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Articles 1 - 7 of 7
Full-Text Articles in Physical Sciences and Mathematics
The Role Of The Alaskan Stream In Modulating The Bering Sea Climate, Tal Ezer, Lie-Yauw Oey
The Role Of The Alaskan Stream In Modulating The Bering Sea Climate, Tal Ezer, Lie-Yauw Oey
CCPO Publications
A numerical ocean circulation model with realistic topography, but with an idealized forcing that includes only lateral transports is used to study the role of the Alaskan Stream (AS) in modulating the Bering Sea (BS) variability. Sensitivity experiments, each one with a different strength of the AS transport reveal a nonlinear BS response. An increase of AS transport from 10 to 25 Sv causes warming (similar to 0.25 degrees C mean, similar to 0.5 degrees C maximum) and sea level rise in the BS shelf due to increased transports of warmer Pacific waters through the eastern passages of the Aleutian …
Topographic Influence On Overflow Dynamics: Idealized Numerical Simulations And The Faroe Bank Channel Overflow, Tal Ezer
CCPO Publications
Properties of the North Atlantic Deep Water (NADW) depend on mixing that occurs in the Denmark Strait (DS) and the Faroe Bank Channel (FBC) overflow regions. How the sill's topography in those regions may affect mixing processes and downstream variability is thus investigated using a high-resolution terrain-following ocean model. Model results agree with observations that show enhanced mixing and entrainment downstream from the sill; however, mixing seems to occur over a longer distance downstream from the FBC sill and more abruptly downstream from the DS sill. Sensitivity experiments with various FBC sill widths demonstrate that the narrow sill is responsible …
Estimation Of Drag Coefficient In James River Estuary Using Tidal Velocity Data From A Vessel-Towed Adcp, Chunyan Li, Arnoldo Valle-Levinson, Larry P. Atkinson, Kuo Chuin Wong, Kamazima M. M. Lwiza
Estimation Of Drag Coefficient In James River Estuary Using Tidal Velocity Data From A Vessel-Towed Adcp, Chunyan Li, Arnoldo Valle-Levinson, Larry P. Atkinson, Kuo Chuin Wong, Kamazima M. M. Lwiza
CCPO Publications
[1] A phase-matching method is introduced to calculate the bottom drag coefficient in tidal channels with significant lateral variation of depth. The method is based on the fact that the bottom friction in a tidal channel causes tidal velocity to have a phase difference across the channel. The calculation involves a few steps. First, the observed horizontal velocity components are analyzed to obtain the amplitude and phase of the velocity at the major tidal frequency. The phase of the longitudinal velocity is then fitted to a relationship derived from the linearized momentum balance. The drag coefficient is then calculated. This …
Inference Of Tidal Elevation In Shallow Water Using A Vessel-Towed Acoustic Doppler Current Profiler, Chunyan Li, Arnoldo Valle-Levinson, Larry P. Atkinson, Tom C. Royer
Inference Of Tidal Elevation In Shallow Water Using A Vessel-Towed Acoustic Doppler Current Profiler, Chunyan Li, Arnoldo Valle-Levinson, Larry P. Atkinson, Tom C. Royer
CCPO Publications
Vessel-towed acoustic Doppler current profilers (ADCPs) have been widely used to measure velocity profiles. Since the instrument is usually mounted on a catamaran floating on the surface, previous studies have used the water surface as the reference level from which the vertical coordinate for the velocity profile is defined. However, because of the tidal oscillation, the vertical coordinate thus defined is time-dependent in an Earth-coordinate system, which introduces an error to the estimated harmonic constants for the velocity. As a result, the total transport will also be in error. This is particularly a problem in shallow waters where the tidal …
Modeling Nutrient And Plankton Processes In The California Coastal Transition Zone: 3. Lagrangian Drifters, J. R. Moisan, Eileen E. Hofmann
Modeling Nutrient And Plankton Processes In The California Coastal Transition Zone: 3. Lagrangian Drifters, J. R. Moisan, Eileen E. Hofmann
CCPO Publications
Two types of numerical Lagrangian drifter experiments were conducted, using a set of increasingly complex and sophisticated models, to investigate the processes associated with the plankton distributions in the California coastal transition zone (CTZ). The first experiment used a one-dimensional (1-D; vertical) time-dependent physical-bio-optical model, which contained a nine-component food web. Vertical velocities, along the track of simulated Lagrangian drifters, derived from a three-dimensional (3-D), primitive equation circulation model developed to simulate the flow observed within the CTZ; were used to parameterize the upwelling and downwelling processes. The second experiment used 880 simulated Lagrangian drifters from a 3-D primitive equation …
Effects Of Wind, Density, And Bathymetry On A One-Layer Southern Ocean Model, John M. Klinck
Effects Of Wind, Density, And Bathymetry On A One-Layer Southern Ocean Model, John M. Klinck
CCPO Publications
Steady solutions from a one-layer, wind-driven, primitive equation model are analyzed to determine the importance of wind forcing, pressure gradient force due to the climatological density distribution and bottom form drag on circulation in the Southern Ocean. Five simulations are discussed: three wind-forced simulations, with differing bathymetry (flat bottom, 15% bathymetry, and full bathymetry), one case with full bathymetry forced with the density-induced pressure force, and one case with full bathymetry forced by both wind and density-induced pressure gradients. The simulations presented here confirm the previous speculation (Munk and Palmen, 1951) that form drag is effective in balancing the driving …
Vorticity Dynamics Of Seasonal Variations Of The Antarctic Circumpolar Current From A Modeling Study, John M. Klinck
Vorticity Dynamics Of Seasonal Variations Of The Antarctic Circumpolar Current From A Modeling Study, John M. Klinck
CCPO Publications
A one-layer numerical model was developed to analyze the vorticity dynamics of the seasonal variations of currents in the Southern Ocean. The model includes the continental geometry and bathymetry of the Southern Ocean and is forced by monthly climatological wind stress. Five cases are considered that compare (i) circulation over a flat bottom to that with bathymetry, (ii) effects of zonally averaged wind stress forcing versus the climatological forcing and (iii) anomaly wind stress (winds with the annual mean removed) versus the full stress. The individual terms in the vorticity conservation equation are calculated from the model solution along two …