Hi Markus,
Thanks for taking on this task :-).
Some general comments:
1) There is no mention of frequency in your definitions. This is true for some of the existing std_name definitions too. However, I note that the description of some of the existing std_names (eg atmosphere_absorption_optical_thickness_due_to_ambient_aerosol) contains the following, which I recommend that we include in all your definitions (CF is used for everything from UV to radio waves): "A coordinate variable of radiation_wavelength or radiation_frequency can be specified to indicate that the optical thickness applies at specific wavelengths or frequencies."
2) Do you really mean _due_to_dry_aerosol? I interpret this to mean in a humid atmosphere you are quantifying the scattering that would occur if, hypothetically, the aerosols were dry rather than their actual ambient state.
3) For the terms with _due_to_pm1(10)_dry_aerosol, is the pm1(10) selection on ambient aerosol of dry aerosol?
3) Dry aerosol is usually described for std_names as '"Dry aerosol" means aerosol without water'. Your description is possibly better, but you might consider going with the former for consistency.
4) I am not sure what you mean by surface_volume_ .
5) You mention that _hemispheric_backscattering_ is scattering into the 'rearward hemisphere relative to the incident beam'. This appears to be the same definition that is already given to both _backscattering_ (eg, backscattering_ratio, histogram_of_backscattering_ratio_over_height_above_reference_ellipsoid) and _backwards_scattering_ (eg, surface_backwards_scattering_coefficient_of_radar_wave, volume_attenuated_backwards_scattering_function_in_air_assuming_no_aerosol_or_cloud). Hence, it appears that we already have duplicate terms in the std_name table. We should probably pick a preferred option, and fix the other one with aliases.
6) We currently don't have any std_names with _due_to_aerosol. They all specify either _ambient_ or _dry_.
Best wishes,
Philip
-----------------------------------------------------------------------
Dr Philip Cameron-Smith, pjc at llnl.gov, Lawrence Livermore National Lab.
-----------------------------------------------------------------------
> -----Original Message-----
> From: cf-metadata-bounces at cgd.ucar.edu [mailto:cf-metadata-
> bounces at cgd.ucar.edu] On Behalf Of Markus Fiebig
> Sent: Wednesday, March 07, 2012 5:29 AM
> To: cf-metadata at cgd.ucar.edu
> Subject: [CF-metadata] new standard names for surface aerosol optical
> properties
>
> Dear all,
>
> since the WMO Global Atmosphere Watch (GAW) programme is moving towards
> using CF standard names as standard vocabulary, I'd like to propose a
> few standard names that represent aerosol properties being observed at
> the GAW surface sites. Since there seem to be various opinions about
> the procedure, I opened a corresponding ticket on the cf metadata track
> system and will now also post my proposal on this mailing list. Here's
> the list of variables and definitions:
>
>
> 1) volume_scattering_coefficient_in_air_due_to_dry_aerosol
>
> The volume scattering coefficient is the fractional change of radiative
> flux per unit path length due to redirection of an incident light beam
> by a component in the reference volume. "Aerosol" means the suspended
> liquid or solid particles in air (except cloud droplets). "Dry aerosol"
> is aerosol at a relative humidity < 40% where it hasn't taken up
> ambient water by hygroscopic growth. The specification of a physical
> process by the phrase "due_to_" process means that the quantity named
> is a single term in a sum of terms which together compose the general
> quantity named by omitting the phrase.
>
>
> 2) volume_absorption_coefficient_in_air_due_to_dry_aerosol
>
> The volume absorption coefficient is the fractional change of radiative
> flux per unit path length due to absorption of an incident light beam
> by a component in the reference volume. "Aerosol" means the suspended
> liquid or solid particles in air (except cloud droplets). "Dry aerosol"
> is aerosol at a relative humidity < 40% where it hasn't taken up
> ambient water by hygroscopic growth. The specification of a physical
> process by the phrase "due_to_" process means that the quantity named
> is a single term in a sum of terms which together compose the general
> quantity named by omitting the phrase.
>
>
> 3)
> volume_hemispheric_backscattering_coefficient_in_air_due_to_dry_aerosol
>
> The volume hemispheric backscattering coefficient is the fractional
> change of radiative flux per unit path length due to redirection of an
> incident light beam into the rearward hemisphere relative to the
> incident beam by a component in the reference volume. It is distinct
> from the backscattering coefficient which isn't integrated over the
> rearward hemisphere. "Aerosol" means the suspended liquid or solid
> particles in air (except cloud droplets). "Dry aerosol" is aerosol at a
> relative humidity < 40% where it hasn't taken up ambient water by
> hygroscopic growth. The specification of a physical process by the
> phrase "due_to_" process means that the quantity named is a single term
> in a sum of terms which together compose the general quantity named by
> omitting the phrase.
