As a quantitative test of moored mixing measurements using [subscript χ]pods, a comparison experiment was conducted at 0°, 140°W in October–November 2008. The following three measurement elements were involved: (i) NOAA’s Tropical Atmosphere Ocean (TAO) mooring with five [subscript χ]pods, (ii) a similar mooring 9 km away with seven [subscript...
Detailed and repeated measurements of nitrate across the Oregon shelf, made
coincident with turbulence measurements, reveal the importance of cross-isopycnal
mixing via turbulence in providing nitrate to the upper water column. Spatial distributions
of vertical gradients and turbulent fluxes in the Oregon coastal ocean reveal variability that
could not have...
Winter stratification on Oregon’s continental shelf often produces a near-bottom layer of dense fluid that acts as an internal waveguide upon which nonlinear internal waves propagate. Shipboard profiling and bottom lander observations capture disturbances that exhibit properties of internal solitary waves, bores, and gravity currents. Wavelike pulses are highly turbulent...
The upwelling-driven coastal jet off Oregon is in geostrophic balance to first order.
The accompanying thermal wind shear is stable to shear instability. Yet enhanced
turbulence is observed in the upwelling jet, typically as long, thin patches with horizontal
to vertical aspect ratios of 10² to 10³ (median value ~300)....
Closely spaced vertical profiles through the bottom boundary layer over a sloping continental shelf during relaxation from coastal upwelling reveal structure that is consistent with convectively driven mixing. Parcels of fluid were observed adjacent to the bottom that were warm (by several millikelvin) relative to fluid immediately above. On average,...
Near the bottom, the velocity profile in the bottom boundary layer over the continental
shelf exhibits a characteristic law-of-the-wall that is consistent with local estimates of
friction velocity from near-bottom turbulence measurements. Farther from the bottom, the
velocity profile exhibits a deviation from the law-of-the-wall. Here the velocity gradient
continues...
Gene regulatory networks are commonly used for modeling biological processes and revealing underlying molecular mechanisms. The reconstruction of gene regulatory networks from observational data is a challenging task, especially considering the large number of players (e.g. genes) involved and the small number of biological replicates available for analysis. Herein, we...
We examined high-resolution cross-shelf distributions of particulate organic carbon
(POC) and dissolved O₂ during the upwelling season off the Oregon coast. Oxygen
concentrations were supersaturated in surface waters, and hypoxic in near-bottom
waters, with greatly expanded hypoxic conditions late in the season. Simplified time-dependent
mass balances on cross-shelf integrated concentrations...
Barotropic tidal currents flowing over rough topography may be slowed by two bottom boundary–related processes: tangential stress of the bottom boundary layer, which is generally well represented by a quadratic drag law, and normal stress from bottom pressure, known as form drag. Form drag is rarely estimated from oceanic observations...
A pair of hydrographic sections, one north and one south of Cape Blanco at 42.9N, was sampled in five summers (1998–2000 and 2002–2003). The NH line at 44.6N lies about 130 km south of the Columbia River, and spans a relatively wide shelf off Newport, Oregon. The CR line at...