Friedrichs Home Page

Marjorie A.M. Friedrichs

Associate Professor of Marine Science

Email: [[marjy]]
Phone: (804) 684-7695
Interests: Studying effects of climate change and other human impacts on coastal & estuarine systems, through the use of coupled biological-physical models.
Office: Andrews Hall 337
Department: Biological Sciences
Lab Website: {{, BioCOM}}

  • B.A., Middlebury College
  • M.S., Massachusetts Institute of Technology/Woods Hole Oceanographic Institution
  • Ph.D., Old Dominion University
Research Interests

My interdisciplinary research program (click here for my lab webpage) focuses on quantifying the historical and future impacts of climate and land-use changes, as well as population growth, urbanization, and local management efforts, on water quality and biogeochemistry in coastal and estuarine systems. Research in the BioCOM lab focuses on combining mathematical computer models with biological, physical and chemical observations. We have a wide variety of funded research projects underway, and are currently looking for additional highly quantitative personnel at the graduate student and post-doctoral level to assist in these modeling efforts. Funded projects currently include studies focused on:

  • Assessing the relative impacts of multiple anthropogenic stressors in estuarine environments, including hypoxia, acidification, and other effects of climate and land-use change
  • comparing and improving existing models of hypoxia within Chesapeake Bay
  • predicting how climate-related environmental changes will affect biogeochemical cycling and ecosystem dynamics on continental shelves and within the Chesapeake Bay

Other interests include satellite remote-sensing, model skill assessment, the estimation of productivity from space-borne sensors, and biogeochemical data assimilation.

Current Projects
  • Chesapeake Hypoxia Analysis and Modeling Program (CHAMP): predicted impacts of climate change on the success of alternative management actions (Funded by NOAA)
  • Multiple stressors in the estuarine environment: What drives changes in the CO2 system? (Funded by NSF)
  • Transitioning an estuarine hypoxia model to operations via a Coastal Ocean Modeling Testbed in the Chesapeake Bay (Funded by NOAA)
  • Synergistic impacts of population growth, urbanization and climate change on watersheds and coastal ecology of the northeastern United States (Funded by NASA)
Recent Publications


  • Kaufman, D.E., M.A.M. Friedrichs, J.C.P. Hemmings and W.O. Smith, Jr., 2018. Assimilating bio-optical glider data during a phytoplankton bloom in the southern Ross Sea. Biogeosciences,15, 73-90, doi: 10.5194/bg-15-73-2018. Open Access.
  • Santos, B. S., D. M. Kaplan, M.A.M. Friedrichs, S. G. Barco, K. L. Mansfield, J. P. Manning, 2018. Consequences of drift and carcass decomposition for estimating sea turle mortality hotspots, Ecological Indicators, 84, 319-336, doi: 10.1016/j.ecolind.2017.08.064. Open Access.


  • Irby, I.D., M.A.M. Friedrichs, F. Da and K. Hinson, 2017. The competing impacts of climate change and nutrient reductions on dissolved oxygen in Chesapeake Bay. Biogeosciences Discussions, in review. doi: 10.5194/bg-2017-416. Open Access.
  • St-Laurent, P., M.A.M. Friedrichs, R.G. Najjar, D.K. Martins, M. Herrmann, S.K. Miller and J. Wilkin, 2017. Impacts of atmospheric nitrogen deposition on surface waters of the western North Atlantic mitigated by multiple feedbacks. Journal of Geophysical Research: Oceans, 122, 8406–8426, doi: 10.1002/2017jc013072. Open Access.
  • Luettich, R.A., L.D. Wright, C.R. Nichols, R. Baltes, M.A.M. Friedrichs, A. Kurapov, A.J. van der Westhuysen, K. Fennel and E. Howlett, 2017. A U.S. Integrated Ocean Observing System Coastal and Ocean Modeling Testbed to improve understanding and operational forecasts of extreme events and chronic environmental conditions, EOS, 98, doi: 10.1029/2017EO078243. Open Access.
  • Moriarty, J.M., C.K. Harris, K. Fennel, MA.M. Friedrichs, K. Xu and  C. Rabouille, 2017. The roles of resuspension, diffusion and biogeochemical processes on oxygen dynamics offshore of the Rhone River, France: a numerical modeling study. Biogeosciences, 14, 1919-1946, doi:10.5194/bg-14-1919-2017. Open Access.
  • Kaufman, D. E., M.A.M. Friedrichs, W.O. Smith, Jr., E.E. Hofmann, M.S. Dinniman, J.C.P. Hemmings, 2017. Climate change impacts on southern Ross Sea phytoplankton, composition, productivity and export. Journal of Geophysical Research: Oceans, 12223392359, doi:10.1002/2016JC012514. Open Access.
  • Lee, Y.J., P.A. Matrai, M.A.M. Friedrichs, V.S. Saba, and the PPARR team, 2016. Net primary productivity estimate and environmental variables in the Arctic Ocean: An assessment of coupled physical-biogeochemical models, J. Geophys. Res. Oceans, 121, 8635-8669. Open Access.
  • Ye, F., Y.J. Zhang, M.A.M. Friedrichs, H.V. Wang, I. Irby, J. Shen, Z. Wang, 2016. A 3D, cross-scale baroclinic model with implicit vertical transport for the upper Chesapeake Bay and its tributaries. Ocean Modeling, 107, 82-96. doi: 10.1016/j.ocemod.2016.10.004 Online Access
  • Irby I.D., M.A.M. Friedrichs, C.T. Friedrichs, A.J. Bever, R.R. Hood, L.W.J. Lanerolle, M. Li, L. Linker, M.E. Scully, K. Sellner, J. Shen, J. Testa, H. Wang, P. Wang, and M. Xia, 2016. Challenges associated with modeling low-oxygen waters in Chesapeake Bay: a multiple model comparison. Biogeosciences, 2011-2028. doi: 10.5194/bg-13-2011-2016. Open Access.
  • Mannino, A., S. Signorini, M. Novak, J. Wilkin, M.A.M. Friedrichs, R.G. Najjar, 2016. Dissolved organic carbon fluxes in the Middle Atlantic Bight: An integrated approach based on satellite data and ocean model products. Journal of Geophysical Research: Biogeosciences, 121, 312-336. doi: 10.1002/2015JG003031. Online Access.
  • Cahill, B., J. Wilkin, K. Fennel, D. Vandemark, and M.A.M. Friedrichs, 2016. Inter-annual and seasonal variability in air-sea CO2 fluxes along the U.S. Eastern Continental Shelf and their sensitivity to increasing air temperatures and variable winds, Journal of Geophysical Research: Biogeosciences, 121, 295-311. doi:10.1002/2015JG002939. Online Access.

