Drifters released offshore of Oregon during predominantly downwelling favorable alongshore winds during three different deployments (October 1994, January 1998, and September 1998) display similar behavior: after being advected around in the offshore eddy field, they move onshore to a particular isobath and are advected poleward alongshore, without coming ashore. Numerical...
As part of an experiment to study wind-driven coastal circulation, 17 hydrographic
surveys of the middle to inner shelf region off the coast of Newport, OR (44.65°N, from
roughly the 90 m isobath to the 10 m isobath) were performed during Summer 1999
with a small, towed, undulating vehicle. The...
We used an in situ steady state ¹⁵N-labeled nitrate (¹⁵NO₃⁻) and acetate (AcO⁻) well-to-wells injection experiment to determine how the availability of labile dissolved organic carbon (DOC) as AcO⁻ influences microbial denitrification in the hyporheic zone of an upland (third-order) agricultural stream. The experimental wells receiving conservative (Cl⁻ and Br)...
This study addresses the occurrence, severity, and extent of hypoxia over the continental shelf of the northern
California Current (40–48.5°N latitude) from 1998 to 2012. Clear seasonal trends exist in the timing and duration
of hypoxia. The highest bottom-water dissolved oxygen concentrations occurred from November to March, and
levels below...
Coarse woody debris (CWD, comprised of snags and downed logs) is an important component of the structure and function of forest ecosystems, one which both influences the availability of fuel for wildfires and can be a result of wildfires. We studied snag persistence, and changes in mass of CWD in...
The fate of biologically available nitrogen (N) and carbon (C) in stream ecosystems is controlled by the coupling of physical transport and biogeochemical reaction kinetics. However, determining the relative role of physical and biogeochemical controls at different temporal and spatial scales is difficult. The hyporheic zone (HZ), where groundwater–stream water...
Biogeochemical reactions associated with stream nitrogen cycling, such as
nitrification and denitrification, can be strongly controlled by water and solute residence
times in the hyporheic zone (HZ). We used a whole‐stream steady state ¹⁵N‐labeled
nitrate (¹⁵NO₃⁻) and conservative tracer (Cl⁻) addition to investigate the spatial and
temporal physiochemical conditions controlling...
Measurements of suspended sediment concentration, velocity, salinity, and turbulent
microscale shear in the near-field region of the Columbia River plume are used to investigate
the mechanisms of sediment resuspension and entrainment into the plume. An east-west
transect was occupied during spring and neap tide periods in August 2005 and May...
Ebola viruses (EBOV) cause severe disease in humans and nonhuman primates with high mortality rates and continue to emerge in new geographic locations, including several countries in West Africa, the site of a large ongoing outbreak. Phosphorodiamidate morpholino oligomers (PMOs) are synthetic antisense molecules that are able to target mRNAs...
We inferred the population densities of blue whales (Balaenoptera musculus) and short-beaked common dolphins (Delphinus delphis) in the Northeast Pacific Ocean as functions of the water-column’s physical structure by implementing hierarchical models in a Bayesian framework. This approach allowed us to propagate the uncertainty of the field observations into the...