A5058297882- Oceanographic and Atmospheric Processes
- Ocean Waves and Remote Sensing
- Tropical and Extratropical Cyclones Research
- Underwater Acoustics Research
- Climate variability and models
- Geology and Paleoclimatology Research
- Geophysical and Geoelectrical Methods
- Geological and Geophysical Studies
- Geological formations and processes
- Underwater Vehicles and Communication Systems
- Coastal and Marine Dynamics
- Marine and fisheries research
- Marine and coastal ecosystems
- Geomagnetism and Paleomagnetism Studies
- Methane Hydrates and Related Phenomena
- Meteorological Phenomena and Simulations
- Fluid Dynamics and Turbulent Flows
- Geophysics and Gravity Measurements
- Arctic and Antarctic ice dynamics
- Scientific Research and Discoveries
- Wind and Air Flow Studies
- Reservoir Engineering and Simulation Methods
- Solar and Space Plasma Dynamics
- Ocean Acidification Effects and Responses
- Fish Ecology and Management Studies
University of Washington Applied Physics Laboratory
2010-2021
University of Washington
2008-2021
Oceanography Society
2015
AMAG Pharmaceuticals (United States)
2009
Woods Hole Oceanographic Institution
1971-2005
Seattle University
2005
Scripps Institution of Oceanography
2003
NOAA National Marine Fisheries Service
2003
Oregon State University
2003
National Oceanic and Atmospheric Administration
2003
The Coupled Boundary Layer Air–Sea Transfer (CBLAST) field program, conducted from 2002 to 2004, has provided a wealth of new air–sea interaction observations in hurricanes. wind speed range for which turbulent momentum and moisture exchange coefficients have been derived based upon direct flux measurements extended by 30% 60%, respectively, airborne Hurricanes Fabian Isabel 2003. drag coefficient (CD) values CBLAST show CD becoming invariant with near 23 m s−1 threshold rather than...
Abstract The authors present inferences of diapycnal diffusivity from a compilation over 5200 microstructure profiles. As observations are sparse, these supplemented with indirect measurements mixing obtained (i) Thorpe-scale overturns moored profilers, finescale parameterization applied to (ii) shipboard upper-ocean shear, (iii) strain as measured by profiling floats, and (iv) shear full-depth lowered acoustic Doppler current profilers (LADCP) CTD Vertical profiles the turbulent dissipation...
The upper ocean's response to three hurricanes [Norbert (1984), Josephine (1984) and Gloria (1985)] is examined using field observations a numerical ocean model. Our goal describe the physical processes that determine structure amplitude of hurricane-driven upper-ocean currents. All these Northern Hemisphere produced rightward-biased mixed-layer current transport. This asymmetry arises because wind stress vector rotates clockwise on right side track remains nearly parallel with inertially...
Vertical propagation of near-inertial period waves has been detected in a series recent velocity profiles by technique vector spectral analysis. This method, previously applied to time, used study the vertical spatial structure obtained Mid-Ocean Dynamics Experiment (MODE). Prior use analysis, however, it is necessary minimize influence variations Brunt-Väisälä frequency. The procedure was normalize current amplitudes and stretch coordinate according WKB scheme. normalized stretched...
The cascade from tides to turbulence has been hypothesized serve as a major energy pathway for ocean mixing. We investigated this along the Hawaiian Ridge using observations and numerical models. A divergence of internal tidal flux observed at ridge agrees with predictions tide Large waves peak-to-peak amplitudes up 300 meters occur on ridge. Internal-wave is enhanced, turbulent dissipation in region near 10 times larger than open-ocean values. Given these elements tides-to-turbulence...
Motionally induced electric and magnetic fields are investigated in the sea, crust, mantle for large-scale low-frequency oceanic flows. It is shown that three-dimensional flows generate horizontal currents not present two-dimensional motions. The resulting penetrate into inducing there currents. degree of mutual induction between ocean depends on parameter δmL, ratio electromagnetic skin depth to scale flow. For δmL≫1 little whereas δmL≪1 strong coupling mantle. variable *,...
An array of instruments air‐deployed ahead Hurricane Frances measured the three‐dimensional, time dependent response ocean to this strong (60 ms −1 ) storm. Sea surface temperature cooled by up 2.2°C with greatest cooling occurring in a 50‐km‐wide band centered 60–85 km right track. The was almost entirely due vertical mixing, not air‐sea heat fluxes. Currents 1.6 and thermocline displacements 50 m dispersed as near‐inertial internal waves. excess 26°C, decreased behind storm primarily...
Abstract Three autonomous profiling Electromagnetic Autonomous Profiling Explorer (EM-APEX) floats were air deployed one day in advance of the passage Hurricane Frances (2004) as part Coupled Boundary Layer Air–Sea Transfer (CBLAST)-High field experiment. The deliberately at locations on hurricane track, 55 km to right and 110 track. These provided profile measurements between 30 200 m situ temperature, salinity, horizontal velocity every half hour during for several weeks afterward. Some...
Abstract An integrated analysis of turbulence observations from four unique instrument platforms obtained over the Hawaiian Ridge leads to an assessment vertical, cross-ridge, and along-ridge structure dissipation rate diffusivity. The diffusivity near seafloor was, on average, 15 times that in midwater column. At 1000-m depth, atop ridge was 30 10 km off ridge, decreasing background oceanic values by 60 km. A weak (factor 2) spring–neap variation observed. also suggest a kinematic...
