| Dielectric and Radiative Properties of Sea Foam at Microwave Frequencies: Conceptual Understanding of Foam Emissivity |
27 Apr 2012 |
29 pages |
| Authors:
Magdalena D Anguelova; Peter W Gaiser; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
 | Foam fraction can be retrieved from space-based microwave radiometric data at frequencies from 1 to 37 GHz. The retrievals require modeling of ocean surface emissivity fully covered with sea foam. To model foam emissivity well, knowledge of foam properties, both mechanical and dielectric, is necessary because these control the radiative processes in foam. We present a physical description of foam dielectric properties obtained from the foam dielectric constant including foam ... |
|
| Dispersion in the Surfzone: Tracer Dispersion Studies |
30 Sep 2011 |
10 pages |
| Authors:
Falk Feddersen; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA
|
| Terrestrial runoff and river input dominates urban pollutant loading rates degrading nearshore and surfzone water quality (e.g., Boehm et al., 2002). Surfzone mixing processes disperse and dilute such (and other types of) pollution. On smaller length-scales (smaller than the water depth), breaking-waves and bed-generated turbulence mix tracer. However, field surfzone observations of turbulence previously have been extremely scarce, and much about surfzone small-scale turbulence is not known. On larger scales ... |
|
| Tidal Flats, Muddy Seafloors, Sandy Coasts, and Inlets |
30 Sep 2011 |
11 pages |
| Authors:
Britt Raubenheimer; Steve Elgar; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
|
| The long-term goal is to develop field-verified models for the evolution of surface-gravity waves, circulation, sediment transport, and the subsequent morphological response in shallow, coastal waters. The objectives of our studies in FY11 were to analyze observations of currents, waves, and bathymetry on tidal flats, and to develop, test, and improve models for tidal-flat processes. Specific goals related to tidal flats were to investigate the relative importance of riverine and ... |
|
| Coastal Bathymetry Using Satellite Observation in Support of Intelligence Preparation of the Environment |
Sep 2011 |
75 pages |
| Authors:
II Myrick Kenneth B; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Subaqueous beach profiles are obtained for littoral regions near Camp Pendleton, CA, using observations of wave motion. Imagery was acquired from WorldView2 Satellite on 24 March 2010. Two sequential images taken 10 seconds apart are used for the analyses herein. Water depths were calculated using linear dispersion relationship for surface gravity waves. Depth profiles were established from shoreline out to 1 kilometer offshore and depths of up to 15 meters. ... |
|
| Waves, Currents, and Bathymetric Evolution Near an Inlet |
14 JUN 2011 |
3 pages |
| Authors:
Steve Elgar; Britt Raubenheimer; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
|
| The long-term objective is to develop field-verified models for the wave fields, circulation patterns, and morphological evolution near inlets and river mouths. Our approach is to collect and analyze field observations of waves, currents, winds, and bathymetry to test hypotheses and to calibrate, evaluate, and improve numerical models. |
|
| The Design and Implementation of a Semi-Autonomous Surf-Zone Robot Using Advanced Sensors and a Common Robot Operating System |
JUN 2011 |
131 pages |
| Authors:
Steven Halle; Jason Hickle; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF PHYSICS
|
| A semi-autonomous vehicle, MONTe, was designed, modeled, and tested for deployment and operation in a surf-zone coastal environment. The MONTe platform was designed to use unique land-based locomotion that incorporates wheel-legs (Whegs (trademark)) and a tail. Semi-autonomy was realized with data from onboard sensors and implemented through the open source Robot Operating System (ROS) hosted on an Ubuntu Linux-based processor. Communications via IEEE 802.11 protocols proved successful for data telemetry ... |
|
| Surf Zone Wave and Current Dynamics |
APR 2011 |
11 pages |
