Dear Jonathan, Roy and Karl,
thank you for your valuable inputs.
I am not very fond of the cell_method solution: I am already very reluctant using it because it is not controlled vocabulary and it is a nightmare to parse to extract valuable metadata automatically. Now that I am discovering that one can use a standard_name with no attached bounds instead of a proper variable name with associated bounds makes me even more reluctant to use it!
But I am not in a favour of encoding huge values of depth either...
... which leaves me being in favour of proposing new standard names by prefixing existing standard names with "ocean_" !
/S?bastien
----- Original Message -----
> From: "Karl Taylor" <taylor13 at llnl.gov>
> To: cf-metadata at cgd.ucar.edu
> Sent: Wednesday, 11 April, 2018 18:45:07
> Subject: Re: [CF-metadata] use of integral_wrt_depth_of_sea_water_practical_salinity
> Dear Sebastien,
>
> One option would be to include in cell_methods the following:
>
> cell_methods = "depth: mean (from surface to sea floor)"
>
> where depth is the standard name for the vertical coordinate, as
> provided for? in
> http://cfconventions.org/Data/cf-conventions/cf-conventions-1.7/cf-conventions.html#cell-methods-no-coordinates
> , and the information in parentheses is non-standard, as provided for in
> http://cfconventions.org/Data/cf-conventions/cf-conventions-1.7/cf-conventions.html#recording-spacing-original-data
> .
>
> I, for one, wouldn't like to see every integral over an entire domain to
> require a new standard_name.? the standard_names should name the
> variable itself and not indicate "method".
>
> best wishes,
> Karl
>
>
> On 4/11/18 10:28 AM, Jonathan Gregory wrote:
>> Dear Sebastien
>>
>> There is an existing standard name of
>> ocean_integral_wrt_depth_of_sea_water_temperature
>> and the one you propose has the same pattern, so it would seem all right to me,
>> and appropriate for your purpose. Otherwise you could set a very large lower
>> depth boundary with the understanding that integrating below the sea floor
>> added nothing, but that's a bit ugly.
>>
>> Best wishes
>>
>> Jonathan
>>
>> ----- Forwarded message from Sebastien Villaume <sebastien.villaume at ecmwf.int>
>> -----
>>
>>> Date: Wed, 11 Apr 2018 13:57:48 +0000
>>> From: Sebastien Villaume <sebastien.villaume at ecmwf.int>
>>> To: cf-metadata at cgd.ucar.edu
>>> Subject: [CF-metadata] use of
>>> integral_wrt_depth_of_sea_water_practical_salinity
>>> X-Mailer: Zimbra 8.6.0_GA_1200 (ZimbraWebClient - FF57 (Linux)/8.6.0_GA_1200)
>>>
>>> Dear list,
>>>
>>> In 2016/2017, a list of new standard names for NEMO output has been proposed and
>>> accepted : http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2016/058964.html
>>>
>>> from that initial list of standard names and after many iterations, one of the
>>> accepted standard name was:
>>>
>>> standard name: integral_wrt_depth_of_sea_water_practical_salinity
>>> units: m
>>>
>>> But the initial list of proposed standard names had actually 2 entries for this
>>> standard name:
>>>
>>> - one entry which is the one that eventually made it to the list (the standard
>>> name above)
>>> - a second entry for the case where the depth is the total depth, from surface
>>> to sea floor: ocean_integral_wrt_depth_of_sea_water_practical_salinity
>>>
>>> During the discussion:
>>> - Alison argued that the 2 entries were actually identical, the second one
>>> being simply a special case of the first one, i.e. when the depth corresponds
>>> to the total depth. She proposed later on to simply dropped the second entry.
>>> - Antonio Cofino argued that in this case the reference to Axis and to bounds
>>> should be removed from the description because in the case of the total depth,
>>> the bounds are not a constant (but function of lat and lon)
>>>
>>> In the published description the reference to an axis and to bounds is still
>>> there.
>>>
>>>
>>>
>>> My immediate problem is that I want to produce a parameter that is the integral
>>> wrt the whole depth of the salinity and I don't know how to do this.
>>>
>>> for a fixed depth of 500m for instance, the metadata for the parameter would be:
>>>
>>> float salinity500(t, y, x) ;
>>> salinity500:standard_name = "integral_wrt_depth_of_sea_water_practical_salinity"
>>> ;
>>> salinity500:units = "m" ;
>>> salinity500:coordinates = "time dpt500 latitude longitude" ;
>>> float dpt500 ;
>>> dpt500:standard_name = "depth_below_geoid" ;
>>> dpt500:units = "m" ;
>>> dpt500:axis = "Z" ;
>>> dpt500:positive = "down" ;
>>> dpt500:bounds = dpt500_bnds ;
>>> float dpt500_bnds(bnds) ;
>>>
>>> and in the dpt500_bnds array, I have : [0., 500.]
>>>
>>> for the total depth, I can't use the same mechanism, because the second value of
>>> the bounds is not a constant, it is a function of lat and lon: [0., f(lat,lon)]
>>>
>>>
>>> How can I solve this?
>>>
>>> Is it possible to reconsider the standard name
>>> ocean_integral_wrt_depth_of_sea_water_practical_salinity (or a variation of
>>> it)?
>>> Another approach could be to keep the existing standard name, add a new standard
>>> name that represents the total water column and use it as an auxiliary
>>> coordinate.
>>>
>>> thanks,
>>> ____________________________________
>>>
>>> Dr. S?bastien Villaume
>>>
>>> M.A.R.S. Analyst
>>> ECMWF Data Governance facilitator
>>>
>>> ECMWF
>>> Shinfield Park,
>>> Reading RG2 9AX, UK
>>> +44 (0)118 949 9301
>>> +44 (0)7825 521592
>>> sebastien.villaume at ecmwf.int
>>> ____________________________________
>>> _______________________________________________
>>> CF-metadata mailing list
>>> CF-metadata at cgd.ucar.edu
>>> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
>> ----- End forwarded message -----
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Received on Fri Apr 13 2018 - 09:22:37 BST
