Grace Chang, Ph.D.

Senior Science Advisor, Director of Research and Development

Grace Chang, Ph.D. Senior Science Advisor, Director of Research and Development

Dr. Grace Chang has more than 25 years of experience in the fields of limnology and oceanography. Dr. Chang has managed programs involving field operations, data processing and analysis, and numerical modeling for environmental characterization, observational monitoring, scientific research, and technology development in support of marine renewable energy, hydrodynamics and sediment transport, and oceanographic research programs. She is recognized for her continued advancement of analytical methods in hydrodynamics and particle characterization through optics and acoustics, as well as for environmental research and monitoring. Dr. Chang has more than 40 peer-reviewed publications and freq...

Grace Chang, Ph.D.

Senior Science Advisor, Director of Research and Development

Renewable Energy

A Numerical Modeling Framework to Evaluate Effects of Offshore Wind Farms on the California Upwelling Ecosystem As project manager, studying the effect of California offshore wind turbines on the wind stress field and upwelling circulation for a number of baseline (no wind farms) and modified (simulated wind farms) scenarios using highly resolved coupled numerical models (atmosphere-ocean circulation). Upwelling index metrics will be computed to quantify changes in upwelling resulting from offshore wind turbine deployment. Upwelling is a dominant driver of ecosystem productivity and variability in eastern boundary currents including the California Current System, which runs along the U.S. West Coast. Given the importance of upwelling in these regions, estimates of upwelling strength (i.e., upwelling indices) are critical for understanding fluctuations in ecosystem properties ranging from temperature and density all the way to distributions and abundances of top predators.

Empowering Communities with a Multi-Use Decision Support Dashboard to Participate in Marine Renewable Energy Planning and Development Collaborating with community organizations to engage community members to guide development of a user-friendly dashboard to give all stakeholders a data-driven voice in the marine renewable energy (MRE) planning and development process. The dashboard will enable interactive visualization and synthesis of multiple layers of ocean use data to promote meaningful stakeholder engagement and communications, and informed and inclusive decision-making, and will be a significant advancement in ocean multi-use management with MRE.

Overcoming WEC Grid Integration Challenges: Coupling Wave Forecasting, WEC Array Controls, and Power Production Implementing machine-learning methods for optimization of wave data assimilation modeling to improve wave forecasting. Accurate wave forecasts will be integrated with wave energy converter (WEC) farm operational controls and energy storage systems to increase certainty in power forecasts. The “complete” power forecast will balance energy variability on grids for energy resiliency and security.

Improving the Efficiency and Effectiveness for Marine Hydrokinetic Permitting: A Toolkit and Engagement for Success Increasing regulators’ understanding of marine energy projects, devices, and their potential environmental impacts while reducing permitting time and costs of marine energy projects. Developing an easily accessible online toolkit that integrates relevant regulatory, scientific, and spatial marine energy data. Working with Kearns & West, H.T. Harvey & Associates, EcoQuants, and others to conduct in-person meetings and webinars with relevant regulators from federal and state agencies to share and gather input on the toolkit and share experts’ understanding of potential impacts and the state of known/unknown science for marine energy projects.

Model Validation and Site Characterization for Early Development Marine Hydrokinetic Sites and Establishment of Wave Classification Scheme, Cook Inlet, Alaska As project manager, assisted the U.S. government in making high-fidelity wave and tidal resource characterization measurements at potential wave and tidal energy sites. Managed field data collection of 12 months of high-quality wave resource and water column current data at three different deployment sites. Characterized suspended particle load (particle concentration, size, and composition) at a potential tidal energy site to inform a regional circulation model and to enable industry to design devices best suited to resist the abrasive and intrusive stresses of suspended materials.

Marine and Hydrokinetic Energy Market Acceleration and Deployment, Environmentally Focused Performed numerical modeling of the effects of nearshore wave propagation in the lee of WEC arrays. Evaluated WEC-specific wave model function and operation. Performed sensitivity analyses of numerical wave models to offshore wave conditions, model parameters, and WEC characteristics. Executed wave models over various offshore wave conditions, for evaluation of nearshore wave propagation in the presence and absence of modeled WECs.

Rapidly Deployable Acoustic Monitoring and Localization System Based on a Low-Cost Wave Buoy Platform Developed a cost-effective, compact array of acoustic vector sensors that characterizes, classifies, and provides accurate location information for anthropogenic and natural sounds in support of environmental monitoring technologies to evaluate the impact of marine and hydrokinetic energy devices. Managed the assessment and laboratory and field testing of acoustic monitoring technologies, design and engineering of underwater acoustic data logging and analysis systems, and development of algorithms to geolocate and characterize sources of sound.

