Biogeochemical response associated with mesoscale structures in the open North Atlantic Ocean

The North Atlantic Ocean is a unique area that has regular occurrences of storm events and mesoscale structures (eddies, fronts). These physical forcings are known to promote episodic fluxes of macronutrients from the deep waters to the oligotrophic photic zone. This fertilizes the surface waters and promotes higher primary production, which in turn stimulates the trophic food web and biogeochemical fluxes. However, the character and magnitude of the biological response vary according to the physics of the mesoscale structure (front, eddy type, wind stress, duration). Here we present an interdisciplinary data set (concentrations of nutrients and chlorophyll a, zooplankton biomass and community structure, aggregate abundance and sinking velocity) that was collected in a cyclonic eddy, which was further impacted by a strong storm event at the Porcupine Abyssal Plain (PAP). We observed two nutrient intrusion events with a 2-fold increase in the surface ocean nutrient concentrations. This increase in nutrients had biological responses ranging from increased chlorophyll to elevated aggregate abundance and export out of the photic zone. At the same time, we also observed changes in the zooplankton community. We will discuss the importance of the mesoscale structures on the biological carbon pump in the open ocean.