Dear Martin,
thank you for your comments!
The difference of graupel and hail is mainly by the definition of the size as far as I know. Graupel: diameter sizes <5mm ; hail >= 5mm. I guess models need to have a two-moment cloud scheme implemented to distinguish between graupel and hail.
In case of single moment schemes which are the general case in most atmospheric climate models, there is just one category for graupel+hail (if a model provides this at all). From
http://www.met.reading.ac.uk/~sws00rsp/teaching/nanjing/microphysics.pdf <
http://www.met.reading.ac.uk/~sws00rsp/teaching/nanjing/microphysics.pdf> it reads that in the UM the graupel+hail is just called graupel. The naming is actually the same in the one moment schemes of COSMO-model and WRF.
I agree with your proposal to extend the description of hail.
Any idea on how to distinguish between the use of graupel definition in a one-moment scheme (graupel includes hail sizes) and in a two moment scheme (graupel < 5mm, hail >= 5mm)?
atmosphere_mass_content_of_graupel
units: kg m-2
"Content" indicates a quantity per unit area. The "atmosphere content" of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used. Graupel consists of heavily rimed snow particles, often called snow pellets; often indistinguishable from very small soft hail except for the size convention that hail must have a diameter greater than 5 mm. Reference: American Meteorological Society Glossary
http://glossary.ametsoc.org/wiki/Graupel.
atmosphere_mass_content_of_hail
units: kg m-2
"Content" indicates a quantity per unit area. The "atmosphere content" of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used. Hail is precipitation in the form of balls or irregular lumps of ice with a diameter of 5mm or more. Reference: American Meteorological Society Glossary
http://glossary.ametsoc.org/wiki/Hail .
mass_fraction_of_hail_in_air
units: 1
Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).
Regards
Burkhardt
> Am 05.04.2018 um 13:32 schrieb Martin Juckes - UKRI STFC <martin.juckes at stfc.ac.uk>:
>
> Dear Burkhardt,
>
>
> the names look good to me, but I have a question about the precise definition of "hail", which has not previously been used in CF standard names. The existing name "graupel_fall_amount" cites the AMS definition for graupel : "Heavily rimed snow particles, often called snow pellets; often indistinguishable from very small soft hail except for the size convention that hail must have a diameter greater than 5 mm." The corresponding AMS definition for hail is:
>
> Precipitation in the form of balls or irregular lumps of ice, always produced by convective clouds, nearly always cumulonimbus.
>
> An individual unit of hail is called a hailstone. By convention, hail has a diameter of 5 mm or more, while smaller particles of similar origin, formerly called small hail, may be classed as either ice pellets or snow pellets. Thunderstorms that are characterized by strong updrafts, large liquid water contents, large cloud-drop sizes, and great vertical height are favorable to hail formation. The destructive effects of hailstorms upon plant and animal life, buildings and property, and aircraft in flight render them a prime object of weather modification studies. In aviation weather observations, hail is encoded A.
> Is this what you intend with the proposed name, including the fixed size threshold of 5mm? I would have considered 4mm diameter balls of ice falling out of the sky as hail, but the 5mm rule appears to be part of the scientific definition of the term.
>
> If so, we could add an abbreviated form of the AMS definition to the standard name descriptions:
> "Hail is precipitation in the form of balls or irregular lumps of ice with a diameter of 5mm or more. Reference: American Meteorological Society Glossary http://glossary.ametsoc.org/wiki/Hail ."
>
> regards,
> Martin
>
>
> ________________________________
> From: CF-metadata <cf-metadata-bounces at cgd.ucar.edu> on behalf of Burkhardt Rockel <rockel at me.com>
> Sent: 04 April 2018 14:13
> To: cf-metadata at cgd.ucar.edu
> Subject: Re: [CF-metadata] Proposal for new standard names
>
> Dear Alison et al.
>
> any progress in putting the below proposed standard names into official CF standard name table?
>
> Regards
> Burkhardt
>
>
>> Am 30.11.2017 um 19:00 schrieb Jonathan Gregory <j.m.gregory at reading.ac.uk>:
>>
>> Dear Burkhardt
>>
>> These fit existing patterns, I believe, so they should be fine. Thanks.
>>
>> Best wishes
>>
>> Jonathan
>>
>> ----- Forwarded message from Burkhardt Rockel <rockel at me.com> -----
>>
>>> Date: Wed, 29 Nov 2017 14:03:14 +0100
>>> From: Burkhardt Rockel <rockel at me.com>
>>> To: cf-metadata at cgd.ucar.edu
>>> Subject: [CF-metadata] Proposal for new standard names
>>> X-Mailer: Apple Mail (2.3445.4.7)
>>>
>>> I propose the following standard names:
>>>
>>> atmosphere_mass_content_of_graupel
>>> units: kg m-2
>>> "Content" indicates a quantity per unit area. The "atmosphere content" of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.
>>>
>>> atmosphere_mass_content_of_hail
>>> units: kg m-2
>>> "Content" indicates a quantity per unit area. The "atmosphere content" of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.
>>>
>>> mass_fraction_of_hail_in_air
>>> units: 1
>>> Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).
>>>
>>> Regards
>>> Burkhardt Rockel
>>>
>>>
>>> -----------
>>> Dr. Burkhardt Rockel
>>> Helmholtz-Zentrum Geesthacht
>>> Institute of Coastal Research / Group Regional Atmospheric Modeling
>>> Max-Planck-Strasse 1
>>> D-21502 Geesthacht
>>> Germany
>>> Phone: +49 4152 87 1803
>>> Fax: +49 4152 87 4 1803
>>> Email: Burkhardt.Rockel (at) hzg.de <http://hzg.de/>
>>> www: http://rockel.staff.coast.hzg.de <http://rockel.staff.coast.hzg.de/>
>>> coordinates: 53.40575 N, 10.428697 E
>>> -----------
>>>
>>>
>>>
>>>
>>>
>>
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>>
>>
>> ----- End forwarded message -----
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