We present a study of the ocean circulation using state of the art numerical and data assimilation techniques. The second chapter of the thesis presents the development and application of generalized inversion to a simple dynamical model of Lake Kinneret. The intent was to develop the necessary tools to implement...
A long and gradual transition between the summer and winter
oceanic regimes was observed off Oregon during the autumn of 1980.
Hydrographic sections and a single current meter mooring between
August and December show the ocean possessed characteristics during
fall that have not been observed during other seasons: a slow...
This investigation is an exploration of the use of inherent optical properties towards further elucidation of coastal circulation processes occurring on the continental shelf and slope in the Middle Atlantic Bight, south of Cape Cod Massachusetts, during 14-Aug to 1-Sep 1996 and 25-Apr to 15-May 1997. Assessing the possibility of...
The time-averaged velocity field in the North Pacific was estimated in two
sets of inverse calculations. The planetary geostrophic equations were the basis for
dynamical models of the flow in each case. The inverse estimates of the circulation
were obtained by minimizing a positive-definite cost function, which measured the
inconsistency...
By implementing a series of mass-conserving nested high-resolution models down to approximately 1 km resolution that have realistic bathymetry, coastline, wind forcing and river run-off, the winter 1996-1997 shelf flow near Cape Mendocino, California, is simulated and compared with available observations from the Strata Formation on Margins (STRATAFORM) marine geology...
A Regional Ocean Modeling System (ROMS) application for the coastal region of Kenya and Tanzania (0-10° S, 38.7-46.98° E) was developed with the aim of better resolving the circulation patterns in the coastal region that is poorly represented in global models. The model has a horizontal resolution of 4 km,...
Motivated by observations of locally enhanced sea level variability near steep
topographic slopes in regions of strong time-mean flows, effects of zonal ridge topography
on zonal oceanic jet flow are investigated. Unstable wave properties and the
dynamics of eddy-mean flow interaction are evaluated as a function of topographic
geometry using...
We designed an experiment to see if turbulence induced by shear instability
could be a mechanism. Using equipment readily available we completed
an experiment from the Ice Island T-3. A sensor array of current meters
and thermistors (described later on) was suspended beneath the sea ice of
Colby Bay, T-3,...
Between January 1973 and May 1975, the National Science Foundation sponsored a cooperative field program of direct measurements of circulation on the continental shelf of the west coast of the Florida peninsula. With a variety of instruments, records of ocean currents, bottom pressure,
coastal sea level and winds over the...
The circular wave basin provides a means of physically modeling the nearshore
without the typical problems associated with end walls. Three different coastal
processes were examined to demonstrate the use of a spiral wavemaker in a circular
wave basin. These were longshore currents, shear waves, and groin circulation. A
beach...
The area near Point Arguello has long been recognized as a location of strong
upwelling. A tongue of biologically active waters was observed in the earliest studies of
this region (Sverdrup and Allen, 1939). More recently, satellite estimates of chlorophyll by
the Coastal Zone Color Scanner (CZCS) on Nimbus-7 have...
Inner-shelf circulation and mechanisms of across-shelf transport of water masses were examined using seven years of observations collected by the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO) program, a long-term monitoring effort along the central Oregon coast. Since 1998, moored velocity and hydrographic measurements have been obtained during the...
Hydrographic and CTD measurements were taken from ninety-eight stations between Honolulu, Hawaii and Kodiak, Alaska from 4 May to 4 June 1984 on the second leg of the Marathon Expedition. This report consists of the cruise track, vertical sections, listings of all discrete hydrographic data, a subsample of the CTD...
The calculated flow field and tide wave propagation in the Chilean Inland
Seas is modeled with a non-linear tidal embayment method (TEA-NL, Westerink
et al, 1988) and assimilation of tide records of the Chilean Hydrographic Institute.
Model is validated for two test cases with assimilated error-free boundary
conditions.
An Inverse...
Surface drifters were depldyed and tracked over the continental shelf and upper continental slope off central California between Point Conception and Point Sur. The drifters were deployed and tracked from aircraft by Aero-Marine Surveys, Inc. under subcontract to Raytheon Service Company as part of the Central California Coastal Circulation Study...
Mesoscale surveys to examine the relationship between the physical processes and biological response along the Antarctic Polar Front (PF) were conducted as part of the US JGOFS Southern Ocean Program during austral spring and summer 1997/98. Multiple crossings of the PF near 170° W, using a towed undulating instrument, provided...
