Lawrence J. Pratt

ORCID: 0000-0003-2183-3020
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About
Contact & Profiles
Research Areas
  • Oceanographic and Atmospheric Processes
  • Fluid Dynamics and Turbulent Flows
  • Tropical and Extratropical Cyclones Research
  • Quantum chaos and dynamical systems
  • Geological formations and processes
  • Geology and Paleoclimatology Research
  • Methane Hydrates and Related Phenomena
  • Climate variability and models
  • Ocean Waves and Remote Sensing
  • Arctic and Antarctic ice dynamics
  • Meteorological Phenomena and Simulations
  • Fish Ecology and Management Studies
  • Marine and fisheries research
  • Reservoir Engineering and Simulation Methods
  • Geophysics and Gravity Measurements
  • Climate change and permafrost
  • Hydraulic Fracturing and Reservoir Analysis
  • Marine and environmental studies
  • Marine and coastal ecosystems
  • Micro and Nano Robotics
  • Complex Systems and Time Series Analysis
  • Hydraulic flow and structures
  • Nonlinear Dynamics and Pattern Formation
  • Geomagnetism and Paleomagnetism Studies
  • Coastal and Marine Dynamics

Woods Hole Oceanographic Institution
2014-2024

Brown University
1996-1997

University of New Hampshire
1997

Duke University
1997

University of Rhode Island
1983-1985

University of Missouri
1963

Abstract This study investigates the anisotropic properties of eddy-induced material transport in near-surface North Atlantic from two independent datasets, one simulated sea surface height altimetry and derived real-ocean drifters, systematically examines interactions between mean- region. The Lagrangian particle dispersion, which is widely used to characterize tracer fluxes, quantified by constructing “spreading ellipses.” analysis consistently demonstrates that this dispersion spatially...

10.1175/jpo-d-11-0191.1 article EN Journal of Physical Oceanography 2012-08-21

The circulation in an ocean basin containing island is studied under nearly geostrophic, beta plane dynamics. model a fluid of uniform density driven by wind forcing or sources and sinks mass at the upper boundary flow. analytically, numerically, as well laboratory through device “sliced cylinder” for circulation. Of particular interest estimate transport between oceanic basin’s boundary. conceived relevant to both wind-driven abyssal waters around deep topographic features such mid-ocean...

10.1357/0022240973224085 article EN Journal of Marine Research 1997-11-01

[1] The baroclinic response to barotropic tidal forcing in the Camarinal Sill area, within Strait of Gibraltar, is investigated with a three-dimensional, fully nonlinear, nonhydrostatic numerical model. aim efforts was assessment three-dimensional effects, which are potentially significant area because rather irregular bottom topography, variable background stratification, and complex structure tides. Model results reveal under relatively moderate flood currents, includes formation internal...

10.1029/2011jc007093 article EN Journal of Geophysical Research Atmospheres 2011-10-18

Abstract Techniques from dynamical systems theory have been applied to study horizontal stirring of fluid in the Philippine Archipelago. The authors’ analysis is based on velocity fields produced by two high-resolution (3 and 6 km) numerical models. Particular attention paid identifying robust surface flow patterns associating them with dominant Lagrangian coherent structures (LCSs). A recurrent wind-driven dipole lee coastline considered detail. associated LCSs form a template for stirring,...

10.1175/2010jpo4336.1 article EN Journal of Physical Oceanography 2010-04-26

At the end of their life cycle, American eel ( Anguilla rostrata ) migrate to Sargasso Sea from freshwater habitats along east coast North America in order spawn planktonic eggs. The eggs develop into larvae that then have reach estuarine and nursery within approximately first year life. A coupled biological—physical model was used study how potential behavioral adaptations influence ability near‐coastal waters. Specifically, several larval swimming behaviors were investigated, including...

