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.villa...@ecmwf.int> 
-----

Date: Wed, 11 Apr 2018 13:57:48 +0000
From: Sebastien Villaume <sebastien.villa...@ecmwf.int>
To: cf-metadata@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. Sébastien 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.villa...@ecmwf.int
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