34 results on '"Chris Mirabito"'
Search Results
2. Evaluation of Deep Neural Operator Models toward Ocean Forecasting.
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Ellery Rajagopal, Anantha N. S. Babu, Tony Ryu, Patrick J. Haley Jr., Chris Mirabito, and Pierre F. J. Lermusiaux
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- 2023
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3. High-Performance Visualization for Ocean Modeling
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Wael H. Ali, Youran Gao, Corbin Foucart, Manan Doshi, Chris Mirabito, Patrick J. Haley, and Pierre F. J. Lermusiaux
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- 2022
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4. Adaptive hierarchic transformations for dynamically p-enriched slope-limiting over discontinuous Galerkin systems of generalized equations.
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Craig Michoski, Chris Mirabito, Clint Dawson 0001, Damrongsak Wirasaet, Ethan J. Kubatko, and Joannes J. Westerink
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- 2011
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5. A Performance Comparison of Continuous and Discontinuous Finite Element Shallow Water Models.
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Ethan J. Kubatko, Shintaro Bunya, Clint Dawson 0001, Joannes J. Westerink, and Chris Mirabito
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- 2009
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6. High-order Discontinuous Galerkin Methods for Nonhydrostatic Ocean Processes with a Free Surface
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Corbin Foucart, Chris Mirabito, Patrick J. Haley, and Pierre F. J. Lermusiaux
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- 2021
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7. Energy and Momentum Lost to Wake Eddies and Lee Waves Generated by the North Equatorial Current and Tidal Flows at Peleliu, Palau
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Sophia Merrifield, Mark A. Merrifield, Jennifer A. MacKinnon, Andrew Lucas, Chris Mirabito, Jonathan D. Nash, Pierre F. J. Lermusiaux, Eric Terrill, Patrick J. Haley, Shaun Johnston, Amy F. Waterhouse, Mika Siegelman, Patrick Colin, and Celia Ou
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Eddy ,Mountain wave ,Energy–momentum relation ,Geophysics ,Current (fluid) ,Wake ,Oceanography ,Geology - Published
- 2019
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8. Joint ocean physics-acoustics inversion and mutual-information based experiment design in realistic ocean fields
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Wael H. Ali, Chris Mirabito, Patrick J. Haley, and Pierre F. Lermusiaux
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Acoustics and Ultrasonics ,Arts and Humanities (miscellaneous) - Abstract
Reliable acoustic exploration and navigation in the ocean requires precise knowledge of the environmental fields (e.g. ocean physics, bathymetry, seabed) and acoustic parameters (e.g. source location and frequencies). However, such knowledge is typically incomplete due to the sparse and heterogeneous observations, and to the complex high-dimensional multiscale dynamics. In this work, we use our stochastic Dynamically Orthogonal Parabolic Equation (DO-ParEq) framework to: (i) model the ocean environment uncertainties computed from a large realistic ocean ensemble forecast, and (ii) predict the resulting stochastic acoustic fields and their probability distributions. We then employ new nonlinear Bayesian learning algorithms that use Gaussian Mixture Models to assimilate ocean-acoustic measurements and jointly infer the unknown properties of the ocean environment, the bathymetry, the acoustic field and parameters, and even the model parameterizations themselves. We showcase the developed techniques in realistic data-assimilative sea experiments in the New York Bight Region and the Mediterranean Sea. Finally, we demonstrate the impact of selecting measurement locations using a mutual-information-based algorithm that maximizes the information content in the learned fields based on the measurement constraints.
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- 2022
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9. Extent of impact of deep-sea nodule mining midwater plumes is influenced by sediment loading, turbulence and thresholds
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Amy Gartman, Raphael Ouillon, Matthew H. Alford, Andrew J. Rzeznik, Dayang Wang, Arnaud Le Boyer, Alexander Breugem, Pierre F. J. Lermusiaux, Thijs Lanckriet, Se-Jong Ju, E. Eric Adams, Jerome A. Smith, Patrick J. Haley, Chris Mirabito, Thomas Peacock, B. Decrop, Carlos Munoz-Royo, Chinmay S. Kulkarni, and Rohit Supekar
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Nodule (geology) ,QE1-996.5 ,0303 health sciences ,010504 meteorology & atmospheric sciences ,Turbulence ,Sediment ,Geology ,Fracture zone ,engineering.material ,01 natural sciences ,Deep sea ,Plume ,Environmental sciences ,03 medical and health sciences ,Oceanography ,engineering ,General Earth and Planetary Sciences ,Environmental science ,GE1-350 ,Plume model ,030304 developmental biology ,0105 earth and related environmental sciences ,General Environmental Science - Abstract
Deep-sea polymetallic nodule mining research activity has substantially increased in recent years, but the expected level of environmental impact is still being established. One environmental concern is the discharge of a sediment plume into the midwater column. We performed a dedicated field study using sediment from the Clarion Clipperton Fracture Zone. The plume was monitored and tracked using both established and novel instrumentation, including acoustic and turbulence measurements. Our field studies reveal that modeling can reliably predict the properties of a midwater plume in the vicinity of the discharge and that sediment aggregation effects are not significant. The plume model is used to drive a numerical simulation of a commercial-scale operation in the Clarion Clipperton Fracture Zone. Key takeaways are that the scale of impact of the plume is notably influenced by the values of environmentally acceptable threshold levels, the quantity of discharged sediment, and the turbulent diffusivity in the Clarion Clipperton Fracture Zone. The extent of impact by midwater discharge plumes from deep-sea nodule mining will be influenced by the quantity of plume sediment, ocean turbulence and acceptable environmental thresholds, according to numerical modelling and direct experiments
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- 2021
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10. Optimal Harvesting with Autonomous Tow Vessels for Offshore Macroalgae Farming
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Manan Doshi, C.A. Goudey, J. Curcio, Pierre F. J. Lermusiaux, H. Goudey, B.C. Koenig, Manmeet S. Bhabra, D. Manganelli, Patrick J. Haley, and Chris Mirabito
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Vehicle dynamics ,Work (electrical) ,Computer science ,Scale (chemistry) ,Path (graph theory) ,Submarine pipeline ,Motion planning ,Field (computer science) ,Variety (cybernetics) ,Marine engineering - Abstract
The rising popularity of aquaculture has led to increased research in offshore algae farming. Central to the efficient operation of such farms is the need for (i) accurate models of the dynamic ocean environment including macroalgae ecosystem dynamics and (ii) intelligent path planning algorithms for autonomous vessels that optimally manage and harvest the algae fields. In this work, we address both these challenges. We first integrate our modeling system of the ocean environment with a model for forecasting the growth and decay of algae fields. These fields are then input into our exact optimal path planning, augmented with the optimal harvesting goals and solved using level set methods. The resulting path is a provable time-optimal route for the vehicle to follow under the constraint of having to monitor or harvest a specified amount of the field to collect. To demonstrate the theory, we simulate algal growth in both idealized and realistic data-assimilative dynamic ocean environments and compute the optimal paths for an autonomous collection vehicle. We demonstrate that our theory and schemes can be used to compute the optimal path in a variety of scenarios - harvesting in the case of discrete farms, a large kelp farm field, or large scale dynamic algal bloom fields.