| Authors:
Jeffrey L. Hanson; Kent K. Hathaway; CORPS OF ENGINEERS KITTY HAWK NC
|
| Ocean bubble production, persistence and transport results from complex interactions occurring between winds, waves, currents and the presence of biological and anthropogenic surfactants in the upper ocean (Thorpe, 1982; Hanson, 1993; Hanson, 1997; Hanson and Phillips, 1999). These processes are amplified in the surf zone as shoaling waves dissipate through interactions with local bathymetry. Existing capabilities to predict nearshore wave dissipation, sea foam and bubble formation, and resulting surf zone ... |
|
| Linking the Surf Zone and Inner Shelf: Cross-shore Transportation Mechanisms |
JAN 2011 |
6 pages |
| Authors:
Adrianus Reniers; ROSENSTIEL SCHOOL OF MARINE AND ATMOSPHERIC SCIENCE MIAMI FL
|
| The long-term goals are to understand surf zone processes, in particular cross-shore exchange related to rip current systems through field observations and numerical modeling. Rip currents occur commonly on most beaches and dominate many. It is recognized that beaches with straight and parallel contours are not a stable morphologic configuration, whereas more complex beaches, which support the existence of rip current morphology, are stable and more common. The research objectives ... |
|
| Video and Field Observations of Wave Attenuation in a Muddy Surf Zone |
2011 |
12 pages |
| Authors:
P. S. Pereira; L. J. Calliari; R. Holman; K. T. Holland; R. M. Guedes; C. K. Amorin; R. G. Cavalcanti; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS MARINE GEOACOUSTICS DIV
|
| Besides the different scales within which coastal processes manifest their energy, the majority of the world's coastal regions exhibit forms of sediment heterogeneity that are physically significant. One example of a heterogeneous environment is Cassino beach. located at the southernmost part of Brazil, a fine-grain-sized sandy beach where fluid mud sporadically is transported to the nearshore and eventually onto the beach. At this site in 2005. as part of a ... |
|
| Modeling & Testing of Inflatable Structures for Rapidly Deployable Port Infrastructures |
Jul 2010 |
42 pages |
| Authors:
Andrew Bloxom; Abel Medellin; Chris Vince; Solomon Yim; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV WEST BETHESDA MD
|
| An experimental investigation of the fluid-structure interaction of a water filled inflatable membrane structure in the near shore environment was performed in the Coastal Marine Engineering Laboratory at the United States Naval Academy. The structure of interest was a 10' x 2' x 0.75' tubular bag developed at the Center for Innovation in Ship Design (CISD) at the Naval Surface Warfare Center (NSWC), Carderock Division as a proof of concept ... |
|
| Surf Zone Wave and Current Dynamics |
2010 |
11 pages |
| Authors:
Jeffrey L. Hanson; Kent K. Hathaway; CORPS OF ENGINEERS KITTY HAWK NC
|
| Ocean bubble production, persistence and transport results from complex interactions occurring between winds, waves, currents and the presence of biological and anthropogenic surfactants in the upper ocean (Thorpe, 1982; Hanson, 1993; Hanson, 1997; Hanson and Phillips, 1999). These processes are amplified in the surf zone as shoaling waves dissipate through interactions with local bathymetry. Existing capabilities to predict nearshore wave dissipation, sea foam and bubble formation, and resulting surf zone ... |
|
| Breaker-induced Surf Zone Radiance |
2010 |
4 pages |
| Authors:
Rob Holman; OREGON STATE UNIV CORVALLIS COLL OF OCEANIC AND ATMOSPHERIC SCIENCES
|
| The overall goal of this work is to develop a predictive relationship between surf zone hydrodynamic properties and radiance measured from overhead EO sensors. The main focus is on the dynamics of strongly-reflective bubbles and aeration caused by breaking waves, with a secondary focus on the optical properties of un-aerated water. The work has two applications: determination of the probability of clear (un-aerated) water glimpses through which bottom targets could ... |
|
| Collaboration with Oregon State University at Duck, NC |
Jun-2009 |
5 pages |
| Authors:
