A5014814357- Oceanographic and Atmospheric Processes
- Climate variability and models
- Marine and coastal ecosystems
- Ocean Waves and Remote Sensing
- Geophysics and Gravity Measurements
- Meteorological Phenomena and Simulations
- Geology and Paleoclimatology Research
- Atmospheric and Environmental Gas Dynamics
- Methane Hydrates and Related Phenomena
- Marine Biology and Ecology Research
- Tropical and Extratropical Cyclones Research
- Arctic and Antarctic ice dynamics
- Coastal and Marine Dynamics
- Underwater Acoustics Research
- Reservoir Engineering and Simulation Methods
- Marine and fisheries research
- Geological and Geophysical Studies
- Offshore Engineering and Technologies
- Advanced Computational Techniques and Applications
- Geological formations and processes
- Maritime Navigation and Safety
- Atmospheric aerosols and clouds
- Marine and Offshore Engineering Studies
- Aeolian processes and effects
- Remote Sensing in Agriculture
Florida State University
2017-2020
Stennis Space Center
2010-2020
Prediction Systems (United States)
2019
United States Naval Research Laboratory
2010-2016
University of Southern Mississippi
2016
Bangor University
2016
K Lab (United States)
2011-2015
United States Department of the Navy
2013
United States Navy
2013
Naval Research Laboratory Ocean Sciences Division
2010
The accuracy of state-of-the-art global barotropic tide models is assessed using bottom pressure data, coastal gauges, satellite altimetry, various geodetic data on Antarctic ice shelves, and independent tracked orbit perturbations.Tide under review include empirical, purely hydrodynamic ("forward"), assimilative dynamical, i.e., constrained by observations.Ten dominant tidal constituents in the diurnal, semidiurnal, quarter-diurnal bands are considered.Since last major model comparison...
The location of the Antarctic Polar Front (PF) was mapped over a 7‐year period (1987–1993) within images satellite‐derived sea surface temperature. mean path PF is strongly steered by topographic features Southern Ocean. topography places vorticity constraints on dynamics that affect spatial and temporal variability. Over deep ocean basins expression weakened, meanders wide latitudinal range. Near large features, width temperature change across front increase, large‐scale meandering...
The variability of sea level and surface geostrophic currents in the Southern Ocean is investigated from first 26 months unclassified Geosat altimeter data (November 1986 to December 1988). Because problems unique Geosat, it has been necessary develop new techniques for analyzing height data. These are presented here, processed used examine relation between mesoscale mean circulation (as determined historical hydrographic data). two shown be significantly correlated, implicating importance...
The India-France SARAL/AltiKa mission is the first Ka-band altimetric dedi-cated to oceanography. objectives are primarily observation of oceanic mesoscales but also include coastal oceanography, global and regional sea level monitoring, data assimilation, operational Secondary ice sheet inland waters monitoring. One year after launch, results widely confirm nominal expectations in terms accuracy, quality availability general.
Global comparisons of barotropic and internal tides generated in an eddy‐resolving ocean circulation model are made with tidal estimates obtained from altimetric sea surface heights altimetry‐constrained tide model. As far as we know, our Hybrid Coordinate Ocean Model (HYCOM) simulations shown here earlier paper the only published high‐resolution global to contain tides, general circulation, mesoscale eddies concurrently. Comparing a data‐assimilative shallow water shows that elevation...
Abstract Two global ocean models ranging in horizontal resolution from 1/12° to 1/48° are used study the space and time scales of sea surface height (SSH) signals associated with internal gravity waves (IGWs). Frequency‐horizontal wavenumber SSH spectral densities computed over seven regions world two simulations HYbrid Coordinate Ocean Model (HYCOM) three Massachusetts Institute Technology general circulation model (MITgcm). High wavenumber, high‐frequency variance follows predicted IGW...
The slopes of the wavenumber spectra sea surface height (SSH) and kinetic energy (KE) have been used to infer “interior” or quasi‐geostrophic (QG SQG) dynamics ocean. However, inspection spectral for altimeter SSH in mesoscale band 70 250 km shows much flatter than QG SQG predictions over most Comparison with from an eddy resolving global ocean circulation model (the HYbrid Coordinate Ocean Model, HYCOM, at 1/12.5° equatorial resolution), which has embedded tides, suggests that may arise...
Abstract Motivated by the recent interest in ocean energetics, widespread use of horizontal eddy viscosity models, and promise high resolution data from planned wide-swath satellite altimeter, this paper explores impacts grid on geostrophic turbulence, with a particular focus spectral kinetic energy fluxes Π(K) computed isotropic wavenumber (K) domain. The utilizes idealized two-layer quasigeostrophic (QG) realistic high-resolution general circulation present-generation gridded altimeter...
Abstract High horizontal‐resolution ( and ) 41‐layer global simulations of the HYbrid Coordinate Ocean Model (HYCOM), forced by both atmospheric fields astronomical tidal potential, are used to construct maps sea surface height (SSH) variability. The HYCOM output is separated into steric nonsteric subtidal, diurnal, semidiurnal, supertidal frequency bands. model SSH compared two data sets that offer some geographical coverage also cover a wide range frequencies—a set 351 tide gauges measure...
