Dear Alejandro and Jonathan,
I would like to remind you of my recent proposal for Emissivity as
below.
Young-In
-----Original Message-----
From: Won, Young-In (GSFC-610.2)[RSIS]
Sent: Monday, February 02, 2009 7:21 PM
To: 'Jonathan Gregory'; 'cf-metadata at cgd.ucar.edu'
Subject: RE: [CF-metadata] Emissivity not found in the current standard
nametable
Dear All,
I would like to propose two (three for the dimension) new standard names
as follows.
1. name: surface_longwave_emissivity
canonical unit: 1 ( unitless number between 0 and 1)
definition: The ratio of energy radiated by the Earth's surface to
energy radiated by a black body at the same temperature in longwave
region.
2. surface_mircrowave_emissivity
canonical unit: 1 ( unitless number between 0 and 1)
definition: The ratio of energy radiated by the Earth's surface to
energy radiated by a black body at the same temperature in microwave
frequency region.
3. name: radiation_frequency (alias: electromagnetic_frequency)
canonical unit: hertz;
definition: The radiation frequency can refer to any electromagnetic
frequency, such as light, heat radiation and radio waves
(copied and modified from "radiation_wavelength". I need
"radiaton_frequency" because the emissivity in our data set is given at
specific frequency).
----------------------------------------------------
Young-In Won, Ph.D.
NASA Goddard Space Flight Center
Mail stop: 610.2
Greenbelt, MD 20771
(301) 614 6749 (O)
(301) 614 5268 (F)
young-in.won at nasa.gov
-----Original Message-----
From: cf-metadata-bounces at cgd.ucar.edu
[mailto:cf-metadata-bounces at cgd.ucar.edu] On Behalf Of Jonathan Gregory
Sent: Wednesday, February 11, 2009 2:20 PM
To: Alejandro Bodas-Salcedo
Cc: cf-metadata at cgd.ucar.edu; Sandrine Bony; Webb, Mark
Subject: [CF-metadata] Proposal for new standard names
Dear Alejandro
> height_of_full_levels_above_reference_ellipsoid [m]
> height_of_half_levels_above_reference_ellipsoid [m]
standard names do not indicate coordinate variables, so the standard
name for these is height_above_reference_ellipsoid, which is already in
the table, and the variable should have a vertical coordinate variable
of model_level_number.
> air_pressure_at_full_levels [Pa]
> air_pressure_at_half_levels [Pa]
Likewise. The standard name is air_pressure.
> b) Cloud condensate mixing ratios [1]
> mixing_ratio_large_scale_cloud_liquid
> mixing_ratio_large_scale_cloud_ice
> mixing_ratio_convective_cloud_liquid
> mixing_ratio_convective_cloud_ice
> mixing_ratio_of_ozone_in_air [1]
Are these the same as
mass_fraction_of_stratiform_cloud_liquid_water_in_air
mass_fraction_of_stratiform_cloud_ice_in_air
mass_fraction_of_convective_cloud_liquid_water_in_air
mass_fraction_of_convective_cloud_ice_in_air
mass_fraction_of_ozone_in_air
which are in the table, or are you intending to draw a precise
distinction between mixing_ratio and mass_fraction? There have been
lengthy discussions on the email list with the outcome that a
distinction is not made except for the case of water vapour in air.
> d) Radiative properties of clouds. Optical depths at 0.67 micron and
> emissivities at 10.5 micron.
The wavelengths should be specified with a scalar coordinate variable of
radiation_wavelength.
> large_scale_cloud_optical_depth [1]
> convective_cloud_optical_depth [1]
For consistency with the existing optical depth standard names, I
suggest these should be
atmosphere_optical_thickness_due_to_large_scale|convective_cloud
> large_scale_cloud_emissivity [1]
> convective_cloud_emissivity [1]
If the variable does specify the wavelength, I think it is OK just to
say emissivity. Young-In Wong has recently proposed
surface_longwave_emissivity, which does not specify a precise
wavelength.
> e) Surface variables. Emissivity at 10.5 micron.
> skin_temperature [K]
The variable called surface_temperature is the temperature at the
interface.
Is that what you mean?
> h) Cloud fractions from CALIPSO/CLOUDSAT simulators. Units: 1.
> calipso_total_cloud_fraction
Should be calipso_cloud_area_fraction like isccp_cloud_area_fraction
(but see also below).
> calipso_low_level_cloud_fraction
> calipso_mid_level_cloud_fraction
> calipso_high_level_cloud_fraction
I'd say low, mid and high are coordinates. They should be specified as
coordinate variables, rather than in the standard name. We have not so
far named cloud layers in this way.
> calipso_cloud_fraction
> calipsonocloudsat_cloud_fraction
> calipso_and_cloudsat_total_cloud_fraction
I'm not sure what these mean.
> i.1 CloudSat Radar Reflectivity Factor (94 GHz)
> cloudsat_radar_reflectivity_94 [dBZ]
The frequency should be specified as a scalar coordinate variable of
radiation_frequency, which is not in the table at present but could be
proposed. The name can then be just cloudsat_radar_reflectivity. Is it
necessary to name "cloudsat" in this? I tend to think it would be better
to be more generic i.e. just radar_reflectivity.
> i.2 CALIPSO Lidar Attenuated Total Backscatter (532 nm)
> calipso_atb_532 [1]
Again, the wavelength is a coordinate and should not be in the name.
Could "total" be omitted? Usually we assume that unqualified concepts
are inclusive.
Thus
lidar_attenuated_backscatter
But I'm not familiar with this so I don't know what the relationship is
between this quantity and the next one
> calipso_molecular_backscatter_532 [m-1 sr-1]
Perhaps you or someone else could clarify. As they don't have the same
units the names should distinguish them more. Are they analogous to
these quantities in the table?
surface_backwards_scattering_coefficient_of_radar_wave: 1
volume_backwards_scattering_coefficient_of_radiative_flux_in_sea_water:m
-1
volume_scattering_coefficient_of_radiative_flux_in_sea_water:m-1
volume_scattering_function_of_radiative_flux_in_sea_water:m-1 sr-1 If
so, similar names should be adopted.
> k) Outputs from ISCCP simulator. Units are [1] otherwise stated.
> isccp_total_cloud_area_fraction
We already have
isccp_cloud_area_fraction
> isccp_mean_cloud_albedo
Could this be simply
cloud_albedo
> isccp_mean_cloud_top_pressure [Pa]
air_pressure_at_cloud_top
is already in the table.
> isccp_mean_brightness_temperature_assuming_clear_sky [K]
> isccp_mean_brightness_temperature [K]
> isccp_mean_optical_depth
With these variables, is isccp necessary? Standard names are intended to
name geophysical quantities. If ISCCP is estimating geophysical
quantities, they do not need isccp in their names. For instance, we
don't have a quantity called hadisst_sea_surface_temperature. The
quantity is just SST, and HadISST is one estimate of it. ISCCP could be
identified in one of the global attributes of the file. I am not sure
why we included a standard name for ISCCP cloud area fraction and
whether we should do so for CALIPSO or this one
> misr_cloud_area_fraction
>
> m) PARASOL-like mono-directional reflectance. Units: 1.
> parasol_reflectance
Could you explain what that means?
Best wishes
Jonathan
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Received on Wed Feb 11 2009 - 13:31:27 GMT
