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Timothy R. Nelson, Ph.D.

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Timothy R. Nelson, Ph.D.
Senior Scientist

Timothy R. Nelson, Ph.D.

Senior Scientist (561) 240-5096 St. Petersburg, FL tnelson@integral-corp.com

Dr. Timothy Nelson is an oceanographer with 10 years of experience researching hydrodynamics, sediment dynamics, and coastal geomorphology. His efforts have focused on quantifying the temporal and spatial evolution of benthic habitat, sediment resuspension, nearbed turbulence, and flooding. Dr. Nelson’s expertise includes geospatial and temporal data processing and analysis tasks related to hydrodynamics, sediment fate and transport, and acoustic effects on marine species. Dr. Nelson’s research has also focused on coastal response, recovery, and resiliency to abrupt changes in morphology, and the development of automated routines to quantify long-term shoreline change.

Dashboard for Marine Energy Site Assessment and Monitoring

Publication

July 01 2024

Site Investigation and Risk Evaluation Using the Spatial Environmental Assessment Toolkit

Publication

July 01 2024

Projected Cross-Shore Changes in Upwelling Induced by Offshore Wind Farm Development Along the California Coast

Publication

April 13 2023

Effect of Floating Offshore Wind Turbines on Atmospheric Circulation in California

Publication

June 01 2022

Advancing Renewable Energy: Integral Awarded Funding from DOE for Open-Water R&D at PacWave

Press Release

April 15 2022

Hydrodynamics

Terminal Sedimentation Analysis, Vallejo, California Applied sedimentation rates derived from bathymetric surveys to hydrodynamic model simulations to inform the engineering design team on potential site response due to proposed pier reconfigurations.
Marina Sedimentation Analysis, Vallejo, California Assisted with the development of numerical models to study changes to sedimentation rates and dredging frequency due to reconfiguration of the marina. Applied sedimentation rates derived from bathymetric surveys to hydrodynamic model simulations to inform the engineering design team on potential site response.
Facility Flooding Analysis, Half Moon Bay, California Evaluated hydrodynamic model simulation of flooding due to riverine discharge and coastal inundation. Results helped inform adaptation strategies to mitigate future flooding at the facility.
River and Wetland Flooding due to Canal Breach, Colorado Developed a 2-dimensional HEC-RAS model to simulate a canal breach during a storm event that resulted in discharge down a steep mountain terrain. Analysis of flood extent and sediment fate and transport assisted with litigation efforts.
Sediment Cap Hydrodynamic Modeling, Confidential Site Utilized a 1-dimensional HEC-RAS model to determine change in river hydrodynamics due to placement of a sediment cap over potentially contaminated sediment.

Sediment Transport Modeling

Temporal and Spatial Benthic Boundary Layer Evolution, South Carolina and Georgia Developed spatial and temporal models to predict bedform evolution, associated turbulence, sediment resuspension, and sediment flux. Analyzed existing published bedform geometries and bedforms from field experiments to develop an equilibrium ripple prediction model that improves predictions compared to existing models. Using seabed sector scanning sonar, developed metrics to quantify ripple shape as a function of variations in ripple length and orientation. Using time series of ripple geometries, further developed a time-dependent model that predicts instantaneous non-equilibrium ripple geometry and orientation under waves and currents.
Low-Density, Centimeter-Scale Sediment Motion, Northern Gulf of Mexico This work focused on improving sediment transport formulations for centimeter-scale low-density agglomerates. This research arose out of a necessity to understand the transport and fate of sand and oil agglomerates (SOAs) that formed along the northern Gulf of Mexico following the Deepwater Horizon accident and oil spill. Because SOAs have a lower density than quartz, a variety of shapes, and large size compared to surrounding sediment, existing sediment transport formulations do not adequately predict their mobility. Conducted research that led to the development of a semi-empirical formulation that predicts incipient motion threshold for SOAs of various sizes and shapes. This was accomplished through laboratory experiments using artificial SOAs with embedded inertial measurement units, 3D-printed SOAs, and computer vision tracking. The results of this work can be applied to existing sediment transport prediction for mixed-grain coral reefs, and to the transport of marine debris, munitions, and other insoluble contaminants.