Real-Time Wave Assessment Tool As co-principal investigator, developed an ocean wave buoy capable of measuring and wirelessly relaying real-time wave data in support of the design, siting, and performance optimization of ocean energy conversion systems. Performed research on wave parameter measurements and calculations. Developed and tested algorithms for computation of wave height, period, and direction from high frequency global positioning system (GPS) data and accelerometer, gyroscope, and magnetometer data. Validated algorithms on a specially designed wave buoy validation stand. Completed several field data collection experiments. This project resulted in the commercialization of the Spotter wave measurement buoy.

Contaminated Sediments

A High-Resolution, Optically-Based Chemical Contaminant Monitoring System for Remedy Performance Evaluation at DoD Contaminated Sediment Sites Demonstrating OPTICS (OPTically-based In-situ Characterization System), a high-resolution chemical contaminant characterization system, as a cost-effective, long-term monitoring method at up to two U.S. Department of Defense (DoD) contaminated sediment sites. Evaluating the utility and cost-effectiveness of the technology compared to traditional sampling methods. The system specifications for the technology will be defined through the demonstrations to provide guidance for end-users of the technology and provide an end-user data analysis tool/interface to facilitate technology transfer. This work is supported by the Environmental Security Technology Certification Program.

Berry’s Creek Study Area, Sediment and Contaminant Transport Investigation, New Jersey Obtained field measurements and performed data analysis for development of a quantitative description of the hydrodynamics and sediment transport in the system, in support of risk analysis and remedial selection and design. Calculated site-wide sediment flux and solids mass balance using measurements of currents and sediment concentration derived from acoustical and optical measurements. Developed a suite of instrumentation for measuring bottom shear stress and particle characteristics using acoustical and optical methods. Quantified continuous time series of concentrations of contaminants of potential concern using a novel optical model and field measurements. Participated in client and agency meetings to explain methodologies and results.

Optically-Based Monitoring of Surface Waters for a Superfund Site Deploying and maintaining hydrodynamics and sediment transport, and OPTICS monitoring systems to provide baseline information with which to measure potential changes in water quality after adjustments to the system (e.g., carp management) are made. Quantifying solids concentration and transport, and concentrations and fluxes of PCBs from near-continuous, in situ measurements of optical and physical properties.

Lower Passaic River Water Column Monitoring for Pre-design Investigation, New Jersey Obtained real-time water quality and hydrodynamic measurements throughout the lower 8.3 miles of the Lower Passaic River to support remedial design. Water column data were used to develop a relationship between in situ data and chemical concentrations and to quantify suspended sediment concentration flux. Results will be used to establish baseline criteria and resuspension engineering performance standards for dredging and capping activities.

Evaluation of Environmental Dredging for Remediating Contaminated Sediments in the Ashtabula River, Ohio Characterized the environmental dredge plume using moored and mobile field measurements. Mapped the extent of the dredge plume using a novel sediment gradient approach. Quantified the volume of the dredge plume and the total mass of dredge sediment released into the water column during dredging activities. Related sediment concentration to concentrations of contaminants of potential concern to estimate the mass of contaminants released during dredging.

Pilot Testing of Optically Based Monitoring of Mercury and Methyl Mercury in the South River, Virginia Deployed multiple optically based sensors, along with ancillary water quality sensors, to collected synchronous data that are associated with chemicals in surface water (e.g., organic carbon, suspended solids). Correlated comprehensive optical and water quality measurements to analytically derived discrete chemical data. Calibrated a statistical model to reliably predict chemical concentrations over time and support a detailed characterization of system dynamics.

Contaminated Sediment Transport in the Kalamazoo River, Michigan Characterized key regions of sediment deposition based on river characteristics, flow, and sediment loads along the Kalamazoo River, to assess sediment trapping efficiencies. Performed a review of previous evaluations of site hydrodynamics and sediment transport. Calculated flow rates and sediment loading throughout the site. Results were used to perform mass balance of sediment loads in impoundments along the river, to estimate trapping efficiencies. Estimated trapping efficiencies were compared to results from previous analytical and numerical assessments.

Lower Passaic River Restoration Project, Modeling Support Activities, New Jersey As project manager, quantified sediment concentration and flux through acoustical and optical measurements, in support of sediment transport modeling activities and river restoration. Computed sediment concentrations and fluxes from acoustical signals. Related sediment movement to riverine and estuarine physical processes through advanced statistical methods. Results from wavelet analysis were presented at professional conferences, including one invited oral presentation.

Conceptual Site Model Delineation of In-Water Site Boundary, Port Angeles Harbor, Washington Obtained hydrodynamic field measurements and performed numerical modeling to support contaminant fate and transport investigations. Conducted a literature review on currents and transport in the Port Angeles harbor region. Analyzed field measurements of currents to determine dominant transport directions. Executed a numerical wave model and validated results with measurements to assess the potential for sediment resuspension and transport during standard and extreme environmental conditions.

