Below are the updated descriptions for the two proposed standard names.
Note CF does not seem to have a definition for albedo though it is used
in a handful of standard_names.
-ted
?toa_lambertian_equivalent_albedo?
?Albedo is the ratio of the outgoing to the incoming power per unit area
(irradiance). A coordinate variable can be used to specify the radiation
wavelength or frequency. ?toa? means top of atmosphere.
?lambertian_equivalent? means the quantity is evaluated for a diffusely
reflecting surface.?
canonical units = 1
?toa_lambertian_equivalent_albedo_multiplied_by_cosine_solar_zenith_angle?
?Albedo is the ratio of the outgoing to the incoming power per unit area
(irradiance). A coordinate variable can be used to specify the radiation
wavelength or frequency. ?toa? means top of atmosphere.
?lambertian_equivalent? means the quantity is evaluated for a diffusely
reflecting surface. ?multiplied_by_cosine_solar_zenith_angle? means that
the quantity has normalized to remove the angular dependence of the
incoming shortwave irradiance?
canonical units = 1
Jonathan Gregory wrote:
> Dear Ted
>
> Thanks for this explanation:
>
>
>> Reflectance is the ratio of outgoing radiance to incoming irradiance
>> giving it units of per steradians.
>> Albedo is the ratio of outgoing irradiance to incoming irradiance
>> and is unitless.
>> Because the proposed quantity is unitless, albedo is the better term.
>> However, albedo is the integral over all angles of the bidirectional
>> reflectance. In general, true
>> planetary albedo would account for this angular dependence. To make clear the
>> assumption regarding the Lambertian surface I still propose using the term
>>
> Lambertian equivalent in the name. Thus:
>
>
>> toa_lambertian_equivalent_albedo
>> toa_lambertian_equivalent_albdeo_multiplied_by_cosine_solar_zenith_angle
>>
>
> OK, with small L in lambertian as you had before (because stdnames are all
> in lower case). Thanks!
>
> Cheers
>
> Jonathan
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Received on Mon May 13 2013 - 16:01:03 BST