Coastal Geomorphology

Coastal Morphometric Analysis CMAT, South Padre Island, Texas Performed analysis and calculation of beach profile morphometrics from survey data. These results were incorporated into the Coastal Morphometrics Analysis Toolkit (CMAT) dashboard for the client.
Quantifying Barrier Island Storm Recovery and Resiliency, Fire Island, New York Conducting ongoing research focused on the collection and analysis of barrier island shoreline, shoreface, beach, and breach topography and bathymetry to determine the resiliency and evolution of barrier islands following tropical and extratropical storms. Utilizing bathymetry, GPS shoreline surveys, airborne imagery, and satellite-derived shorelines, developed metrics to describe breach evolution that demonstrate the importance of geology in breach migration and spit development in channel stability. The metrics were used to develop a hybrid Delft 3-dimensional XBeach geomorphic numerical model of breach evolution to identify processes controlling breach development and their influence on surrounding shoreline erosion and bay water levels. Satellite-derived shorelines were used to show the temporal and spatial extent of downdrift shoreline erosion following breach formation.

Renewable Energy

Marine Renewable Energy Support, Sandia National Laboratories (SNL) Supporting the development of a QGIS Python plugin for the Spatial Environmental Analysis Toolkit (SEAT). The goal of this effort is to improve performance, lower costs, and accelerate the deployment of marine and hydrokinetic energy technologies. Developed routines for analysis of benthic habitat changes, larval transport impacts, acoustic effects, and power generation potential. Assisted in the development of numerical models and workshop tutorial documentation for SEAT using the SNL-Delft 3-dimensional current energy conversion module.
Evaluation of Marine Species Acoustic Exposure for Offshore Wind Turbine Construction, Mid-Atlantic Bight Assisted with the development of analytical routines and data analysis to determine number of marine species affected by offshore wind turbine construction. Results are used for the development of the construction and operations plan.
Offshore Wind and Upwelling, California Energy Commission, California Assisted with the analysis of an atmosphere-ocean modeling effort to understand hydrodynamic changes by floating offshore wind turbines.

Raghukumar, K., T. Nelson, M. Jacox, C. Chartrand, J. Fiechter, G. Chang, L. Cheung, and J. Roberts. 2023. Projected cross-shore changes in upwelling induced by offshore wind farm development along the California coast. SEANOE. https://doi.org/10.17882/94046.

Van Ormondt, M., T.R. Nelson, C.J. Hapke, and D. Roelvink. 2020. Morphodynamic modeling of the wilderness breach, Fire Island, New York. Part I: Model set-up and validation. Coast. Eng. 157:103621. https://doi.org/10.1016/j.coastaleng.2019.103621.

Nelson, T.R., and J.L. Miselis. 2019. Method for observing breach geomorphic evolution: Satellite observation of the Fire Island wilderness breach. Proceedings of Coastal Sediments, 2019. World Scientific Publishing Co. pp. 71-84. https://doi.org/10.1142/9789811204487_0007.

Brenner, O.T., E. Lentz, C.J. Hapke, R. Henderson, K. Wilson, and T.R. Nelson. 2018. Characterizing storm response, and recovery using the beach change envelope. Geomorph. 300:189-202.

Schippers, M.M.A., N.G., Jacobsen, P.S. Dalyander, and R. McCall. 2017. Incipient motion of sand-oil agglomerates. Proceedings of Coastal Dynamics, 2017. pp. 1290–1301. Helsingør, Denmark.

Hapke, C.J., N.G. Plant, R.E. Henderson, W.C. Schwab, and T.R. Nelson. 2016. Decoupling processes and scales of shoreline morphodynamics. J. Marine Geol. 381:42-53. https://doi.org/10.1016/j.margeo.2016.08.008

Nelson, T.R., and C.J. Hapke. 2015. Shoreface response and recovery to Hurricane Sandy: Fire Island, NY. Proceedings of Coastal Sediments, 2015. World Scientific Publishing Co. https://doi.org/10.1142/9646

Van Ormondt, M., C.J. Hapke, D.J.A. Roelvink, and T.R. Nelson. 2015. The effects of geomorphic changes on water levels in Great South Bay during hurricane. Proceedings of Coastal Sediments, 2015. World Scientific Publishing Co. https://doi.org/10.1142/9646