William J Plant; WASHINGTON UNIV SEATTLE APPLIED PHYSICS LAB
|
| A dual-polarized, coherent, X-band microwave radar called RiverRad was deployed at the Coastal Engineering Field Research Facility at Duck, NC in April, 2008. The purpose of the deployment was to utilize this calibrated radar to calibrate a marine radar operated by Oregon State University (OSU) on a long-term basis at Duck and to study microwave backscatter in the surf zone. Data from RiverRad were compared with those from the marine ... |
|
| Diurnal Sea Breeze-Driven Cross-Shore Exchange on the Inner Shelf in Central Monterey Bay |
Mar-2009 |
59 pages |
| Authors:
John E Hendrickson; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Cross-shore exchange on the inner shelf has important impacts on the ecosystem, transporting heat, nutrients, pollutants and phytoplankton between the midshelf and surf zone. The effects of a strong (cross-shore wind stress, Tsx 0.05Pa) diurnal (7-25 hrs) sea breeze on cross-shore exchange at Marina, Monterey Bay, California is investigated using two years of continuous winds, waves, and ocean velocities. Surface wind stress has spectral peaks at 1, 2, and 3 ... |
|
| Characterization of Episodic Rip Current Pulsations in the Inner Shelf During RCEX 2007 |
Mar-2009 |
63 pages |
| Authors:
Andrea C O'Neill; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| As the Navy thrusts operations into global brown water environments, a more complete understanding of the phenomena ships and swimmers will encounter in nearshore regions is necessary. Rip currents remain infamous and important characteristics of the nearshore environment. These events not only impinge upon swimmers' safety, but may play a key role transferring water, containing nutrients, biologics, and even shore-/ship-borne pollution, between the surf zone and open ocean environments. Vertical ... |
|
| Limits of Wave Runup and Corresponding Beach-Profile Change from Large-Scale Laboratory Data. Revision |
Jan-2009 |
58 pages |
| Authors:
Tiffany M Roberts; Ping Wang; Nicholas C Kraus; UNIVERSITY OF SOUTH FLORIDA TAMPA DEPT OF GEOLOGY
|
| The dataset from the SUPERTANK laboratory experiment was analyzed to examine wave runup and the corresponding upper limit of beach-profile change. Thirty SUPERTANK runs were investigated that included both erosional and accretionary wavey conditions with random and monochromatic waves. The upper limit of beach change U(L) was found to approximately equal the vertical excursion of total wave runup, R(tw). An exception was runs where beach or dune scarps were produced, ... |
|
| Ship Dynamics in the Surf Zone Model Testing |
Jul-2008 |
29 pages |
| Authors:
Miguel Quintero; Faydra Schaffer; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD SHIP SYSTEMS INTEGRATION AND DESIGN DEPARTMENT
|
| The aim of this project was to generate data to identify the forces and motions on a ship model while positioned in breaking surf. The two types of breaking waves analyzed were plunging and spilling waves. A 140 feet long model test basin at the Naval Surface Warfare Center Carderock Division (NSWCCD) was used to create the waves with a flap wave maker and the heave motions, pitch motions, and ... |
|
| Environmental Support to Amphibious Craft, Patrol Boats, and Coastal Ships: An Annotated Bibliography |
05 MAR 2008 |
48 pages |
| Authors:
Charles M. Bachmann; Robert A. Fusina; C. R. Nichols; Jack McDermid; NAVAL RESEARCH LAB WASHINGTON DC
|
| This annotated bibliography is a selection of citations to books, articles, documents, and data bases highlighting environmental conditions that impact the safety and performance of amphibious craft, patrol boats, and ships designed for coastal operations. Each citation is followed by a brief summary and evaluation of the source (i.e., the annotation). Most annotations will define the scope of the source, list significant cross references, and identify the relevant environmental conditions. ... |
|
| Bedforms and Mine Burial in the Nearshore |
MAR 2008 |
8 pages |
| Authors:
Edith L. Gallagher; Rob Holman; FRANKLIN AND MARSHALL COLL LANCASTER PA BIOLOGY DEPT
|