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- 2020
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11. Towards Bayesian Ocean Physical- Biogeochemical- Acidification Prediction and Learning Systems for Massachusetts Bay
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Pierre F. J. Lermusiaux, Patrick J. Haley, Abhinav Gupta, and Chris Mirabito
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State variable ,Biogeochemical cycle ,Advection ,Environmental science ,Upwelling ,Ocean acidification ,Atmospheric sciences ,Bayesian inference ,Bay ,Physics::Atmospheric and Oceanic Physics ,Mixing (physics) - Abstract
Better quantitative understanding and accurate data-assimilative predictions of the three-dimensional and time-dependent ocean acidification (OA) processes in coastal regions is urgently needed for the protection and sustainable utilization of ocean resources. In this paper, we extend and showcase the use of our MIT-MSEAS systems for high-resolution coupled physical-biogeochemical-acidification simulations and Bayesian learning of OA models in Massachusetts Bay, starting with simple empirical and equilibrium OA models. Simulations are shown to have reasonable skill when compared to available in situ and remote data. The impacts of wind forcing, internal tides, and solitary waves on water transports and mixing, and OA fields, are explored. Strong wind events are shown to reset circulations and the OA state in the Bay. Internal tides increase vertical mixing of waters in the shallow regions. Solitary waves propagating off Stellwagen Bank coupled with lateral turbulent mixing provide a pathway for exchange of surface and deep waters. Both of these effects are shown to impact biological activity and OA. A mechanism for the creation of multiple subsurface chlorophyll maxima is presented, involving wind-induced upwelling, internal tides, and advection of near surface fields. Due to the measurement sparsity and limited understanding of complex OA processes, the state variables and parameterizations of OA models are very uncertain. We thus present a proof-of-concept study to simultaneously learn and estimate the OA state variables and model parameterizations from sparse observations using our novel dynamics-based Bayesian learning framework for high-dimensional and multi-disciplinary estimation. Results are found to be encouraging for more realistic OA model learning.
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- 2020
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12. Multi-resolution Probabilistic Ocean Physics-Acoustics Modeling: Validation in the New Jersey Continental Shelf
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Patrick J. Haley, Chris Mirabito, Pierre F. J. Lermusiaux, C. Emerson, Wael H. Ali, C. S. Chiu, Manmeet S. Bhabra, and Phil Abbot
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geography ,geography.geographical_feature_category ,Continental shelf ,Probabilistic logic ,Geophysics ,Solid modeling ,Sonar ,Physics::Geophysics ,Ocean dynamics ,Eddy ,Transmission (telecommunications) ,Hindcast ,Physics::Atmospheric and Oceanic Physics ,Geology - Abstract
The reliability of sonar systems in the littoral environment is greatly affected by the variability of the surrounding nonlinear ocean dynamicS. This variability occurs on multiple scales in space and time, and involves multiple interacting processes, from internal tides and waves to meandering fronts, eddies, boundary layers, and strong air-sea interactionS. We utilize our high-resolution MSEAS-PE ocean modeling system to hindcast the ocean physical environment off the New Jersey continental shelf for the end of June 2009, and then utilize our new MSEAS probabilistic acoustic NAPE and WAPE solvers in a coupled ocean physics-acoustic modeling fashion to predict the transmission and integrated transmission losses, respectively. The coupled models are described, and their predictions verified against independent ocean physics observations and sound propagation measurements from acoustic sources and receivers in the region. Our high-resolution ocean simulations are shown to substantial reduce the RMSE and bias of the coarser simulationS. Our acoustic simulations of deterministic and stochastic TL fields also show significant skill.
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- 2020
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13. Reduced Order Modeling for Stochastic Prediction Onboard Autonomous Platforms at Sea
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Pierre F. J. Lermusiaux, Patrick J. Haley, J. P. Heuss, Chris Mirabito, Emanuel Coelho, Kevin D. Heaney, and Martha Schönau
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Meteorology ,Stochastic process ,Dynamic mode decomposition ,Environmental science ,Projection (set theory) ,Reduced order - Abstract
We describe and investigate several Dynamic Mode Decomposition (DMD) and reduced order projection methods for regional stochastic ocean predictions. We then showcase some of their results as applied to a 300-member set of ensemble forecasts from the POSYDON-POINT sea experiment in the Middle Atlantic–New York Bight region for the period 23–27 August 2018 as well as to a 42-day data-driven reanalysis from the AWACS–SW06 sea experiment in the Middle Atlantic Bight region for the period 14 August to 24 September 2006. We discuss these results for use by autonomous platforms in uncertain scenarios as well the combination of DMD with ideas from large-ensemble forecasting and Dynamically-Orthogonal (DO) differential equations.
