Suslin V.V., Churilova T.Ya., Latushkin A.A., Shokurova I.G., Shokurov M.V., Moiseeva N.A., Efimova T.V., Pryahina S.F.
Algorithm of assessment of photosynthetically available radiation near the bottom of the Black Sea shelf was developed and validated. Two-weekly, monthly, and long-term average maps of photosynthetically available radiation were obtained for the period from September 1997 to 2018, based on regional satellite ocean color products and regional spectral bio-optical properties of optically active substances, which profiles were obtained with statistical analysis of long-term measurements from profiling BioArgo floats. Estimates of the photosynthetically available radiation near the bottom of the Black Sea shelf are presented on two-weekly maps with a spatial resolution of 2.5 km by 2.5 km of longitude and latitude for the period from January 1998 to December 2018 on the website at http://blackseacolor.com/browser3.html. Interannual variability of photosynthetically available radiation near the shelf bottom was analyzed for six small designated areas: Zernov’s Phyllophora field, Karkinitsky Bay, in the center of the shelf slope zone, near Odessa, the mouth of the Danube River and Western Crimea. The analyses for summer months revealed an increase of photosynthetically available radiation near the shelf bottom in some areas during the period from 1998 to 2018. However, it was not observed for the winter months. The accuracy of the photosynthetically available radiation assessment is ~50%.