Sediment Transport Analysis at the United Heckathorn Superfund Site, Richmond, California Developed a sediment transport conceptual site model from field and analytic results to address sediment management questions. Determined the magnitude and frequency of sediment resuspension and the magnitude and direction of sediment flux from analysis of field data.

Environmental Monitoring

Environmental Monitoring and Analysis in Support of Port of Bunbury Dredging Activities, Koombana Bay, Western Australia As project manager, calculated water column suspended solids concentration from acoustical and optical measurements to establish background and exceedance levels of total suspended solids concentration at monitoring and reference sites during Port of Bunbury Inner Harbour dredging activities. Reference sites, zone of influence, and zones of moderate and high impact were determined. Performed analysis of solids variability as related to physical forcing processes, in order to ascertain potential sources of elevated solids. Utilized a combined current and wave bottom shear stress model to help determine sediment stability of a proposed dredge material disposal site and validated the model with SEDflume laboratory results.

Currents, Waves, and Suspended Sediment Monitoring, Baker Bay, Washington As project manager, led field activities to monitor water column and near-bed currents, surface waves, and water quality at seven different sites in Baker Bay, Washington, over a 6-week period. Long-term hydrodynamics and water quality measurements will enable the estimation of sediment accumulation in Baker Bay, as well as sediment shoaling in two important navigation channels, Ilwaco and Chinook Channels, to aid the U.S. Army Corps of Engineers in determination of dredging needs in the region.

Oceanography

Improved Observation and Parameterization of Bottom Boundary Layer Turbulence and Particle Properties, San Francisco Bay, California As co-principal investigator, used novel acoustical and optical instrumentation and laboratory-based sediment experiments deployed in wave-driven estuarine waters of San Francisco Bay to directly observe relationships between physical dynamics and biogeochemical properties of suspended particles. The field and laboratory results are used to inform a large-eddy simulation model that resolves high-resolution variability of the turbulent, sediment-laden boundary layer. This work was funded by the National Science Foundation (NSF).

Nearshore Sound Propagation of and Species’ Response to Active-Source Seismic Surveys, Offshore Oregon, United States As co principal investigator, measuring the particle motion component and pressure amplitude variations of the acoustic disturbance from seismic survey explosions along the Cascadia Subduction Zone. High-intensity acoustic pulse information will be correlated with behavioral responses of fishes and invertebrates in the Redfish Rocks Marine Reserve using acoustic telemetry, tracking, and acceleration of tagged animals. This project is funded by the NSF.

Adaptive Mapping of the Hypoxic Zone, Gulf of Mexico Collaborated with Autonomous Surface Vehicles (ASV), LLC to develop enhanced autonomous hypoxia mapping capabilities for surface, subsurface, and near-bottom waters of the Gulf of Mexico and other water bodies affected by hypoxia. The results of this National Oceanic and Atmospheric Administration (NOAA) Small Business Innovation Research were transitioned to a NOAA Ocean Technology Transition (OTT) project to demonstrate an efficient and cost-effective method of monitoring hypoxic conditions. The NOAA OTT effort is being conducted in partnership with the University of Southern Mississippi, L3 Harris ASV, and the Gulf of Mexico Coastal Ocean Observing System (GCOOS).

Prediction of Optical Variability in Dynamic Nearshore Environments, Santa Cruz, California; Waimanalo, Hawaii; and Duck, North Carolina As lead principal investigator, developed a system for forecasting marine optical conditions in the surf zone and nearshore coastal ocean using field measurements, analytical methods, and numerical modeling. Obtained field measurements of key physical and optical properties in three surf zone sites. Analyzed optical data to determine underwater visibility and probability of detection given site water depth. Related optical variability to physical forcing processes. Oversaw development and validation of wave and hydrodynamic models to predict optical variability from forecasted physical processes. Was lead author of a peer-reviewed publication presenting these results.

Radiance in a Dynamic Ocean (RaDyO): Radiance and Visibility as Affected by Inherent Optical Properties, and Imaging System Performance and Visibility as Affected by the Physical Environment, San Diego and Santa Barbara, California Led and co-managed a team of principal investigators in an investigation of the sources of variability of optical properties for the interpretation of images from underwater electro-optical systems. Participated in two field experiments to obtain water column optical properties from stationary and mobile platforms, including the Research Platform FLoating Instrument Platform (RP FLIP). Determined sources of variability of underwater visibility that included upper ocean mixing from wind forcing and stratification as well as eddy-induced phytoplankton blooms. Calculated the modulation transfer function and used advanced statistics to determine the relationship between physical and optical properties and imaging performance. Investigated the effects of stratification and scattering layers on imaging performance. Authored or co-authored three papers published in peer-reviewed journals.