Nelson, T.R., and G. Voulgaris. 2015. A spectral model for estimating temporal and spatial evolution of rippled seabeds. Ocean Dyn. 65(2):155-171. https://doi.org/10.1007/s10236-014-0801-y

Nelson, T.R., and G. Voulgaris. 2014. Temporal and spatial evolution of wave-induced ripple geometry: Regular vs. irregular ripples. J. Geophys. Res. Oceans 119(2):664-688. https://doi.org/10.1002/2013JC009020

Nelson, T.R., G. Voulgaris, and P. Traykovski. 2013. Predicting wave-induced ripple equilibrium geometry. J. Geophys. Res. Oceans 118:1-19. https/doi.org/10.1002/jgrc.20241

Warner, J.C., B. Armstrong, C.S. Sylvester, G. Voulgaris, T.R. Nelson, W.C. Schwab, and J.F. Denny. 2012. Storm-induced inner-continental shelf circulation and sediment transport: Long Bay, South Carolina. Cont. Shelf Res. 42:51-63. https://doi.org/10.1016/j.csr.2012.05.001

Stalk, C.A., J.L. Miselis, T.R. Nelson, B.J. Reynolds, J.J. Fredericks, N.T. DeWitt, A.S. Farmer, H.S. Wilcox, and M.K. Lemon. 2018. Coastal bathymetry data collected in June 2018 from Fire Island, New York—Wilderness breach and shoreface: U.S. Geological Survey data release. https://doi.org/10.5066/F7PC30N8

Jenkins, R.L., P.S. Dalyander, A.M. Penko, J.W. Long, and T.R. Nelson. 2017. Laboratory observations of artificial sand and oil agglomerates video and velocity data. U.S. Geological Survey data release. https://doi.org/10.5066/F76D5R69

Hapke, C.J., T.R. Nelson, R.E. Henderson, O.T. Brenner, and J.L. Miselis. 2017. Morphologic evolution of the wilderness area breach at Fire Island, NY. 2012-15: U.S. Geological Open Fire Report 2017-1116. U.S. Geological Survey Open-File Report 2017–1116. 17 pp. https://doi.org/10.3133/ofr20171116

Nelson, T.R., J.L. Miselis, C.J. Hapke, R.E. Henderson, O.T. Brenner, B.J. Reynolds, and K.E. Wilson. 2017. Coastal bathymetry data collected in May 2015 from Fire Island, New York—the wilderness breach and shoreface. U.S. Geological Survey Data Series 1049. https://doi.org/10.3133/ds1049

Nelson, T.R., J.L. Miselis, C.J. Hapke, R.E. Henderson, O.T. Brenner, B.J. Reynolds, and K.E. Wilson. 2017. Bathymetry data collected in October 2014 from Fire Island, New York—the wilderness breach, shoreface, and bay. U.S. Geological Survey Data Series 1034. https://doi.org/10.3133/ds1034

Nelson, T.R., J.L. Miselis, C.J. Hapke, K.E. Wilson, R.E. Henderson, O.T. Brenner, B.J. Reynolds, and M.E. Hansen. 2016. Coastal bathymetry data collected in June 2014 from Fire Island, New York—the wilderness breach and shoreface. U.S. Geological Survey Data Series 1007. https://doi.org/10.3133/ds1007

McWilliams, S., J. Roberts, C.A. Jones, T.R. Nelson, C. Chartrand, and S. Olson. 2024. Site investigation and risk evaluation using the spatial environmental assessment toolkit. Offshore Technology Conference, Houston, TX. May.  https://doi.org/10.4043/35225-MS

Sherwood, C.R., A.L. Aretxabaleta, P. Traykovski, J.R. Over, E. Lyons, D.S. Foster, J.L. Miselis, T.R. Nelson, and E. Sogut. 2023. Contributions to uncertainty in runup forecasts. Proceedings of Coastal Sediments, 2023. World Scientific Publishing Co. Singapore. pp. 401–418. https://doi.org/10.1142/9789811275135_0037

Nelson, T.R., J.L. Miselis. 2020. Morphodynamic evolution of a natural inlet. 2020 Ocean Sciences Meeting, San Diego, CA. Abstract CP24A-03

Doran, K., J. Birchler, J. Brown, C. Krakenburg, and T. R. Nelson. 2019. Applications of lidar and imagery for understanding coastal change hazards and vulnerability: an update from the National Assessment of Coastal Change Hazards project. Joint Airborne Lidar Bathymetry Technical Center of Expertise Annual Meeting.

