The magnitude of particulate carbon export from the upper ocean and efficiency of its transfer into the interior remains one of the least predictable processes influencing the global carbon cycle. The…

This is a grant awarded by the National Aeronautics and Space Administration (NASA) Shared Services Center to Skidmore College, a private liberal arts college located in Saratoga Springs, New York. The grant, valued at $1,160,966.94, supports a hypothesis-driven study of particle fluxes in the ocean to advance the understanding of the ocean biological carbon pump. The study is part of the broader EXPORTS program, which aims to develop mechanistic models predicting the strength and efficiency of carbon export from the upper ocean. The grant does not have a set-aside designation. Skidmore College has a history of receiving federal grants to support STEM education research, biological research, and other initiatives aligned with agency missions in education, science, and safety.

The magnitude of particulate carbon export from the upper ocean and efficiency of its transfer into the interior remains one of the least predictable processes influencing the global carbon cycle. The overarching goal of the exports program is to develop mechanistic models predicting the strength and efficiency of this exported carbon. A central requirement one might argue the central requirement of the ambitious set of field measurements necessary to develop satellite-driven models is accurate measurement of sinking particle fluxes and their biological and chemical compositions. These measurements must be embedded in a broader suite of physical, biological, and optical observations, so a second requirement is that the team quantifying particle flux cooperates and works closely with the broader exports science team. Here, we propose a hypothesis-driven study of particle fluxes that both advances our understanding of the ocean biological carbon pump and meets the broader program goals above. The broad hypothesis of the exports program is that the strength and efficiency of the biological carbon pump can be predicted from satellite ocean color observations. Implicit in this hypothesis are a number of assumptions which must be tested. The specific hypotheses we will address are 1) that the biological origin of the particles sinking out of the euphotic zone exerts significant control on both the magnitude of the sinking carbon flux and its rate of attenuation with depth; and 2) that temporal variability in the magnitude and attenuation of sinking particle flux is caused by biological processes.