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- 2020
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14. Real-time Probabilistic Coupled Ocean Physics-Acoustics Forecasting and Data Assimilation for Underwater GPS
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J. Boyle, Wael H. Ali, Patrick J. Haley, Lee Freitag, Aaron Scott Kofford, J. Murray, Abhinav Gupta, E. Dorfman, A. Laferriere, Chris Mirabito, Emanuel Coelho, Sudip Jana, Kevin D. Heaney, G. Shepard, Pierre F. J. Lermusiaux, A. Morozov, and Michael Goldsmith
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geography ,geography.geographical_feature_category ,Meteorology ,Positioning system ,Computer science ,business.industry ,Probabilistic logic ,Atmospheric model ,Data assimilation ,Software deployment ,Global Positioning System ,Underwater ,business ,Oceanic basin - Abstract
The widely-used Global Positioning System (GPS) does not work underwater. This presents a severe limitation on the communication capabilities and deployment options for undersea assets such as AUVs and UUVs. To address this challenge, the Positioning System for Deep Ocean Navigation (POSYDON) program aims to develop an undersea system that provides omnipresent, robust positioning across ocean basins. To do so, it is critically important to accurately model sound waves and signals under diverse, and often uncertain, undersea environmental conditions. Probabilistic estimates of the four-dimensional variability of the fields of sound speed, salinity, temperature, and currents are thus needed. In this paper, we employ our MSEAS primitive-equation and error subspace data-assimilative ensemble ocean forecasting system during two realtime POSYDON sea exercises, one in winter 2017 and another in August 2018. We provide real-time high-resolution estimates of sound speed fields and their uncertainty, and describe the ocean conditions from submesoscales eddies and internal tides to warm core rings and larger-scale circulations. We verify our results against independent data of opportunity; in all cases, we show that our probabilistic forecasts demonstrate skill.
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- 2020
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15. A future for intelligent autonomous ocean observing systems
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Deepak N. Subramani, Patrick J. Haley, Arkopal Dutt, J. Lin, Chinmay S. Kulkarni, Abhinav Gupta, Chris Mirabito, Sudip Jana, Pierre F. J. Lermusiaux, Tapovan Lolla, and Wael H. Ali
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010101 applied mathematics ,010504 meteorology & atmospheric sciences ,Computer science ,0101 mathematics ,Oceanography ,01 natural sciences ,0105 earth and related environmental sciences - Published
- 2017
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16. Optimal Planning and Sampling Predictions for Autonomous and Lagrangian Platforms and Sensors in the Northern Arabian Sea
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Andrey Y. Shcherbina, Jing Lin, Abhinav Gupta, Craig M. Lee, Pierre F. J. Lermusiaux, Patrick J. Haley, Arkopal Dutt, Chris Mirabito, Deepak N. Subramani, Wael H. Ali, Chinmay S. Kulkarni, Sudip Jana, and Avijit Gangopadhyay
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010101 applied mathematics ,symbols.namesake ,010504 meteorology & atmospheric sciences ,Meteorology ,symbols ,Optimal planning ,Environmental science ,Sampling (statistics) ,0101 mathematics ,Oceanography ,01 natural sciences ,Lagrangian ,0105 earth and related environmental sciences - Published
- 2017
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17. CALYPSO 2019 Cruise Report: field campaign in the Mediterranean
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Gino Cristofano, Carlos Castilla, Andrey Y. Shcherbina, Pablo Almaraz García, M. Rubio, Tamay M. Özgökmen, Pierre Marie Poulain, Amala Mahadevan, Luca R. Centurioni, Joan Mateu Horrach Pou, Cedric M. Guigand, Raymond Graham, Evan Goodwin, John T. Allen, Marc Torner, Noemi Calafat, Margaret Conley, Guilherme Salvador-Vieira, Nikolaos Zarokanellos, A. Miralles, Simon Ruiz, Uwe Send, Eva Alou-Font, Ananda Pascual, Irina I. Rypina, Harilal Meenambika Aravind, Nikolaus Wirth, Said Ouala, Benjamin Casas, Pau Balaguer, Matthias Lankhorst, Benjamin A. Hodges, Baptiste Mourre, Helga S. Huntley, Shaun Johnston, Irene Lizaran, Gabriel Navarro, Eric A. D'Asaro, Mara Freilich, Alice Ren, Joaquin Tintore, Angélica Enrique Navarro, Isabel Caballero, Francesco Falcieri, Daniel L. Rudnick, Mathieu Dever, Eugenio Cutolo, Pierre F. J. Lermusiaux, Michael Ohmart, Daniel Rodriguez Tarry, Chris Mirabito, and Andrea Carbornero
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Mediterranean climate ,Oceanography ,Cruise ,Environmental science ,Field campaign - Published
- 2020
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18. SeaVizKit: Interactive Maps for Ocean Visualization
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Chinmay S. Kulkarni, Manan Doshi, Patrick J. Haley, Abhinav Gupta, Pierre F. J. Lermusiaux, Chris Mirabito, Corbin Foucart, Mohamad H. Mirhi, Deepak N. Subramani, and Wael H. Ali
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Creative visualization ,Multivariate statistics ,010504 meteorology & atmospheric sciences ,Emergency management ,010505 oceanography ,business.industry ,Computer science ,media_common.quotation_subject ,Big data ,01 natural sciences ,Data science ,Visualization ,Data visualization ,Multiple time ,business ,Interactive visualization ,0105 earth and related environmental sciences ,media_common - Abstract
With the increasing availability of high-resolution comprehensive spatio-temporal ocean models and observation systems, ocean data visualization has become ubiquitous. This is due to the major impact of ocean products on disaster management, shipping, fisheries, autonomy, coastal operations, and scientific studies. Yet, there are several challenges for effective communication of data through visualization techniques. Specifically, ocean data is multivariate (e.g. temperature, salinity, velocity, etc.), is available for multiple depths and multiple time instants, and contains uncertainties, all of which leads to large, multi-dimensional datasets. Thus, it is necessary to have an interactive multiscale multivariate visualization tool that can assist scientists, engineers, policy makers, and the public in making insights from big data produced by ocean predictions and observations. In this work, we present a 3D (spatial) + 1 (temporal) multi-resolution multivariate visualization tool that produces interactive, dynamic, fast and portable ocean maps.
