Martin, this is a bit more complicated
the radiative fluxes used in climate studies are usually spectrally integrated and usually for these bradband fluxes there is a distinction between solar broadband and IR broadband fluxes. now for these broadband fluxes we also like to distinguish between clear-sky and all-sky fluxes and for the clear-sky downward fluxes there is a difference if these are based on observations under clear-sky conditions or if they are based on simulations where clouds were simply removed (but not the higher water vapor compared to clear-sky) I would look if there are some definitions for radiative fluxes in the radiation or climate section ...? Stefan On 2/18/2011 2:27 PM, Schultz, Martin wrote:
Dear colleagues, I am trying to clean up some data files and make them CF compliant. But I am confused about the standard name that I could use for (measured) irradiation. There is an entry "downwelling_spectral_radiative_flux_in_air Downwelling radiation is radiation from above. It does not mean "net downward". "spectral" means per unit wavelength or as a function of wavelength; spectral quantities are sometimes called "monochromatic". Radiation wavelength has standard name radiation_wavelength. When thought of as being incident on a surface, a radiative flux is sometimes called "irradiance". In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called "vector irradiance". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics." This definition explicitly mentions "irradiance", so I guess I am close to the solution. However, the irradiance measurement data I have are not "spectral". I did not find a standard_name entry "downwelling_radiative_flux_in_air" which I would have expected to be the integral flux. There are only various variants of "surface_net..." or "surface_spectral..." fluxes. These don't help, or am I wrong here? Unless I am mistaken or have overlooked something obvious, I therefore propose to add a standard_name tabel entry: "downwelling_radiative_flux_in_air Downwelling radiation is radiation from above. It does not mean "net downward". When thought of as being incident on a surface, a radiative flux is sometimes called "irradiance". In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called "vector irradiance". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. For spectrally resolved radiative flux or net radiative flux see downwelling_spectral_radiative_flux_in_air or surface_net_downward_radiative_flux, respectively." Best regards, Martin Schultz = Dr. Martin G. Schultz, IEK-8, Forschungszentrum Jülich = = D-52425 Jülich, Germany = = ph: +49 (0)2461 61 2831, fax: +49 (0)2461 61 8131 = = email: m.schu...@fz-juelich.de = = web: http://www.fz-juelich.de/icg/icg-2/m_schultz = ------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------ Forschungszentrum Juelich GmbH 52425 Juelich Sitz der Gesellschaft: Juelich Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498 Vorsitzender des Aufsichtsrats: MinDirig Dr. Karl Eugen Huthmacher Geschaeftsfuehrung: Prof. Dr. Achim Bachem (Vorsitzender), Dr. Ulrich Krafft (stellv. Vorsitzender), Prof. Dr.-Ing. Harald Bolt, Prof. Dr. Sebastian M. Schmidt ------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------ _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
-- Stefan Kinne MPI-Meteorology Bundesstrasse 53 20146 Hamburg stefan.ki...@zmaw.de tel +49 40 41173 383 fax +49 40 41173 298 _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata