WHOI PO

Title: Breaking Down and Sinking Through: Mechanisms and Fluxes of Marine Snow

Abstract: 
Understanding the behavior of sinking particles is critical for advancing our knowledge of the biological carbon pump. This seminar presents two interconnected studies that explore the mechanical and dynamic properties of marine snow across experimental and in situ contexts. The first project focuses on simulating controlled laminar shear environments to quantify the mechanical strength of marine snow aggregates. A novel laboratory instrument, coupled with an analytical solution for the flow regime, generated laminar shear conditions comparable in magnitude to those in the ocean’s mixed layer. The findings provided a universal framework for understanding particle fragmentation across various particle types and stress magnitudes.

The second study transitions to the open ocean, where we deploy low-cost open-faced camera systems during the NASA EXPORTS campaigns. This new method captures high-resolution, time-resolved imagery of particle flux events, enabling the visualization of episodic pulses in fecal pellet and aggregate flux. By modeling carbon content at the individual particle level and validating it with parallel sediment trap data, we uncover diel patterns and type-specific flux attenuation not accessible through traditional methods.

Together, these studies bridge laboratory experimentation and field observation, offering new insights into the mechanical integrity and episodic variability of sinking particles that shape the biological carbon pump.