| The threat of mines has an enormous impact on Naval operations. Methods exist for search and identification of proud mines, but the potential existence of buried mines is of considerable concern. This work will help to describe the process of mine burial owing to bottom bedform movement by quantifying the expected time scales and depths of disturbance of the natural bed in the nearshore. As waves work the sediments on ... |
|
| Validation Test Report for Delft3D |
29 FEB 2008 |
47 pages |
| Authors:
Y. L. Hsu; James D. Dykes; Richard A. Allard; David W. Wang; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS
|
| This report describes the model setup, parameter selection and model validation of the Delft3D modeling system in nearshore applications. Delft3D, developed by Delft Hydraulics, is a complete coastal hydrodynamic modeling system, capable of simulating hydrodynamic processes due to waves, tides, river flow, and winds. Three high-fidelity observation data sets are used for validation tests. The first data set is from the Nearshore Sediment Transport Study (NSTS) data at Santa Barbara, ... |
|
| Diagnostic-Photographic Determination of Drag/Lift/Torque Coefficients of High Speed Rigid Body in Water Column |
01-Jan-2008 |
51 pages |
| Authors:
Peter C Chu; Chenwu Fan; Paul R Gefken; NAVAL POSTGRADUATE SCHOOL MONTEREY CA NAVAL OCEAN ANALYSIS AND PREDICTION LAB
|
| Prediction of rigid body falling through water column with a high speed (such as Mk-84 bomb) needs formulas for drag/lift and torque coefficients, which depend on various physical processes such as supercavitation and bubbles. A diagnostic-photographic method is developed in this study to determine the drag/lift and torque coefficients for a fast moving rigid-body in water column. The diagnostic part is to derive the relationships (called diagnostic relationships) between (drag, ... |
|
| Bioluminescence Potential in the Transition Zone to Very Shallow Water (VSW) |
Jan-2008 |
9 pages |
| Authors:
Mark A Moline; CALIFORNIA POLYTECHNIC STATE UNIV SAN LUIS OBISPO
|
| The long-term goal is to advance our understanding of the ecology of bioluminescent organisms and the mechanisms governing the temporal and depth-dependent variability of bioluminescence in the coastal ocean. With improvements in technology, finer-scale resolution and concurrent physical, chemical and biological data are available to advance our understanding of the forcing mechanisms governing the temporal and depth-dependent variability of bioluminescence in environments of Naval relevance. In addition, few measurements of ... |
|
| A Real-Time Nearshore Wave and Current Prediction System |
2008 |
|
| Authors:
Richard A. Allard; James D. Dykes; Yuan-Huang L. Hsu; James M. Kaihatu; Daniel Conley; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS
|
 | A nearshore wave, tide and current prediction system was demonstrated during the MREA04 Trial in the Portuguese coastal waters near Pinheiro do Cruz during the early spring of 2004. Daily forecasts of regional scale wave and tidal information and nearshore waves and currents were generated in DIOPS utilizing a suite of regional and nearshore models forced with data from meteorological and oceanographic production centers. A limited beach experiment was conducted ... |
|
| RCEX: Rip Current Experiment |
30 SEP 2007 |
6 pages |
| Authors:
Ad Reniers; ROSENSTIEL SCHOOL OF MARINE AND ATMOSPHERIC SCIENCE MIAMI FL DIV OF APPLIED MARINE PHYSICS
|
| The long-term goals are to understand surf zone processes related to rip current systems through field observations. Rip currents occur commonly on most beaches and dominate many. In the past decade, it is recognized that beaches with straight and parallel contours are not a stable morphologic configuration whereas more complex beaches, which support the existence of rip current morphology, are stable and more common. The research objectives of the proposed ... |
|
| RCEX: Rip Current Experiment |
30 SEP 2007 |
8 pages |
| Authors:
Timothy P. Stanton; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF OCEANOGRAPHY
|