10.4319/lo.2014.59.5.1704 article EN Limnology and Oceanography 2014-08-24

Kinematic models predict that a coherent structure, such as jet or an eddy, in unsteady flow can exchange fluid with its surroundings. The authors consider the significance of this effect for fully nonlinear, dynamically consistent, barotropic model meandering jet. calculated volume transport associated is comparable to crossing Gulf Stream through detachment rings. Although and idealized other ways, calculations suggest mechanism may be important lateral potential vorticity budget analyses...

10.1175/1520-0485(1999)029<2635:lmafei>2.0.co;2 article EN other-oa Journal of Physical Oceanography 1999-10-01

Abstract Motivated by discrepancies between Eulerian transport estimates and the behavior of Lagrangian surface drifters, near-surface pathways processes in North Atlantic are studied using a combination data, altimetric heights, statistical analysis trajectories, dynamical systems techniques. Particular attention is paid to issue subtropical-to-subpolar intergyre fluid exchange. The velocity field used this study composed steady drifter-derived background flow, upon which time-dependent...

10.1175/2011jpo4498.1 article EN Journal of Physical Oceanography 2011-01-24

Abstract. Fluid parcels can exchange water properties when coming into contact with each other, leading to mixing. The trajectory encounter mass and a related simplified quantity, the volume, are introduced as measure of mixing potential flow. volume quantifies fluid that passes close reference over finite time interval. Regions characterized by low such cores coherent eddies, have potential, whereas turbulent or chaotic regions large high potential. diagnostic is used characterize in three...

10.5194/npg-24-189-2017 article EN cc-by Nonlinear processes in geophysics 2017-05-03

Vorticity fronts can form in a shear flow as the result of fast patches fluid catching up with slower ones. This process and its consequences are studied an inviscid two-dimensional model consisting piecewise uniform-vorticity layers. Calculations using method contour dynamics for ‘intrusive’ initial states indicate that leading edge front evolves into robust structure whose propagation speed be accounted by simple shock-joining theory. Behind several different effects occur depending upon...

10.1017/s0022112085003032 article EN Journal of Fluid Mechanics 1985-12-01

Abstract The hydraulic state of the exchange circulation through Strait Gibraltar is defined using a recently developed critical condition that accounts for cross-channel variations in layer thickness and velocity, applied to output high-resolution three-dimensional numerical model simulating tidal exchange. uses coastal-following curvilinear orthogonal grid, which includes, addition Gibraltar, Gulf Cadiz Alboran Sea. forced at open boundaries specification surface elevation characterized by...

10.1175/2009jpo4075.1 article EN Journal of Physical Oceanography 2009-04-21

Abstract The overflow of dense water from the Nordic Seas through Faroe Bank Channel (FBC) has attributes suggesting hydraulic control—primarily an asymmetry across sill reminiscent flow over a dam. However, this aspect never been confirmed by any quantitative measure, nor is position control section known. This paper presents comparison several different techniques for assessing criticality oceanic overflows applied to data set velocity and hydrographic sections FBC. These include 1)...

10.1175/jpo2969.1 article EN Journal of Physical Oceanography 2006-12-01

Whereas long-wave theories have proved successful in describing, the nonlinear effects of single obstructions on narrow flows, can fail when several are present. This failure is demonstrated using a simple laboratory flow which predicted by theory to be unstable, but stability practice short-wave effects. A dispersive leads an interpretation short waves as combination cnoidal and solitary waves, upstream control found for second (downstream) obstacle only.

10.1175/1520-0469(1984)041<1214:onfwmo>2.0.co;2 article EN other-oa Journal of the Atmospheric Sciences 1984-04-01

Abstract We investigate and quantify stirring due to chaotic advection within a steady, three-dimensional, Ekman-driven, rotating cylinder flow. The flow field has vertical overturning horizontal swirling motion, is an idealization of motion observed in some ocean eddies. characterized by strong background rotation, we explore variations Ekman Rossby numbers, $E$ ${R}_{o} $ , over ranges appropriate for the mesoscale submesoscale. A high-resolution spectral element model used conjunction...