The mesoscale sea-surface circulation pattern within 400 km off Chile and between 18°S and 40°S latitude is described using chlorophyll and temperature images from the Coastal Zone Color Scanner NIMBUS-7 satellite. The data base is a set of four mosaics developed from band-3 (550 nm) images taken on June 4...
This report documents the oceanographic and meteorological measurements made by the Mooring Observations component of the Coastal Ocean Advances in Shelf Transport (COAST) project during the upwelling experiment from May to August 2001. The focus of COAST is to study the cross-shelf transport processes in a wind-driven system by making...
Numerical model and assimilation experiments were conducted in the tropical Pacific Ocean to obtain a better understanding of the processes that control the cold tongue surface mixed layer temperature balance during August 1999 to July 2004. The numerical model was first applied to test two hypotheses (asymmetric background currents and...
In eastern boundary current upwelling ecosystems, mesoscale circulation features such as eddies and upwelling filaments play a prominent role in the transfer of water and the associated plankton from the productive nearshore to the oligotrophic deep sea. The relationship between mesoscale circulation, zooplankton distributions, and the across-shelf transport of coastal...
Ocean circulation is an important component in Earth's climate system. Predicting future climate and circulation changes requires an improved understanding of the past relationship between climate and ocean currents. The neodymium isotope composition (εNd) of water masses is frequently used as a quasi-conservative tracer to reconstruct ocean circulation. The current...
Tropical coral reef ecosystems are very important from both the ecological and economical
points of view. However, they are also particularly fragile, and have been
declining in recent years in most regions of the world, since they are highly susceptible
to anthropogenic stressors operating at global scales (e.g., global warming...
CTD observations were made over the continental shelf and upper continental slope from the coast to approximately 60 km off central California between latitudes 34°N and 37.5°N. The measurements were made by Raytheon Service Company as part of the Central California Coastal Circulation Study sponsored by the Minerals Management Service....
Influences of tidal and slower (subtidal) oceanic flows over the continental shelf and slope off Oregon are studied using a high-resolution ocean circulation model and comparative model-data analyses. The model is based on the Regional Ocean Modeling System (ROMS), a fully nonlinear, three-dimensional model (using hydrostatic and Boussinesq approximations). The...
Wecoma cruise W8807A was conducted in late July and early August 1988 as part of the Coastal Transition Zone project. CTD observations were made over a standard grid in the coastal transition zone off northern California between 37°N and 39.5°N that was occupied repeatedly during June, July and August; this...
Wecoma cruise W8706A was conducted in June 1987 as part of the pilot study for the Coastal Transition Zone project. CTD observations were made in the coastal transition zone off northern California between 37.5°N and 41.5°N and along 43°13'N off Coos Bay, Oregon. Altogether 133 stations were completed successfully. They...
Wecoma cruise W8702B was conducted in February 1987 as part of the pilot study for the Coastal Transition Zone project. CTD observations were made in the coastal transition zone off northern California between 37.5°N and 4l.5°N. Stations were planned along three alongshore transects, at distances of 60, 90 and 150...
CTD observations were made over the continental shelf and upper
continental slope from the coast to approximately 60 km off central California
between latitudes 34°N and 37.5°N. The measurements were made by Raytheon
Service Company as part of the Central California Coastal Circulation Study
sponsored by the Minerals Management Service....
CTD observations were made over the continental shelf and upper
continental slope from the coast to approximately 60 km off central California
between latitudes 34°N and 37.5°N. The measurements were made by Raytheon
Service Company as part of the Central California Coastal Circulation Study
sponsored by the Minerals Management Service....
CTD observations were made over the continental shelf and upper
continental slope from the coast to approximately 60 km off central California
between latitudes 34°N and 37.5°N. The measurements were made by Raytheon
Service Company as part of the Central California Coastal Circulation Study
sponsored by the Minerals Management Service....
The effects of alongshore variability in topography (banks and capes) and spatial variability in the wind forcing, including the wind-stress curl, on coastal ocean circulation are studied using a combination of observations and model simulations. Satellite sea surface temperature observations are used to describe the seasonal evolution of temperature fronts...
The local and remote sources of variability of the South Atlantic Ocean are investigated using a set of numerical experiments and satellite data. A global, eddy-permitting, numerical simulation is analyzed to investigate the dynamical links between the Antarctic Circumpolar Current (ACC) and the Malvinas Current (MC). The model results indicate...
The atmospheric response to the oceanic forcing in the eastern Pacific along the northern equatorial sea surface temperature (SST) front is investigated in terms of sensible and latent heat flux during the 6-month period 28 July 1999 through 27 January 2000. Of particular interest is the atmospheric boundary layer (ABL)...