| Parameterizing Internal Wave Boundary Mixing in a Canyon |
11-Nov-2009 |
9 pages |
| Authors:
Eric Kunze; James B Girton; WASHINGTON UNIV SEATTLE APPLIED PHYSICS LAB
|
 | This project, in collaboration with Eric Kunze at the University of Victoria, aimed to increase our understanding of (primarily tidal) internal wave processes and how they affect diapycnal mixing in the coastal ocean, with an eventual goal of improved representation of baroclinic tides and mixing parameterizations in numerical models. Our work is expected to add significantly to the knowledge of the internal wave field, its interactions with topography, and implications ... |
|
| Interannual Variability of the Upper Ocean in the Southeast Pacific Stratus Cloud Region |
01-Oct-2009 |
18 pages |
| Authors:
Toshiaki Shinoda; Jialin Lin; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS
|
| Persistent stratus/stratocumulus cloud decks in the southeast Pacific near the coasts of Peru and northern Chile play an important role in regional and global climate variability. Interannual variability of the upper ocean under stratus cloud decks in the southeast Pacific is investigated using ocean general circulation model (OGCM) experiments. The model was first forced with daily surface fluxes based on the NCEP-NCAR reanalysis and satellite-derived surface shortwave and longwave radiation ... |
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| Numerical Simulations and Observations of Surface Wave Fields Under an Extreme Tropical Cyclone |
Sep-2009 |
21 pages |
| Authors:
Tetsu Hara; Edward J Walsh; Yalin Fan; Isaac Ginis; C Wayne Wright; RHODE ISLAND UNIV NARRAGANSETT GRADUATE SCHOOL OF OCEANOGRAPHY
|
| The performance of the wave model WAVEWATCH III under a very strong, category 5, tropical cyclone wind forcing is investigated with different drag coefficient parameterizations and ocean current inputs. The model results are compared with field observations of the surface wave spectra from an airborne scanning radar altimeter, National Data Buoy Center (NDBC) time series, and satellite altimeter measurements in Hurricane Ivan (2004). The results suggest that the model with ... |
|
| Investigation of ELF Signals Associated with Mine Warfare: A University of Idaho and Acoustic Research Detachment Collaboration |
30-Jun-2009 |
69 pages |
| Authors:
Dennis Sullivan; Jeffrey L Young; Robert G Olsen; Christopher L Wagner; IDAHO UNIV MOSCOW
|
| The questions that are being asked in this investigation are: (1) once an ELF signal is generated, how far does it propagate and still be detectable and (2) how can such signals be modeled, excited and measured? To this end, the scenario considered is one in which an ELF source of the electric or magnetic kind is located in or above water, such as a lake or ocean. This source ... |
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| Lagrangian Validation of Numerical Drifter Trajectories Using Drifting Buoys: Application to the Agulhas System |
20-May-2009 |
9 pages |
| Authors:
van; E van Sebille; P J Leeuwen; A Biastoch; C N de Barron; W P Ruijter; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS
|
| The skill of numerical Lagrangian drifter trajectories in three numerical models is assessed by comparing these numerically obtained paths to the trajectories of drifting buoys in the real ocean. The skill assessment is performed using the two-sample Kolmogorov -Smirnov statistical test. To demonstrate the assessment procedure, it is applied to three different models of the Agulhas region. The test can either be performed using crossing positions of one-dimensional sections in ... |
|
| Vertical Structure of Bottom Ekman Tidal Flows: Observations, Theory, and Modeling From the Northern Adriatic |
17-Apr-2009 |
26 pages |
| Authors:
Milivoj Kuzmic; Ivica Janekovic; Paul J Martin; Jeffrey W Book; M Wimbush; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| From September 2002 to May 2003, fifteen bottom-mounted, acoustic Doppler current profilers measured currents of the northern Adriatic basin. Tidal fluctuations at all seven of the major Adriatic frequencies were synthesized from a response tidal analysis of these measurements. Most observed tidal current ellipses were nearly reversing, but near the bottom, tidal current ellipses all shortened and broadened, semidiurnal currents led upper water column currents, and diurnal tidal current ellipse ... |
