NSF Award
2220659
The ocean naturally moves carbon produced by living organisms from the atmosphere to deep water, and this plays an important role in how Earth’s climate may respond to increasing amounts of carbon dioxide. Additionally, some have proposed attempting to intentionally accelerate this process in an effort to reverse human carbon dioxide emissions. However, teasing apart the different biological influences that drive sinking carbon remains a major challenge. The tools that are required to measure sinking carbon are often expensive and specialized, limiting their accessibility. In this project, a camera-equipped sediment trap that catches and identifies sinking particles will be developed, tested, and refined. It will utilize openly shared software, and hardware designs that are based upon commercially-available components, to enable easier adoption by other researchers. This project will also provide opportunities for mentoring and training to a graduate student and undergraduate summer students, and would support an early-career researcher.<br/><br/>The biological carbon pump, which delivers organic carbon into the ocean’s interior, has received focused scientific attention for decades because it maintains the ocean’s vertical dissolved inorganic carbon gradient, and is closely linked to global climate via exchange of carbon dioxide with the atmosphere. Ongoing anthropogenic impacts on the ocean may drive future changes in the efficiency of the biological carbon pump, which would have important climate implications. Intentionally increasing the input of biological carbon into the ocean, either through nutrient fertilization or biomass injection, is also proposed as a candidate method to increase ocean carbon sequestration. The development of widely-available tools for measuring sinking organic matter fluxes is therefore of great importance. The first objective of this project is to develop and test a sediment trap controller that would simplify the construction and deployment of neutrally-buoyant sediment traps based upon commercially-available profiling floats, thus broadening the potential user base of such traps. The second objective is to integrate with the trap controller a low-cost, upward-looking in situ camera to image sinking particles. Characterizing this camera’s laboratory and field performance under a variety of platform hydrodynamic conditions, and developing software for onboard data reduction, will lay the groundwork for its use to quantify sinking carbon fluxes aboard autonomous platforms. Finally, recognizing that the lower mesopelagic zone (defined here as 500-1000 m) is critical to observations of biological carbon sequestration over long timescales, the third project objective is to optimize these tools for use at these typically under-sampled depths.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
