Temporal variability of near-bottom dissolved oxygen during upwelling off central Oregon Public Deposited

Downloadable Content

Download PDF

This is the publisher’s pdf. The article is copyrighted by the American Geophysical Union and published by John Wiley & Sons, Inc. It can be found at:


Attribute NameValues
  • In the productive central-Oregon coastal upwelling environment, wind-driven upwelling, tides, and topographic effects vary across the shelf, setting the stage for varied biogeochemical responses to physical drivers. Current, temperature, salinity, and dissolved oxygen (DO) measurements from three moorings deployed during the upwelling seasons of 2009–2011 off the central-Oregon coast are analyzed over three time bands (interannual, subtidal, tidal) to explore the relationship between mid (70 m) and inner-shelf (15 m) upwelling dynamics and the associated effect on DO. Topographic effects are observed in each time band due to the Heceta and Stonewall Bank complex. Seasonal cumulative hypoxia (DO < 1.4 mL L⁻¹) calculations identify two regions, a well-ventilated inner shelf and a midshelf vulnerable to hypoxia (98 ± 15 days annually). On tidal timescales, along-shelf diurnal (K1) velocities are intensified over the Bank, 0.08 m s⁻¹ compared with 0.03 m s⁻¹ to the north. Interannual variability in the timing of spring and fall transitions, defined using glider-measured continental slope source water temperature, is observed on the midshelf. Interannual source water DO concentrations vary on the order of 0.1 mL L⁻¹. Each spring and summer, DO decline rates are modulated by physical and biological processes. The net observed decrease is about 30% of the expected draw down due to water-column respiration. Physical processes initiate low-oxygen conditions on the shelf through coastal upwelling and subsequently prevent the system via advection and mixing from reaching the potential anoxic levels anticipated from respiration rates alone.
Resource Type
Date Available
Date Issued
  • Adams, K. A., J. A. Barth, and F. Chan (2013), Temporal variability of near-bottom dissolved oxygen during upwelling off central Oregon, Journal of Geophysical Research: Oceans, 118, doi:10.1002/jgrc.20361.
Journal Title
Journal Volume
  • 118
Rights Statement
Funding Statement (additional comments about funding)
  • The authors would like to acknowledge the Gordon and Betty Moore Foundation for the support of the MI_LOCO program (grant 1661). This is contribution 440 from PISCO, the Partnership for Interdisciplinary Studies of Coastal Oceans funded primarily by the David and Lucile Packard Foundation and the Gordon and Betty Moore Foundation. We thank our OSU glider group colleagues, specifically K. Shearman, A. Erofeev, Z. Kurokawa, and P. Mazzini, for glider data collection along the Newport Hydrographic line supported by National Science Foundation (NSF) grants OCE-0527168 and OCE-0961999. M. Levine provided the COAST and NH10 mooring data. The NH10 program is funded by the National Science Foundation through the cooperative agreement OCE-0424602 known as CMOP (Coastal Margin Observation & Prediction) and by NOAA through NANOOS (Northwest Association of Networked Ocean Observing Systems), the Pacific Northwest Regional Association of the U.S. Integrated Ocean Observing System (IOOS).
Peer Reviewed



This work has no parents.