On 7 July 2015 - Reply by Mike Carlomusto: Alison, I agree with your assessment - the proposed standard name "cloud_phase_category" and the existing standard name thermodynamic_phase_of_cloud_water_particles_at_cloud_top are redundant.
Your proposed addition of three values - clear_sky, super_cooled_liquid_water and unknown - to thermodynamic_phase_of_cloud_water_particles_at_cloud_top is an excellent solution and acceptable for the GOES-R Cloud Top Phase product. Mike On 3 July 2015 Alison Pamment wrote: > Thread "new standard_name needed for cloud_phase (an enumeration > type)" > (http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2013/056424.html) > > Current status: Under discussion. > cloud_phase_category (canonical units: 1) 'Cloud phase category is a > string, taking one of the following standardised values: clear_sky, > liquid_water, super_cooled_liquid_water, mixed_phase, ice, unknown. > For a data variable it is encoded as an integer using flag_values and > flag_meanings.' > > This name received some brief discussion on the mailing list and was > agreed at the time. However, I was looking through existing names > whose definitions also refer to flag_values and flag_meanings because > I wanted to check that the wording of the proposed definition is > broadly consistent. In doing so I came across the name > thermodynamic_phase_of_cloud_water_particles_at_cloud_top, introduced > into the standard name table at Version 24 (June 2013), for use with > Meteosat Second Generation (MSG) data. The existing name is defined as > follows: > ' "cloud_top" refers to the top of the highest cloud. "Water" means > water in all phases. A variable with the standard name of > thermodynamic_phase_of_cloud_water_particles_at_cloud_top contains > integers which can be translated to strings using flag_values and > flag_meanings attributes. Alternatively, the data variable may contain > strings which indicate the thermodynamic phase. These strings are > standardised. Values must be chosen from the following list: liquid; > ice; mixed.' > > Although the list of standardised values is not the same as proposed > for GOES-R, I think the existing name is basically the same quantity > as the one requested. My suggestion is that, instead of adding the new > name, we expand the definition of the existing name to allow for all > the strings needed for both MSG and GOES-R data, as follows: > ' "cloud_top" refers to the top of the highest cloud. "Water" means > water in all phases. A variable with the standard name of > thermodynamic_phase_of_cloud_water_particles_at_cloud_top contains > integers which can be translated to strings using flag_values and > flag_meanings attributes. Alternatively, the data variable may contain > strings which indicate the thermodynamic phase. These strings are > standardised. Values must be chosen from the following list: liquid; > ice; mixed; clear_sky; super_cooled_liquid_water; unknown.' > > The standardised strings for liquid_water and mixed_phase would be > slightly different from those agreed in the discussion of the current > proposal, but if the names are to be combined I think we would need to > stick with the earlier strings so as not to invalidate existing MSG data. > Expanding the list of standardised strings would not affect existing > data as I don't think there is any requirement to use all possible > values of flag_values and flag_meanings within a particular data > variable. One of the reasons for using standard names in CF is to > avoid accidental duplication of quantities with the same meaning but > different names, so I think that expanding the existing definition is the > right way to go. Do you agree? Michael Carlomusto [email protected]<mailto:[email protected]> Harris Corp. Government Communications Systems Division (GCSD), GOES-R Ground System Melbourne, FL, USA (321) 309-7905
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