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| Use of the Oregon State University Tidal Inversion Software (OTIS) to Generate Improved Tidal Prediction in the East-Asian Seas |
10-Apr-2009 |
35 pages |
| Authors:
Paul J Martin; Scott R Smith; Pamela G Posey; Gretchen M Dawson; Shelley H Riedlinger; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| The Oregon State University (OSU) Tidal Inversion Software (OTIS) is being automated, tested and used to generate tidal solutions in the East-Asian Seas (EAS) region. This effort was undertaken to improve the tidal solutions within a relocatable version of the Navy Coastal Ocean Model (NCOM). Tests were conducted within the EAS and with a smaller domain within the EAS, the Yellow Sea, to look at the effects on OTIS of ... |
|
| Hydrodynamic Design of a Dead Weight Anchor Device Optimized for Station Keeping and Suppression of Subsequent Burial on Sedimentary Beds in Coastal Environments |
31-Mar-2009 |
10 pages |
| Authors:
Gerald D'Spain; Scott Jenkins; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB
|
| Simulations of station keeping and burial of a dead weight anchor device were performed using the Vortex Lattice Mine Burial/Migration Model (VORTEX). The VORTEX model was developed at Scripps Institution of Oceanography under previous ONR funding, (Inman and Jenkins, 2002; Jenkins and Inman 2002, Jenkins and Wasyl 2006). This model has been validated in field experiments conducted under ONR's Mine Burial Program. |
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| Influence of the Antarctic Circumpolar Current on the Atlantic Meriodional Circulation |
Mar-2009 |
65 pages |
| Authors:
David J Widener; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The physics of the Meridional Overturning Circulation and inter-hemispheric heat transport is explored with an emphasis on the upper and central ocean using a general ocean circulation model. The ability of the Antarctic Circumpolar Current, bathymetry, and surface temperature and wind stresses to influence the MOC and inter hemispheric heat transport is considered. All experiments are based on an idealized model of intermediate complexity with analysis focused on the interplay ... |
|
| 2008 Program of Study: Perspectives and Challenges in GFD (Geophysical Fluid Dynamics) |
Mar-2009 |
|
| Authors:
Raffaele Ferrari; Raymond T Pierrehumbert; Herbert E Huppert; Christopher J Garrett; Stephan Fauve; Kerry Emanuel; Stephen W Childress; George Veronis; Neil J Balmforth; Charles Doering; John Marshall; Timour Radko; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA DEPT OF PHYSICAL OCEANOGRAPHY
|
 | PRINCIPAL LECTURES. Steve Childress: Dynamo Theory and GFD; Charlie Doering: Convection, Stability and Turbulence; Kerry Emanuel: Waves and Vortices Driven by Interfacial Fluxes; Stephan Fauve: Turbulent Dynamos: experiments, nonlinear saturation of the magnetic field and field reversals; Raffaele Ferrari: Energetics of a Turbulent Ocean; Chris Garrett: Ocean Mixing, Internal Tides and Tidal Power; Herbert Huppert: Gravity Currents and Solidification; John Marshall: GFD Experiments in Climate; Ray Pierrehumbert: Atmospheric Escape; Timour ... |
|
| Software Design Description for the HYbrid Coordinate Ocean Model (HYCOM), Version 2.2 |
12-Feb-2009 |
157 pages |
| Authors:
E J Metzger; A J Wallcraft; S N Carroll; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| This document describes the software design and code of the HYbrid Coordinate Ocean Model (HYCOM) version 2.2. It includes the mathematical formulation and solution procedures for HYCOM 2.2 as well as flow charts and descriptions of the programs, modules, and subroutines. |
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| Analysis of Near-Surface Oceanic Measurements Obtained During CBLAST-Low |
09-Feb-2009 |
|
| Authors:
Albert J Plueddemann; John H Trowbridge; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
|
| Measurements obtained during the low-wind component of the Coupled Boundary Layers and Air-Sea Transfer program (CBLAST-Low) were used to elucidate the energetics of the ocean surface boundary layer. This work addressed the closure of the turbulent kinetic energy (TKE) budget, the relationship between TKE and dissipation, and the roles of wave breaking and Langmuir circulation in controlling turbulent diffusivity. The measurements occurred primarily during conditions in which shear, buoyancy and ... |
|
| North Pacific Acoustic Laboratory: Analysis of Shadow Zone Arrivals and Acoustic Propagation in Numerical Ocean Models |