| Long term goals are to understand processes that cause the formation and maintenance of quasi-stationary rip channel / shoal systems in the surf zone. It is now recognized that this 3D configuration of the surf zone bathymetry is widespread and more representative than the simpler straight and parallel beaches that have been studied in recent years. A combination of detailed field observations and concurrent numerical modeling of the system are ... |
|
| Modeling of Hurricane Impacts |
01 SEP 2007 |
28 pages |
| Authors:
Dano Roelvink; Ad Reniers; Ap van Dongeren; Jaap van Thiel de Vries; UNESCO-THE INST FOR WATER EDUCATION DELFT (NETHERLANDS)
|
| This fourth interim report describes ongoing development and validation of the XBeach model as part of the MORPHOS project and other activities over the period March-August 2007 (period extended due to late approval to continue) |
|
| Setup in the Surfzone |
SEP 2007 |
|
| Authors:
Alex Apotsos; MASSACHUSETTS INST OF TECH CAMBRIDGE
|
| Surfzone wave height transformation and wave-breaking-driven increases in the mean sea level (setup) are examined on alongshore-uniform beaches with alongshore homogeneous and inhomogeneous wave forcing. While previously derived models predict wave heights adequately (root-mean-square errors typically less than 20%), the models can be improved by tuning a free parameter or by using a new parameterization based on the deep-water wave height. Based on a sensitivity analysis of the cross-shore momentum ... |
|
| Morphologic Modeling of Multiple Barrier Island Breaches for Regional Application |
01-May-2007 |
15 pages |
| Authors:
Magnus Larson; Nicholas C Kraus; Kenneth J Connell; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS COASTAL AND HYDRAULICS LAB
|
| This paper introduces a time-dependent model of regional barrier island breaching for multiple openings, whether as permanent inlets or as new breaches to the same bay. The model allows an arbitrary number of breaches and is forced by tide, storm surge, and wave set up. Limitations on the hydrodynamics, hence calculated breach evolution, are those associated with the Keulegan inlet model. The model includes possible closure or limited breaching by ... |
|
| Nearshore Canyon Experiment |
MAR 2007 |
4 pages |
| Authors:
Robert T. Guza; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA
|
| The objective of the Nearshore Canyon Experiment (NCEX) was to understand the effect of complex continental-shelf bathymetry on surface gravity waves and on the breaking-wave-driven circulation onshore of the irregular bathymetry. The NCEX observations were the first extensive quantitative field measurements of the effect of severe alongshore bathymetric inhomogeneities (here a submarine canyon) on incident waves, and on the surfzone circulation. |
|
| Evaluation of Delft3D Performance in Nearshore Flows |
28 DEC 2006 |
27 pages |
| Authors:
Y. L. Hsu; James D. Dykes; Richard A. Allard; James M. Kaihatu; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| The Delft3D modeling system, developed by Delft Hydraulics (www.wldelft.nl) is capable of simulating hydrodynamic processes due to waves, tides, rivers, winds, and coastal currents. It can be used to provide surf prediction for areas with complicated bathymetry where the use of a one-dimensional surf model is inappropriate. Delft3D has many model options and free parameters. The main objective of this investigation is to examine the effects of these selections on ... |
|
| Boussinesq Modeling of Alongshore Swash Zone Currents |
DEC 2006 |
20 pages |
| Authors:
Q. J. Chen; LOUISIANA STATE UNIV BATON ROUGE DEPT OF CIVIL AND ENVIRONMENTAL ENGINEERING
|
| The report documents the theoretical and numerical investigations on wave propagation over porous beds as well as on alongshore surf and swash currents. The study has been carried out in the framework of wave-resolving Boussinesq-type models. First, we have derived a new set of Boussinesq-type equations for nonlinear waves and surf-zone currents over a permeable beach (Chen 2006). A Stokes-type analysis and rational expansions were carried out to examine the ... |
|
| Modeling and Characterization of Microbarom Signals in the Pacific |
