PMEL Project: Global Observations of Biogeochemistry and Ocean Physics
PhD, Ocean Sciences, University of California Santa Cruz (2021).
Dr. Xiang is working with Dr. Paul Quay (UW Oceanography), Dr. Rolf Sonnerup (UW CICOES/NOAA PMEL), and Dr. Andrea Fassbender (NOAA PMEL) to investigate the elemental carbon/nitrogen/phosphorous (C/N/P) stoichiometry of
exported organic matter using observed dissolved nutrient data in the upper ocean. Specifically, we will calculate nutrient gradients in the surface ocean globally using measured dissolved inorganic carbon, nitrate, and phosphate concentrations compiled in the Global Ocean Data Analysis Project (GLODAP). Nitrogen fixation and carbon dioxide gas exchange are two critical processes that connect dissolved nutrient gradients to C/N/P ratios of organic matter exported from the surface ocean. The magnitude of elemental C/N/P ratios exerts an important control on the efficiency of carbon sequestration from the atmosphere. This work will improve our understanding of regional variations of C/N/P of exported organic matter to better characterize the ocean’s biological pump, and shed light on its impact on atmospheric carbon dioxide in the context of rapidly changing climate.