Feb-2009 |
12 pages |
| Authors:
Brian Dushaw; WASHINGTON UNIV SEATTLE APPLIED PHYSICS LAB
|
| Over the decade 1996-2006, acoustic sources located off central California and north of Kauai transmitted to receivers distributed throughout the northeast and north central Pacific. Some of the observations included shadow-zone arrivals, that appear at travel times aligned with the lower cusps of the acoustic time front predicted by ray calculations, but with the depth of the receiver lies well below the depths of the predicted cusps. Several models for ... |
|
| High-Resolution Numerical Atmospheric and Ocean Simulations of Typhoon Maemi (September 2003) |
Jan-2009 |
7 pages |
| Authors:
Travis A Smith; T Campbell; R Allard; J Dykes; R J Small; S Riedlinger; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| High-resolution numerical simulations of the Korean Straits and East Sea utilizing the Coupled Ocean-Atmosphere Mesoscale Prediction System (COAMPS), the Navy Coastal Ocean Model (NCOM), and the SWAN wave model are conducted to examine the ocean and atmosphere model skill and response to Typhoon Maemi (September 2003). Due to the rarity of an intense tropical cyclone making landfall on the Korean Peninsula and traversing through the East China Sea, this study ... |
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| Detection of Rossby Waves in Multi-Parameters in Multi-Mission Satellite Observations and HYCOM Simulations in the Indian Ocean |
Jan-2009 |
12 pages |
| Authors:
Jay F Shriver; Bulusu Subrahmanyam; David M Heffner; David Cromwell; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| Rossby waves are difficult to detect with in situ methods. However, as we show in this paper, they can be clearly identified in multi-parameters in multi-mission satellite observations of sea surface height (SSH), sea surface temperature (SST) and ocean color observations of chlorophyll-a (chl-a), as well as 1/12-deg global HYbrid Coordinate Ocean Model (HYCOM) simulations of SSH, SST and sea surface salinity (SSS) in the Indian Ocean. While the surface ... |
|
| The Visible Signature Modelling and Evaluation ToolBox |
Dec-2008 |
111 pages |
| Authors:
Joanne B Culpepper; Rodney A J Borg; DEFENSE SCIENCE AND TECHNOLOGY ORGANIZATION VICTORIA (AUSTRALIA) MARITIME PLATFORMS DIV
|
| A new software suite, the Visible Signature ToolBox (VST), has been developed to model and evaluate the visible signatures of maritime platforms. The VST is a collection of commercial, off-the-shelf software and DSTO developed programs and procedures. The software can logically be divided into image generation and probability of detection (POD) modelling codes. CAMOGEN (CAMOuflage GENeration) and CAMEO-SIM (CAMouflage Electro-Optic SIMulation) provide the image generation, whereas ORACLE provides the POD ... |
|
| Topographic Effects on the Path and Evolution of Loop Current Eddies |
Dec-2008 |
20 pages |
| Authors:
Patrick J Hogan; Kyung Hoon Hyun; UNIVERSITY OF SOUTHERN MISSISSIPPI HATTIESBURG
|
| Eddy-topography (ET) interactions are important in determining the path and evolution of oceanic eddies, including Loop Current Eddies (LCE) in the Gulf of Mexico (GOM). We use the Hybrid Coordinate Ocean Model and satellite altimetry data to investigate the ET interactions and the impact on LCE pathway evolution in the GOM. Satellite altimetry reveals that LCEs translate dominantly westward in the central GOM and strongly collide and reflect against topography ... |
|
| The Sonar Simulation Toolset, Release 4.6: Science, Mathematics, and Algorithms |
01-Oct-2008 |
123 pages |
| Authors:
Robert P Goddard; WASHINGTON UNIV SEATTLE APPLIED PHYSICS LAB
|
| The Sonar Simulation Toolset (SST) is a computer program that produces simulated sonar signals, enabling users to build an artificial ocean that sounds like a real ocean. Such signals are useful for designing new sonar systems, testing existing sonars, predicting performance, developing tactics, training operators and officers, planning experiments, and interpreting measurements. SST's simulated signals include reverberation, target echoes, discrete sound sources, and background noise with specified spectra. Externally generated ... |
|
| An Underwater Light Attenuation Scheme for Marine Ecosystem Models |
Oct-2008 |
12 pages |
| Authors:
ZhongPing Lee; Bradley Penta; Raphael M Kudela; Sherry L Palacios; Deric J Gray; Jason K Jolliff; Igor G Shulman; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| Simulation of underwater light is essential for modeling marine ecosystems. A new model of underwater light attenuation is presented and compared with previous models. In situ data collected in Monterey Bay, CA. during September 2006 are used for validation. It is demonstrated that while the new light model is computationally simple and efficient it maintains accuracy and flexibility. When this light model is incorporated into an ecosystem model, the correlation ... |
|
| Combining Satellite Ocean Color Imagery and Circulation Modeling to Forecast Bio-Optical Properties: Comparison of Models and Advection Schemes |
Oct-2008 |
17 pages |
| Authors:
Rebecca E Green; Richard W Jr; Dong S Ko; Tamara L Townsend; Robert A Arnone; Gould; Regina D Smith; Peter M Flynn; Brandon J Casey; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| Remote sensing of ocean color provides synoptic surface ocean bio-optical properties but is limited to real-time or climatological applications. Many applications, including navy mission planning using electro-optical sensor performance models, would benefit from a forecast capability. To achieve this, we couple satellite imagery with numerical circulation models to provide short-term (24-48 hr) forecasts of bio-optical properties. These are first-order approaches; they do not account for any biogeochemical mechanistic processes (growth, ... |
|
| FY07 NRL DoD High Performance Computing Modernization Program Annual Reports |
05-Sep-2008 |
109 pages |
| Authors:
Portia A Shingler; Beth A Howell; NAVAL RESEARCH LAB WASHINGTON DC CENTER FOR COMPUTATIONAL SCIENCE
|
| These reports summarize the accomplishments of the NRL Principal Investigators who received computer allocations on the DoD High Performance Computing Modernization Program Shared Resource Center in FY07. |
|
| Upper-Ocean Thermal Structure and the Western North Pacific Category 5 Typhoons. Part 1. Ocean Features and the Category 5 Typhoons' Intensification |
Sep-2008 |
20 pages |
| Authors:
Dong-Shan Ko; I -I Lin; Chun-Chien Wu; Iam-Fei Pun; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| Category 5 cyclones are the most intense & devastating cyclones on earth. With increasing observations of category 5 cyclones, such as Hurricane Katrina (2005), Rita (2005), Mitch (1998), and Supertyphoon Maemi (2003) found to intensify on warm ocean features (i.e., regions of positive sea surface height anomalies detected by satellite altimeters), there is great interest in investigating the role ocean features play in the intensification of category 5 cyclones. Based ... |
|
| The Gulf Stream Pathway and the Impacts of the Eddy-Driven Abyssal Circulation and the Deep Western Boundary Current |
06-Jul-2008 |
33 pages |
| Authors:
Harley E Hurlburt; Patrick J Hogan; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| A hydrodynamic model of the subtropical Atlantic basin and the Intra-Americas Sea (9-47 deg N) is used to investigate the dynamics of Gulf Stream separation from the western boundary at Cape Hatteras and its mean pathway to the Grand Banks. The model has five isopycnal Lagrangian layers in the vertical and allows realistic boundary geometry, bathymetry, wind forcing, and a meridional overturning circulation (MOC), the latter specified via ports in ... |
|
| Steering of Upper Ocean Currents and Fronts by the Topographically Constrained Abyssal Circulation |
06-Jul-2008 |
35 pages |
| Authors:
Harley E Hurlburt; Patrick J Hogan; E J Metzger; Charles E Tilburg; Jay F Shriver; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| A two-layer theory is used to investigate (1) the steering of upper ocean current pathways by topographically constrained abyssal currents that do not impinge on the bottom topography and (2) its application to upper ocean - topographic coupling via flow instabilities where topographically constrained eddy-driven deep mean flows in turn steer the mean pathways of upper ocean currents and associated fronts. In earlier studies the two-layer theory was applied to ... |
|
| The Effects of Surface Gravity Waves on Coastal Currents: Implementation, Phenomenological Explanation, and Realistic Simulation with ROMS |
30 MAY 2008 |
13 pages |
| Authors:
James C. McWilliams; Yusuke Uchiyama; CALIFORNIA UNIV REGENTS LOS ANGELES
|