SEP 2006 |
70 pages |
| Authors:
Milton Garces; Mark Willis; HAWAII UNIV KAILUA-KONA INFRASOUND LAB
|
| Naturally occurring sources of infrasound include (but are not limited to) severe weather, volcanoes, bolides, earthquakes, surf, mountain waves, and, the focus of this research, nonlinear ocean wave interactions. Man-made sources of infrasound also exist, such as airplane activity, military testing, rocket launches, and nuclear explosions (Bedard and Georges, 2000). Due to its low frequency, infrasound can travel global distances with relatively low attenuation while higher frequency audible sound is ... |
|
| Longshore Sediment Transport Rate Calculated Incorporating Wave Orbital Velocity Fluctuations |
SEP 2006 |
233 pages |
| Authors:
Ernest R. Smith; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS COASTAL AND HYDRAULICS LAB
|
| Laboratory experiments were performed to study and improve longshore sediment transport rate predictions. Measured total longshore transport in the laboratory was approximately three times greater for plunging breakers than spilling breakers. Three distinct zones of longshore transport were observed across the surf zone: incipient breaker zone, inner surf zone, and swash zone. Transport at incipient breaking was influenced by breaker type; inner surf zone transport was dominated by wave height, ... |
|
| Modeling of Hurricane Impacts, Interim Report 2 |
AUG 2006 |
28 pages |
| Authors:
Dano Roelvink; Ad Reniers; Ap van Dongeren; Dirk-Jan Walstra; UNESCO-THE INST FOR WATER EDUCATION DELFT (NETHERLANDS)
|
| This report is the second progress report of the project "Modeling of Hurricane Impacts." The main objective of the XBeach model is to provide a robust and flexible environment in which to test morphological modelling concepts for the case of dune erosion, overwashing and breaching. The top priority is to provide numerical stability; first order accuracy is accepted since there is a need for small space steps and time steps ... |
|
| Including Nearshore Processes in Phase-Averaged Hydrodynamics Models |
AUG 2006 |
47 pages |
| Authors:
Bradley D. Johnson; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS COASTAL AND HYDRAULICS LAB
|
| The large spatial and time scales of the numerical modeling projects of the U.S. Army Corps of Engineers (USACE) requires the use of computationally efficient phase-averaged hydrodynamic models derived by averaging the equations of motion over a representative short wave period. Guidance in modeling nearshore regions with phase-averaged hydrodynamic models is provided herein. Physical processes unique to the surf zone are described along with methods of incorporating these effects to ... |
|
| Simulation and Analysis of Dart Dispense Events with Collisions |
2006 |
|
| Authors:
William E. Dietz; James Y. Baltar; Kevin Losser; Morris Morell; DIGITAL FUSION HUNTSVILLE AL
|
| Current approaches to beach and surf zone mine clearance depend on the dispensing of large numbers of darts from a parent missile or projectile. The mine clearance mission requires a uniform distribution of darts over the target area. The dispersal pattern is affected by many factors, including the angle of attack, velocity, and rotational rate of the parent vehicle, the aerodynamic design of the darts, dart collision, and the different ... |
|
| Assimilating Data into a Circulation Model |
05 DEC 2005 |
4 pages |
| Authors:
Jennifer Shore; Thomas Lippmann; OHIO STATE UNIV COLUMBUS BYRD POLAR RESEARCH CENTER
|
| The purpose of this grant was to develop data assimilation methods for state-of-the-art nearshore oceanographic circulation models. The data for the assimilation effort was provided from the collaborative Nearshore Canyon Experiment (NCEX) held in the fall of 2003. This research led to the development and implementation of a time-distributed averaging procedure (TDAP) within the Ozkan-Kirby (OK) nearshore circulation model to assimilate dense surface velocity observations obtained at NCEx. |
|
| Acoustic Focusing in Shallow Water and Bubble Radiation Effects |
20 OCT 2005 |
9 pages |
| Authors:
