This study investigates wind-driven circulation in the vicinity of the Heceta Bank complex along the Oregon shelf. Numerical experiments forced with steady winds (0.1 Pa) are conducted; upwelling and downwelling cases are compared. The asymmetric bank bathymetry is the only configurational difference from the symmetric bank runs analyzed in Part...
This study examines how coastal banks influence wind-driven circulation along stratified continental shelves. Numerical experiments are conducted for idealized symmetric banks; the standard bank (200 km long and 50 km wide) has dimensions similar to the Heceta Bank complex along the Oregon shelf. Model runs are forced with 10 days...
We present the evolution of oceanographic conditions off the western coast of South America between 1996 and 1999, including the cold periods of 1996 and 1998–1999 and the 1997–1998 El Niño, using satellite observations of sea level, winds, sea surface temperature (SST), and chlorophyll concentration. Following a period of cold...
We investigate the utility of adding a 365 nm ultraviolet (UV) light source to the ExoMars panoramic camera (PanCam) scheduled for launch in 2013. The modification makes it feasible to monitor rover drill cuttings for aromatic organic molecules and provide constraints on polycyclic aromatic hydrocarbons (PAH) as a function of...
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...
The submarine Amsterdam-St. Paul (ASP) Plateau, bisected by the Southeast Indian Ridge (SEIR), is a bathymetric high rising ~2 km above the surrounding seafloor that includes the islands of Amsterdam and St. Paul; this excess volcanism is attributed to a mantle hot spot. We obtained new Sr, Nd, and Pb...
A hydrodynamic model incorporating a self‐consistent treatment of ocean self‐attraction and loading (SAL), and a physically based parameterization of internal tide (IT) drag, is used to assess how accurately barotropic tides can be modeled without benefit of data, and to explore tidal energetics in the last glacial maximum (LGM). M2...
Measurements of tidal currents on the central Oregon shelf are available from several sources, including recent high frequency (HF) coastal radar and Acoustic Doppler Profiler (ADP) deployments, and historical current moorings. In this paper we use a generalized inverse (GI) approach to compare these data to, and then assimilate them...
In conjunction with the USArray component of
EarthScope, long period magnetotelluric (MT) data are
being acquired in a series of arrays across the continental US.
Initial deployments in 2006 and 2007 acquired data (10–
10,000 s) at 110 sites covering the US Pacific Northwest,
distributed with the same nominal spacing...
Tidal energy dissipation is estimated for eight semi‐diurnal and diurnal constituents using a global inverse solution constrained by TOPEX/Poseidon altimeter data. Very similar spatial patterns are obtained for all semi‐diurnal constituents, with about one third of the total dissipation occurring in the deep ocean over rough topography. Maps for diurnal...
Seismic reflection profiles shot across the Cascadia forearc show that a 5–15 km thick band of reflections, previously interpreted as a lower crustal shear zone above the subducting Juan de Fuca plate, extends into the upper mantle of the North American plate, reaching depths of at least 50 km. In...
Wide-angle and vertical incidence seismic data from Seismic Hazards Investigations in Puget Sound (SHIPS), gravity modeling, and seismicity are used to derive two-dimensional crustal models beneath the Strait of Juan de Fuca. The Eocene volcanic Crescent-Siletz terrane is significantly thicker than previously recognized and extends from near the surface to...
High‐resolution three‐dimensional (3‐D) seismic reflection data acquired on the R/V Thomas G. Thompson in 2000 reveal a pair of bottom simulating reflections (BSRs) across a broad region of southern Hydrate Ridge, offshore Oregon. The primary BSR (BSRp) is a regionally extensive reflection that lies 120–150 m below seafloor and exhibits...
We present a modeling study of the upwelling ocean circulation off central Chile (34°–40°S). Using a primitive equation model, we make a numerical simulation of the ocean circulation for summer of 1993, a year characterized by moderate but persistent equatorward winds. The results indicate the formation of an eastern boundary...
The formation mechanisms and pathways of intermediate water in the Southern Ocean are analyzed from output of a high-resolution ocean general circulation model. Deep winter mixed layer formation in the Southern Ocean is diagnosed from the model results and is found to be mostly consistent with observations. Diapycnal water mass...
The Agulhas Current is the western boundary current of the South Indian Ocean and is thought to play an important role in the global overturning circulation. In this study, we investigate the contribution from the wind stress field over each ocean basin of the southern hemisphere to the variability of...
The mass accumulation rates of sedimentary components (carbonate, organic carbon, opal, barite, reactive phosphate, iron, terrigenous minerals, etc.) are used in many paleoceanographic reconstructions to learn about temporal and spatial changes in surficial Earth processes including wind stress and direction, oceanic circulation, weathering rates, marine productivity and ecosystem structure, climate...