Note that the new name effective_radius_of_cloud_particles_at_cloud_top takes away any mention of water, so now any particle is included.
John On Dec 19, 2013, at 03:44, [email protected] wrote: > Dear Jonathan, > > "Condensed_water" is indeed the phrase used in CF standard names to refer to > liquid water and ice collectively, not just liquid. Essentially it means "non > gaseous H2O". We also have names that refer separately to "liquid_water" and > "ice" so that all the quantities can be distinguished. For water in all its > phases (collectively) we simply use the term "water". I can't presently think > of a concise alternative to "condensed_water" to describe the necessary > concept. I suppose we could be more explicit and use "liquid_water_and_ice" > although this would make the names longer. Do others have strong feelings > about this? > > "Condensed_water" is used in 22 existing names, 16 of which refer to cloud. > The other 6 are soil water quantities. > > I think the existing name > effective_radius_of_cloud_condensed_water_particles_at_cloud_top is certainly > the quantity you are looking for. However, I take your point about particles > and I agree that it would actually make more sense to change this name to > effective_radius_of_cloud_particles_at_cloud_top. It is shorter (always a > plus point!) and it is consistent with the general approach that we have > taken before that, unless we explicitly distinguish between different types > of object, (e.g. convective/stratiform cloud, seasalt/sulfate aerosol, > latent/sensible heat flux, etc.) then the name applies to the generic object > (cloud, aerosol, heat flux). > > I don't think we need to change any of the other condensed_water names, even > the cloud ones, because they don't refer to particles. For example, > mass_fraction_of_cloud_condensed_water_in_air and > mass_concentration_of_condensed_water_in_soil still seem OK. > > 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: Jonathan Wrotny [mailto:[email protected]] >> Sent: 18 December 2013 19:17 >> To: Pamment, Alison (STFC,RAL,RALSP); [email protected] >> Subject: Re: [CF-metadata] Proposed new standard name: >> effective_radius_of_cloud_particle_at_cloud_top >> >> Dear Alison, >> >> Thanks for the information. I had been looking at an older version of >> the standard names table by accident and missed this quantity. However, >> after looking at it, I am a little confused by the phrase >> "condensed_water." I think of condensed water as liquid water that has >> condensed from water vapor, but definition states: "condensed_water" >> means liquid and ice. Why is ice included here? Is "condensed" to be >> interpreted more generally such that liquid and/or ice particles are >> included in the cloud? If the latter, then why not use a more general >> phrase such as "cloud_particle" to cover all types of possible >> particles: e.g. liquid, ice, mixed liquid/ice? To me, the use of >> "condensed_water" in the name then "liquid and ice" in the definition is >> confusing. >> >> If this standard name is meant apply to both liquid and/or ice particles >> in the cloud, then I think that it could suffice for our GOES-R data >> product, but in that case, I would suggest a minor re-write of the name. >> >> Sincerely, >> >> Jonathan >> >> On 12/17/2013 6:58 AM, [email protected] wrote: >>> Dear Jonathan and Randy, >>> >>> You are correct that we already have the standard name >> effective_radius_of_cloud_liquid_water_particle_at_liquid_water_cloud_to >> p which is obviously aimed at liquid particles. We do, however, also have >> the existing name >> effective_radius_of_cloud_condensed_water_particles_at_cloud_top >> defined as: 'The effective radius of a size distribution of particles, such >> as >> aerosols, cloud droplets or ice crystals, is the area weighted mean radius of >> particle size. It is calculated as the ratio of the third to the second >> moment >> of the particle size distribution. "cloud_top" refers to the top of the >> highest >> cloud. "condensed_water" means liquid and ice.' I think this is probably the >> quantity you need, rather than adding another standard name. >>> >>> 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. >>> >>> >>> From: CF-metadata [mailto:[email protected]] On >> Behalf Of Jonathan Wrotny >>> Sent: 15 December 2013 21:56 >>> To: [email protected] >>> Subject: [CF-metadata] Proposed new standard name: >> effective_radius_of_cloud_particle_at_cloud_top >>> >>> Dear CF board, >>> >>> Back in May, a colleague of mine, Randy Horne, submitted a new proposed >> name for the effective radius of a cloud particle at the top of a cloud. Our >> proposed standard name was >> "effective_radius_of_cloud_particle_at_cloud_top". We did not hear back >> from any CF posters at the time in regards to this proposal, and are hoping >> to re-start this proposal now. >>> >>> The motivation for this new standard name is a data product on the future >> GOES-R geostationary platform. This product is the effective radius for a >> cloud particle at the top of a cloud. The GOES-R product will not >> distinguish >> between water and ice particles, however. Currently, the CF database has a >> similar standard name but for liquid particles only >> (effective_radius_of_cloud_liquid_water_particle_at_liquid_water_cloud_t >> op). This standard name does not suffice for the GOES-R data product, >> hence, the proposal for a slightly more general standard name which would >> cover both water and ice particles at the cloud top. Here is our current >> proposal: >>> >>> Standard Name: >>> >>> effective_radius_of_cloud_particle_at_cloud_top >>> >>> Definition: >>> >>> The effective radius of a size distribution of particles, such as aerosols, >> cloud droplets or ice crystals, is the area weighted mean radius of particle >> size. It is calculated as the ratio of the third to the second moment of the >> particle size distribution. cloud_top refers to the top of the highest cloud >> and cloud_particle refers to either a liquid water droplet or ice crystal. >>> >>> Canonical Units: >>> >>> m >>> >>> Thanks for your consideration of this proposal. All comments are >> welcome. >>> >>> Sincerely, >>> >>> Jonathan Wrotny > > -- > Scanned by iCritical. > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata ------------------------------------ John Graybeal Sr. Data Manager, Metadata & Semantics M +1 408 675-5445 skype: graybealski Marinexplore 920 Stewart Drive Sunnyvale 94085 California, USA www.marinexplore.com _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
