Planktonic blooms from the Patagonian Shelf to the Open Waters of the Atlantic Sector of the Southern Ocean

The Patagonian shelf hosts some of the largest chlorophyll-a blooms of the Southern Ocean. Previous studies have shown that several physical processes, including shelfbreak upwelling and tidal mixing, as well as nutrient loads from continental and groundwater discharges and aeolian dust deposition can sustain these blooms. The vigorous exchanges of mass between the deep ocean and the Patagonian shelf are also thought to be an important source of micro-nutrients for the fertilization of the Southern Ocean, the main reason why the Atlantic basin dominates the primary productivity cycle of the subpolar region. We have developed a high-resolution, coupled ecosystem/iron/circulation model to quantitatively examine the physical and bio-chemical processes underlying Patagonia’s chlorophyll-a blooms and the interaction between this shelf and the deep ocean.