| Wave-current interaction is incorporated into the Regional Ocean Modeling System (ROMS) on the basis of the multi-scale asymptotic theory derived by McWilliams et al. (2004) using a vortex force formalism to investigate its importance in a wide range of coastal oceanic phenomena. The relationship between different wave-averaged current theories, in particular with a widely-used radiation stress formalism, is explored (Lane et al., 2007). A forced dissipative long-wave model is developed ... |
|
| Forecasting Coastal Optical Properties using Ocean Color and Coastal Circulation Models |
01 FEB 2008 |
9 pages |
| Authors:
Robert A. Arnone; Brandon J. Casey; Dong S. Ko; Peter M. Flynn; L. Carrolo; Sherwin Ladner; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| Coupling the 3-D ocean optical imagery with 3-D circulation models provides a new capability to understand coastal processes. Particle distribution derived from ocean color optical properties were coupled with numerical circulation models to determine a 24 hour forecast of particle concentrations. A 3-D particle concentration field for the coastal ocean was created by extending the surface satellite bio-optical properties vertically by parameterzing an expediential Gaussian depth profile. The shape of ... |
|
| Nonhydrostatic Hindcasts of High Amplitude Internal Waves in the Mid-Atlantic Bight |
30 JAN 2008 |
6 pages |
| Authors:
Patrick C. Gallacher; Michael Schaferkotter; William E. Avera; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| From late July to early September 2006 an intense field program, Shallow Water 2006 (SW06), was conducted in the Mid-Atlantic Bight (MAB) off of the New Jersey coast The goal of the program is to the determine the environmental processes that affect shallow water acoustic propagation and scattering and to understand the dynamics of the generation and evolution of those processes a phenomena that dominates much of the hydrodynamics in ... |
|
| Statistical Characteristics of the Global Surface Current Speeds Obtained from Satellite Altimetry and Scatterometer Data |
01-Jan-2008 |
17 pages |
| Authors:
Peter C Chu; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF OCEANOGRAPHY
|
| Near-real time ocean surface currents derived from satellite altimeter (JASON-1, GFO, ENVISAT) and scatterometer (QSCAT) data on 1 degree 1 degree resolution for world oceans (60 degrees S to 60 degrees N) are available online as Ocean Surface Current Analyses Real Time (OSCAR) . The probability distribution function (PDF) of the current speeds (w), constructed from global OSCAR data from 1992 to 2008, satisfies the two-parameter Weibull distribution reasonably well, ... |
|
| 2008 Report for the Project Entitled: A Comprehensive Modeling Approach Towards Understanding and Prediction of the Alaskan Coastal System Response to Changes in an Ice-diminished Arctic |
Jan-2008 |
10 pages |
| Authors:
NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Our research combines state-of-the-art regional modeling of sea ice, ocean, atmosphere and ecosystem to provide a system approach to advance the knowledge and predictive capability of the diverse impacts of changing sea ice cover on the bio-physical marine environment of coastal Alaska and over the larger region of the western Arctic Ocean. The focus of this project on seasonally ice-free Alaskan coasts and shelves is in direct support of the ... |
|
| Coastal Mixing |
15 NOV 2007 |
3 pages |
| Authors:
Eric A. D'Asaro; Ren C. Lien; WASHINGTON UNIV SEATTLE APPLIED PHYSICS LAB
|
| We seek to understand the mechanisms of turbulence and mixing in shallow water sufficiently well to be able to specify useful parameterizations for coastal circulation models. We seek to understand the links between mixing rates, the circulation and productivity of the coastal ocean. We seek to develop the technology to make accurate Lagrangian measurement of ocean processes and the analysis techniques to use it. The short-term objective was to analyze ... |
|
| Modeling of Mud-Wave Interaction: Mud-Induced Wave Transport & Wave-Induced Mud Transport |
NOV 2007 |
63 pages |
| Authors:
Johan C. Winterwerp; DELFT HYDRAULICS (NETHERLANDS)
|
| This report describes the set-up and mathematical-physical formulations of a model simulating the interaction between soft mud deposits and waves. This model presumes a two-layer schematization, the lower layer consisting of liquefiable mud of high density and viscosity, and the upper layer of low viscous water. From an analytical solution of the 2L schematization the dispersion relation for the wave propagation and attenuation is derived, which can be re-written in ... |
