A5014075002- Oceanographic and Atmospheric Processes
- Ocean Waves and Remote Sensing
- Climate variability and models
- Geology and Paleoclimatology Research
- Tropical and Extratropical Cyclones Research
- Underwater Acoustics Research
- Marine and coastal ecosystems
- Geophysical and Geoelectrical Methods
- Geomagnetism and Paleomagnetism Studies
- earthquake and tectonic studies
- Coastal and Marine Dynamics
- Seismic Waves and Analysis
- Methane Hydrates and Related Phenomena
- Underwater Vehicles and Communication Systems
- Geological and Geophysical Studies
- Geological formations and processes
- Geophysics and Gravity Measurements
- Earthquake Detection and Analysis
- Marine and fisheries research
- Marine Biology and Ecology Research
- Ionosphere and magnetosphere dynamics
- Offshore Engineering and Technologies
- Fluid Dynamics and Mixing
- Ocean Acidification Effects and Responses
- Enhanced Oil Recovery Techniques
University of Hawaii System
1997-2024
University of Hawaiʻi at Mānoa
2010-2022
University of Hawaii at Hilo
2020
Scripps Institution of Oceanography
1983-2003
Oregon State University
2003
National Oceanic and Atmospheric Administration
2003
NOAA National Marine Fisheries Service Pacific Islands Fisheries Science Center
2003
NOAA National Marine Fisheries Service
2003
Woods Hole Oceanographic Institution
1997
University of California, San Diego
1987
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...
Travel times of reciprocal 1000-km range acoustic transmissions, determined from the 1987 Reciprocal Tomography Experiment, are used to study barotropic tidal currents and a large-scale, coherent baroclinic tide in central North Pacific Ocean. The difference travel determines currents, while sum displacement isotachs (or equivalently, isotherms). current accounts for 90% observed differential time variance. measured harmonic constants eight major constituents meter measurements agree well...
Abstract A high-resolution primitive equation model simulation is used to form an energy budget for the principal semidiurnal tide (M2) over a region of Hawaiian Ridge from Niihau Maui. This includes Kaena Ridge, one three main internal generation sites along and study site Hawaii Ocean Mixing Experiment. The 0.01°–horizontal resolution has high level skill when compared satellite in situ sea observations, moored ADCP currents, notably reasonable agreement with microstructure data....
Easterly trade winds from near-equatorial islands in the central Pacific weakened before each El Niño between 1950 and 1978, except for 1963 Niño. The weakening of easterlies their later collapse did not occur uniformly over several months, but rather through a series strong westerly wind bursts lasting 1 to 3 weeks. may force equatorial Kelvin waves ocean that can both initiate sustain sea surface warming characteristics events.
Author Posting. © The Oceanography Society, 2014. This article is posted here by permission of Society for personal use, not redistribution. definitive version was published in 27, no. 2 (2014): 138-150, doi:10.5670/oceanog.2014.49.
The ocean is key to understanding societal threats including climate change, sea level rise, warming, tsunamis, and earthquakes. Because the difficult costly monitor, we lack fundamental data needed adequately model, understand, address these threats. One solution integrate sensors into future undersea telecommunications cables. This mission of SMART subsea cables initiative (Science Monitoring And Reliable Telecommunications). would "piggyback" on power communications infrastructure a...
Prominent oscillations of the meridional current, with a mean period approximately 20 days, have been observed in upper ocean over several years from May 1979 to October 1985 using moored current measurements along Pacific equator at 95°, 110°, 124°,140°W and 152°W, as well off (but near) 110° 140°W. The fluctuations are relatively narrowband (±0.005 cpd) frequency. A 95% statistically significant peak power spectra occurred 124° 140°W, but not 95° 152°W where spectral peaks were smaller....
Abstract Moored current, temperature, and conductivity measurements are used to study the temporal variability of M2 internal tide generation above Kaena Ridge, between Hawaiian islands Oahu Kauai. The energy conversion from barotropic baroclinic measured near ridge crest varies by a factor 2 over 6-month mooring deployment (0.5–1.1 W m−2). flux just off undergoes similar modulation as conversion. largely because changes in phase perturbation pressure, suggesting variable work done on...
The Joint Task Force, Science Monitoring And Reliable Telecommunications (JTF SMART) Subsea Cables, is working to integrate environmental sensors for ocean bottom temperature, pressure, and seismic acceleration into submarine telecommunications cables. purpose of SMART Cables support climate observation, sea level monitoring, observations Earth structure, tsunami earthquake early warning disaster risk reduction, including hazard quantification. Recent advances include regional pilot systems...
The theory of electromagnetic induction by motional sources in the ocean is examined from a first principles point view. field expanded mathematically poloidal and toroidal magnetic modes based on Helmholtz decomposition. After deriving set Green functions for an unbounded constant depth conductivity underlain arbitrary one‐dimensional conducting earth, exact integral equations are obtained which describe process vertically varying conductivity. Approximate solutions constructed...
