Program Manager, Coastal Ocean Modeling
Program Manager, Coastal Ocean Modeling


Tarang Khangaonkar is a principal program manager specializing in coastal ocean modeling at the Pacific Northwest National Laboratory (PNNL) Sequim where he provides leadership in numerical modeling studies related to estuarine hydrodynamics, water quality, sediment transport, and fate and transport analysis.

His experience spans back to the early 1990s, with various types of models capable of circulation and water quality kinetics. He has engaged in several water quality pollution management studies including simulations of temperature response, calculations of dissolved oxygen depletions, sediment deposition, long-term effluent flushing and pH buffering, and performing diffuser design optimization. Many of these studies have been water quality impact assessments in support of hydropower Federal Energy Regulatory Commission relicensing, mixing zone analysis for National Pollutant Discharge Elimination System permitting, and total maximum daily load assessments. 

Khangaonkar and his team led the development of a high-resolution three-dimensional finite volume hydrodynamic and transport model for the Pacific Northwest region of Puget Sound and Georgia Basin through support from the United States Environmental Protection Agency and in collaboration with Washington State Department of Ecology. This model includes a comprehensive biogeochemical component and is now the “workhorse” for analyzing water quality and circulation, nutrient pollution management, and response to sea level rise, climate change, and ocean acidification. The team conducted numerous applications of this tool to assist with nearshore habitat restoration planning, design, and analysis to support the re-establishment of fish migration pathways and assessment of basin-wide water quality impacts.

Disciplines and Skills

  • Coastal circulation and hydrodynamic modeling
  • Water quality and biogeochemical processes modeling
  • Effluent mixing and fate and transport modeling
  • Nearshore habitat restoration design
  • Climate change and sea level rise
  • Ocean acidification
  • Sediment transport and littoral processes
  • Toxics fate and transport modeling
  • Integrated modeling of riverine, floodplain, estuarine, and coastal watersheds


  • PhD in applied marine physics and ocean engineering, University of Miami
  • MS in ocean engineering, University of Miami
  • BS in naval architecture, Indian Institute of Technology

Affiliations and Professional Service

  • Member of the steering committee for the Puget Sound Ecosystem Monitoring Program - Modeling work group 
  • Research professor - School of interdisciplinary Arts and Sciences at the University of Washington - Tacoma
  • Editorial board of Ecological Modelling, a peer reviewed journal published by Elsevier
  • Research professor – Huxley College of the Environment, Department of Environmental Sciences, Western Washington University
  • Estuarine and Coastal Modeling Conference Organizing Committee (2017 to present)
  • American Geophysical Union
  • American Society of Civil Engineers

Awards and Recognitions

  • Registered Professional Engineer, Civil (#32167), Washington State of Civil Engineers



  • James A., J. Lanksbury, T.P. Khangaonkar, and J. West. 2020. "Evaluating Exposures of Bay Mussels (Mytilus trossulus) to Contaminants of Emerging Concern through Environmental Sampling and Hydrodynamic Modeling." Science of the Total Environment 709. doi:10.1016/j.scitotenv.2019.136098
  • Tian Z., K. Peter, A. Gipe, H. Zhao, F. Hou, D.A. Wark, and T.P. Khangaonkar, et al. 2020. "Suspect and Nontarget Screening for Contaminants of Emerging Concern in an Urban Estuary." Environmental Science & Technology 54, no. 2:889-901. PNNL-SA-151250. doi:10.1021/acs.est.9b06126


  • Premathilake M., and T.P. Khangaonkar. 2019. "FVCOM-plume – A Three-dimensional Lagrangian Outfall Plume Dilution and Transport Model for Dynamic Tidal Environments: Model Development." Marine Pollution Bulletin. PNNL-SA-144750. [In Press]
  • Khangaonkar, T.,  Nugraha, A.,  Xu, W., &  Balaguru, K. ( 2019).  Salish Sea Response to Global Climate Change, Sea Level Rise, and Future Nutrient Loads. Journal of Geophysical Research: Oceans,  124.