>
>
> 4)
> surface_volume_scattering_coefficient_at_stp_in_air_due_to_pm1_dry_aero
> sol
>
> The volume scattering coefficient is the fractional change of radiative
> flux per unit path length due to redirection of an incident light beam
> by a component in the reference volume. "Aerosol" means the suspended
> liquid or solid particles in air (except cloud droplets). "Dry aerosol"
> is aerosol at a relative humidity < 40% where it hasn't taken up
> ambient water by hygroscopic growth. The specification of a physical
> process by the phrase "due_to_" process means that the quantity named
> is a single term in a sum of terms which together compose the general
> quantity named by omitting the phrase. "surface" means the lower
> boundary of the atmosphere. "at_stp" refers to a volume at standard
> conditions of temperature (273.15 K) and pressure (1013.25 hPa). "pm1"
> refers to the fraction of aerosol particles with an aerodynamic
> diameter of less than or equal to 1 micrometer.
>
>
> 5)
> surface_volume_scattering_coefficient_at_stp_in_air_due_to_pm10_dry_aer
> osol
>
> The volume scattering coefficient is the fractional change of radiative
> flux per unit path length due to redirection of an incident light beam
> by a component in the reference volume. "Aerosol" means the suspended
> liquid or solid particles in air (except cloud droplets). "Dry aerosol"
> is aerosol at a relative humidity < 40% where it hasn't taken up
> ambient water by hygroscopic growth. The specification of a physical
> process by the phrase "due_to_" process means that the quantity named
> is a single term in a sum of terms which together compose the general
> quantity named by omitting the phrase. "surface" means the lower
> boundary of the atmosphere. "at_stp" refers to a volume at standard
> conditions of temperature (273.15 K) and pressure (1013.25 hPa). "pm10"
> refers to the fraction of aerosol particles with an aerodynamic
> diameter of less than or equal to 10 micrometers.
>
>
> 6)
> surface_volume_absorption_coefficient_at_stp_in_air_due_to_pm1_dry_aero
> sol
>
> The volume absorption coefficient is the fractional change of radiative
> flux per unit path length due to absorption of an incident light beam
> by a component in the reference volume. "Aerosol" means the suspended
> liquid or solid particles in air (except cloud droplets). "Dry aerosol"
> is aerosol at a relative humidity < 40% where it hasn't taken up
> ambient water by hygroscopic growth. The specification of a physical
> process by the phrase "due_to_" process means that the quantity named
> is a single term in a sum of terms which together compose the general
> quantity named by omitting the phrase. "surface" means the lower
> boundary of the atmosphere. "at_stp" refers to a volume at standard
> conditions of temperature (273.15 K) and pressure (1013.25 hPa). "pm1"
> refers to the fraction of aerosol particles with an aerodynamic
> diameter of less than or equal to 1 micrometers.
>
>
> 7)
> surface_volume_absorption_coefficient_at_stp_in_air_due_to_pm10_dry_aer
> osol
>
> The volume absorption coefficient is the fractional change of radiative
> flux per unit path length due to absorption of an incident light beam
> by a component in the reference volume. "Aerosol" means the suspended
> liquid or solid particles in air (except cloud droplets). "Dry aerosol"
> is aerosol at a relative humidity < 40% where it hasn't taken up
> ambient water by hygroscopic growth. The specification of a physical
> process by the phrase "due_to_" process means that the quantity named
> is a single term in a sum of terms which together compose the general
> quantity named by omitting the phrase. "surface" means the lower
> boundary of the atmosphere. "at_stp" refers to a volume at standard
> conditions of temperature (273.15 K) and pressure (1013.25 hPa). "pm10"
> refers to the fraction of aerosol particles with an aerodynamic
> diameter of less than or equal to 10 micrometers.
>
>
> 8)
> surface_volume_hemispheric_backscattering_coefficient_at_stp_in_air_due
> _to_pm1_dry_aerosol
>
> The volume hemispheric backscattering coefficient is the fractional
> change of radiative flux per unit path length due to redirection of an
> incident light beam into the rearward hemisphere relative to the
> incident beam by a component in the reference volume. It is distinct
> from the backscattering coefficient which isn't integrated over the
> rearward hemisphere. "Aerosol" means the suspended liquid or solid
> particles in air (except cloud droplets). "Dry aerosol" is aerosol at a
> relative humidity < 40% where it hasn't taken up ambient water by
> hygroscopic growth. The specification of a physical process by the
> phrase "due_to_" process means that the quantity named is a single term
> in a sum of terms which together compose the general quantity named by
> omitting the phrase. "surface" means the lower boundary of the
> atmosphere. "at_stp" refers to a volume at standard conditions of
> temperature (273.15 K) and pressure (1013.25 hPa). "pm1" refers to the
> fraction of aerosol particles with
> an aerodynamic diameter of less than or equal to 1 micrometers.
