A5001047340- Oceanographic and Atmospheric Processes
- Tropical and Extratropical Cyclones Research
- Ocean Waves and Remote Sensing
- Coastal and Marine Dynamics
- Marine animal studies overview
- Marine and coastal ecosystems
- Underwater Acoustics Research
- Marine and fisheries research
- Climate variability and models
- Geological formations and processes
- Coastal wetland ecosystem dynamics
- Marine and coastal plant biology
- Geology and Paleoclimatology Research
- Methane Hydrates and Related Phenomena
- Arctic and Antarctic ice dynamics
- Magnetic properties of thin films
- Aquatic and Environmental Studies
- Fish Ecology and Management Studies
- Physics of Superconductivity and Magnetism
- Adventure Sports and Sensation Seeking
- Water Treatment and Disinfection
- Spectroscopy and Quantum Chemical Studies
- Coastal and Marine Management
- Avian ecology and behavior
- Advanced Condensed Matter Physics
Oregon State University
2014-2025
University of California, San Diego
2024
Woods Hole Oceanographic Institution
2001-2023
NOAA National Marine Fisheries Service
2008-2023
NOAA National Marine Fisheries Service Alaska Fisheries Science Center
1998-2023
Helmholtz-Zentrum Hereon
2020
Naval Postgraduate School
2020
National Taiwan University
2011-2019
National Taiwan Ocean University
2011
Shanghai Ocean University
2010
Numerical simulations of the Hudson River estuary using a terrain‐following, three‐dimensional model (Regional Ocean Modeling System (ROMS)) are compared with an extensive set time series and spatially resolved measurements over 43 day period large variations in tidal forcing river discharge. The is particularly effective at reproducing observed temporal both salinity current structure, including tidal, spring neap, discharge–induced variability. Large stratification between neap tides...
The dynamics of lateral circulation in an idealized, straight estuary under varying stratification conditions is investigated using a three-dimensional, hydrostatic, primitive equation model order to determine the importance momentum budget within estuary. For all runs, about 4 times as strong during flood tides ebbs. This flood–ebb asymmetry due feedback between and along-channel tidal currents, well time-varying over cycle. As increased, significantly reduced because adverse pressure...
The tidally varying circulation, stratification, and salt flux mechanisms are investigated in a shallow wedge estuary where fluvial tidal velocities large the steady baroclinic circulation is comparatively weak. study integrates field observations numerical simulations of Merrimack River estuary. At moderate to high discharge short highly stratified, while at lower discharges it shifts longer, more weakly stratified estuary; transition occurs when length salinity intrusion similar excursion....
Abstract The subtidal salt balance and the mechanisms driving downgradient flux in Hudson River estuary are investigated using measurements from a cross-channel mooring array of current meters, temperature conductivity sensors, along-estuary shipboard surveys obtained during spring 2002. Steady (subtidal) vertical shear dispersion, resulting estuarine exchange flow, was dominant mechanism flux, varied by over an order magnitude spring–neap cycle, with maximum values neap tides minimum tides....
Abstract A tidally and cross-sectionally averaged model based on the temporal evolution of quasi-steady Hansen Rattray equations is applied to simulate salinity distribution vertical exchange flow along Hudson River estuary. The achieves high skill at hindcasting residual velocity variation during a 110-day period in 2004 covering wide range river discharges tidal forcing. approach an existing framework that has been modified improve relative observations. external forcing capture...
The southbound migration of the eastern North Pacific stock gray whales (Eschrichtius robustus) was documented by National Marine Fisheries Service from 13 December 1997 to 24 February 1998, 2000 5 March 2001 and 12 2002. Research protocol essentially identical that used in previous surveys. This involved single observers independently searching for recording data on effort sighting time, location, count direction-headed. In 1997/98, there were 2,346 pods (3,643 whales) counted during 435.0h...
Abstract In most estuarine systems it is assumed that the dominant along-channel momentum balance between integrated pressure gradient and bed stress. Scaling amplitude of circulation based on this has been shown to have predictive skill. However, a number authors recently highlighted important nonlinear processes contribute subtidal dynamics at leading order. study, previously validated numerical model Hudson River estuary used examine forces driving residual test skill two linear scaling...
The temporal response of the length a partially-mixed estuary to changes in freshwater discharge, Qf , and tidal amplitude, UT is studied using 108 day time series collected along Hudson River spring summer 2004 long-term (13.4 year) record near-surface salinity. When was moderately high, tidally-averaged estuary, L5, here defined as distance from mouth up-estuary location where vertically-averaged salinity five psu, fluctuated by more than 47 km over spring-neap cycle, ranging 28 >75 km....
Abstract We present observations of shoaling nonlinear internal bores off the coast central California. The dataset includes 15 moorings deployed during September–October 2017 and cross-shore shipboard surveys. describe structure evolution large-amplitude as they transit from 9 km (100-m depth) to 1 offshore (10 m). observe that two arrive each semidiurnal period, both propagating southwest; total, 72% are tracked 10-m isobath. bore speeds subtidally modulated, but there is additional...