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- 2019
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19. Plastic Pollution in the Coastal Oceans: Characterization and Modeling
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S. J. Levang, John Marshall, Pierre F. J. Lermusiaux, P.J. Haley, C. Noble, Manan Doshi, Francesco Trotta, Abhinav Gupta, Chinmay S. Kulkarni, Thomas Peacock, Chris Mirabito, G. R. Flierl, P. F. J. Lermusiaux, M. Doshi, C. S. Kulkarni, A. Gupta, P. J. Haley, C. Mirabito, F. Trotta, S. J. Levang, G. R. Flierl, J. Marshall, T. Peacock, and C. Noble
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Shore ,geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,010505 oceanography ,Advection ,01 natural sciences ,Ocean dynamics ,Oceanography ,Settling ,Submarine pipeline ,Plastic pollution ,Bay ,Seabed ,Geology ,Ocean modeling, Lagrangian field analysis, Flow map composition, Marine plastic, Settling, FTLE, Lagrangian coherent structures, Massachusetts Bay ,0105 earth and related environmental sciences - Abstract
To cleanup marine plastics, accurate modeling is needed. We outline and illustrate a new partial-differential-equation methodology for characterizing and modeling plastic transports in time and space (4D), showcasing results for Massachusetts Bay. We couple our primitive equation model for ocean dynamics with our composition based advection for Lagrangian transport. We show that the ocean physics predictions have skill by comparison with synoptic data. We predict the fate of plastics originating from four sources: rivers, beach and nearshore, local Bay, and remote offshore. We analyze the transport patterns and the regions where plastics accumulate, comparing results with and without plastic settling. Simulations agree with existing debris and plastics data. They also show new results: (i) Currents set-up by wind events strongly affect floating plastics. Winds can for example prevent Merrimack outflows reaching the Bay; (ii) There is significant chaotic stirring between nearshore and offshore floating plastics as explained by ridges of Lagrangian Coherent Structures (LCSs); (iii) With 4D plastic motions and settling, plastics from the Merrimack and nearshore regions can settle to the seabed before offshore advection; (iv) Internal waves and tides can bring plastics downward and out of main currents, leading to settling to the deep bottom. (v) Attractive LCSs ridges are frequent in the northern Cape Cod Bay, west of the South Shore, and southern Stellwagen Bank. They lead to plastic accumulation and sinking along thin subduction zones.
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- 2019
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20. Scalable Coupled Ocean and Water Turbine Modeling for Assessing Ocean Energy Extraction
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Corbin Foucart, Benedetto Rocchio, Stefania Zanforlin, Chris Mirabito, F. J. Pierre Lermusiaux, P.J. Haley, and Stefano Deluca
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business.industry ,Water turbine ,Rotor (electric) ,020209 energy ,02 engineering and technology ,Aerodynamics ,Computational fluid dynamics ,Regional Ocean Modeling System ,law.invention ,Software ,law ,Marine energy ,0202 electrical engineering, electronic engineering, information engineering ,Environmental science ,business ,Tidal power ,Marine engineering - Abstract
The interest in hydrokinetic conversion systems has significantly grown over the last decade with a special focus on cross-flow systems, generally known as Vertical Axis Water Turbines (VAWTs). However, analyzing of regions of interest for tidal energy extraction and outlining optimal rotor geometry is currently very computationally expensive via conventional 3D Computational Fluid Dynamics (CFD) methods. In this work, a VAWT load prediction routine developed at University of Pisa based upon the Blade Element-Momentum (BEM) theory is presented and validated against high-resolution 2D CFD simulations. Our model is able to work in two configurations, i.e. Double-Multiple Stream tube (DMST) mode, using 1D flow simplifications for quick analyses, and Hybrid mode, coupled to a CFD software for more accurate results. As a practical application, our routine is employed for a site assessment analysis of the Cape Cod area to quickly highlight oceanic regions with high hydrokinetic potential, where further higher-order and more computationally expensive CFD analyses can be performed. Ocean data are obtained from data-assimilative ocean simulations predicted by the 4D regional ocean modeling system of the Multidisciplinary Simulation, Estimation, and Assimilation Systems (MSEAS) group of the Massachusetts Institute of Technology.
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- 2019
21. Distributed Implementation and Verification of Hybridizable Discontinuous Galerkin Methods for Nonhydrostatic Ocean Processes
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P.J. Haley, Pierre F. J. Lermusiaux, Chris Mirabito, and Corbin Foucart
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010504 meteorology & atmospheric sciences ,Computer science ,010103 numerical & computational mathematics ,Internal wave ,01 natural sciences ,Finite element method ,Ocean dynamics ,Ocean surface topography ,Discontinuous Galerkin method ,Projection method ,Applied mathematics ,0101 mathematics ,Boussinesq approximation (water waves) ,Navier–Stokes equations ,0105 earth and related environmental sciences - Abstract
Nonhydrostatic, multiscale processes are an important part of our understanding of ocean dynamics. However, resolving these dynamics with traditional computational techniques can often be prohibitively expensive. We apply the hybridizable discontinuous Galerkin (HDG) finite element methodology to perform computationally efficient, high-order, nonhydrostatic ocean modeling by solving the Navier-Stokes equations with the Boussinesq approximation. In this work, we introduce a distributed implementation of our HDG projection method algorithm. We provide numerical experiments to verify our methodology using the method of manufactured solutions and provide preliminary benchmarking for our distributed implementation that highlight the advantages of the HDG methodology in the context of distributed computing. Lastly, we present simulations in which we capture nonhydrostatic internal waves that form as a result of tidal interactions with ocean topography. First, we consider the case of tidally-driven oscillatory flow over an abrupt, shallow seamount, and next, the case of strongly-stratified, oscillatory flow over a tall seamount. We analyze and compare our simulations to other results in literature.