>
>
> 9)
> surface_volume_hemispheric_backscattering_coefficient_at_stp_in_air_due
> _to_pm10_dry_aerosol
>
> The volume hemispheric backscattering coefficient is the fractional
> change of radiative flux per unit path length due to redirection of an
> incident light beam into the rearward hemisphere relative to the
> incident beam by a component in the reference volume. It is distinct
> from the backscattering coefficient which isn't integrated over the
> rearward hemisphere. "Aerosol" means the suspended liquid or solid
> particles in air (except cloud droplets). "Dry aerosol" is aerosol at a
> relative humidity < 40% where it hasn't taken up ambient water by
> hygroscopic growth. The specification of a physical process by the
> phrase "due_to_" process means that the quantity named is a single term
> in a sum of terms which together compose the general quantity named by
> omitting the phrase. "surface" means the lower boundary of the
> atmosphere. "at_stp" refers to a volume at standard conditions of
> temperature (273.15 K) and pressure (1013.25 hPa). "pm10" refers to the
> fraction of aerosol particles wit
> h an aerodynamic diameter of less than or equal to 10 micrometers.
>
>
> 10) volume_scattering_coefficient_in_air_due_to_aerosol
>
> The volume scattering coefficient is the fractional change of radiative
> flux per unit path length due to redirection of an incident light beam
> by a component in the reference volume. "Aerosol" means the suspended
> liquid or solid particles in air (except cloud droplets). "Aerosol"
> without further qualification such as dry or ambient means that the
> aerosol humidity state is stated in the data. The specification of a
> physical process by the phrase "due_to_" process means that the
> quantity named is a single term in a sum of terms which together
> compose the general quantity named by omitting the phrase.
>
>
> 11) volume_absorption_coefficient_in_air_due_to_aerosol
>
> The volume absorption coefficient is the fractional change of radiative
> flux per unit path length due to absorption of an incident light beam
> by a component in the reference volume. "Aerosol" means the suspended
> liquid or solid particles in air (except cloud droplets). "Aerosol"
> without further qualification such as dry or ambient means that the
> aerosol humidity state is stated in the data. The specification of a
> physical process by the phrase "due_to_" process means that the
> quantity named is a single term in a sum of terms which together
> compose the general quantity named by omitting the phrase.
>
>
> 12) volume_hemispheric_backscattering_coefficient_in_air_due_to_aerosol
>
> The volume hemispheric backscattering coefficient is the fractional
> change of radiative flux per unit path length due to redirection of an
> incident light beam into the rearward hemisphere relative to the
> incident beam by a component in the reference volume. It is distinct
> from the backscattering coefficient which isn't integrated over the
> rearward hemisphere. "Aerosol" without further qualification such as
> dry or ambient means that the aerosol humidity state is stated in the
> data. The specification of a physical process by the phrase "due_to_"
> process means that the quantity named is a single term in a sum of
> terms which together compose the general quantity named by omitting the
> phrase.
>
>
> 13)
> surface_volume_scattering_coefficient_at_stp_in_air_due_to_pm1_aerosol
>
> The volume scattering coefficient is the fractional change of radiative
> flux per unit path length due to redirection of an incident light beam
> by a component in the reference volume. "Aerosol" means the suspended
> liquid or solid particles in air (except cloud droplets). "Aerosol"
> without further qualification such as dry or ambient means that the
> aerosol humidity state is stated in the data. The specification of a
> physical process by the phrase "due_to_" process means that the
> quantity named is a single term in a sum of terms which together
> compose the general quantity named by omitting the phrase. "surface"
> means the lower boundary of the atmosphere. "at_stp" refers to a volume
> at standard conditions of temperature (273.15 K) and pressure (1013.25
> hPa). "pm1" refers to the fraction of aerosol particles with an
> aerodynamic diameter of less than or equal to 1 micrometer.
>
>
> 14)
> surface_volume_scattering_coefficient_at_stp_in_air_due_to_pm10_aerosol
>
> The volume scattering coefficient is the fractional change of radiative
> flux per unit path length due to redirection of an incident light beam
> by a component in the reference volume. "Aerosol" means the suspended
> liquid or solid particles in air (except cloud droplets). "Aerosol"
> without further qualification such as dry or ambient means that the
> aerosol humidity state is stated in the data. The specification of a
> physical process by the phrase "due_to_" process means that the
> quantity named is a single term in a sum of terms which together
> compose the general quantity named by omitting the phrase. "surface"
> means the lower boundary of the atmosphere. "at_stp" refers to a volume
> at standard conditions of temperature (273.15 K) and pressure (1013.25
> hPa). "pm10" refers to the fraction of aerosol particles with an
> aerodynamic diameter of less than or equal to 10 micrometers.