|
| FY06 NRL DoD High Performance Computing Modernization Program Annual Reports |
31 OCT 2007 |
124 pages |
| Authors:
Portia A. Shingler; Beth A. Howell; NAVAL RESEARCH LAB WASHINGTON DC CENTER FOR COMPUTATIONAL SCIENCE
|
| This book is a compilation of reports on all the work accomplished by NRL scientists and engineers and their collaborators using the DoD High Performance Computing Modernization Program's (HPCMP) resources for fiscal year 2006. The reports encompass work performed by researchers at all three NRL sites: Washington, DC; Stennis Space Center, Mississippi; and Monterey, California. These reports are categorized according to the primary Computational Technology Area (CTA) as specified by ... |
|
| Mask Waves Benchmark |
OCT 2007 |
69 pages |
| Authors:
Timothy C. Smith; Lauren K. Hanyok; Michael J. Hughes; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD
|
| This report documents the Maneuvering and Seakeeping Basin wavemaker performance from 2004 to 2007. This report contains benchmark wave cases for comparison with future evaluations of the wavemaker performance. Fifteen data sets were examined for wave amplitude and frequency variability due to spatial position, season, and wavemaker repairs. Wave amplitude variability from wave cycle-to-cycle and between runs was also quantified. Excel macros were developed to aid future comparisons. |
|
| Understanding Recent Variability in the Arctic Sea Ice Cover -- Synthesis of Model Results and Observations |
SEP 2007 |
83 pages |
| Authors:
John Whelan; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This thesis provides a continuation of the analysis of the diminishing sea ice trend in the Arctic Ocean by examining results from the NPS 1/12 degree pan-Arctic coupled ice-ocean model. While many previous studies have analyzed changes in ice extent and concentration, this research focuses on ice thickness as it gives a better representation of ice volume variability. The skill of the model is examined by comparing its ice thickness ... |
|
| 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 ... |
|
| Modeling Nearshore Waves for Hurricane Katrina |
AUG 2007 |
15 pages |
| Authors:
Jane M. Smith; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS
|
| Modeling of nearshore waves under extreme events presents challenges, including the interaction of waves with storm surge, wave generation by complex wind files, and wave dissipation in wetlands. The purpose of this technical note is to demonstrate the application of the Steady-State Spectral Wave model STWAVE for modeling nearshore waves during Hurricane Katrina. STWAVE is under development in the System-Wide Water Resources Program (SWWRP). |
|
| 1/32 Degree Real-Time Global Ocean Prediction and Value-Added Over 1/16 Degree Resolution |
30 JUL 2007 |
26 pages |
| Authors:
Jay Shriver; Harley E. Hurlburt; Ole M. Smedstad; Alan J. Wallcraft; Robert C. Rhodes; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| A 1/32 degree global ocean nowcast/forecast system has been developed by the Naval Research Laboratory at the Stennis Space Center. It started running at the Naval Oceanographic Office in near real-time on 1 Nov. 2003 and has been running daily in real-time since I Mar. 2005. It became an operational system on 6 March 2006, replacing the existing 1/16 degree system which ceased operation on 12 March 2006. Both systems ... |
|
| Observations and Modeling of the Shelf Circulation North of the Monterey Bay during August 2006 |
JUN 2007 |
125 pages |
| Authors:
Rebecca E. Wolf; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| In August of 2006 the Adaptive Sampling and Prediction (ASAP) experiment was conducted near the northern Monterey Bay. Multiple assets were used to gain a better understanding of three-dimensional upwelling centers. Data were collected at two separate mooring locations using Acoustic Doppler Current Profilers (ADCPs). The focus of this thesis is to determine the effects of local wind forcing on the ocean circulation and provide a comparison between the data ... |
|
| Wind Speed Variability over the Marmara Sea |
APR 2007 |
2 pages |
| Authors:
Ahmet B. Kara; Alan J. Wallcraft; Ewa Jarosz; Mark Bourassa; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| Between 2000 and 2006, wind speed measurements were collected over the Marmara Sea by the SeaWinds scatterometer on the QuikSCAT satellite at a spatial resolution of 0.25 x 0.25 degrees. Relatively small interannual variability was noted in monthly mean wind speeds. Typically. wind speed during the summer was weaker by approximately 2 m/s than that observed in winter. This remotely sensed wind data set is intended for various air-sea interaction ... |