  • Khangaonkar, T.; Nugraha, A.; Wang, T. Hydrodynamic Zone of Influence Due to a Floating Structure in a Fjordal Estuary—Hood Canal Bridge Impact Assessment. J. Mar. Sci. Eng. 2018, 6, 119.
  • Nugraha, A.; Khangaonkar, T. Detailed Hydrodynamic Feasibility Assessment for Leque Island and Zis a Ba Restoration Projects. J. Mar. Sci. Eng. 2018, 6, 140.
  • Khangaonkar T, A Nugraha, W Xu, W Long, L Bianucci, A Ahmed, T Mohamedali, and G Pelletier. 2018. Analysis of Hypoxia and Sensitivity to Nutrient Pollution in Salish Sea. Journal of Geophysical Research – Oceans, 123(7): 4735-4761. doi: 10.1029/2017JC013650


  • Jason E. Hall, Tarang P. Khangaonkar, Casimir A. Rice, Joshua Chamberlin, Todd Zackey, Frank Leonetti, Michael Rustay, Kurt Fresh, Anna Kagley, and Mindy Rowse. Characterization of Salinity and Temperature Patterns in a Large River Delta to Support Tidal Wetland Habitat Restoration. Northwest Science 2018 92 (1), 36-52
  • Khangaonkar T, A Nugraha, S Hinton, D Michalsen D, S Brown. 2017b. Sediment Transport into the Swinomish Navigation Channel, Puget Sound—Habitat Restoration versus Navigation Maintenance Needs. Journal of Marine Science and Engineering 5(2): 1-22 doi: 10.3390/jmse5020019
  • Khangaonkar T., W. Long, and W. Xu.  2017.  "Assessment of Circulation and Inter-Basin Transport in the Salish Sea including Johnstone Strait and Discovery Islands Pathways."  Ocean Modelling, Volume 109, 2017, Pages 11-32, ISSN 1463-5003,


  • Khangaonkar, T., W. Long, B. Sackmann, T. Mohamedali , and A. Hamlet. 2016  Sensitivity of Circulation in the Skagit River Estuary to Sea Level Rise and Future Flows. Northwest Science 90(1): 94-118. 2016.


  • Wang , T., T. Khangaonkar, W. Long and G. Gill. 2014. Development of a Kelp-Type Structure Module in a Coastal Ocean Model to Assess the Hydrodynamic Impact of Seawater Uranium Extraction Technology. J. Mar. Sci. Eng. 2014, 2, 81-92; doi:10.3390/jmse2010081.


  • Khangaonkar, T. and T. Wang. 2013. Potential alteration of fjordal circulation due to a large floating structure—Numerical investigation with application to Hood Canal basin in Puget Sound, Applied Ocean Research, Volume 39, January 2013, Pages 146-157, ISSN 0141-1187, 10.1016/j.apor.2012.11.003.


  • Khangaonkar, T. , B. Sackmann, W. Long, T. Mohamedali , and M. Roberts. 2012. Simulation of annual biogeochemical cycles of nutrient balance, phytoplankton bloom(s), and DO in Puget Sound using an unstructured grid model. Ocean Dynamics. (2012) 62:1353–1379. DOI 10.1007/s10236-012-0562-4
  • Kim, T. and T. Khangaonkar. 2012. An Offline Unstructured Biogeochemical Model (UBM) for Complex Estuarine and Coastal Environments.  Environmental Modelling & Software 31 (2012) 47-63


  • Khangaonkar, T.,  Z. Yang, T. Kim, and M. Roberts. 2011.  Tidally Averaged Circulation in Puget Sound Sub-basins:  Comparison of Historical Data, Analytical Model, and Numerical Model.  Journal of Estuarine Coastal and Shelf Science, Volume 93, Issue 4, 20 July 2011, Pages 305-319.
  • Yang, Z., T. Wang, T. Khangaonkar, S. Breithaupt. 2011. Integrated modeling of flood flows and tidal hydrodynamics over a coastal floodplain. Journal of Environmental Fluid Mechanics , Volume 12, Issue 1, pp. 63-80.
  • Khangaonkar, T. and Z. Yang, 2011. A High Resolution Hydrodynamic Model of Puget Sound to Support Nearshore Restoration Feasibility Analysis and Design. Ecological Restoration. 29(1-2):173-184.
  • Breithaupt, S. and T.Khangaonkar. 2011.  Effects of Wetland Restoration on Floodplain Hydrodynamics under Extreme Flooding Conditions. Ecological Restoration. 29(1-2):161-172.


