[PAOCQ] Amala Mahadevan (WHOI)

“Coupled Dynamics of Nitrate, Phytoplankton, and Eddies: Implications for Oceanic Productivity”

The interaction between physical and biological processes plays a crucial role in shaping the distribution of nitrate, a key nutrient for phytoplankton. In nutrient-limited subtropical oceans, phytoplankton growth is constrained by the vertical transport of nutrients into the sunlit layer—a process strongly influenced by physical dynamics and the underlying nutrient distribution. Conversely, phytoplankton uptake alters nitrate distribution, creating feedback mechanisms that modulate nutrient availability. Using global datasets to analyze nitrate distribution patterns, we propose a simple theoretical framework to explain the observed slope of iso-nitrate surfaces and vertical nitrate gradients. Results from a three-dimensional process study model highlight and differentiate the impacts of mesoscale and submesoscale eddy dynamics on nutrient fluxes. By varying phytoplankton growth rates, we demonstrate that nutrient transport is influenced not only by eddy processes but also by the rate of nutrient uptake by phytoplankton.

PAOC Colloquium —

Interdisciplinary seminar series that brings together the whole PAOC (Program in Atmospheres, Oceans, and Climate) community. Seminar topics include all research concerning the physics, chemistry, and biology of the atmospheres, oceans and climate, as well as talks about societal impacts of climatic processes.

Contact: paoc-colloquium-comm@mit.edu