Spatial Distribution of the Suspended Particulate Matter Concentration in the Northeastern Black Sea from Hydrooptical Measurements

Abstract— The suspended particulate matter (SPM) concentration in the northeastern Black Sea was calculated from light attenuation coefficient measurements on the cruise 106 of the R/V Professor Vodyanitsky April 18–May 13, 2019. The relationship of the SPM concentration with the characteristics of seawater dynamics and hydrology was investigated. The spatial distributions of the SPM concentration was obtained, and the current state of the vertical optical structure of Black Sea waters was assessed. The generalized vertical structure of the hydrological parameters and SPM concentration was obtained by isopycnic averaging of data for all deep-water stations. The profile of the SPM concentration reflects the typical features of the optical structure of Black Sea waters, showing four main optical layers: surface, intermediate, boundary, and deep. SPM concentrations in the upper layer (at a 5 m depth), in the main pycnocline, and in the redox zone are also considered.