On the seasonality of the wavelength of the maximum of the reflectance spectrum in the Black Sea according to satellite data

Abstract

A method for estimating the wavelength of the maximum of the reflectance spectrum of a water surface is proposed. It is based on spline interpolation of reflectances at 469, 488, 531, 547, 555 nm that were recorded with the MODIS-Aqua satellite sensor. The approach was tested using reflectance spectra that were measured with a floating spectral radiometer; it was applied to the set of MODIS images of the Black Sea from 2003 to 2011. We found that the wavelength of the reflectance spectrum peak of water surface shifts towards shorter wavelengths from April to September in the open Black Sea. This phenomenon is attributable to seasonal variations of the composition and contents of optically significant admixtures that are associated with the annual cycle of the vital activities of the phytoplankton.