Time‐dependent, three‐dimensional, upwelling circulation on the continental shelf off the Oregon coast is studied using a primitive equation numerical model. A limited area domain with a high‐resolution curvilinear grid is utilized. The response of the coastal ocean to forcing by observed wind stress and heat flux during the summer 2001...
A three‐dimensional primitive‐equation model for application to the nearshore surf zone has been developed. This model, an extension of the Princeton Ocean Model (POM), predicts the wave‐averaged circulation forced by breaking waves. All of the features of the original POM are retained in the extended model so that applications can...
A data assimilation system (DAS) of the wind‐driven, mesoscale shelf circulation off the Oregon coast is developed. The DAS assimilates low‐pass filtered surface velocity measurements, obtained from land‐based high‐frequency coastal radar arrays, into a primitive equation coastal ocean model using a sequential optimal interpolation scheme. Inhomogeneous and anisotropic estimates of...
This is the second part of a modeling study of wind-forced flow on the continental shelf off northern California in the region (37°-40°N) of the Coastal Ocean Dynamics Experiment (CODE). Gan and Allen [2002] analyzed the shelf flow response to idealized wind stress forcing in a process-oriented study. The study...
Three-component (NPZ), four-component (NPZD), and five-component (NNPZD) nitrogen-based ecosystem models are compared. The fixed points of the zerodimensional systems, with no spatial variation except light attenuation by water, are determined. A linear-stability analysis shows that unstable steady solutions exist for all three models. Time-periodic solutions are found in these regions....
Csanady (1998) presents solutions for time-dependent wind-driven flow in a barotropic
coastal ocean. We disagree with two of his three boundary condition options and wish to
clarify the origin of the non-wavelike aspect of the flow
An optimal interpolation (OI) sequential algorithm is implemented for a three-dimensional primitive equation model to assimilate current measurements from acoustic Doppler profilers moored on the Oregon shelf as a part of the Coastal Ocean Advances in Shelf Transport (COAST) upwelling experiment (May–August 2001). A stationary estimate of the forecast error...
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...
The coastal ocean may experience periods of fluctuating
along-shelf wind direction, causing shifts between
upwelling and downwelling conditions with responses that
are not symmetric. We seek to understand these asymmetries
and their implications on the Eulerian and Lagrangian flows.
We use a two-dimensional (variations across-shelf and with
depth; uniformity along-shelf)...
The Oregon Coastal Transition Zone (OCTZ) extends several hundred
kilometers offshore where shelf flows interact with the northern California Current. A
primitive-equation numerical ocean model is used to study the upwelling circulation in this
region from 1 May to 1 November 2001. This OCTZ model obtains initial and boundary
conditions...
Seasonal cycles of coastal wind stress, adjusted sea level (ASL), shelf currents, and water
temperatures off the west coast of North America (35°N to 48°N) are estimated by fitting annual and
semiannual harmonics to data from 1981-1983. Longer records (9-34 years) of monthly ASL indicate
that these two harmonics adequately...
Past measurements off the coast of central Oregon and Washington have shown that the rapid change
from northward monthly mean winter winds to southward summer winds forces a "spring transition" of
the coastal ocean: sea levels and temperatures drop, and mean surface currents shift from northward to
southward. Current and...
An Eulerian analysis for wave forcing of three-dimensional (3D) wave-averaged mean
circulation in the surf zone is presented. The objective is to develop a dynamically
consistent formulation for applications in a 3D primitive equation model. The analysis is
carried out for the case of shallow-water linear waves interacting with wave-averaged...
The linear stability of a coastal transition zone (CTZ) jet is analyzed using a six-layer quasi-geostrophic model with observed basic state velocity profiles. The velocity profiles are obtained from objectively analyzed hydrographic and acoustic doppler data from the 1987 CTZ pilot experiment. Along-jet perturbation wave-lengths of 260-265 km are found...
Knowledge of the physical oceanography of continental shelves has increased tremendously in recent years, primarily as a result of new current and hydrographic measurements made in locations where no comparable measurements existed previously. In general, observations from geographically distinct continental shelves have shown that the nature of the flow may...
A two-part modeling study of the wind-forced flow on the continental shelf off
northern California in the region (37°–40°N) of the Coastal Ocean Dynamics Experiment
(CODE) is pursued. This paper involves a process-oriented study with idealized wind
stress forcing. Gan and Allen [2002] involves forcing with observed winds and heat...
The sensitivity of model-produced time-dependent wind-driven circulation on the
continental shelf to the turbulent closure scheme employed is studied with a twodimensional
approximation (variations across-shelf and in depth) using the Princeton
Ocean Model. The level 2.5 Mellor-Yamada closure (MY), k-ε closure, and K-Profile
Parameterization schemes are used to evaluate the...
We simulated the erosion and accretion of a natural beach using a wave-resolving
eddy-diffusive model of water and suspended sediment motion in the bottom boundary
layer. Nonlinear advection was included in this one-dimensional (vertical profile) model
by assuming that waves propagated almost without change of form. Flows were forced by...
The response of alongshore currents V over the continental shelf and of coastal sea level ζ along the
Pacific coast of North America to atmospheric forcing on large alongshore scales (100-2000 km) during
May-July 1981 (Coastal Ocean Dynamics Experiment (CODE) 1) and May-July 1982 (CODE 2) has
been studied using...
We study the statistical properties of the coastal wind field along the west coast of North America for
two summers. 1981 and 1982 Coastal Ocean Dynamics Experiments 1 and 2, respectively), and the
Intervening winter using measured winds and geostrophic winds calculated from Fleet Numerical Oceanography
Center atmospheric pressure analyses....