Akulova О.B., Bukatyi V.I.
This study presents the results of the light attenuation coefficient measurements in the range of 400–800 nm in the waters of Lake Teletskoye, obtained in a summer cruise (19–23 June 2018). During the cruise in various locations, the attenuation coefficient values varied (to the base of natural logarithm) in the range of 0.2–4.4 m–1 within the stated wave-length range.
The relative spectral effect of the suspended matter was calculated along with the other major optically active components of the lake water: yellow matter, chlorophyll-a and pure water to assess the contribution of suspension to the total attenuation coefficient. Suspended matter spectral contribution to light attenuation at 430 nm wavelength appeared in the range of 2.3–33.4 %, and at 550 nm — 5.9–47.8 %. Optical microscopy was used to determine the particle size distribution and the number concentration of suspended particles. According to the measurements, weight-average particle radii in the water samples varied primarily within the range 0.5–0.8 μm, while the concentrations differed from 0.9∙106cm–3 to 3.3∙106cm–3. Particle size distribution was approximated by the Junge function with a determination coefficient from 0.63 to 0.99.