Recent work by S. Lentz et al. documents offshore transport in the inner shelf due to a wave-driven return
flow associated with the Hasselmann wave stress (the Stokes–Coriolis force). This analysis is extended using
observations from the central Oregon coast to identify the wave-driven return flow present and quantify the...
The spatial and temporal variability of inner-shelf circulation along the central Oregon coast during the
2004 upwelling season is described using a 70-km-long array of moorings along the 15-m isobath. Circulation
at three stations located onshore of a submarine bank differed from that of a station north of the bank,...
The event-scale variability of across-shelf transport was investigated using observations made in 15 m of
water on the central Oregon inner shelf. In a study area with intermittently upwelling-favorable winds and
significant density stratification, hydrographic and velocity observations show rapid across-shelf movement of
water masses over event time scales of...
During the upwelling season in central California, northwesterly winds along the
coast produce a strong upwelling jet that originates at Point Año Nuevo and flows
southward across the mouth of Monterey Bay. A convergent front with a mean
temperature change of 3.77 ± 0.29°C develops between the warm interior waters...
Observations, from the Oregon continental shelf, describe the slumping of a coastal
upwelling front in response to a reversal of winds from upwelling-to downwelling-favorable.
Initially, the front outcropped in a surface mixed layer of depth 10–20 m with a
pronounced cross-shelf density gradient. Following wind reversal, both the unbalanced
cross-shelf...
Wind-driven coastal ocean upwelling supplies nutrients to the
euphotic zone near the coast. Nutrients fuel the growth of phytoplankton,
the base of a very productive coastal marine ecosystem
[Pauly D, Christensen V (1995) Nature 374:255–257]. Because
nutrient supply and phytoplankton biomass in shelf waters are
highly sensitive to variation in...
A high-resolution numerical model with idealized topography is used to investigate the degree to which a coastal upwelling jet separates from the shelf as it flows around a submarine bank depending on the wind strength and the horizontal scale of the bank. Experiments were run using several wind forcing magnitudes...
Data from the SeaWinds scatterometer on the
QuikSCAT satellite are used to estimate upwelling around
Cabo Frio, Brazil, due to Ekman transport and Ekman
pumping. The region close to shore (up to 200 km from the
coast) is characterized by negative wind stress curl
(upwelling favorable) year-round, with maximum values...
In the northern California Current, the onset of the 2005
upwelling season was five weeks later than usual, and well established
upwelling with a cold surface signature did not
occur until about seven weeks after this. As part of the joint
US-Canada Pacific hake survey, from 14–16 July 2005 we...
A fluorescent dye tracer was injected into the
pycnocline on the Oregon shelf at a depth of 9–10 m. It
spread rapidly cross-shelf as two distinct layers, one above
the other in the water column, split by interleaving dye-free
water. The vertical scale of these layers, and associated
density steps,...
Sea surface temperature (SST) fronts are determined for the 2001–2004 time period
from Geostationary Operational Environmental Satellites (GOES) data in the California
Current System (CCS). The probability of detecting a SST front at an individual pixel
location in the CCS is presented as a bi-monthly climatology. Fronts clearly indicate the...
Horizontal current measurements from an array of moored acoustic Doppler profilers are assimilated sequentially into a model of coastal wind-driven circulation off Oregon during the upwelling season of May–August 2001. Model results are compared against independent moored and ship survey data to document a positive effect of velocity data assimilation...
During summer 2001, high-resolution hydrographic, velocity, and bio-optical surveys
were conducted over Heceta Bank off central Oregon. North of the bank, upwelling
over simple bottom topography exhibited a classic response with a midshelf, baroclinic
coastal jet and upwelled isopycnals. The coastal upwelling jet follows the bank
topography as it widens...
The Coastal Ocean Advances in Shelf Transport (COAST) program conducted an
interdisciplinary study of coastal upwelling off central Oregon during summer 2001.
Two intensive field efforts during May–June and August 2001 were coordinated with
ocean circulation, ecosystem, and atmospheric modeling of the region. A primary
goal was to contrast the...
Observations of internal solitary waves (ISWs) and of their role in sediment
resuspension during the Coastal Mixing and Optics 1996 (CMO 96) experiment are
reported. The largest resuspension events observed in the experiment can be related to
retarded flow under the wave footprint. Two distinctly different periods of resuspension
events...
Data from Geostationary Operational Environmental
Satellites are used to study the seasonal evolution of
temperature fronts in the northern California Current
System (CCS), focusing on the interactions with
topographic features. Fronts first appear close to the coast
in response to upwelling winds, moving offshore with the
continuous input of energy...
Repeated mesoscale surveys of waters over the shelf and slope off Oregon were
conducted during spring and summer of 2001 to study the spatial structure of the velocity
and hydrographic fields. The ocean response to wind forcing is compared between a
region of relatively simple topography with alongshore uniformity and...
Velocity measurements from 17 deployments of moored acoustic Doppler current
profilers obtained during four summer upwelling seasons are used to describe the crossshelf
divergence of Ekman transport in the inner shelf off Oregon. For each deployment
the measured surface and bottom cross-shelf transports were compared with estimates
of the theoretical...
MicroSoar, an undulating profiler capable of measuring turbulence parameters such as Thorpe scales and thermal dissipation rate while being towed at speeds of up to 4 m s⁻¹, offers the possibility of obtaining a close-to-synoptic image of mixing over large spatial areas. In this paper, the method of calculating Thorpe...
By mapping the three-dimensional density field while simultaneously tracking a subsurface, isopycnal float, direct observations of upwelling along a shelfbreak front were made on the southern flank of Georges Bank. The thermohaline and bio-optical fields were mapped using a towed undulating vehicle, and horizontal velocity was measured with a shipboard...