Proceedings PaperSolar ultraviolet radiation penetration and photochemical effect on colored dissolved organic matter in coastal waters
|Format||Member Price||Non-Member Price|
The photochemical effect of solar ultraviolet radiation on colored dissolved organic matter has been recently revealed. This effect consists in the change of spectral absorption of sea water in the UV band. In the present paper the experimental data are parameterized to include this effect into radiative transfer theory. A radiative transfer model is developed for calculation of the spectral UV flux at different depths in the sea. The resulting nonlinear radiative transfer equation is solved by the consequent iteration method using quasi-single scattering approximation. Calculations of the spectral irradiance within 290 - 400 nm band were carried out for different solar zenith angles and for different total amounts of ozone. A model of spectral optical properties of sea water inherent to the coastal zone was used. By convolution of irradiance spectra with the DNA action spectrum the biologically effective UV dose rates were calculated. It is shown that solar UV-light effect on the colored dissolved organic matter absorption leads to about 40% increase of the DNA dose rates at a depth of 4 m.