Seasonal dynamics of the phenomenon of massive coccolithophore blooms across the Bay of Biscay as revealed from space

摘要

In view of the importance of a quantitative assessment of production by aquatic biota of calcium carbonate in the world's oceans, a new approach is developed to use ocean colour data from such sensors as MODIS and MERIS in order to map massive blooms of coccolithophores. The approach developed utilizes the Levenberg-Marquardt technique (LMT) and a hydro-optical model (HOM) encompassing inter alia the optical properties of Emiliania hexleyi and the detached coccoliths. In combination, LMT and HOM constitute a retrieval tool for operational detection and quantitative assessment of the concentration of algal chlorophyll and coccoliths. A practical application of the approach is illustrated for the Bay of Biscay. Seasonal and inter-annual dynamics of this phenomenon are studied in conjunction with the ecological mechanisms indigenous to the aquatic environments under investigation.