Eddy energetics in the central equatorial Pacific Ocean is examined using Acoustic Doppler Current Profiler velocities and CTD densities collected during Hawaii-to-Tahiti Shuttle Experiment, 1979–80. Three distinct sources of eddy energy are identified with varying degrees statistical reliability, interpreted as evidence for three separate instabilities mean flow field. An instability at just north equator occurs primarily boreal summer fall. It arises from cyclonic shear between Equatorial...
Spectral analysis of scattered island and coastal tide-gage records from the Pacific Ocean reveals presence a coherent sea level fluctuation at 4–6 days period. The oscillation is distinct baroclinic, inertia-gravity wave fluctuations same periods that are trapped to central equatorial zone. Concomitant surface weather data demonstrates forced by atmospheric pressure but does not respond statically like an "Inverted barometer". basinwide character uniform westward propagation suggest...
Abstract A 3-month mooring deployment (August–November 2002) was made in 2425-m depth, on the south flank of Kaena Ridge, Hawaii, to examine tidal variations within 200 m steeply sloping bottom. Horizontal currents and vertical displacements, inferred from temperature fluctuations, are dominated by semidiurnal internal tide with amplitudes ≥ 0.1 s−1 ∼100 m, respectively. series sensors detected tidally driven overturns scales m. Thorpe scale analysis yields a time-averaged dissipation near...
Abstract Observations of semidiurnal surface currents in the Kauai Channel, Hawaii, are interpreted light interaction internal tides with energetic surface-intensified mesoscale currents. The impacts on tide propagation a cyclone 55-km diameter and ∼100-m vertical decay scale, as well vorticity waves ∼100-km wavelength 100–200-m scales, investigated using 3D ray tracing. Doppler-shifted intrinsic frequency is assumed to satisfy classic hydrostatic wave dispersion relation, local buoyancy...
Profiles of potential density obtained from CTD casts at two stations different distances the Hawaiian ridge are examined for evidence diapycnal turbulent mixing as indicated by inversions and internal-wave vertical strain. Results independent used to produce ensemble-averaged distributions number Thorpe scale. Both parameters were found be higher over slope topography 2500-m depth than in deep ocean, 110 km north. scale–based estimates rate dissipation kinetic energy diffusivity elevated an...
The coherence between single bottom pressure and barotropic velocity records collected in the North Pacific during BEMPEX air pressure, wind stress, stress curl derived from FNOC products are examined over 200‐1 day period band. Strong all atmospheric variables is seen, nonlocal (maximum up to 1000 km southeast) dominating at periods longer than ≈10 d being prevalent shorter periods, consistent with predictions existing models of atmospherically‐forced motion. azimuth maximum relative ocean...
Abstract The global spatial distribution of the turbulent diapycnal diffusivity in abyssal ocean is reexamined light growing body microstructure data revealing bottom-intensified mixing regions rough topography. A direct and nontrivial implication observed intensification that Kρ, depth dependent patchily distributed horizontally across world’s oceans. Theoretical observational studies show upon a variety energy sources processes whose contributions to are sufficiently complex their physical...
Abstract Observations of semidiurnal currents from high-frequency radio Doppler current meters and moored acoustic profilers (ADCPs) in the Kauai Channel, Hawaii, are described compared with two primitive equation numerical models tides. The separating islands Oahu Kauai, is a site strong internal tide generation by barotropic tides flowing over Kaena Ridge, subsurface extension Oahu. nature impacts Channel were intensively studied during 2002–03 near-field component Hawaii Ocean Mixing...
We examine the mean zonal momentum balance in tropical mid‐Pacific using a year of acoustic Doppler current profiler velocities and conductivity‐temperature‐depth densities from Hawaii‐to‐Tahiti Shuttle Experiment. All significant contributions mean, annual cycle, higher‐frequency flow fields are determined with exception vertical stresses. find that even neglecting stresses, equation is rough at 90–117‐m depth all latitudes 4°S to 10°N. While formal error bars large, this reproducible over...
The utility of studying low-frequency surface weather phenomena with long time series meteorological data from tropical Pacific islands is demonstrated. wind stress changes associated El Niño events in the period 1950–78 are examined at seven locations. Zonal anomalies equator near date line often exhibit strengthening and subsequent weakening trade winds prior to each Niño, as originally suggested by Wyrtki. An exception weak 1963 which preceded meridional equator. strongest zonal...
The equation of continuity is used to estimate profiles vertical velocity between 25 and 120 m from moored current measurements in arrays nested within the triangle with vertices located at 1°30′S, 140°W along equator 140° 110°W during December 1983 through March 1984 May‐September 1984. All directions 4‐ 5‐month mean values were upward. ensemble averaged was 2.2 × 10 −5 s −1 . Upwelling speeds decreased eastward.