Hello Heiko,
I don't have a strong opinion, but am just testing the water ...
I wonder how one would define these standard names so that they were
correct for all uses, for example from a three layer model to the
ISCCP datasets.
In your example, would a model_level_number coordinate of [1, 2, 3]
fit your needs, possibly with an auxiliary coordinate of ['low',
'medium', 'high']? Would we need a standard name for the auxiliary
coordinate, or would a long name suffice?
All the best,
David
---- Original message from Heiko Klein (11AM 25 Apr 12)
> Date: Wed, 25 Apr 2012 11:49:06 +0200
> From: Heiko Klein <Heiko.Klein at met.no>
> User-Agent: Mozilla/5.0 (X11; Linux i686; rv:11.0) Gecko/20120327
> Thunderbird/11.0.1
> To: "cf-metadata at cgd.ucar.edu" <cf-metadata at cgd.ucar.edu>
> Subject: [CF-metadata] Standard_name for cloud-cover by phenomenon
>
> Hei,
>
> in grib, clouds are described as low, medium and high clouds, e.g.
> 73,74,75. Those are described by phenomenon, e.g.
>
> high cloud type: Clouds of genera Cirrus, Cirrocumulus and Cirrostratus.
>
> low cloud type: Clouds of genera Stratocumulus, Stratus, Cumulus, etc.
>
> medium cloud type: Clouds of the genera Altocumulus, Altostratus, etc.
>
> (see
>
> In CF, this can currently only be expressed by
> cloud_area_fraction_in_atmosphere_layer and a not very well defined
> 'vertical' parameter, e.g. by sigma:
> http://www.ecmwf.int/products/data/archive/data_faq.html#clouddefinitions
>
>
> When translating from grib to CF, this is not very satisfying:
> Either I add some dummy sigma-values, which will look like I have a
> model with just three levels, or I use 3 variables, all with the
> same 'standard_name="cloud_area_fraction"' which looses some useful
> information. In both cases, the data-user will need to know
> something which cannot be expressed by CF.
>
>
> Looking at the page
> http://cf-pcmdi.llnl.gov/documents/cf-standard-names/ecmwf-grib-mapping
> there are mentioned 3 'standard_names' which are not in the
> standard_name-table yet, and I propose to do so:
>
> low_cloud_area_fraction
> medium_cloud_area_fraction
> high_cloud_area_fraction
>
> in additon (though this is not in grib), I would like to add
> fog_area_fraction (or surface_cloud_area_fraction).
>
>
> Best regards,
>
> Heiko
>
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--
David Hassell
National Centre for Atmospheric Science (NCAS)
Department of Meteorology, University of Reading,
Earley Gate, PO Box 243,
Reading RG6 6BB, U.K.
Tel : 0118 3785613
Fax : 0118 3788316
E-mail: d.c.hassell at reading.ac.uk
Received on Wed Apr 25 2012 - 04:36:42 BST
