The Project analyses using Remote Sensing and Cruise measurements the onset of the Spring Bloom (timing, maximum intensity and duration) in the Bay of Biscay region and investigates the conditions triggering the bloom. satellite and in situ surface chlorophyll measurements during the Spring Bloom period are also compared with simultaneous altimetric and SST measurements to analyse the role of the physical mesoscale structure in the observed chlorophyll distribution. A long-term satellite archive of chlorophyll concentration is finally analysed in order to describe the seasonal cycles of satellite chlorophyll a concentration in oceanic environment of the Bay of Biscay and in adjacent shelf and shelf-break regions. The analysed regions present with highly contrasting hydrodynamic regimes and include the wind induced upwellings along the Galician and Cantabrian coasts, the tidal mixed and tidal frontal regimes of the Western English Channel, the shelf environment of weak tides in the Celtic Sea and the region of internal wave mixing along the Celtic shelf-break. These shelf and shelf-break environments are the only ones that can sustain a relevant standing stock of phytoplankton after the Spring Bloom has decayed.
