Spectral Approach to Assessment of Phytoplankton Photosynthesis Rate in the Black Sea Based on Satellite Information: Methodological Aspects of the Regional Model Development

The work presents the underpinning for using of the spectral approach for assessment of primary productivity indicators based on remote sensing data. Existing information has been analysed. Problems, which should be solved for practical implementation of the spectral model of primary production in the Black Sea based on satellite data, have been identified. It has been shown that application of the regional algorithms for the assessment of the Black Sea primary productivity indicators on the basis of satellite data has improved the accuracy of model assessment of phytoplankton pigment concentration in the sea. Obtained for the last decade data of bio-optical water properties and photo-physiological characteristics of phytoplankton in the Black Sea allow to switch to the new level of regional models, which take into account not only amount, but also the spectral composition of radiation available for photosynthesis. The spectral model takes into account differences in phytoplankton light absorption efficiency between seasons as well as between euphotic zone layers separated by thermocline. Conceptually, this model is more realistic, and could be used not only for operational monitoring of the Black Sea waters, but also for development of predictive models for the sea ecosystem changes.