Nelson, T. R., P.S. Dalyander, D.P. Frank, E.R. Braithwaite, A.M. Penko, J. Calantoni, and R.L. Jenkins. 2018. Incipient motion threshold of variable density, size, and shape sand and oil agglomerates. 2018 Ocean Sciences Meeting, Portland, OR. Abstract MG51A-0.

Van Ormondt, M., C.J. Hapke, T.R. Nelson, and D.J.A. Roelvink. 2018. Morphodynamic modeling of the Fire Island wilderness breach. 2018 Ocean Sciences Meeting, Portland, OR. Abstract CD33A-06.

Hapke, C. J., M. van Ormondt, T.R. Nelson, and J. L. Miselis. 2018. Characterizing the morphologic evolution of a breach system: Fire Island, NY. 2018 Ocean Sciences Meeting, Portland, OR. Abstract CD34A-0115.

Nelson, T. R., P.S. Dalyander, R.L. Jenkins, A.M. Penko, J.W. Long, D.P. Frank, E.R. Braithwaite, and J. Calantoni. 2017. Incipient motion of sand and oil agglomerates. Gulf of Mexico Oil Spill and Ecosystem Science Conference 2017, New Orleans, LA.

Nelson, T.R., P.S. Dalyander, R.L. Jenkins, A.M. Penko, J.W. Long, D.P. Frank, E.R. Braithwaite, and J. Calantoni. 2016. Incipient motion of sand and oil agglomerates. 2016 AGU Fall Meeting, San Francisco, CA.

Hapke, C.J., N.P. Plant, R.E. Henderson, W.C. Schwab, T.R. Nelson. 2016. Decoupling shoreline behavior over variable time and space scales. 2016 AGU Fall Meeting, San Francisco, CA.

Nelson, T.R., J.L. Miselis, C.J. Hapke, and M. van Ormondt. 2016. Barrier island breaching in response to extreme storms: Morphodynamic evolution of the Fire Island wilderness breach. 2016 Ocean Sciences Meeting, New Orleans, LA.

Miselis, J. L., J.E. McNinch, C.J. Hapke, S.D. Locker, and T. R. Nelson. 2016. Towards quantifying shoreface contributions to littoral sediment budgets. 2016 Ocean Sciences Meeting, New Orleans, LA.

Hapke, C. J., and T. R. Nelson. 2014. Sustained morphologic changes to the shoreface related to Hurricane Sandy: Fire Island, NY. AGU Fall Meeting 2014. Abstract EP22A-06.

Nelson, T.R., and G. Voulgaris. 2014. Temporal and spatial evolution of inner shelf ripple geometry and irregularity. 2014 Ocean Science Meeting, Honolulu, HI.

Nelson, T.R., and G. Voulgaris. 2012. The influence of ripple geometry on seabed roughness and vertical suspended sediment concentration profiles. 2012 Ocean Sciences Meeting, Salt Lake City, UT. Book of Abstracts, pp. 337-338.

Nelson, T.R., and G. Voulgaris. 2011. Predicting the temporal and spatial evolution of regular and irregular ripple geometry under varying hydrodynamic forcing. 2011 GSA Annual Meeting, Minneapolis, MN. Geological Society of America Abstracts with Programs, Vol. 43(5), 497.

Nelson, T.R., G. Voulgaris, and J.C. Warner. 2008. A model to predict the evolution of suspended sediment concentration profiles and bedforms before, during, and after storm events. Eos Trans. AGU, 89(53), Fall Meet. Suppl., Abstract OS21E-1206.

Nelson, T.R., G. Voulgaris, and J.C. Warner. 2008. Temporal and spatial evolution of small scale ripples on the inner shelf. 2008 Ocean Sciences Meeting, Orlando, FL. Book of Abstracts, 293-294.

Nelson, T.R., G. Voulgaris, D.M. Hanes, and J.C. Warner. 2004. Spatial and temporal variability of wave ripple wavelengths in the inner shelf. Eos Trans. AGU, 85(47), Fall Meet. Suppl., Abstract No. OS21B-1232.

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