|
| Multi-Model Super-Ensemble Ocean Prediction: An Operational Example Using a Kalman Filter in the Adriatic Sea |
APR 2007 |
2 pages |
| Authors:
Michel Rixen; Jeffery W. Book; Paul J. Martin; Nadia Pinardi; Paolo Oddo; Jacopo Chiggiato; Nello Russo; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| Multi-model Super-Ensembles (SE) aim at combining optimally different models. A dynamic Kalman Filter version of this technique was applied to a unique set of in-situ data and operational ocean models during the Dynamics of the Adriatic in Real-Time (DART) field experiment. The technique was shown to significantly improve forecasting skills. |
|
| Application of Creeping Sea-Fill Methodology to the Wind Speed over the Caspian Sea |
APR 2007 |
2 pages |
| Authors:
Murat Gunduz; Ahmet B. Kara; Alan J. Wallcraft; E. J. Metzger; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| Numerical weather prediction (NWP) products include possible errors near coastal regions. The effects of such errors on near-surface wind speed, which is one of the critical variables for coastal applications, are investigated over the Caspian Sea. For this purpose, a creeping sea-fill methodology developed by Kara, Wallcraft, and Hurlburt was applied to the coarse resolution (1.125 degrees x 1.125 degrees) wind speed data obtained from the European Centre for Medium-Range ... |
|
| A Correction for Land Contamination of Atmospheric Variables near Land-Sea Boundaries |
APR 2007 |
17 pages |
| Authors:
A. B. Kara; Alan J. Wallcraft; Harley E. Hurlburt; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| Ocean models need over-ocean atmospheric forcing. However, such forcing is not necessarily provided near the land-sea boundary because (1) the atmospheric model grid used for forcing is frequently much coarser than the ocean model grid, and (2) some of the atmospheric model grid over the ocean includes land values near coastal regions. This paper presents a creeping sea-fill methodology to reduce the improper representation of scalar atmospheric forcing variables near ... |
|
| Naval Research Laboratory Ecological -- Photochemical -- Bio-optical--Numerical Experiment (Neptune) Version 1: A Portable, Flexible Modeling Environment Designed to Resolve Time-dependent Feedbacks Between Upper Ocean Ecology, Photochemistry, and Optics |
21 FEB 2007 |
52 pages |
| Authors:
Jason K. Jolliff; John C. Kindle; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS
|
| A modeling system has been constructed that combines ecological element cycling, photochemical processes, and bio-optical processes into a single simulation that may be coupled to hydrodynamic models that provide temperature fields as well as the advection/diffusion of state variables. The model is derived from a history of ocean biogeochemical models that describe the transformation of elemental reservoirs (carbon, nitrogen, phosphorus) based upon lower-trophic order ecosystem function. The model description of ... |
|
| NPAL Modeling-Internal Wave Effects/Theory and Modeling of Internal Wave Effects on Acoustic Propagation |
08 FEB 2007 |
3 pages |
| Authors:
Frank S. Henyey; WASHINGTON UNIV SEATTLE APPLIED PHYSICS LAB
|
| North Pacific Acoustic Laboratory (NPAL) is the name for a set of experiments on long-range acoustic propagation through the ocean. For a sound to travel far in the ocean, its frequency must be low; sound at 70HZ was frequently used in NPAL experiments. It is common for the propagation of sound to be described in terms of ray tracing, a theory that assumes the frequency is high. An obvious question ... |
|
| Cycling the Representer Algorithm for Data Assimilation with the Lorenz Attractor |
FEB 2007 |
15 pages |
| Authors:
H. E. Ngodock; S. R. Smith; G. A. Jacobs; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
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| Realistic dynamic systems are often strongly nonlinear, particularly those for the ocean and atmosphere. Applying variational data assimilation to these systems requires a tangent linearization of the nonlinear dynamics about a background state for the cost function minimization. The tangent linearization may be accurate for limited time scales. Here it is proposed that linearized assimilation systems may be accurate if the assimilation time period is less than the tangent linear ... |
