Cape Verde Frontal Zone in summer 2017: lateral transports of mass, dissolved oxygen and inorganic nutrients

Abstract

Abstract. The circulation patterns in the confluence of the North Atlantic subtropical and tropical gyres delimited by the Cape Verde Front (CVF) were examined during a field cruise in summer 2017. We collected hydrographic data, dissolved oxygen (O2) and inorganic nutrients along the perimeter of a closed box embracing the Cape Verde Frontal Zone (CVFZ). The detailed spatial (horizontal and vertical) distribution of water masses, O2 and inorganic nutrients in the CVF was analyzed, allowing for the independent estimation of the transports of these properties in the subtropical and tropical domains down to 2000 m. Overall, at surface and central levels, a net westward transport of 3.76 Sv was observed, whereas at intermediate levels, a net 3 Sv transport northward was obtained. We observed O2 and inorganic nutrient imbalances in the domain consistent with O2 consumption and inorganic nutrient production by organic matter remineralization, resulting in a net transport of inorganic nutrients to the ocean interior by the circulation patterns.

High-resolution variability of dissolved and suspended organic matter in the Cape Verde Frontal Zone

“…The Cape Verde Frontal Zone (CVFZ) is located in the Eastern margin of the North Atlantic Ocean, off the Mauritanian coast (Figure 1). In this area, North Atlantic Central Water (NACW), transported southwards by the Canary Current, meets South Atlantic Central Water (SACW), transported northwards by the Mauritanian Current, creating a well-defined northeastsouthwest thermohaline front (Zenk et al, 1991;Peŕez-Rodrıǵuez et al, 2001;Martıńez-Marrero et al, 2008;Pelegrıá nd Peña-izquierdo, 2015;Burgoa et al, 2021). This area is also under the influence of the NW Africa Eastern Boundary Upwelling Ecosystem (EBUE) (Messiéand Chavez, 2015).…”