The effect of advection on the nutrient reservoir in the North Atlantic subtropical gyre.
Though critically important in sustaining the ocean's biological pump, the cycling of nutrients in the subtropical gyres is poorly understood. The supply of nutrients to the sunlit surface layer of the ocean has traditionally been attributed solely to vertical processes. However, horizontal advection may also be important in establishing the availability of nutrients. Here we show that the production and advection of North Atlantic Subtropical Mode Water introduces spatial and temporal variability in the subsurface nutrient reservoir beneath the North Atlantic subtropical gyre. As the mode water is formed, its nutrients are depleted by biological utilization. When the depleted water mass is exported to the gyre, it injects a wedge of low-nutrient water into the upper layers of the ocean. Contrary to intuition, cold winters that promote deep convective mixing and vigorous mode water formation may diminish downstream primary productivity by altering the subsurface delivery of nutrients.
Palter
Jaime B
JB
Division of Earth and Ocean Science, Nicholas School of the Environment and Earth Science, Duke University, Durham, North Carolina 27708, USA. jbp3@duke.edu
Lozier
M Susan
MS
Barber
Richard T
RT
D001267:Atlantic Ocean; D002734:Chlorophyll / Q000378:metabolism*; D004058:Diffusion; D020387:Food Chain; D007700:Kinetics; D009566:Nitrates / Q000378:metabolism*; D010839:Phytoplankton / Q000378:metabolism; D011312:Pressure; D012621:Seasons; D012623:Seawater / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors; D014329:Tropical Climate; D014872:Water Movements
D009566:Nitrates; D002734:Chlorophyll