Impacts of Mesoscale Eddies on Nutrient Supply to the Upper Ocean

Vertical sections of temperature, salinity, density and chlorophyll fluorescence
Vertical sections of temperature, salinity, density and chlorophyll fluorescence collected by the SeaHorse in the Sargasso Sea (27 July - 2 August 2005). Values of parameters indicated by colorbar above each plot. White line indicates the depth of the 26.255 kg m-3 isopycnal.

The mechanisms by which nutrients are supplied to the surface layers of the open ocean constitute a fundamental constraint on the productivity of marine ecosystems, and set an upper limit on the so-called “biological pump” in the ocean's carbon cycle. In the oligotrophic gyres, geochemical tracers indicate rates of net community production far surpass that which can be sustained by physically-driven nutrient inputs from wintertime convective mixing and turbulent diffusion. Researchers in the Ocean Sciences Division participated in the EDdies Dynamics, MIxing, Export, and Species composition field program (EDDIES, http://science.whoi.edu/users/olga/eddies/EDDIES_Project.html). The goal of this research was to collect a set of measurements that documented phytoplankton physiological response, changes in community structure, export and the biogeochemical ramifications of eddy induced upwelling and mixing in the Sargasso Sea.

For further information, contact Dr. Blair Greenan.

Reference:

Greenan, B. J. W. 2008. Shear and Richardson number in a mode-water eddy. Deep-Sea Res. Pt. II. 55: 1161-1178.