Spectral Relations of Hydro-Optical Characteristics in Coastal Waters of the South Coast of Crimea

Abstract

The article studies interrelations of the beam attenuation coefficient in different spectrum regions and spectral relations of beam attenuation coefficient to the Secchi depth in the coastal waters of the South Coast of Crimea. The data were used of in situ optical measurements obtained in 2008–2014 from a stationary oceanographic platform installed in the coastal waters of the South Coast of Crimea near the village of Katsiveli. According to the measurement data the relation was determined of the beam attenuation coefficient in eight parts of the spectrum in the wavelength range of 416–640 nm to the Secchi depth, which varies from 6 m to 17.5 m. Spectral distributions of the beam attenuation coefficient at different Secchi depths in coastal and deep sea waters were compared. As a result, it is concluded that the relationships between the spectral attenuation coefficient and the Secchi depth in coastal waters are not applicable to deep sea waters. It is shown that the feature of such equations in coastal waters is related to the higher concentration of fine suspended matter in them. Intercorrelation parameters were calculated of beam attenuation coefficients in different spectrum regions in coastal waters. High correlation coefficients make it possible to reconstruct distribution of the attenuation coefficient in a wide spectral range based on measurements at one wavelength in any spectrum region. The optimal spectral region to measure the beam attenuation coefficient is 468–527 nm.