Authors:Takaya Uchida, Dhruv Balwada, Ryan P. Abernathey, Galen A. McKinley, Shafer K. Smith & Marina Lévy
Abstract: The primary productivity of the Southern Ocean ecosystem is limited by iron availability. Away from benthic and aeolian sources, iron reaches phytoplankton primarily when iron-rich subsurface waters enter the euphotic zone. Here, eddy-resolving physical/biogeochemical simulations of a seasonally-forced, open-Southern-Ocean ecosystem reveal that mesoscale and submesoscale isopycnal stirring effects a cross-mixed-layer-base transport of iron that sustains primary productivity. The eddy-driven iron supply and consequently productivity increase with model resolution. We show the eddy flux can be represented by specific well-tuned eddy parametrizations. Since eddy mixing rates are sensitive to wind forcing and large-scale hydrographic changes, these findings suggest a new mechanism for modulating the Southern Ocean biological pump on climate timescales.
Link: https://ssl1236e2e6fb99dfbac0e1b58f364c6f3e05f.vpn.nuist.edu.cn/articles/s41467-020-14955-0
