Developing an Equilibrator Inlet Mass Spectrometer for Underway Measurements of a Suite of Noble Gases

Woods Hole Oceanographic Institution, Woods Hole MA

Investigators

Abstract

Coastal seas are responsible for large air-sea carbon fluxes. Most studies on coastal carbon fluxes combine measurements of the partial pressure of CO2 with a gas exchange parameterization that was designed for the open ocean. However, open ocean gas exchange parameterizations are likely not suitable for application in coastal regions due to issues such as fetch, surfactants, bottom topography, and enhanced bubble fluxes due to wave breaking. Noble gases are biologically and chemically inert and therefore are excellent tracers of physical processes, such as air-sea gas exchange. In addition, because there are five stable noble gases with a range of physicochemical properties, the noble gases respond differently to physical forcing and can be used to separate and quantify physical processes, such as bubble injection and diffusive air-sea gas exchange. Noble gases have successfully been used in the open ocean to construct air-sea gas exchange parameterizations. However, they have not been used in the coastal zone because the heterogeneity in coastal regions makes measurements of the noble gases by traditional means impractical. The PI requests funding to develop an underway mass spectrometer that can measure a suite of noble gases (Ne, Kr, and Xe) from the underway system of a ship. The system could be used in coastal zones to produce a gas exchange parameterization specifically designed for coastal regions. In addition, it could be used to quantify gas exchange in other heterogeneous environments, such as around ice floes, and could be used on icebreakers to study sea ice formation. Broader Impacts: The design of the proposed system will be made widely available through peer-reviewed and web-posted publications, which will include the detailed information necessary for replication of this system by interested research groups. The measurements made using the EIMS-NoG will serve to improve current knowledge of coastal areas air-sea gas exchange rates, and clarify the role of such regions as CO2 sinks/sources. The PI is involved in mentoring of a number of undergraduate students, including female students (through Summer Student and Minority Fellowship program). The PI will also be using the instrument as an educational tool for a large number of undergraduate students (45) during cruises of R/V Tioga, the ship where the instrument will be housed through the large period of the project.