The bio‐optical state of ocean waters and remote sensing 1

• DOI: 10.4319/lo.1978.23.2.0247
• Publication Date: 2010-03-27T17:11:55Z
• Authors: Raymond C. Smith; Karen S. Baker
• Keywords: 13. Climate action; 14. Life underwater; 01 natural sciences; 0105 earth and related environmental sciences

The diffuse attenuation coefficient for irradiance, KT, is a physical measure of the bio‐optical state of ocean waters. From an analysis of irradiance, KT, and pigment concentration, the specific attenuation due to chlorophyll‐like pigments is found to be 0.016 ± 0.003 [m−1 (mg pigment m−3)−1]. The bio‐optical state of ocean waters can be remotely sensed by spacecraft sensors. KT is readily measured at sea and is highly correlated with and dependent on the chlorophyll‐like pigment concentration, CK. This pigment concentration and KT provide a measure of the fraction of radiant energy attenuated by phytoplankton. This fraction, in turn, is closely related to the production equations formulated by Bannister and can be directly incorporated into a general theory of phytoplankton dynamics. CK may also be used as an index of primary productivity. The determination of the bio‐optical state of ocean waters by surface vessel provides direct information concerning the productivity of these waters; to the extent that the bio‐optical state can be determined by satellite, it may be possible to examine important parameters of the marine ecosystem rapidly and repeatedly.