All of this makes sense to me. It prompts me to ask: Is 'cloud' actually a process? Or should the standard due_to definition clause be updated to include process or substance?
John On Dec 19, 2013, at 09:49, Gary Meehan <[email protected]> wrote: > Dear CF board, > > I would like to close the loop on a question posed this past April pertaining > to the definition associated with the standard name, > atmosphere_optical_thickness_due_to_cloud. At the time, it was observed by > the original poster that the definition of this standard > name does not make a connection to the presence of cloud contributing to the > atmosphere optical thickness quantity. As a result, it was > proposed that the definition of this standard name be amended by introducing > the sentence "Cloud means the component > of extinction owing to the presence of liquid or ice water particles." The > definition of this standard name, in its entirety, would thus read as follows: > > The optical thickness is the integral along the path of radiation of a volume > scattering/absorption/attenuation coefficient. > The radiative flux is reduced by a factor exp(-optical_thickness) on > traversing the path. A coordinate variable of radiation_wavelength > or radiation_frequency can be specified to indicate that the optical > thickness applies at specific wavelengths or > frequencies. The atmosphere optical thickness applies to radiation passing > through the entire atmosphere. "Cloud" means > the component of extinction owing to the presence of liquid or ice water > particles. 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. > > The goal of re-posting this question to the Board is to inquire if it feels > that an update to the definition is warranted, and if > the proposed wording is thus acceptable. Updating the definition in this > manner would make it consistent with the definitions > of the other atmosphere_optical_thickness_due_to_<process> standard names. > > Sincerely, > > Gary > -- > Gary Meehan > Senior Staff Scientist > Atmospheric and Environmental Research > 131 Hartwell Avenue, Lexington, MA 02421-3126 > Tel (781) 761-2228 • Fax (781) 761-2299 > e-mail: [email protected] > _______________________________________________ > 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
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