Grant B. Deane; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB
|
| The long-term goals of the "Acoustic Focusing in Shallow Water and Bubble Radiation Effects" project is as follows: (1) understand the role of wave-induced bubbles in the upper ocean boundary layer on the performance of underwater communications systems and ambient noise generation, (2) study the implications of focusing by surface gravity waves on Doppler sonar and acoustic communications systems in shallow and very shallow water, and (3) study the performance ... |
|
| Waves, Currents, and Sediment Transport in the Surf Zone Along Long, Straight Beaches |
AUG 2005 |
308 pages |
| Authors:
Yoshimitsu Tajima; Ole S. Madsen; MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF CIVIL ENGINEERING
|
| This study presents a theoretical model for predictions of nearshore hydrodynamic characteristics and the local sediment transport rate along long, straight beaches. The wave may be periodic or random, the beach may be plane or barred, and the bed may be concrete or covered with movable natural sand grains. The present model must be efficient and flexible so that it can accommodate iterative computations for time-varying and, hence, arbitrary beach ... |
|
| Australian DefenceScience. Volume 13, Number 2, Winter |
Jan-2005 |
|
| Authors:
DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION CANBERRA (AUSTRALIA)
|
| CONTENTS: Extra protection for combat suits - DSTO is researching the ability of modified activated carbons to counter toxic chemicals and biological pathogens in order to increase the level of protection offered by combat suits against chemical and biological warfare agents. Viewing device on target to reduce frontline risk - In urban warfare, bullet or fragment wounds to the head or face are proportionally higher than wounds to other parts ... |
|
| DIOPS: A PC-Based Wave, Tide and Surf Prediction System |
2005 |
7 pages |
| Authors:
Richard Allard; James Dykes; James Kaihatu; Dean Wakeham; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| The Distributed Integrated Ocean Prediciton System (DIOPS) is a PC- based wave tide and surf prediction system designed to provide DoD accurate and timely surf predictions for essentially any world-wide location. Regional and coastal wave predictions are made by the Simulating Waves Nearshore (SWAN) wave module that is typically initialized by offshore directional wave spectra from the Fleet Numerical Meteorological and Oceanography Center (FNMOC). Tide and storm surge predictions are ... |
|
| Wave Momentum Flux Parameter: A Descriptor for Nearshore Waves |
16 JUL 2004 |
19 pages |
| Authors:
Steven A. Hughes; ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS COASTAL AND HYDRAULICS LAB
|
| A new parameter representing the maximum depth-integrated wave momentum flux occurring over a wave length is proposed for characterizing the wave contribution to nearshore coastal processes on beaches and at coastal structures. This parameter has units of force per unit crest width, and it characterizes flow kinematics in nonbreaking waves at a given depth better than other wave parameters that do not distinguish increased wave nonlinearity. The wave momentum flux ... |
|
| Field Observation of Setup |
JUN 2004 |
45 pages |
| Authors:
Sean P. Yemm; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Setup is defined as the superelevation of mean water surface within the surfzone and is caused by the reduction in wave momentum shoreward of the breaking point and compensating positive pressure gradient. Data were acquired north of Scripps Canyon on a gently sloping section of beach, which was homogenous in along-shore morphology, during the Nearshore Canyon Experiment, 2004. Pressure sensors were deployed both above and below the bed. Wave heights ... |
|
| Remote Characterization of Littoral Dynamics in Support of Expeditionary Warfare |
2004 |
10 pages |
| Authors:
K. T. Holland; Jack Puleo; Nathaniel G. Plant; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS MARINE GEOSCIENCES DIV
|
