1. Division of Earth and Ocean Science, Nicholas School of the Environment and Earth Science, Duke University, Durham, North Carolina 27708, USA
2. Division of Coastal Systems Science and Policy, Nicholas School of the Environment and Earth Science, Duke University Marine Laboratory, 135 Duke Marine Lab Road, Beaufort, North Carolina 28516, USA

Correspondence to: Jaime B. Palter¹ Correspondence and requests for materials should be addressed to J.B.P. (Email: jbp3@duke.edu).

Abstract

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.

MORE ARTICLES LIKE THIS

These links to content published by NPG are automatically generated.