Results from three separate velocity profilers operated nearly simultaneously in the northwest Atlantic 1975 are used to form a composite shear spectrum over vertical wavelengths 100 m down few centimeters. This exercise constitutes an intercomparison of different measurement techniques and reveals which is approximately fiat at WKB-scaled level k = 0.01 cpm through k0 ≈ 0.1 cpm, then falls as k−1 buoyancy wavenumber (N3/ε)1/2 determined by local average Väisälä frequency N volume-averaged...
Tropical cyclones (TCs) change the ocean by mixing deeper water into surface layers, direct air–sea exchange of moisture and heat from sea surface, inducing currents, waves, waves internal to ocean. In turn, changed influences intensity TC, primarily through action cooler temperatures that modify fluxes. The Impact Typhoons on Ocean in Pacific (ITOP) program made detailed measurements three different TCs (i.e., typhoons) their interaction with western Pacific. ITOP coordinated meteorological...
The volume transport of the Florida Current is determined from motionally induced voltage difference between and Grand Bahama Island. Simultaneous measurements potential differences by velocity profiling have a correlation 0.97. calibration factor 25+/- 0.7 sverdrups per volt, root-mean-square discrepancy sverdrup. about one-half open-circuit value, implying that conductance sediments lithosphere equal to water column.
Abstract Lateral stirring is a basic oceanographic phenomenon affecting the distribution of physical, chemical, and biological fields. Eddy at scales on order 100 km (the mesoscale) fairly well understood explicitly represented in modern eddy-resolving numerical models global ocean circulation. The same cannot be said for smaller-scale processes. Here, authors describe major field experiment aimed observing understanding processes responsible 0.1–10 km. Stirring varying intensity were...
The Mediterranean Sea produces a salty, dense outflow that is strongly modified by entrainment as it first begins to descend the continental slope in eastern Gulf of Cadiz. current accelerates 1.3 meters per second, which raises internal Froude number above 1, and intensely turbulent through its full thickness. loses about half density anomaly roughly doubles volume transport entrains less saline North Atlantic Central water. Within 100 kilometers downstream, turned Coriolis force until...
The response of the ocean to hurricanes was investigated using aircraft-deployable expendable current profilers (AXCP). goals were observe and separate surface wave mixed layer (SML) velocities under storms map across-track along-track velocity temperature in thermocline. Custom instrumentation prepared, including slower failing AXCPs, AXCP equipment installed on NOAA WP-3D aircraft. Research flights made into two 1984 hurricanes: Norbert, eastern Pacific off Baja California (19°N, 109°W),...
An autonomous, profiling float called EM‐APEX was developed to provide a quantitative and comprehensive description of the ocean side hurricane‐ocean interaction. measures temperature, salinity pressure CTD quality relative horizontal velocity with an electric field sensor. Three prototype floats were air‐deployed into upper ahead Hurricane Frances (2004). All worked properly returned highly resolved response category 4 hurricane. At launched 55 km right track, hurricane generated large...
Bulk properties of the Denmark Strait overflow (DSO) plume observed in velocity and hydrography surveys undertaken 1997 1998 are described. Despite presence considerable short-term variability, it is found that pathway evolution density anomaly remarkably steady. Bottom stress measurements show core matches well with a rate descent controlled by friction. The estimated entrainment diagnosed from dilution distance shows marked increase at approximately 125 km sill, leading to net consistent...
Abstract Repeat transects of full-depth density and velocity are used to quantify generation radiation the semidiurnal internal tide from Kaena Ridge, Hawaii. A 20-km-long transect was sampled every 3 h using expendable current profilers absolute profiler. Phase amplitude baroclinic velocity, pressure, vertical displacement were computed, as energy flux. Large barotropically induced isopycnal heaving strong energy-flux divergence observed on steep flanks ridge where upward downward beams...
Near-inertial with horizontal scales ∼O(10 km) dominate profiles of velocity finestructure collected in the North Pacific Subtropical Front during January 1980. Considerable spatial variability is observed. Two features particular contain most energy: a 20 cm s−1 amplitude (λz = 100 m) wave on warm edge front propagating downward and away from front, low wavenumber 500 reflecting off surface. The wavegroup four times as energetic local downgoing near-inertial field. Its structure not...
Numerical modeling of three-dimensional estuarine circulation is often challenging due to complex flow features and strong density gradients. In this paper the skill a specific model assessed against high-resolution data set, obtained in river-dominated mesotidal estuary with autonomous underwater vehicles shipborne winched profiler. The measurements provide detailed view salt wedge dynamics Columbia River estuary. Model examined under contrasting forcing conditions, covering spring freshet...
A parameterization based on internal wave/wave interaction theory, which infers turbulence production from finescale wave shear, is applied to 114 full-water-depth velocity profiles in the Sargasso Sea. An average eddy diffusivity of 0.1 × 10−4 m2 s−1, independent depth, inferred. This value consistent with microstructure measurements abyssal basins eastern North Atlantic and Pacific. It an order magnitude smaller than values inferred a simple vertical advection-diffusion balance or bulk...
Strong semidiurnal internal tides are observed near Mendocino Escarpment in full-depth profile time series of velocity, temperature, and salinity. Velocity density profiles combined to estimate the tide energy flux. Divergence this flux demonstrates that its source is barotropic interacting with escarpment. A baroclinic 7 kW m−1 radiates from escarpment, corresponding 3% 220 fluxing poleward surface tide. Energy concentrated packets emanate flanks ridge surmounting escarpment one site ∼90 km...
We report on a combined modeling and observational effort to understand the Denmark Strait Overflow (DSO). Four cruises over course of 3 years mapped hydrographic properties velocity fields with high spatial resolution. The observations reveal mean path dense water, as well presence strong barotropic flows, energetic variability, bottom friction entrainment. A regional sigma coordinate numerical model interbasin exchange using realistic topography an overflow forced only by upstream...