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- 2018
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22. Real-time sediment plume modeling in the Southern California bight
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Sudip Jana, Andrew J. Rzeznik, Deepak N. Subramani, Thomas Peacock, Pierre F. J. Lermusiaux, Abhinav Gupta, Carlos Munoz Royo, P.J. Haley, Chinmay S. Kulkarni, Arkopal Dutt, Chris Mirabito, Rohit Supekar, and Wael H. Ali
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010504 meteorology & atmospheric sciences ,Earth science ,Sediment ,01 natural sciences ,Deep sea ,010305 fluids & plasmas ,Data modeling ,Plume ,Deep sea mining ,Sustainable management ,0103 physical sciences ,Environmental science ,Marine ecosystem ,Seabed ,0105 earth and related environmental sciences - Abstract
With advances in engineering and technology, mining the deep sea for untapped rare metal resources from the bottom of the ocean has recently become economically viable. However, extracting these metal ores from the seabed creates plumes of fine particles that are deposited at various depths within the ocean, and these may be extremely harmful to the marine ecosystems and its components. Thus, for sustainable management, it is of utmost importance to carefully monitor and predict the impact of such harmful activities including plume dispersion on the marine environment. To forecast the plume dispersion in real-time, data-driven ocean modeling has to be coupled with accurate, efficient, and rigorous sediment plume transport computations. The goal of the present paper is to demonstrate the real-time applications of our coupled 3D-and time data-driven ocean modeling and plume transport forecasting system. Here, the region of focus is the southern California bight, where the PLUMEX 2018 deep sea mining real-time sea experiment was recently conducted (23 Feb - 5 Mar, 2018). Specifically, we demonstrate the improved capabilities of the multiscale MSEAS primitive equation ocean modeling system to capture the complex oceanic phenomenon in the region of interest, the application of the novel method of composition to efficiently and accurately compute the transport of sediment plumes in 3D+1 domains, and the portability of our software and prediction system to different operational regions and its potential in estimating the environmental impacts of deep sea mining activities, ultimately aiding sustainable management and science-based regulations.
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- 2018
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23. Data-driven learning and modeling of AUV operational characteristics for optimal path planning
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Andrew Girard, Joseph R. Edwards, Chinmay S. Kulkarni, Deepak N. Subramani, Joshua R. Smith, Chris Mirabito, Pierre F. J. Lermusiaux, Sudip Jana, Diana Wickman, and Patrick J. Haley
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Service (systems architecture) ,Engineering ,Traverse ,business.industry ,Real-time computing ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,Power budget ,Power (physics) ,Path (graph theory) ,Minification ,Motion planning ,Underwater ,business ,Simulation - Abstract
Autonomous underwater vehicles (AUVs) are used to execute an increasingly challenging set of missions in commercial, environmental and defense industries. The resources available to the AUV in service of these missions are typically a limited power supply and onboard sensing of its local environment. Optimal path planning is needed to maximize the chances that these AUVs will successfully complete long-endurance missions within their power budget. A time-optimal path planner has been recently developed to minimize AUV mission time required to traverse a dynamic ocean environment at a specified speed through the water. For many missions, time minimization is appropriate because the AUVs operate at a fixed propeller speed. However, the ultimate limiting constraint on AUV operations is often the onboard power supply, rather than mission time. While an empirical or theoretical relationship between mission time and power could be applied to estimate power usage in the path planner, the real power usage and availability on an AUV varies mission-to-mission, as a result of multiple factors, including vehicle buoyancy, battery charge cycle, fin configuration, and water type or quality. In this work, we use data collected from two mid-size AUVs operating in various conditions to learn the mission-to-mission variability in the power budget so that it could be incorporated into the mission planner.
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- 2017
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24. Time-optimal path planning: Real-time sea exercises
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Pierre F. J. Lermusiaux, Deepak N. Subramani, Josh Smith, Patrick J. Haley, Sudip Jana, Andrew Girard, Chinmay S. Kulkarni, Joe Edwards, Diana Wickman, and Chris Mirabito
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geography ,Engineering ,geography.geographical_feature_category ,Meteorology ,business.industry ,Computation ,Plan (drawing) ,Software ,Path (graph theory) ,Motion planning ,Underwater ,business ,Sound (geography) ,REMUS ,Marine engineering - Abstract
We report the results of sea exercises that demonstrate the real-time capabilities of our fundamental time-optimal path planning theory and software with real ocean vehicles. The exercises were conducted with REMUS 600 Autonomous Underwater Vehicles (AUVs) in the Buzzards Bay and Vineyard Sound Regions on 21 October and 6 December 2016. Two tests were completed: (i) 1-AUV time-optimal tests and (ii) 2-AUV race tests where one AUV followed a time-optimal path and the other a shortest-distance path between the start and finish locations. The time-optimal planning proceeded as follows. We first forecast, in real-time, the physical ocean conditions in the above regions and times utilizing our MSEAS multi-resolution primitive equation ocean modeling system. Next, we planned time-optimal paths for the AUVs using our level-set equations and real-time ocean forecasts, and accounting for operational constraints (e.g. minimum depth). This completed the planning computations performed onboard a research vessel. The forecast optimal paths were then transferred to the AUV operating system and the vehicles were piloted according to the plan. We found that the forecast currents and paths were accurate. In particular, the time-optimal vehicles won the races, even though the local currents and geometric constraints were complex. The details of the results were analyzed off-line after the sea tests.