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| Scour and Burial Mechanics of Objects in the Nearshore |
Jan-2007 |
14 pages |
| Authors:
Michael D Richardson; Thomas F Wever; Scott A Jenkins; Douglas L Inman; Joseph Wasyl; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB
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| A process-based, numerical, hydrodynamic vortex lattice mine scour/burial model (VORTEX) is presented that simulates scour and burial of objects of arbitrary shape resting on a granular bed in the nearshore. There are two domains in the model formulation: a far-field where burial and exposure occur due to changes in the elevation of the seabed and a near-field involving scour and transport of sediment by the vortices shed from the object. ... |
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| Multi-Sensor Improved Sea Surface Temperature (MISST) for GODAE |
2007 |
13 pages |
| Authors:
Chelle L. Gentemann; Gary A. Wick; James Cummings; Eileen Maturi; REMOTE SENSING SYSTEMS SANTA ROSA CA
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| The Multi-sensor Improved Sea Surface Temperatures (MISST) for the Global Ocean Data Assimilation Experiment (GODAE) project intends to produce an improved, high-resolution, global, near-real-time (NRT), sea surface temperature analysis through the combination of satellite observations from complementary infrared (IR) and microwave (MW) sensors and to then demonstrate the impact of these improved sea surface temperatures (SSTs) on operational ocean models, numerical weather prediction (NWP), and tropical cyclone intensity forecasting. The ... |
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| Assessing the Impact of GODAE Boundary Conditions on the Estimate and Prediction of the Monterey Bay and California Central Coast Circulation |
2007 |
9 pages |
| Authors:
Christopher A. Edwards; Andrew M. Moore; Carl Wunsch; James D. Doyle; Franklin B. Schwing; David Foley; CALIFORNIA UNIV SANTA CRUZ CA OCEAN SCIENCES DEPT
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| The practical demonstration of basin-scale ocean state estimation has been realized through the Global Ocean Data Assimilation Experiment (GODAE) whose projects provide complete descriptions of the temperature, salinity, and velocity structure of the global ocean. The ocean circulation, temperature and salinity distributions of coastal regions are characterized by smaller scale processes typically not resolved by basin-scale estimates of the ocean structure. The overarching goal of this project is to assess ... |
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| Time-Frequency Modeling of Shallow Water Environments: Rigid vs. Fluid Seabed |
2007 |
6 pages |
| Authors:
Jun Zhang; Bertrand Gottin; Antonia Papandreou-Suppappola; Cornel Ioana; ARIZONA STATE UNIV TEMPE DEPT OF ELECTRICAL ENGINEERING
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| When the ocean seabed is considered to be rigid, the ideal waveguide model can be used to model the shallow water environment. However, a more realistic ocean waveguide model treats the ocean floor as a boundary between two different fluid media. In this paper, a frequency-domain characterization of shallow water environments is proposed based on this realistic waveguide model with a fluid boundary. First, the time-frequency characteristics of this model ... |
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| The Application of Sea Level Pressure and Vorticity Fields derived from the University of Washington Planetary Boundary Layer Model in the NOAA Ocean Prediction Center |
Sep-2006 |
7 pages |
| Authors:
Von; Joan M Ahn; Joseph M Sienkiewicz; Gregory M McFadden; NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION CAMP SPRINGS MD OCEAN PREDICTION CENTER
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| The SeaWinds scatterometer onboard the NASA QuikSCAT satellite has been providing forecasters in the Ocean Prediction Center (OPC) with Near-Real Time (NRT) ocean vector winds over large ocean areas since 1999. Although QuikSCAT's impact on the analysis and forecast process has been significant to the short-term wind warning process, this positive impact has not carried over to the analysis of the sea level pressure field over the open oceans. In ... |
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