Variability in the Index of Light Absorption by a Yellow Substance in the Surface Layer of Lake Teletskoye

Abstract

Experimental data obtained in summer 2017 in the course of field hydrophysical studies on the variation in the index of light absorption by a yellow substance in the surface layer of Lake Teletskoye (Altai Mountains) are presented. The calculated values of the index of light absorption by a yellow substance (in natural logarithms) in the spectrum range 400–800 nm during the period under study were within 0.1–2.1 m–1. The yellow substance concentration in Lake Teletskoye, found according to the optical method by the measured index of light absorption by the yellow substance, varied within 2.9–5.1 g/m3. To estimate the effect of light absorption by the yellow substance on the total attenuation, the relative spectral contribution of main optically active lake water components (yellow substance, suspended matter, chlorophyll, and clean water) to the spectral absorption index over the water body under study has been calculated. It has been revealed that the yellow substance makes the maximum contribution at all points (in total, 21 sampling points) of the lake.