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- 2017
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25. Autonomy for surface ship interception
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Patrick J. Haley, Pierre F. J. Lermusiaux, Tapovan Lolla, Chris Mirabito, Yuming Liu, F. S. Hover, G. Shaw, Joseph R. Edwards, Dick K. P. Yue, Deepak N. Subramani, C. Li, Ajay Jain, K. E. Railey, and N. Pulsone
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Current (stream) ,Geography ,Meteorology ,Ocean current ,Motion planning ,Interception ,Wake ,Tacking ,Regional Ocean Modeling System ,Wedge (geometry) ,Marine engineering - Abstract
In recent years, the use of autonomous undersea vehicles (AUVs) for highly time-critical at-sea operations involving surface ships has received increased attention, magnifying the importance of optimal interception. Finding the optimal route to a moving target is a challenging procedure. In this work, we describe and apply our exact time-optimal path planning methodology and the corresponding software to such ship interception problems. A series of numerical ship interception experiments is completed in the southern littoral of Massachusetts, namely in Buzzards Bay and Vineyard Sound around the Elizabeth Islands and Martha's Vineyard. Ocean currents are estimated from a regional ocean modeling system. We show that complex coastal geometry, ship proximity, and tidal current phases all play key roles influencing the time-optimal vehicle behavior. Favorable or adverse currents can shift the optimal route from one island passage to another, and can even cause the AUV to remain nearly stationary until a favorable current develops. We also integrate the Kelvin wedge wake model into our path planning software, and show that considering wake effects significantly complicates the shape of the time-optimal paths, requiring AUVs to execute sequences of abrupt turns and tacking maneuvers, even in highly idealized scenarios. Such behavior is reminiscent of ocean animals swimming in wakes. In all cases, it is shown that our level set partial differential equations successfully guide the time-optimal vehicles through regions with the most favorable currents, avoiding regions with adverse effects, and accounting for the ship wakes when present.
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- 2017
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26. An a priori error estimate for the local discontinuous Galerkin method applied to two-dimensional shallow water and morphodynamic flow
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Clint Dawson, Chris Mirabito, and Vadym Aizinger
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Numerical Analysis ,Mathematical optimization ,Conservation law ,Applied Mathematics ,Finite element method ,Computational Mathematics ,Nonlinear system ,Flow (mathematics) ,Discontinuous Galerkin method ,Applied mathematics ,Boundary value problem ,Exner equation ,Shallow water equations ,Analysis ,Mathematics - Abstract
The application of discontinuous Galerkin (DG) methods to the numerical solution of the two- and three-dimensional shallow water equations has seen increased interest over the past decade. In this article, previous work by the second author and several collaborators on the application and analysis of the DG method is extended to coupled shallow water/bed morphology dynamics, also called morphodynamics. Morphodynamic boundary value problems are used to simultaneously model shallow water hydrodynamics and sediment transport processes in estuarine and coastal systems. The governing equations of interest arise when the two-dimensional Saint-Venant equations are tightly coupled to the corresponding Exner equation. The tight coupling of these two processes presents numerous modeling and analytical challenges. The resulting nonlinear system is incompletely parabolic, and contains a nonconservative product. In this work, some of these analytical challenges are tackled by applying a local discontinuous Galerkin method to the morphodynamic system; the quantities of interest and their gradients are solved separately. A general, semidiscrete finite element formulation is presented, and after justifying some mild assumptions, a new a priori error estimate for the system is derived. © 2014 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 31: 397–421, 2015
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- 2014
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27. Fully coupled methods for multiphase morphodynamics
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Joannes J. Westerink, Craig Michoski, Chris Mirabito, Damrongsak Wirasaet, Ethan J. Kubatko, and Clint Dawson
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Engineering ,business.industry ,Numerical analysis ,System of linear equations ,Symbolic computation ,Finite element method ,Discontinuous Galerkin method ,Convergence (routing) ,Dissipative system ,Applied mathematics ,Geotechnical engineering ,business ,Shallow water equations ,Water Science and Technology - Abstract
We present numerical methods for a system of equations consisting of the two dimensional Saint–Venant shallow water equations (SWEs) fully coupled to a completely generalized Exner formulation of hydrodynamically driven sediment discharge. This formulation is implemented by way of a discontinuous Galerkin (DG) finite element method, using a Roe Flux for the advective components and the unified form for the dissipative components. We implement a number of Runge–Kutta time integrators, including a family of strong stability preserving (SSP) schemes, and Runge–Kutta Chebyshev (RKC) methods. A brief discussion is provided regarding implementational details for generalizable computer algebra tokenization using arbitrary algebraic fluxes. We then run numerical experiments to show standard convergence rates, and discuss important mathematical and numerical nuances that arise due to prominent features in the coupled system, such as the emergence of nondifferentiable and sharp zero crossing functions, radii of convergence in manufactured solutions, and nonconservative product (NCP) formalisms. Finally we present a challenging application model concerning hydrothermal venting across metalliferous muds in the presence of chemical reactions occurring in low pH environments.
