Through the development and implementation of a ground-breaking robotic approach, REFINE aims at understanding and quantifying the physical, biological and biogeochemical processes controlling the biological carbon pump in the oceanic twilight zone.

Located between the euphotic and the abyssal zones, the twilight zone (~100 and 1000 m depths) exerts a fundamental control on the biological carbon pump, a key component of the oceanic CO2 sequestration. Yet, being not properly sampled during oceanographic cruises and escaping satellite detection, it remains one of the least known environments on Earth. REFINE will develop an explorative ground-breaking robotic-based approach of the twilight zone, specifically emphasizing the role of phyto- and zooplankton communities, to address the processes controlling the fate of organic carbon photosynthetically produced in the euphotic zone. REFINE will focus on five zones, each representative of the diversity of biogeochemical conditions and responses to climate change in the global ocean. The in-depth analysis of the resulting REFINE robotic time-series will allow developing unique carbon flux budgets within the TZ, and understand the physical and plankton-driven mechanisms controlling them.