Role of Eddies in the Carbon Pump of Eastern Boundary Upwelling Systems – Demonstration Case Canary Current System

The project will perform a multi-facetted, multi-component field study on the role of the different types of eddies (cyclonic, anticyclonic, anticyclonic mode water) for the lateral transport of bio- geochemical properties and its coupling to the carbon pump in the Canary Current System (CanCS), one of the most productive Eastern Boundary Upwelling Systems (EBUS). The study includes concerted observation and modelling components.

The approach taken follows in part the concept of a successful pilot study of one single anti- cyclonic modewater eddy, carried out off West Africa in 2014. Based on results from this pilot study we aim here on observing all three types of eddies, applying new observing methods, and adding a numerical modeling component. The new observing methods include enhancement of observa- tions at the CVOO and the synergy provided by the MOSES field array in combination with two full R/V Meteor/Merian research cruises dedicated entirely to the study of the structure and temporal evolution of the three different eddy types.



Oceanic eddies affect the physical, biogeochemical and biological properties of coastal upwelling areas. It is hypothesized that climate change will alter the characteristics and statistics of oceanic eddies with probably profound effects on the dynamics and functions of coastal upwelling systems. Considering the extremely high socio-economic relevance of coastal upwelling areas we are planning within the scope of REEBUS a multidisciplinary approach to investigate the influence of oceanic eddies on coastal upwelling systems and thus deepen our understanding of the eddy-driven linkage between physical, biogeochemical and biological processes.

The aim of REEBUS is to gain new insights into the role of eddies, particularly with regard to the CO2 source and sink function of eastern boundary upwelling systems. Furthermore, the biological carbon pump in upwelling areas as well as in associated oligotrophic regions is a focus area of the REEBUS investigation (see below figure 1). Since the biological pump plays a central role in the functioning of upwelling ecosystems, their biodiversity and the ecosystem services they provide. Within REEBUS, the coastal upwelling area off Mauritania, West Africa will be investigated which represents one of the most productive upwelling areas in the eastern boundary current systems.

In total, three major field campaigns and several smaller field surveys are planned in 2019 and 2020. The observation approach is extremely multi-disciplinary and includes a variety of modern components allowing an early identification and thus a purposive investigation of individual oceanic eddies. Additionally, the multi-disciplinary and multi-methodical approach used in REEBUS can also be applied to other eastern upwelling systems for further systematic comparative studies and will thus help to better predict the effect of global change on such important upwelling system.

Figure 1. Schematic illustration of the biological pump in the West African upwelling system and the multi-disciplinary aspects covered and investigated by the single REEBUS work packages (WP1 – WP7).



REEBUS Consortium and Collaboration Partners