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- 2013
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28. Dynamic p-enrichment schemes for multicomponent reactive flows
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Clinton N Dawson, Damrongsak Wirasaet, Ethan J. Kubatko, Craig Michoski, Chris Mirabito, and Joannes J. Westerink
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geography ,geography.geographical_feature_category ,65Mxx, 65Nxx, 80A30, 80A32, 35-XX, 76-XX, 65-XX, 76Vxx, 76Rxx ,Scalar (mathematics) ,Fluid Dynamics (physics.flu-dyn) ,Environmental engineering ,FOS: Physical sciences ,Physics - Fluid Dynamics ,010103 numerical & computational mathematics ,Local variation ,Inlet ,01 natural sciences ,6. Clean water ,010101 applied mathematics ,Discontinuous Galerkin method ,Applied mathematics ,0101 mathematics ,Data flow model ,Water Science and Technology ,Mathematics - Abstract
We present a family of p-enrichment schemes. These schemes may be separated into two basic classes: the first, called \emph{fixed tolerance schemes}, rely on setting global scalar tolerances on the local regularity of the solution, and the second, called \emph{dioristic schemes}, rely on time-evolving bounds on the local variation in the solution. Each class of $p$-enrichment scheme is further divided into two basic types. The first type (the Type I schemes) enrich along lines of maximal variation, striving to enhance stable solutions in "areas of highest interest." The second type (the Type II schemes) enrich along lines of maximal regularity in order to maximize the stability of the enrichment process. Each of these schemes are tested over a pair of model problems arising in coastal hydrology. The first is a contaminant transport model, which addresses a declinature problem for a contaminant plume with respect to a bay inlet setting. The second is a multicomponent chemically reactive flow model of estuary eutrophication arising in the Gulf of Mexico., Comment: 29 pages, 7 figures, 3 tables
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- 2011
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29. Discontinuous Galerkin methods for modeling Hurricane storm surge
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Ethan J. Kubatko, Nishant Panda, Corey J. Trahan, Craig Michoski, Joannes J. Westerink, Chris Mirabito, and Clint Dawson
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Meteorology ,Discontinuous Galerkin method ,Wind stress ,Storm surge ,Storm ,Tropical cyclone ,Surge ,Shallow water equations ,Finite element method ,Water Science and Technology - Abstract
Storm surge due to hurricanes and tropical storms can result in significant loss of life, property damage, and long-term damage to coastal ecosystems and landscapes. Computer modeling of storm surge can be used for two primary purposes: forecasting of surge as storms approach land for emergency planning and evacuation of coastal populations, and hindcasting of storms for determining risk, development of mitigation strategies, coastal restoration and sustainability. Storm surge is modeled using the shallow water equations, coupled with wind forcing and in some events, models of wave energy. In this paper, we will describe a depth-averaged (2D) model of circulation in spherical coordinates. Tides, riverine forcing, atmospheric pressure, bottom friction, the Coriolis effect and wind stress are all important for characterizing the inundation due to surge. The problem is inherently multi-scale, both in space and time. To model these problems accurately requires significant investments in acquiring high-fidelity input (bathymetry, bottom friction characteristics, land cover data, river flow rates, levees, raised roads and railways, etc.), accurate discretization of the computational domain using unstructured finite element meshes, and numerical methods capable of capturing highly advective flows, wetting and drying, and multi-scale features of the solution. The discontinuous Galerkin (DG) method appears to allow for many of the features necessary to accurately capture storm surge physics. The DG method was developed for modeling shocks and advection-dominated flows on unstructured finite element meshes. It easily allows for adaptivity in both mesh (h) and polynomial order (p) for capturing multi-scale spatial events. Mass conservative wetting and drying algorithms can be formulated within the DG method. In this paper, we will describe the application of the DG method to hurricane storm surge. We discuss the general formulation, and new features which have been added to the model to better capture surge in complex coastal environments. These features include modifications to the method to handle spherical coordinates and maintain still flows, improvements in the stability post-processing (i.e. slope-limiting), and the modeling of internal barriers for capturing overtopping of levees and other structures. We will focus on applications of the model to recent events in the Gulf of Mexico, including Hurricane Ike.
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- 2011
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30. Implementation of a discontinuous Galerkin morphological model on two-dimensional unstructured meshes
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Ethan J. Kubatko, S. Bunya, Clinton N Dawson, Chris Mirabito, and Joannes J. Westerink
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Finite volume method ,Mechanical Engineering ,Computational Mechanics ,General Physics and Astronomy ,Finite element method ,Physics::Geophysics ,Computer Science Applications ,Mechanics of Materials ,Mesh generation ,Discontinuous Galerkin method ,Applied mathematics ,Geotechnical engineering ,Galerkin method ,Shallow water equations ,Sediment transport ,Physics::Atmospheric and Oceanic Physics ,Geology ,Bed load - Abstract
The shallow water equations are used to model large-scale surface flow in the ocean, coastal rivers, estuaries, salt marshes, bays, and channels. They can describe tidal flows as well as storm surges associated with extreme storm events, such as hurricanes. The resulting currents can transport bed load and suspended sediment and result in morphological changes to the seabed. Modeling these processes requires tightly coupling a bed morphology equation to the shallow water equations. Discontinuous Galerkin finite element methods are a natural choice for modeling this coupled system, given the need to solve these problems on unstructured computational meshes, as well as the desire to implement hp-adaptivity for capturing the dynamic features of the solution. However, because of the presence of non-conservative products in the momentum equations, the standard DG method cannot be applied in a straightforward manner. To rectify this situation, we summarize and follow an extended approach described by Rhebergen et al., which uses theoretical results due to Dal Maso et al. appearing in earlier work. In this paper, we focus on aspects of the implementation of the morphological model for bed evolution within the Advanced Circulation (ADCIRC) modeling framework, as well as the verification of the RKDG method in both h (mesh spacing) and p (polynomial order). This morphological model is applied to a number of coastal engineering problems, and numerical results are presented, with attention paid to the effects of h- and p-refinement in these applications. In particular, it is observed that for sediment transport, piecewise constant (i.e., finite volume) approximations of the bed are very over-diffusive and lead to poor sediment solutions.
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- 2011
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31. A Performance Comparison of Continuous and Discontinuous Finite Element Shallow Water Models
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Clint Dawson, Ethan J. Kubatko, Joannes J. Westerink, Chris Mirabito, and Shintaro Bunya
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Numerical Analysis ,Series (mathematics) ,Applied Mathematics ,Mathematical analysis ,General Engineering ,Degrees of freedom (statistics) ,Finite element method ,Theoretical Computer Science ,Computational Mathematics ,Test case ,Computational Theory and Mathematics ,Continuity equation ,Discontinuous Galerkin method ,Conservation of mass ,Shallow water equations ,Software ,Mathematics - Abstract
We present a comparative study of two finite element shallow water equation (SWE) models: a generalized wave continuity equation based continuous Galerkin (CG) model--an approach used by several existing SWE models--and a recently developed discontinuous Galerkin (DG) model. While DG methods are known to possess a number of favorable properties, such as local mass conservation, one commonly cited disadvantage is the larger number of degrees of freedom associated with the methods, which naturally translates into a greater computational cost compared to CG methods. However, in a series of numerical tests, we demonstrate that the DG SWE model is generally more efficient than the CG model (i) in terms of achieving a specified error level for a given computational cost and (ii) on large-scale parallel machines because of the inherently local structure of the method. Both models are verified on a series of analytic test cases and validated on a field-scale application.