Turbulent mixing of salt is examined in a shallow wedge estuary with strong fluvial and tidal forcing. A numerical model the Merrimack River used to quantify turbulent stress, shear production, buoyancy flux. Little occurs during flood tides despite velocities because bottom boundary layer turbulence dislocated from stratification elevated water column. During ebbs, salinity fronts form at series bathymetric transitions. At fronts, near‐bottom velocity stress are low, but shear, flux...
Wetland‐estuarine‐shelf interaction processes in the Plum Island Sound and Merrimack River system Massachusetts coast are examined using high‐resolution unstructured grid, finite volume, primitive equations, coastal ocean model. The computational domain covers estuarine entire intertidal area with a horizontal resolution of 10–200 m. Driven by five tidal constituents forcing at open boundary on inner shelf eastern Gulf Maine, model has successfully simulated 3‐D flooding/drying process,...
Abstract Isohaline coordinate analysis is used to compare the exchange flow in two contrasting estuaries, long (with respect tidal excursion) Hudson River and short Merrimack River, using validated numerical models. The isohaline averages fluxes salinity space rather than physical space, yielding that incorporates both subtidal precisely satisfies Knudsen relation. can be consistently applied subtidally tidally dominated estuaries. In Hudson, similar results from Eulerian analysis,...
The ability to determine a bulk estuarine turnover timescale that is well defined under realistic conditions in high demand for research and management. We compare how timescales vary with tidal river forcing from idealized scenarios using three-dimensional circulation model of the Yaquina Bay estuary order understand limitations benefits different methods future application. Using results, we formula approaches—the prism method, freshwater fraction relatively new calculation method based on...
Animal telemetry is maturing into a viable method for observing the ocean as it can be used to monitor both environmental conditions and biological metrics along movement trajectories of marine animals. As part Cormorant Oceanography Project, we have augmented biologging tag with an external fast response temperature sensor collect profiles from backs foraging birds. Cormorants dive between 50 250+ times day forage prey so they provide hard-to-match temporal spatial coverage coastal within...
We give a detailed description of the semidiurnal‐band current and temperature variability observed during Internal Waves on Continental Margin (IWAVES) field experiments 1996 1997 off Mission Beach, California. This was dominated by internal tide, structure tide slope shelfbreak region different from that narrow shelf. On shelfbreak, alongshore propagating coastal‐trapped waves. In this region, currents were predominantly oriented in direction. lower half water column at depth H 350 m,...
During the Internal Waves on Continental Margin (IWAVES) field experiments of 1996 and 1997 off Mission Beach, California (32.75°N), we observed energetic, diurnal‐band motions across entire study site in water depths ranging from 15 to 500 m spanning a cross‐shore distance km. The spectral peak currents was at diurnal frequency (σ Di = 1 cpd) sufficiently well resolved be clearly separated slightly higher local inertial (ƒ 1.08 cpd). These were surface enhanced clockwise circularly...
Abstract A series of dye releases in the Hudson River estuary elucidated diapycnal mixing rates and temporal variability over tidal fortnightly time scales. Dye was injected bottom boundary layer for each four during different phases tide spring–neap cycle. Diapycnal occurs primarily through entrainment that is driven by shear production layer. On flood extended vertically mixed layer, its concentration decreased abruptly near base pycnocline, usually at a height corresponding to velocity...
Coupled physical-biological models are capable of linking the complex interactions between environmental factors and physical hydrodynamics to simulate growth, toxicity transport infectious pathogens harmful algal blooms (HABs). Such simulations can be used assess predict impact HABs on human health. Given widespread increasing reliance coastal communities aquatic systems for drinking water, seafood recreation, such predictions critical making informed resource management decisions. Here we...
Abstract A two‐dimensional array of 14 seafloor pressure sensors was deployed to measure properties tidally generated, nonlinear, high‐frequency internal waves over a km by 12 area west Stellwagen Bank in Massachusetts Bay during summer 2009. Thirteen wave packets propagated through the region 6.5 days (one packet every semidiurnal cycle). Propagation speed and direction were determined triangulation, using arrival times distances between triads sensor locations. Wavefront curvature ranged...
Abstract The inner shelf, the transition zone between surfzone and midshelf, is a dynamically complex region with evolution of circulation stratification driven by multiple physical processes. Cross-shelf exchange through shelf has important implications for coastal water quality, ecological connectivity, lateral movement sediment heat. Inner-Shelf Dynamics Experiment (ISDE) was an intensive, coordinated, multi-institution field experiment from September–October 2017, conducted into near...
Abstract The inner shelf is a region inshore of that part the roughly obeys Ekman dynamics and offshore surf zone. Importantly, this where surface bottom boundary layers are in close proximity, overlap, interact. internal tide carries substantial amount energy into were it eventually dissipates contributes to mixing. A transformation due complex interaction with bottom, distinctions between nonlinear waves depression elevation blurred, indeed, polarity reversals incoming take place. From an...