Initial development of a compact in-situ sensor for measuring the 13C isotope ratio of DIC in the ocean

Woods Hole Oceanographic Institution, Woods Hole MA

Investigators

Abstract

The ability to measure the carbon-13 isotope ratio of dissolved inorganic carbon in the ocean could contribute to studies on carbon dioxide uptake by phytoplankton, the ocean’s uptake of anthropogenic carbon dioxide, the biogeochemistry of hydrothermal systems on the seafloor, and climate research. Applications of such a sensor exist in the laboratory and field, and in locations ranging from coastal waters to the deep ocean. This sensor will enable an improved understanding of the global carbon cycle and biogeochemical processes. This sensor will lay the foundation for developing in situ isotope sensors that can target other gases and will have impact on sensors for other fields (for example, planetary ocean exploration, biomedical applications and industrial applications). To further broaden participation in ocean science, technology, and engineering fields, high school and undergraduate students will be mentored through research opportunities in the laboratory. Through established programs undergraduate students will be brought into the lab for summer research experiences. Through established connections with local schools, high school students will be mentored on research projects. The PIs will develop a hollow core fiber-based sensing approach for the in situ analysis of dissolved inorganic carbon. This sensing approach will rely on absorption spectroscopy in hollow core optical fibers and will have application to dissolved-phase gas sensing. Utilizing the core design of a recently developed sensor for in situ methane detection, that was demonstrated at depths of up to 2000 m, hollow core fibers will be used for isotope analysis in the laboratory, a key first step towards developing an in situ system. Utilization of the hollow core fiber approach, will enable sensors to be made smaller, due to the inherent minute nature of the fibers. The development of smaller sensors will enable additional platforms to be used for deployments in the future. 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.