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- 2009
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32. Time-evolving acoustic propagation modeling in a complex ocean environment
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Ying-Tsong Lin, Pierre F. J. Lermusiaux, Wayne G. Leslie, James F. Lynch, T. van Zon, M.E.G.D. Colin, Patrick J. Haley, F.P.A. Lam, Chris Mirabito, L. A. te Raa, Arthur E. Newhall, Timothy F. Duda, Massachusetts Institute of Technology. Department of Mechanical Engineering, Haley, Patrick, Lermusiaux, Pierre F. J., Leslie, Wayne G., and Mirabito, Chris
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Naval architecture ,Engineering ,Amplitude ,business.industry ,Acoustics ,Speed of sound ,Wind wave ,Acoustic model ,Acoustic wave ,Internal wave ,business ,Sonar - Abstract
During naval operations, sonar performance estimates often need to be computed in-situ with limited environmental information. This calls for the use of fast acoustic propagation models. Many naval operations are carried out in challenging and dynamic environments. This makes acoustic propagation and sonar performance behavior particularly complex and variable, and complicates prediction. Using data from a field experiment, we have investigated the accuracy with which acoustic propagation loss (PL) can be predicted, using only limited modeling capabilities. Environmental input parameters came from various sources that may be available in a typical naval operation. The outer continental shelf shallow-water experimental area featured internal tides, packets of nonlinear internal waves, and a meandering water mass front. For a moored source/receiver pair separated by 19.6 km, the acoustic propagation loss for 800 Hz pulses was computed using the peak amplitude. The variations in sound speed translated into considerable PL variability of order 15 dB. Acoustic loss modeling was carried out using a data-driven regional ocean model as well as measured sound speed profile data for comparison. The acoustic model used a two-dimensional parabolic approximation (vertical and radial outward wavenumbers only). The variance of modeled propagation loss was less than that measured. The effect of the internal tides and sub-tidal features was reasonably well modeled; these made use of measured sound speed data. The effects of nonlinear waves were not well modeled, consistent with their known three-dimensional effects but also with the lack of measurements to initialize and constrain them., Netherlands. Ministry of Defence, United States. Office of Naval Research (Grant N00014-12-1-0944 (ONR6.2)), United States. Office of Naval Research (Grant N00014-08-1-1097 (ONR6.1)), United States. Office of Naval Research (Grant N00014-08-1-0680 (PLUS-SEAS))
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- 2013
33. Adaptive hierarchic transformations for dynamically $p$-enriched slope-limiting over discontinuous Galerkin systems of generalized equations
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Chris Mirabito, Craig Michoski, Damrongsak Wirasaet, Clint Dawson, Joannes J. Westerink, and Ethan J. Kubatko
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Physics and Astronomy (miscellaneous) ,FOS: Physical sciences ,010103 numerical & computational mathematics ,01 natural sciences ,Discontinuous Galerkin method ,Error analysis ,Control theory ,Limiter ,Applied mathematics ,0101 mathematics ,Mathematics ,Physics::Computational Physics ,Numerical Analysis ,Series (mathematics) ,Applied Mathematics ,Fluid Dynamics (physics.flu-dyn) ,Probability and statistics ,Limiting ,Physics - Fluid Dynamics ,Computational Physics (physics.comp-ph) ,Finite element method ,Computer Science Applications ,010101 applied mathematics ,Computational Mathematics ,Modeling and Simulation ,Physics - Data Analysis, Statistics and Probability ,76Rxx, 65Mxx, 65Nxx, 35Lxx, 35Dxx ,Hyperbolic partial differential equation ,Physics - Computational Physics ,Data Analysis, Statistics and Probability (physics.data-an) - Abstract
We study a family of generalized slope limiters in two dimensions for Runge-Kutta discontinuous Galerkin (RKDG) solutions of advection--diffusion systems. We analyze the numerical behavior of these limiters applied to a pair of model problems, comparing the error of the approximate solutions, and discuss each limiter's advantages and disadvantages. We then introduce a series of coupled $p$-enrichment schemes that may be used as standalone dynamic $p$-enrichment strategies, or may be augmented via any in the family of variable-in-$p$ slope limiters presented., Comment: 39 pages, 8 figures, 3 tables
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- 2010
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34. Ocean dynamics and numerical modeling of canyons and shelfbreaks
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Patrick J. Haley, Glen Gawarkiewicz, Pierre F. J. Lermusiaux, Timothy F. Duda, Chris Mirabito, Massachusetts Institute of Technology. Department of Mechanical Engineering, Lermusiaux, Pierre F. J., Haley, Patrick, and Mirabito, Chris
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Quantitative precipitation estimation ,Acoustics and Ultrasonics ,Meteorology ,Field (physics) ,Geophysics ,law.invention ,Ocean dynamics ,Waves and shallow water ,Nonlinear system ,Arts and Humanities (miscellaneous) ,law ,Discontinuous Galerkin method ,Hydrostatic equilibrium ,Focus (optics) - Abstract
Multiscale ocean dynamics and multi-resolution numerical modeling of canyons and shelfbreaks are outlined. The dynamics focus is on fronts, currents, tides, and internal tides/waves that occur in these regions. Due to the topographic gradients and strong internal field gradients, nonlinear terms and non-hydrostatic dynamics can be significant. Computationally, a challenge is to achieve accurate simulations that resolve strong gradients over dynamically significant space- and time-scales. To do so, one component are high-order schemes that are more accurate for the same efficiency than lower-order schemes. A second is multi-resolution grids that allow optimized refinements, such as reducing errors near steep topography. A third are methods that allow to solve for multiple dynamics, e.g., hydrostatic and non-hydrostatic, seamlessly. To address these components, new hybridizable discontinuous Galerkin (HDG) finite-element schemes for (non)-hydrostatic physics including a nonlinear free-surface are introduced. The results of data-assimilative multi-resolution simulations are then discussed, using the primitive-equation MSEAS system and telescoping implicitly two-way nested domains. They correspond to collaborative experiments: (i) Shallow Water 06 (SW06) and the Integrated Ocean Dynamics and Acoustics (IODA) research in the Middle Atlantic Bight region; (ii) Quantifying, Predicting and Exploiting Uncertainty (QPE) in the Taiwan-Kuroshio region; and (iii) Philippines Straits Dynamics Experiment (PhilEx).
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- 2014
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