| Over the last decade there has been an increasing military interest in conditions and processes occurring in very shallow water and surf zone regions, typically less than 10 m depth. Interestingly, this region is extremely diverse and dynamic meaning that characterizations of environmental conditions necessary for successful expeditionary warfare operations may be limited to a particular location (on the order of lOOs of meters) or a relatively short time interval ... |
|
| High-Resolution Multibeam Deepwater Cable Route Survey in High-Relief Seafloor Area |
01-Sep-2003 |
10 pages |
| Authors:
Frederick Arnold; Mike Harrison; Roland Poeckert; Geoffrey Faneros; THALES GEOSOLUTIONS (PACIFIC) INC SAN DIEGO CA
|
| In support of monitoring for nuclear tests, a Hydroacoustic Data Acquisition System (HDAS) monitoring system is to be installed at Ascension Island. The system consists of two hydrophone arrays linked by fibre optic cable to the island. A survey to select cable routes from PanAm Beach on Ascension Island to the proposed hydrophone sites was conducted in the summer of 2002. The survey utilised various acoustic sensors, single beam and ... |
|
| Countermine Operations in Very Shallow Water and Surf Zone: The Role of Bottom Crawlers |
Sep-2003 |
11 pages |
| Authors:
Tony Aponick; Chuck Bernstein; FOSTER-MILLER INC WALTHAM MA
|
| In littoral warfare, strategic, operational and tactical mobility is an obvious advantage to naval forces that rely on unobstructed sea lanes. Naval mines can diminish or deny this advantage by reducing freedom of maneuverability and preventing naval forces from controlling or shaping the battlefield. In the Surf Zone (SZ) region, small autonomous crawling robots are being developed by the Office of Naval Research to perform mine hunting missions in support ... |
|
| Wave Breaking Bubble Production and Channel Characterization of the Surf Zone |
AUG 2003 |
7 pages |
| Authors:
Grant B. Deane; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB
|
| The long-term goal of this research is to understand underwater acoustic communications propagation through the surf zone. A secondary goal was to see if high-intensity, transient sound caustics created by shoaling surf could be exploited to improve the detection of buried objects in the surf zone. |
|
| Barrier Island Erosion During a Winter Cold Front in Mississippi Sound |
MAY 2003 |
17 pages |
| Authors:
Timothy R. Keen; Gregory Stone; James Kaihatu; Y. L. Hsu; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS
|
| The present study uses high-resolution hydrodynamic and sedimentation models to evaluate the sedimentation patterns inferred in the previous study. This work is examining the sensitivity of erosion on the sound side of West Ship Island to the tidal stage and changes in coastline due to beach replenishment. Water levels and mean currents for a range of tidal conditions and typical cold front winds are being computed using POM. Waves within ... |
|
| Chapter 2: Frequency Domain Wave Models in the Nearshore and Surf Zones |
2003 |
31 pages |
| Authors:
James M. Kaihatu; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| In deep water (kh) 1, where k is the wave number and h the water depth), second-order wave nonlinearity can be described as a small correction to the underlying linear wave. Perturbation expansions in wave steepness E = ka, where a is the wave amplitude, are used (Phillips, 1960), and at second-order only non-resonant (bound) waves are possible among triads of wave frequencies. Thus the interacting waves with the frequency-vector ... |
|
| Standoff Systems and Technologies for Near Shore Mine Countermeasures (MCM) |
01-Apr-2002 |
10 pages |
| Authors:
Brian Almquist; OFFICE OF NAVAL RESEARCH ARLINGTON VA
|
| The Office of Naval Research "ONR" published a Broad Agency Announcement "BAA" to solicit concepts that would lead to the development of technologies for the rapid, organic, standoff breaching of surf zone "SZ" and beach zone "BZ" mines and obstacles. The BAA solicitation resulted in three concepts that are currently funded by ONR and are referred to as the Future Countermine Counter-Obstacle "CMCO" Systems. Two are aircraft deployed and one ... |
|
Reports by Keyword(s)
SURF
