Improved estimates of net community production in the Subarctic Pacific and Canadian Arctic Ocean using ship-based autonomous measurements and computational approaches ...

• Main Author: Izett, Robert William
• Format: Text
• Language: English
• Published: University of British Columbia 2021
• Subjects: Arctic; Arctic Ocean; Subarctic
• Online Access: https://dx.doi.org/10.14288/1.0398454; https://doi.library.ubc.ca/10.14288/1.0398454

This PhD thesis focuses on the development of new tools for measuring marine net community production (NCP), an important ecological variable quantifying the metabolic balance between photosynthesis and community-wide respiration. A common approach to estimating NCP exploits the seawater oxygen-to-argon ratio (O₂/Ar) and derived biological O₂ saturation anomaly, ΔO₂/Ar, as a tracer of net biological production. Using ship-based mass spectrometry, ΔO₂/Ar can be measured at high-resolution, enabling surface water NCP quantification from evaluations of the mixed layer O₂ budget. However, resulting NCP estimates may be biased by the vertical mixing flux of low- or high-O₂ water into the ocean’s surface, while the requirement of mass spectrometry to measure ΔO₂/Ar has largely constrained ship-based NCP quantification to ocean regions sampled by research vessels. These challenges have limited our ability to accurately observe NCP variability, particularly in coastal or under-sampled waters. This thesis addresses ...