Premium
THE OPTICAL CHARACTERIZATION OF NATURAL WATERS BY MEANS OF AN “EXTINCTION COEFFICIENT” 1
Author(s) -
Smith Raymond C.
Publication year - 1968
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1968.13.3.0423
Subject(s) - molar absorptivity , extinction (optical mineralogy) , radiant energy , photosynthesis , environmental science , visibility , attenuation coefficient , optics , biological system , physics , chemistry , biology , radiation , biochemistry
Natural waters are frequently characterized by an extinction coefficient that is generally recognized as a function of the spectral response of the photoprocess as well as of the spectral transmission of the water. The extinction coefficients for two distinct water types are calculated for three types of photoreceptors to demonstrate the manner in which the extinction coefficient depends upon the photoprocess. The visual response of the human eye and the photosynthetic response of Chlorella have been chosen as examples of biological photoprocesses: these are compared with a hypothetical receptor sensitive to the total radiant energy from 350 to 700 m µ . Extinction coefficients for the two water types have been calculated which relate specifically to: the total radiant energy within the limits 350 to 700 m µ ; the visibility of objects in the water; and the photosynthetic activity of the chosen plant. Support is given for the suggestion that the extinction coefficient for the total radiant energy beween 350 and 700 m µ provides the most accurate method for characterizing the photosynthetically useful radiant energy in natural waters.