10.1017/jfm.2013.583 article EN Journal of Fluid Mechanics 2013-12-05

We analyze the geometry of Lagrangian motion and material barriers in a time-dependent, three-dimensional, Ekman-driven, rotating cylinder flow, which serves as an idealization for isolated oceanic eddy other overturning cells with cylindrical ocean atmosphere. The flow is forced at top through oscillating upper lid, response depends on frequency amplitude lid oscillations. In particular, changes near resonant tori unforced whose frequencies are rationally related to forcing frequencies....

10.1063/1.4916086 article EN Chaos An Interdisciplinary Journal of Nonlinear Science 2015-03-30

Abstract Unique in situ observations of atmospheric conditions over the Red Sea and coastal Arabian Peninsula are examined to study dynamics regional impacts local land‐sea breeze cycle (LSBC). During a 26‐month data record spanning 2008–2011, observed LSBC events occurred year‐round, frequently exhibiting cross‐shore wind velocities excess 8 m/s. Observed onshore offshore features both land‐ sea‐breeze phases presented, their seasonal modulation is considered. Weather Research Forecasting...

10.1029/2019jd031007 article EN cc-by-nc-nd Journal of Geophysical Research Atmospheres 2019-11-16

The kinematics and dynamics of linear neutral modes propagating in a mean zonal jet are studied an effort to understand how particle pathways within across oceanic jets, such as the Gulf Stream, determined. Sinuous-, varicose-, mixed-mode waves superposed on cusped jets that governed by quasigeostrophic characterized piecewise uniform potential vorticity. Significant excursions (greater than wave amplitude) trajectories found vicinity steering lines lie horizontal plane motion, particularly...

10.1175/1520-0485(1995)025<1451:ptiqjn>2.0.co;2 article EN Journal of Physical Oceanography 1995-06-01

Abstract Hood Canal, a long fjord in Washington State, has strong tides but limited deep-water renewal landward of complex constriction. Tide-resolving hydrographic and velocity observations at the constriction, with depth-cycling towed body, varied markedly during three consecutive years, partly because stratification variations. To determine whether hydraulic control is generally important to interpret lee waves, blocking, other features, criticality estimated over full tidal cycles for...

10.1175/2010jpo4312.1 article EN Journal of Physical Oceanography 2010-01-19

Abstract The overflow of the dense water mass across Greenland–Scotland Ridge (GSR) from Nordic Seas drives Atlantic meridional overturning circulation (AMOC). is a large basin with an enormous reservoir capacity. volume above GSR sill depth in Seas, according to previous estimates, sufficient supply decades transport. This capacity buffers overflow’s responses atmospheric variations and prevents abrupt shutdown AMOC. In this study, authors use numerical analytical model show that effective...

10.1175/jpo-d-12-087.1 article EN Journal of Physical Oceanography 2012-10-05

Abstract The structure, variability, and regional connectivity of the Tokar Gap jet (TGJ) are described using WRF Model analyses supporting atmospheric datasets from East African–Red Sea–Arabian Peninsula (EARSAP) region during summer 2008. Sources TGJ’s unique quasi-diurnal nature association with atypically high moisture transport traced back to larger-scale dynamics influencing its forcing. These include seasonal shifts in intertropical convergence zone (ITCZ), variability monsoon North...

10.1175/jcli-d-14-00635.1 article EN Journal of Climate 2015-05-14

The method of lobe analysis is used and extended to analyze a time-dependent, boundary-trapped recirculation. recirculation gyre occurs in numerical model wind-driven flow around an island, but the underlying geometry similar persistent eddies such as Alboran Gyre Great Whirl. Even steady (weak forcing) limit, leaks fluid due fact that surface Ekman pumping above it directed downward. authors show this leakage rapidly superseded by chaotic transport into out when time dependence sets in....

10.1175/1520-0485(2002)032<0080:ctomap>2.0.co;2 article EN other-oa Journal of Physical Oceanography 2002-01-01
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