Dynamics of Aggregates and Sinking Carbon Fluxes in a Turbulent Ocean

The ocean's biological pump, a critical component of the Earth's carbon cycle, transports organic matter from the surface ocean to depth, which is dominated by the sinking particles, often in the form of large (1 mm) marine snow aggregates. Controls on carbon export are thought to be driven solely by ecological processes that produce and repackage sinking particles. Here, we present observations illustrating the important roles that storm-generated turbulence has on the abundance, characteristics and sinking fluxes of sinking particles. Turbulence creates and destroys aggregates and the vertical mixing induced by storms enhances their vertical transport. Evidence of the importance of biological processes is also observed. In all, these observations illustrate the complex interplay of physical and biological processes regulating the ocean's biological pump and the challenges in creating a predictive understanding of its function.