Multidisciplinary Ocean Sensors for Environmental Analysis and Networks (MOSEAN), Hawaii and Santa Barbara, California Acted as project manager to develop, test, and validate new sensors that are capable of sampling biological, chemical, and optical variables and demonstrated new interdisciplinary sensor suites for use with a variety of autonomous, unattended, stationary and mobile sampling platforms in coastal and deep ocean environments. Managed and participated in the development and operations of two real time mooring platforms (one at a depth of more than 4,500 m and the other at 25 m) designed to test and validate newly engineered ocean sensors. Performed research on optical methods for characterizing particles, including sediment, phytoplankton, and harmful algal blooms. Was lead author on four papers published in peer-reviewed journals.

Southern California Coastal Ocean Observing System (SCCOOS): Shelf to Shoreline Observatory Development, Santa Barbara, California As lead principal investigator and SCCOOS Mooring Working Group member, managed and participated in the development and operations of a real-time interdisciplinary mooring platform deployed in 80 m of water on a shelf break. Researched the delivery of nutrients, particles, and pollutants from offshore to the nearshore coastal ocean. Coordinated data collection with SCCOOS members from the University of California at Los Angeles and Scripps Institution of Oceanography.

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Grace Chang, Ph.D.

Education & Credentials

Continuing Education

Professional Affiliations

Grace Chang, Ph.D.

Related Resources

Relevant Experience

Renewable Energy

Contaminated Sediments

Environmental Monitoring

Oceanography

Grace Chang, Ph.D.

Education & Credentials

Continuing Education

Professional Affiliations

Grace Chang, Ph.D.

Related Resources

OPTICS (OPTically-based In-situ Characterization System)

Resource

The Benthic Zone (January 2025 Edition): Integral’s Sediment Newsletter

Press Release

Optically-Based Evaluation of Stormwater as a Potential Source of Polychlorinated Biphenyls (PCBs) to Pearl Harbor, Hawaii

Poster

Integrated, Real-Time, Multi-Scale System for Monitoring Avian Interactions with Offshore Wind Energy Technologies

Poster

SEABIRD: System for Environmental Assessment of Bird/Bat Interactions with Real-Time Detection

Publication

Performance of an Acoustic Sensing Array in an Energetic Tidal Channel

Publication

Performance Characteristics of the NoiseSpotter: An Acoustic Monitoring and Localization System

Publication

Wave Energy Converter Arrays: Optimizing Power Production While Minimizing Environmental Effects

Publication

Assessment of Wave Energy Resources and Factors Affecting Conversion

Publication

Wave Data Assimilation in Support of Wave Energy Converter Power Prediction: Yakutat, Alaska Case Study

Publication

Evaluation of stormwater as a potential source of polychlorinated biphenyls (PCBs) to Pearl Harbor, Hawaii

Publication

A High-Resolution, Optically-Based Chemical Contaminant Monitoring System for Remedy Performance Evaluation at U.S. Department of Defense Contaminated Sediment Site

Poster

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

Publication

Use of SPI Technology to Quantitatively Evaluate the Effects of Carp Removal on Surface Sediment Conditions in a Michigan Lake

Poster

Navigating California's Unique Legal, Permitting, and Environmental Risks for Offshore Wind

Video

Grace Chang Coauthors Paper on the Variability of Floc Characteristics in a Shallow Estuary

Press Release

Tidal Turbine and Marine Habitats

Video

Effect of Floating Offshore Wind Turbines on Atmospheric Circulation in California

Publication

Department of Energy Awards $200,000 for Small Business Research and Development to Integral Consulting Inc.

Press Release

Novel Marine Energy Environmental Compliance Reporting Application Summarizes Disparate Content by Tags and Location

Resource

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

Press Release

Yes, Your Geoscience Degree Can Lead to a Job Outside of Academia

Press Release

Sediment Transport: Key Research Findings Published in Limnology and Oceanography Letters

Press Release

Marine Renewables: Grace Chang, Kaustubha Raghukumar, and Frank Spada Coauthor Article in Frontiers in Marine Science

Press Release

CalWave, San Diego

Case Study

National Science Foundation

Case Study

Office of Naval Research—Vandenberg Space Force Base and Los Angeles International Airport (LAX)

Case Study

OPTICS Study on Mercury Releases to South River

Case Study

Waves Anywhere: Real-Time Wave Modeling at Integral

Case Study

Relevant Experience

Renewable Energy

Contaminated Sediments

Environmental Monitoring

Oceanography