Improved estimates of net community production in the Subarctic Pacific and Canadian Arctic Ocean using ship-based autonomous measurements and computational approaches
department or school: Science, Faculty of
department or school: Earth, Ocean and Atmospheric Sciences, Department of
data provider: DSpace
degree campus: UBCV
creator: Izett, Robert William
issued: 2021-06-17T20:29:22Z
issued: 2021
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: 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 these limitations by combining high-resolution, underway sampling in the Subarctic Northeast Pacific and Canadian Arctic Ocean with instrumentation development and numerical analyses to yield new tools for NCP quantification from ship-based observations. Using measurements of nitrous oxide within and below the mixed layer and the output from a numerical ocean circulation model, I evaluate two approaches for correcting surface NCP estimates for biases caused by vertical mixing fluxes of O₂ in coastal and offshore waters. Applying these approaches produces new NCP estimates that reveal elevated productivity along the continental margin of the Subarctic Pacific and near regions of strong nutrient input from glaciers and wind-driven mixing in the Arctic. I also develop a new approach for NCP quantification based on surface seawater O₂ and nitrogen (N₂) observations obtained using a custom-built autonomous ship-based measurement system. This approach combines high-reso…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/78720
note: IMPROVED ESTIMATES OF NET COMMUNITY PRODUCTION IN THE SUBARCTIC PACIFIC AND CANADIAN ARCTIC OCEAN USING SHIP-BASED AUTONOMOUS MEASUREMENTS AND COMPUTATIONAL APPROACHES by Robert Izett B. Sc., The University of Victoria, 2015 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILISOPHY in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Oceanography) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) June 2021 © Robert Izett, 2021 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the dissertation entitled: Improved estimates of net community production in the Subarctic Pacific and Canadian Arctic Ocean using ship-based autonomous measurements and computational approaches submitted by Robert Izett in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Oceanography. Examining Committee: Philippe Tortell, Earth, Ocean and Atmospheric Sciences, University of British Columbia Supervisor Roberta Hamme, School of Earth and Ocean Sciences, University of Victoria Supervisory Committee Member Kristin Orians, Earth, Ocean and Atmospheric Sciences, University of British Columbia University Examiner Bernard Laval, Civil Engineering, University of British Columbia University Examiner Laurie Juranek, College of Earth, Ocean and Atmospheric Sciences, Oregon State University External Examiner Additional Supervisory Committee Members: Susan Allen, Earth, Ocean and Atmospheric Sciences, University of British Columbia Supervisory Committee Member Debby Ianson, Institute of Ocean Sciences, Department of Fisheries and Oceans Canada Supervisory Committee Member iii Abstract 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…
has type: Thesis/Dissertation
date issued: 2021-11
is shown at: 10.14288/1.0398454
language: eng
degree discipline: Oceanography
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Tortell, Philippe Daniel, 1972-
type: Text
identifier URI: http://hdl.handle.net/2429/78720