A new UV submersible spectroradiometer has been employed to
determine the diffuse attenuation coefficient for irradiance in
the clearest natural waters Kw(\lambda) with emphasis
on the spectral region from 300 to 400 nm.
Kw(\lambda) can be related to the inherent optical
properties of pure water in particular the total absorption
coefficient aw(\lambda) and the molecular scattering
coefficient bm(\lambda), by means of equations derived
from radiative transfer theory. The authors present an analysis
showing that limiting values of Kw(\lambda) can be
estimated from aw(\lambda) and vice versa. Published
aw(\lambda) dat, which show discrepancies much larger
than their estimated accuracies, are briefly reviewed and then
compared, via the authors' analysis, with Kw(\lambda)
data the authors' own new and previously published data as well
as relevant data of others). This comparative analysis and new
data allow a consistent and accurate set of optical properties
for the clearest natural waters and for pure fresh water and
saltwater to be estimated from 300 to 800 nm.
R. C. Smith, K. S. Baker, "Optical properties of the clearest
natural waters (200-800 nm)," Appl.
Opt.,20, 177-184 (1981).