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...
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...
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,...
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)....
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...
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...