[CF-metadata] CF standard names for chemical constituents and aerosols

[Philip J. Cameronsmith1]

On Tue, 21 Oct 2008, Jonathan Gregory wrote:

> I think that a stronger argument for this than the size of the standard name
> table, which should be no problem for software, is that chemical models may
> internally have array dimensions for species, in which case it would be
> natural to write out arrays of results. Are the models indeed like that?

Hi,

I generally agree with Jonathan, but my purpose here is only to answer 
Jonathan's question (above).

Every major atmospheric chemistry model I know of keeps their species in a 
single array within the code.  However, on output there are some models 
that keep the whole array together as a 5d array on output (lat, lon, lev, 
species, time), and there are some that output each specie as a separate 
4D array (lat, lon, lev, time).

I expect that most models could change between the two output modes 
without too much heartache.

Having worked with both output styles, I personally prefer to output the 
species separately, because I find it easier when working with multiple 
chemical mechanisms and multiple models (and would therefore recommend 
using separate species for CF too).

Note: different aerosol sizes in models can be handled as multiple species 
or as an additional dimension.

Best wishes,

      Philip

------------------------------------------------------------------------
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
------------------------------------------------------------------------