Wind-driven coastal upwelling brings subsurface water onto the central-Oregon shelf after the spring transition each year. This cold and salty source water is oxygen-poor, yet above the hypoxic threshold, dissolved oxygen < 1.4 ml l⁻¹. Once on the shelf, dissolved oxygen (DO) concentrations of upwelled near-bottom waters are modified by...
An autonomous, in-situ instrument was developed to detect dissolved copper in seawater, suitable for deployment on time scales from weeks to months. A commercially available in-situ nitrate analyzer (YSI 9600) was adapted to measure copper (II) in seawater by chemiluminescence. Modifications included construction of a photomultiplier (PMT) based detector and...
Inner-shelf circulation and mechanisms of across-shelf transport of water masses were examined using seven years of observations collected by the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO) program, a long-term monitoring effort along the central Oregon coast. Since 1998, moored velocity and hydrographic measurements have been obtained during the...
Carbon dioxide (CO₂) fluxes between the ocean and atmosphere on continental margins are difficult to diagnose because these regions experience large variability over spatial and temporal scales spanning meters to basins and hours to years, respectively. In a global sense, continental margins could represent a significant atmospheric CO₂ sink, equivalent...
Small pelagic fish represent a critical trophic link between plankton and large predators in marine upwelling ecosystems such as the California Current System. Populations of these fish are highly variable over time and are characterized by extreme fluctuations in abundance, which have significant ecosystem impacts. The causes driving
this instability...