Climate and Forecast Standard Names
downwelling_radiance_per_unit_wavelength_in_air
deprecated
downwelling_spectral_radiance_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. Radiance is the radiative flux in a particular direction, per unit of solid angle. The direction from which it is coming must be specified, for instance with a coordinate of zenith_angle. If the radiation does not depend on direction, a standard name of isotropic radiance should be chosen instead.