[CF-metadata] "positive" attribute

[Forrest Hoffman]

Bryan:

Jonathan Gregory has been offering suggestions and help off list for a 
suite of new standard_names I would like to propose.  Jonathan pointed 
out that the sign convention is specified in the standard_name, so use 
of the "positive" attribute is not needed.

Thanks!

Forrest

Bryan Lawrence wrote:
> Hi Forrest
>
> Are some of these going to be implicit in the standard name? (I imagine no 
> always, so I can see the sense of the argument). Personally I don't have a 
> problem with introducing an extended controlled vocabulary into the positive 
> argument.
>
> Cheers
> Bryan
>
> On Tuesday 26 June 2007 15:03:31 Forrest Hoffman wrote:
>   
>> Much of the CF-1.0 convention seems to be atmospherically biased.  I
>> know that's because it is the atmospheric scientists that pioneered all
>> these developments.  In attempting to adopt this methodology for other
>> components of Earth System Models, I'm concluding it may be necessary to
>> extend the convention to adequately support the needs of these components.
>>
>> For example, it appears to me that the "positive" attribute for CF-1.0
>> variables is really used to describe vertical directionality.  This
>> attribute is often traditionally associated with atmospheric radiation
>> variables.  In CMOR, the only valid attribute values are "up" and "down."
>>
>> In terrestrial biogeochemistry various sign conventions exist, and I had
>> hoped to use the "positive" attribute to describe the desired convention
>> where vertical directionality is not important or known.  The values I
>> had initially hoped to use for the "positive" attribute for some
>> biogeochemistry variables were "into biosphere" and "out of biosphere"
>> and "into pool" and "out of pool."
>>
>> It would seem that "vertical-directionality" would be a more appropriate
>> attribute where the "positive" attribute has been traditionally
>> applied.  I'm sure nobody wants to change this now, but I'm looking for
>> suggestions for attributes that might describe sign conventions where
>> directionality is either not vertical or is more conceptually abstract.
>> We could establish a "negative" attribute, but users might expect some
>> kind of correspondence with the "positive" attribute.  A
>> "sign-convention" attribute might work, but it might have many possible
>> values.  Any other suggestions?
>>
>> Forrest
>>     
>
>   

-- 
Forrest Hoffman                       mailto:forrest at climatemodeling.org
Oak Ridge National Laboratory         mailto:forrest at computer.org
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