard_Names for chemicals and aerosols
The combination of the prases and forms given above results in groups of Standard_Names for chemicals and aerosols:
Please note that we suggest changes for the names with '?' above and also for the medium prefix 'atmosphere' to be consistent with the general concept 'in_<medium>'.
Odd names that do not fit in any group following the general concepts
We suggest changes to modify these names, so that they would fit in the general concepts explained here and allow for the automatic creation of individual names from groups of CF standard names. These could be added using aliases.