Abstract The effects of a parameterized linear internal wave drag on the semidiurnal barotropic and baroclinic energetics realistically forced, three-dimensional global ocean model are analyzed. Although main purpose parameterization is to improve surface tides, it also influences tides. relatively coarse resolution ~8 km only permits generation propagation first three vertical modes. Hence, this represents energy conversion subsequent breaking unresolved high total tidal input spatial...
The effects of horizontal resolution and wave drag damping on the semidiurnal M2 tidal energetics are studied for two realistically-forced global HYbrid Coordinate Ocean Model (HYCOM) simulations with 41 layers resolutions 8 km (1∕12.5∘; H12) 4 (1∕25∘; H25). In both simulations, surface error is minimized by tuning strength linear drag, which a parameterization surface-tide energy conversion to unresolved baroclinic modes. tide TPXO8-atlas, an altimetry constrained model, 2.6 cm. Compared...
From moored data, primarily temperature, of the Mid‐Ocean Dynamics Experiment (Mode I) and its successor experiments we find a statistical description mesoscale variability. In Mode I area itself spectral characteristics thermocline deep water are different. The is conveniently described as being made up three bands: ‘low‐frequency’ band dominated by zonal velocity fluctuations, an ‘eddy‐containing’ in which field nearly isotropic, ‘high‐frequency’ consistent with models geostrophic...
Abstract Motivated by the potential of oceanic mesoscale eddies to drive intrinsic low-frequency variability, this paper examines geostrophic turbulence in frequency–wavenumber domain. Frequency–wavenumber spectra, spectral fluxes, and transfers are computed from an idealized two-layer quasigeostrophic (QG) model, a realistic high-resolution global ocean general circulation gridded satellite altimeter products. In QG energy low wavenumbers, arising nonlinear interactions via well-known...
The majority of the eddy kinetic energy (EKE) in ocean is found on scales 50 km to 500 km, encompassed by mesoscale eddies and meanders rings boundary currents. Mesoscale play a critical role dynamics circulation with instabilities strong mean currents generating upper ocean. Interactions between transfer from deep where interact bottom topography generate abyssal flows momentum back global Hybrid Coordinate Ocean Circulation Model (HYCOM) compared long‐term observations surface drifters,...
Abstract The jets in the equatorial Pacific Ocean of a realistically forced global circulation model with horizontal resolution cause strong loss phase coherence semidiurnal internal tides that propagate equatorward from French Polynesian Islands and Hawaii. This is quantified baroclinic energy analysis, which semidiurnal‐band terms are separated into coherent, incoherent, cross terms. For time scales longer than year, coherent flux approaches zero values at equator, while total ∼500 W/m....
The stationarity of the internal tides generated in a global eddy-resolving ocean circulation model forced by realistic atmospheric fluxes and luni-solar gravitational potential is explored.The root mean square (RMS) variability M 2 tidal amplitude approximately mm or less over most exceeds regions with larger amplitude.The RMS approaches weaker areas such as tropical Pacific eastern Indian Ocean, but smaller than near generation regions.Approximately 60% variance complex due to...
SeaWiFS estimates of surface chlorophyll concentrations are reported for the region U.S. JGOFS study in Southern Ocean (∼ 170°W, 60°S). Elevated was observed at fronts, near edge seasonal ice sheet, and above Pacific‐Antarctic Ridge. The elevated levels associated with Ridge surprising since even crest ridge is depths > 2000 m. This phytoplankton biomass likely result mesoscale physical‐biological interactions where Antarctic Circumpolar Current (ACC) encounters ridge. Four cruises...
Analysis of satellite ocean color, sea surface temperature, and ice cover data reveals consistent patterns between biological production, iron availability, physical forcings in the Southern Ocean. The consistency these patterns, conjunction with information on conditions during last glacial maximum (LGM), enables estimates export production at LGM. LGM Ocean experienced increased wind speeds, colder atmospheric temperatures, deposition dust, a greatly expanded winter cover. These variations...
This paper examines the effect of “stencil width” on surface ocean geostrophic velocity and vorticity estimated from differentiating gridded satellite altimeter sea height products. In oceanographic applications, value first derivative at a central grid point is generally obtained by differencing heights adjacent points. called “three‐point stencil centered difference”. Here width increased three to five, seven, nine points, using well‐known formulae numerical analysis literature. The...
Abstract Motivated by the ubiquity of time series in oceanic data, relative lack studies geostrophic turbulence frequency domain, and interest quantifying contributions intrinsic nonlinearities to spectra, this paper examines spectra spectral fluxes surface flows domain. Spectra are computed from idealized two-layer quasigeostrophic (QG) models realistic ocean general circulation models, as well gridded satellite altimeter data. The variance streamfunction (akin sea height) velocity...