"CMG Research: Delayed Settling of Marine Snow Through Density Transitions and Consequences for the Ocean Carbon Cycle"

University Of North Carolina At Chapel Hill, Chapel Hill NC

Investigators

Abstract

Funds are provided to improve understanding of the fluid dynamics behind marine aggregate settling, in particular investigating the processes by which marine snow, an aggregate of small particles within a mucous-like matrix, accumulates at density transitions and their implications for prolonged residence times in the surface ocean. This will be accomplished through a combination of careful laboratory fluid dynamics experiments and rigorous mathematical hydrodynamic theory in concert with state-of-the-art biogeochemical laboratory measurements. The consequences of these prolonged residence times will be assessed by biogeochemical measurements of the rates of microbial activity, and conversion of particulate organic carbon to dissolved organic carbon and CO2. A synthesis of the biological and physical components will be achieved by combined experiments that directly measure organic matter transformation during settling through a stratified seawater column, linking the physical and biological timescales under conditions representative of the ocean. The results of this work should inform development of improved models of carbon sequestration in the deep ocean, an essential process in the global carbon cycle. The project will contribute to the scientific workforce by supporting an early career faculty member, as well as the continued training of a post-doctoral associate, two graduate students, and four undergraduate students.