Hi Alison,
This is now fine with me. Thank you for being so thorough :-).
Philip
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Dr Philip Cameron-Smith, [email protected], Lawrence Livermore National Lab.
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> -----Original Message-----
> From: [email protected] [mailto:[email protected]]
> Sent: Thursday, December 06, 2012 4:26 AM
> To: [email protected]
> Cc: [email protected]; Cameron-smith, Philip
> Subject: RE: [CF-metadata] FW: Standard_name for cloud-cover by phenomenon
>
> Dear Heiko, Philip, All,
>
> Earlier this year Heiko Klein proposed the following three standard names for
> cloud:
> high_type_cloud_area_fraction
> medium_type_cloud_area_fraction
> low_type_cloud_area_fraction
> which received a considerable amount of discussion regarding both the names
> and their definitions.
>
> Towards the end of the discussion (16th May) Philip Cameron-Smith asked two
> questions:
>
> > Are there any other visual classification schemes in common use other than
> the current SYNOP one?
> >
> > Is the current SYNOP scheme likely to change significantly?
> >
> > This isn't my field, so I don't know the answers. If the answer to both
> > questions
> is 'no', then I will drop all my objections.
>
> No one responded directly to Philip's questions and Heiko asked on 11th June
> whether we could regard the names as accepted. I have now reviewed the full
> discussion and note that Eizi Toyoda stated
> (http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2012/055649.html) that
> the SYNOP scheme has remained unchanged since 1975 and was unlikely to do
> so in the near future, so I think we can take that as a 'no' to Philip's
> second
> question. Regarding Philip's first question, I note that Bruce Wright
> expressed
> the view (http://mailman.cgd.ucar.edu/pipermail/cf-
> metadata/2012/055642.html) that the classification scheme is sufficiently
> widely used that it doesn't need to be attributed to any particular 'owner'.
> I have
> also confirmed with Heiko (offlist) that there isn't any 'competitor' to the
> SYNOP
> classification, so I think we can also answer 'no' to the first question.
>
> As there are no further outstanding objections to these names, they are now
> accepted for addition to the standard name table.
>
> Based on the definition of the existing cloud_area_fraction name and the
> discussion of the proposed names I have written definitions as follows:
>
> high_type_cloud_area_fraction: ' High type clouds are: Cirrus, Cirrostratus,
> Cirrocumulus. "X_area_fraction" means the fraction of horizontal area occupied
> by X. Cloud area fraction is also called "cloud amount" and "cloud cover".
> X_type_cloud_area_fraction is determined on the basis of cloud type and not on
> the vertical location of the cloud.'
>
> medium_type_cloud_area_fraction: 'Middle type clouds are: Altostratus,
> Altocumulus, Nimbostratus. "X_area_fraction" means the fraction of horizontal
> area occupied by X. Cloud area fraction is also called "cloud amount" and
> "cloud
> cover". X_type_cloud_area_fraction is determined on the basis of cloud type
> and not on the vertical location of the cloud.'
>
> low_type_cloud_area_fraction: ' Low type clouds are: Stratus, Stratocumulus,
> Cumulus, Cumulonimbus. "X_area_fraction" means the fraction of horizontal
> area occupied by X. Cloud area fraction is also called "cloud amount" and
> "cloud
> cover". X_type_cloud_area_fraction is determined on the basis of cloud type
> and not on the vertical location of the cloud.'
>
> These names and definitions will be added at the next update of the standard
> name table.
>
> Best wishes,
> Alison
>
> ------
> Alison Pamment Tel: +44 1235 778065
> NCAS/British Atmospheric Data Centre Email: [email protected]
> STFC Rutherford Appleton Laboratory
> R25, 2.22
> Harwell Oxford, Didcot, OX11 0QX, U.K.
>
>
>
> > -----Original Message-----
> > From: CF-metadata [mailto:[email protected]] On Behalf
> > Of Heiko Klein
> > Sent: 11 June 2012 09:41
> > To: Cameron-smith, Philip
> > Cc: [email protected]
> > Subject: Re: [CF-metadata] FW: Standard_name for cloud-cover by
> > phenomenon
> >
> > Hi All,
> >
> > after 3 weeks of silence on this subject, I assume there was no-one
> > who answered with 'yes' to Philips questions, and there are no longer
> > objections on using the standardard-names:
> >
> > low_type_cloud_area_fraction
> > medium_type_cloud_area_fraction
> > high_type_cloud_area_fraction
> >
> >
> > Can I hope for these standard-names to appear in the next version of
> > standard-names?
> >
> > Best regards,
> >
> > Heiko
> >
> > On 2012-05-16 19:08, Cameron-smith, Philip wrote:
> > > Hi All,
> > >
> > > I just refreshed my memory of ISCCP, and I should not have been
> > > using it as an example in the way that I did (my apologies).
