In 2007 Andrea Fassbender became a graduate student in the School of Oceanography at the University of Washington, earning a Master’s degree in 2010. For her PhD, Andrea is working with Dr. Christopher Sabine at NOAA’s Pacific Marine Environmental Laboratory (PMEL) to better understand the ocean’s role in the global carbon cycle.
Currently ~1 million surface ocean carbon measurements are made per year; however, these measurements are not evenly distributed in space and time. As a result, the seasonal and annual surface ocean carbon variability in most locations is unknown or poorly constrained.
Moorings provide useful platforms from which oceanic carbon measurements can be made autonomously; allowing for better temporal resolution of local carbon cycle processes. Currently, pCO2 and pH are the only measurable carbonate system species (Dissolved Inorganic Carbon, Total Alkalinity, pCO2, and pH) that can be monitored autonomously on a mooring. Measurement of two carbonate system species allows for full calculation of all other carbonate system variables; however, because pH and pCO2 strongly co-vary, they are one of the least desirable pairs for this computation.
Andrea is working with scientists and engineers at NOAA PMEL to develop a new instrument that will measure surface ocean concentrations of Dissolved Inorganic Carbon (DIC) on a mooring for up to one year. Because DIC and pCO2 (or pH) do not co-vary strongly, they are a more ideal pair of measurements to make for surface ocean carbon studies.
In addition to instrument development, Andrea works with carbon data from moorings located in the North Pacific Ocean to evaluate seasonal variability in regional carbon cycling. Determining which processes dominate sub-seasonal to interannual variability in the carbon cycle, and how these processes may vary over different time scales, will help to advance our understanding of the North Pacific Ocean carbon sink.