in a Changing Ocean
This project aims to assess the relevance of oceanic subtropical cyclonic (C) and anticyclonic (A) mesoscale eddies in the context of the Biological Pump (i.e the production of organic matter and its transport to the deep ocean). To achieve this goal, we will study the linkage in the dynamics of mesoscale (O~100 km) and sub-mesoscale (O~10 km) physical processes and their biological and biogeochemical impacts, along the life history of a C and A eddy (from their generation to a mature stage), in the Canary Current Corridor.
The overarching hypothesis of the project is that sub-mesoscale secondary circulation and vertical mixing in mesoscale eddies shape community structure, diversity, functioning and metabolism of planktonic communities, which, in turns, dictate vertical carbon fluxes -both in dissolved (DOC) and particulate (POC) forms- to the ocean interior. Therefore, an accurate assessment of the efficiency of the biological carbon pump in eddies demands process-orientated studies at the sub-mesoscale (as we aim to carry out in this project), that are not currently addressed with traditional field sampling programs. To achieve our goals, we propose an ambitious trans-disciplinary observational program, based on two oceanographic cruises: one during the early stages of generation of C and A eddies, and another, 4-5 months later when the eddies are at a more mature and developed stage. We will combine traditional oceanographic methods with novel instrumentation (e. g. buoys and gliders - see image below) to sample down to the sub-mesoscale.
The level of complexity of this project in terms of fieldwork activities, logistics and interdisciplinary science (combining physical oceanography, biogeochemistry, and biological oceanography) will require the coordination of several research groups with a proven record of experience and skills in their respective fields of knowledge, that have been collaborating for more than a decade in the coupling between physical processes, plankton community structure and metabolism, and carbon biogeochemistry in the Canary Current region. Moreover, near 15 well-known national and international researchers will collaborate in the project.
At the social level, we anticipate that our results will help to understand and validate numerical models used to predict the role that ocean eddies play in the formation, transport and sequestration of organic carbon in the deep ocean, ameliorating the anthropogenic carbon increase in the atmosphere. This would have profound implications for the estimation of new production in eastern boundary upwelling systems (EBUs), where eddy corridors are recurrently found, and, therefore, for the functioning of these systems as sources-sinks of CO2 to the atmosphere as well as seafood suppliers. From the economic perspective, new knowledge generated in e-IMPACT would be thus greatly valuable for the exploitation and sustainable management of marine resources in EBUs. e- IMPACT is linked to Joint Exploration of the Twilight Zone Ocean Network (JETZON) and it is aligned with sustainable development Goals 13 (Climate Action) and 14 (Life Below Water).