>
>
> 15)
> surface_volume_absorption_coefficient_at_stp_in_air_due_to_pm1_aerosol
>
> The volume absorption coefficient is the fractional change of radiative
> flux per unit path length due to absorption of an incident light beam
> by a component in the reference volume. "Aerosol" means the suspended
> liquid or solid particles in air (except cloud droplets). "Aerosol"
> without further qualification such as dry or ambient means that the
> aerosol humidity state is stated in the data. The specification of a
> physical process by the phrase "due_to_" process means that the
> quantity named is a single term in a sum of terms which together
> compose the general quantity named by omitting the phrase. "surface"
> means the lower boundary of the atmosphere. "at_stp" refers to a volume
> at standard conditions of temperature (273.15 K) and pressure (1013.25
> hPa). "pm1" refers to the fraction of aerosol particles with an
> aerodynamic diameter of less than or equal to 1 micrometers.
>
>
> 16)
> surface_volume_absorption_coefficient_at_stp_in_air_due_to_pm10_aerosol
>
> The volume absorption coefficient is the fractional change of radiative
> flux per unit path length due to absorption of an incident light beam
> by a component in the reference volume. "Aerosol" means the suspended
> liquid or solid particles in air (except cloud droplets). "Aerosol"
> without further qualification such as dry or ambient means that the
> aerosol humidity state is stated in the data. The specification of a
> physical process by the phrase "due_to_" process means that the
> quantity named is a single term in a sum of terms which together
> compose the general quantity named by omitting the phrase. "surface"
> means the lower boundary of the atmosphere. "at_stp" refers to a volume
> at standard conditions of temperature (273.15 K) and pressure (1013.25
> hPa). "pm10" refers to the fraction of aerosol particles with an
> aerodynamic diameter of less than or equal to 10 micrometers.
>
>
> 17)
> surface_volume_hemispheric_backscattering_coefficient_at_stp_in_air_due
> _to_pm1_aerosol
>
> The volume hemispheric backscattering coefficient is the fractional
> change of radiative flux per unit path length due to redirection of an
> incident light beam into the rearward hemisphere relative to the
> incident beam by a component in the reference volume. It is distinct
> from the backscattering coefficient which isn't integrated over the
> rearward hemisphere. "Aerosol" means the suspended liquid or solid
> particles in air (except cloud droplets). "Aerosol" without further
> qualification such as dry or ambient means that the aerosol humidity
> state is stated in the data. The specification of a physical process by
> the phrase "due_to_" process means that the quantity named is a single
> term in a sum of terms which together compose the general quantity
> named by omitting the phrase. "surface" means the lower boundary of the
> atmosphere. "at_stp" refers to a volume at standard conditions of
> temperature (273.15 K) and pressure (1013.25 hPa). "pm1" refers to the
> fraction of aerosol partic
> les with an aerodynamic diameter of less than or equal to 1
> micrometers.
>
>
> 18)
> surface_volume_hemispheric_backscattering_coefficient_at_stp_in_air_due
> _to_pm10_aerosol
>
> The volume hemispheric backscattering coefficient is the fractional
> change of radiative flux per unit path length due to redirection of an
> incident light beam into the rearward hemisphere relative to the
> incident beam by a component in the reference volume. It is distinct
> from the backscattering coefficient which isn't integrated over the
> rearward hemisphere. "Aerosol" means the suspended liquid or solid
> particles in air (except cloud droplets). "Aerosol" without further
> qualification such as dry or ambient means that the aerosol humidity
> state is stated in the data. The specification of a physical process by
> the phrase "due_to_" process means that the quantity named is a single
> term in a sum of terms which together compose the general quantity
> named by omitting the phrase. "surface" means the lower boundary of the
> atmosphere. "at_stp" refers to a volume at standard conditions of
> temperature (273.15 K) and pressure (1013.25 hPa). "pm10" refers to the
> fraction of aerosol parti
> cles with an aerodynamic diameter of less than or equal to 10
> micrometers.
>
> _______________________________________
> Dr. Markus Fiebig
>
> Dept. Atmospheric and Climate Research (ATMOS)
> Norwegian Institute for Air Research (NILU)
> P.O. Box 100
> N-2027 Kjeller
> Norway
>
> Tel.: +47 6389-8235
> Fax : +47 6389-8050
> e-mail: Markus.Fiebig at nilu.no
> skype: markus.fiebig
>
>
> _______________________________________________
> CF-metadata mailing list
> CF-metadata at cgd.ucar.edu
> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
Received on Fri Mar 09 2012 - 18:31:05 GMT