> > >
> > > Are there any other visual classification schemes in common use
> > > other than the current SYNOP one?
> > >
> > > Is the current SYNOP scheme likely to change significantly?
> > >
> > > This isn't my field, so I don't know the answers. If the answer to
> > > both questions is 'no', then I will drop all my objections.
> > >
> > > If the answer to either question is 'yes', then I would suggest that
> > > either the description be general enough to cover the different
> > > schemes, or we return to the idea of putting the name of the scheme
> > > into the std_name.
> > >
> > > Best wishes to all,
> > >
> > > Philip
> > >
> > > --------------------------------------------------------------------
> > > ---
> > >
> > > Dr Philip Cameron-Smith, [email protected], Lawrence Livermore National Lab.
> > >
> > > --------------------------------------------------------------------
> > > ---
> > >
> > > *From:*TOYODA Eizi [mailto:[email protected]]
> > > *Sent:* Tuesday, May 15, 2012 10:42 PM
> > > *To:* Cameron-smith, Philip; Wright, Bruce; [email protected]
> > > *Subject:* Re: [CF-metadata] FW: Standard_name for cloud-cover by
> > phenomenon
> > >
> > > Hi Philip,
> > >
> > > Very precicely speaking, what we propose is simulation of
> > > high/medium/low cloud area fractions following SYNOP rules. Some
> > > operational NWP models do a kind of simulation of cloud that would
> > > be observed by humans at surface. This is a kind of substitute of
> > > manned surface observation, so I believe it will be useful more and more.
> > >
> > > Regarding generality. Some people may consider it roughly
> > > compatible with height-based definitions like ISCCP. It's up to
> > > users. But we have to make definition clear, mainly to avoid
> > > comments requesting use of vertical coordinate variable. Cloud
> > > type-based classifications doesn't have natural vertical coordinate,
> > > and new names are only necessary for such parameters. Height-based
> > > classifications can be described with existing standard name
> > > "cloud_area_fraction
> > > <http://cf-pcmdi.llnl.gov/documents/cf-standard-names/standard-name-
> > table/19/cf-standard-name-table.html>"
> > > with vertical coordinate variable.
> > >
> > > Synoptic observation (coordinated by WMO) is probably only
> > > well-known type-based classification. And it has been unchanged at
> > > least since 1975, and I personally think it isn't likely to change for
> > > many
> years.
> > >
> > > Above is my understanding but I believe and hope original proposal
> > > from Heiko is not too far from that.
> > >
> > > So now I see no problem to register
> > > high/middle/low_type_cloud_area_fraction .
> > >
> > > Best Regards,
> > >
> > > Eizi
> > >
> > > ----- Original Message -----
> > >
> > > *From:*Cameron-smith, Philip <mailto:[email protected]>
> > >
> > > *To:*Wright, Bruce <mailto:[email protected]> ;
> > > [email protected] <mailto:[email protected]>
> > >
> > > *Sent:*Wednesday, May 16, 2012 3:55 AM
> > >
> > > *Subject:*Re: [CF-metadata] FW: Standard_name for cloud-cover by
> > > phenomenon
> > >
> > > Thanks, Bruce. Those emails helped crystalize it for me.
> > >
> > > Heiko, Eizi, are you proposing that the definition of
> > high/medium/low_type_cloud_area_fraction follow the SYNOP rules
> > precisely?
> > >
> > >
> > >
> > > Or will it be general enough to allow similar protocols, eg from
> > > ISCCP?
> > >
> > >
> > >
> > > If it is highly specific then I still feel it would be better to
> > > include the
> > provenance (eg, WMOSYNOP).
> > >
> > > If the definition will be somewhat general then I will drop my
> > > objection. I am still not enthusiastic about using the work 'type'
> > > in this way, but I confess that I cannot think of a better
> > > alternative.
> > >
> > > Best wishes,
> > >
> > > Philip
> > >
> > >
> > > --------------------------------------------------------------------
> > > ---
> > >
> > > Dr Philip Cameron-Smith, [email protected], Lawrence Livermore
> > > National
> > Lab.
> > >
> > >
> > > --------------------------------------------------------------------
> > > ---
> > >
> > > *From:*[email protected]
> > > [mailto:[email protected]] *On Behalf Of *Wright,
> > Bruce
> > > *Sent:* Tuesday, May 15, 2012 7:21 AM
> > > *To:* [email protected]
> > > *Subject:* [CF-metadata] FW: Standard_name for cloud-cover by
> > phenomenon
> > >
> > > Not sure if this was reply from Karl, went to the whole list or just
> > > to me.