  • Yang, Z. and T. Khangaonkar, 2010. Multi-scale Modeling of Puget Sound Using an Unstructured-grid Coastal Ocean Model: from Tide flats to Estuaries and Coastal Waters. Ocean Dynamics. Volume 60, Number 6, 1621-1637.
  • Yang, Z., T. Khangaonkar, and T. Wang. 2010. Use of Advanced Meteorological Model Output for Coastal Ocean Modeling in Puget Sound. International Journal  of Coastal and Ocean Modeling Systems. Volume 2, Number 2, pp. 101-117.
  • Yang, Z., T. Khangaonkar, M. Calvi, K. Nelson, 2010.   “Simulation of cumulative effects of nearshore restoration projects on estuarine hydrodynamics”, Ecological Modelling, Volume 221, Issue 7, Pages 969-977
  • Yang, Z., K. Sobocinski, D. Heatwole, T. Khangaonkar, R. Thom, R.Fuller.  2010.   Hydrodynamic and ecological assessment of nearshore restoration: A modeling study, Ecological Modelling, Volume 221, Issue 7, Pages 1043-1053


  • Yang., Z. and T. Khangaonkar.  2009.  “Modeling tidal circulation and stratification in Skagit River estuary using an unstructured grid ocean model”.  Ocean Modeling, Volume 28, Issues 1-3, pages 34-49.


  • Yang Z, and T. Khangaonkar.  2008.  "Modeling of Salt Intrusion, Intertidal Mixing, and Circulation in a Braided Estuary."  Journal of Coastal Research. JCR (52):171-180. 
  • Khangaonkar, T., Z. Yang, J Paik, and F Sotiropoulos.  2008.  "Simulation of Hydrodynamics at Stratified Reservoirs Using a Staged Modeling Approach."  Journal of Coastal Research. JCR (Special Issue: 52):79-86.
  • Yang, Z., and T. Khangaonkar.  2008.  "Modeling of Coastal Effluent Transport: an Approach to Linking of Far-field and Near-field Models."  Acta Oceanologica Sinica 27:21-30.
  • Tang, H., J. Paik, F. Sotiropoulos, and T. Khangaonkar.  2008.  "Three-Dimensional Numerical Modeling of Initial Mixing of Thermal Discharges at Real-Life Configurations."  Journal of Hydraulic Engineering 134(9):1210-1224.  doi:10.1061/(ASCE)0733-9429(2008)134:9(1210)
  • Khangaonkar, T. and Z. Yang.  April 2008. “Dynamic Response of Stream Temperatures to Boundary and Inflow Perturbation due to Reservoir Operations”.  River Research and Applications. 24: 420–433 (2008)
  • Burkholder, B.,G.E. Grant, R. Haggerty, T. Khangaonkar and P. J. Wampler.  February 2008.  “Influence of hyporheic flow and geomorphology on temperature of a large, gravel-bed river, Clackamas River, Oregon, USA”.  Hydrological Process. 22, 941–953 (2008)


  • Frick WE, T. Khangaonkar, AC Sigleo, and Z Yang. 2007. "Estuarine-ocean exchange in a North Pacific estuary: comparison of steady state and dynamic model." Estuarine, Coastal and Shelf Science 74(1-2):1-11. 


  • Khangaonkar, T., Z. Yang, C. DeGasperi, and K. Marshall.  2005. “Modeling Hydrothermal Response of a Reservoir to Modifications at a High Head Dam.”  Water International 30(3): 378-388.


  • DeGasperi, C. and T. Khangaonkar. 1997. A Steady State Model of the Willamette River: Implications for Flow Control of Dissolved Oxygen and Phytoplankton Biomass. River Quality Dynamics and Restoration.  Edited by Antonius Laenen and David Dunnette.


  • Khangaonkar, T., and B. LeMehaute.  1992.  “Hydrodynamic Collapse of a Cylindrical Cavity on Dry Bed.” Applied Ocean Research, 14: 141-154.


  • Khangaonkar, T., and B. LeMehaute. 1991. “Initial Free Surface Disturbances from Wave Records.' Applied Ocean Research, 13(3): 110-115.
  • Khangaonkar, T., and B. LeMehaute. 1991. “Extended KDV Equation for Explosion Generated Water Waves.” Ocean Engineering, 18(5): 435-450.


  • LeMehaute, B., and T. Khangaonkar. 1990. “Dynamic Interaction of Intense Rain with Water Waves.” Journal of Physical Oceanography, .20: 1805-1812.


  • LeMehaute, B., S. Wang, and T. Khangaonkar. 1989. “Advances in Impulsively Waves.” Water Wave Kinematics.