> > >
> > > Regards,
> > > Bruce
> > >
> > >
> > > --------------------------------------------------------------------
> > > ----
> > >
> > > *From:*Karl Taylor [mailto:[email protected]]
> > > *Sent:* 15 May 2012 15:09
> > > *To:* Wright, Bruce
> > > *Subject:* Re: [CF-metadata] Standard_name for cloud-cover by
> > phenomenon
> > >
> > > All,
> > >
> > > Also, sorry to step in late and not having read all the
> > > communications on this ... but for your consideration:
> > >
> > > In Bruce's second case, wouldn't it be better to use a vertical
> > > coordinate (specifically the bounds on it) to indicate the cloud
> > > layer being considered? The standard name "cloud_area_fraction"
> > > could then be used, and the coordinate would tell whether it was
> > > low, middle, or high (and would also quantitatively specify what is
> > > meant by those qualitative terms).
> > >
> > > Best regards,
> > > Karl
> > >
> > > On 5/15/12 2:07 AM, Wright, Bruce wrote:
> > >
> > > All,
> > >
> > >
> > >
> > > Sorry to wade into this discussion late, but I believe part of
> > > the
> > >
> > > difficulty experienced in the discussions here are a consequence
> > > of
> > >
> > > mixing two distinct 'concepts':
> > >
> > >
> > >
> > > 1. Cloud Height Classification Based on Cloud Types
> > >
> > >
> > >
> > > There is a well-recognised allocations of cloud types to height-bands.
> > >
> > > These types and bands are nicely illustrated both in tabular
> > > form and
> > >
> > > visually on the Cloud Appreciation Society website at:
> > >
> > >
> > > http://cloudappreciationsociety.org/collecting/about-cloud-classific
> > > atio
> > >
> > > ns/
> > >
> > > http://cloudappreciationsociety.org/collecting/
> > >
> > >
> > >
> > > I believe that this allocation to height bands is sufficiently
> > >
> > > well-known to be characterized without attributing an owner (e.g.
> > WMO)
> > >
> > > or an observation process (e.g. SYNOP), as Heiko argued. Thus,
> > > (if
> > >
> > > required) these should probably be given the standard names:
> > >
> > >
> > >
> > > low_type_cloud_area_fraction
> > >
> > > medium_type_cloud_area_fraction
> > >
> > > high_type_cloud_area_fraction
> > >
> > >
> > >
> > > *However*, at present I would argue that these can only be
> > > accurately
> > >
> > > determined by a human inspection of the sky, which leads us to
> > > the
> > >
> > > second concept...
> > >
> > >
> > >
> > > 2. Cloud Height Classification Based on Height Ranges
> > >
> > >
> > >
> > > Most automated systems, be they cloud base recorders, numerical
> > models
> > >
> > > or other forecasting processes, will assign a cloud height class
> > > based
> > >
> > > on a height range. In this case, I would argue that the
> > > following set of
> > >
> > > standard names are more appropriate:
> > >
> > >
> > >
> > > low_cloud_area_fraction
> > >
> > > medium_cloud_area_fraction
> > >
> > > high_cloud_area_fraction
> > >
> > >
> > >
> > > I acknowledge that different height ranges will be adopted by
> > > different
> > >
> > > users, but, as Heiko states, this approach will at least allow
> > >
> > > Intercomparison, and the exact details of the height ranges used
> > > could
> > >
> > > be included as additional (non-CF Standard) metadata.
> > >
> > >
> > >
> > >
> > >
> > > Having presented these two 'concepts', I would suggest that the
> > > second
> > >
> > > is likely to be the most useful, in an age where the human
> > > observers are
> > >
> > > significantly outnumbered by automated observing and forecasting
> > >
> > > systems. However, there is no reason why both sets of standard
> > > names
> > >
> > > could not to adopted.
> > >
> > >
> > >
> > > My contribution to the debate - I hope it's helpful.
> > >
> > >
> > >
> > > Regards,
> > >
> > > Bruce
> > >
> > >
> > > --------------------------------------------------------------------
> > > ----
> > >
> > > _______________________________________________
> > > CF-metadata mailing list
> > > [email protected]
> > > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
> > >
> > >
> > >
> > > _______________________________________________
> > > CF-metadata mailing list
> > > [email protected]
> > > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
> > >
> >
> > --
> > Dr. Heiko Klein Tel. + 47 22 96 32 58
> > Development Section / IT Department Fax. + 47 22 69 63 55
> > Norwegian Meteorological Institute http://www.met.no
> > P.O. Box 43 Blindern 0313 Oslo NORWAY
> >
> >
> > _______________________________________________
> > CF-metadata mailing list
> > [email protected]
> > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
> --
> Scanned by iCritical.
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