  • Lee, Y., P.A. Matrai, M.A.M. Friedrichs, V.S. Saba and the Arctic PPARR team, 2015. An assessment of phytoplankton primary productivity in the Arctic Ocean from satellite ocean color/in situ chlorophyll-a based models. Journal of Geophysical Research - Oceans, 6508-6541. doi: 10.1002/2015JC011018. Open Access.
  • Feng, Y., M.A.M. Friedrichs, J. Wilkin, H. Tian, Q. Yang, E.E. Hofmann, J.D. Wiggert, R.R. Hood, 2015. Chesapeake Bay nitrogen fluxes derived from a land-estuarine ocean biogeochemical modeling system: Model description, evaluation and nitrogen budgets. Journal of Geophysical Research - Biogeosciences, 1666-1695. doi:10.1002/2015JG002931. Open Access.
  • Yang, Q., H. Tian, M.A.M. Friedrichs, C. S. Hopkinson, C. Lu, R. G. Najjar, 2015. Increased nitrogen export from eastern North America to the Atlantic Ocean due to climatic and anthropogenic changes during 1901-2008. Journal of Geophysical Research: Biogeosciences, 120, 1046-1068, doi:10.1002/2014JG002763. Online Access.
  • Tian, H., Q. Yang, R. Najjar, W. Ren, M.A.M. Friedrichs, C.S. Hopkinson, S. Pan, 2015. Anthropogenic and climatic influences on carbon fluxes from eastern North America to the Atlantic Ocean: A process-based modeling study. Journal of Geophysical Research - Biogeosciences, 120, 757-772, doi:10.1002/2014JG002760. Open Access.
  • Yang, Q.H. TianM.A.M. FriedrichsM. LiuX. Li, and J. Yang2015Hydrological Responses to Climate and Land-Use Changes along the North American East Coast: A 110-Year Historical ReconstructionJournal of the American Water Resources Association, 51, 47-67. doi:10.1111/jawr.12232. Online Access.

  • Kaufman, D.E.M.A.M. Friedrichs, W. O. Smith, B. Y. Queste, K. J. Heywood, 2014. Biogeochemical variability in the southern Ross Sea as observed by a glider deployment. Deep-Sea Research I, 92, 93-106, doi:10.1016/j.dsr.2014.06.011. Open Access.
  • Smith, W.O., Jr., K.T. Goetz, D.E. Kaufman, B.Y. Queste, V. Asper, D.P. Costa, M.S. Dinniman, M.A.M. Friedrichs, E.E. Hofmann, K.J. Heywood, J.M. Klinck, J.T. Kohut, and C.M. Lee. 2014. Multiplatform, multidisciplinary investigations of the impacts of Modified Circumpolar Deep Water in the Ross Sea, Antarctica. Oceanography  27(2), doi:10.5670/oceanog.2014.36. Open Access.
  • Xiao, Y., and M.A.M. Friedrichs, 2014. Using biogeochemical data assimilation to assess the relative skill of multiple ecosystem models: effects of increasing the complexity of the planktonic food web. Biogeosciences, 11, 3015-3030, doi:10.5194/bg-11-3015-2014. Open Access.
  • Xiao, Y. and M.A.M. Friedrichs, 2014. The assimilation of satellite-derived data into a one-dimensional lower trophic level marine ecosystem model. Journal of Geophysical Research-Oceans, 119, 2691-2712, doi:10.1002/2013JC009433. Open Access.

  • Bever, A. J.M.A.M. Friedrichs, C. T. Friedrichs, M. E. Scully, L. W. J. Lanerolle, 2013. Combining observations and numerical model results to improve estimates of hypoxic volume within the Chesapeake Bay, USA. Journal of Geophysical Research: Oceans, 118, 10, 4924-4944. Open Access.
  • Signorini, S. R., A. Mannino, R. G. Najjar Jr., M.A.M. Friedrichs, W.-J. Cai, J. Salisbury, Z. A. Wang, H. Thomas, and E. Shadwick, 2013. Surface ocean pCO2 seasonality and sea-air CO2 flux estimates for the North American east coast. Journal of Geophysical Research: Oceans, 118, 10, 5439-5460, doi:10.1002/jgrc.20369. Open Access. 
  • Luettich, R. A., L.D. Wright, R. Signell, C. Friedrichs, M. Friedrichs, J. Harding, K. Fennel, E. Howlett, S. Graves, E. Smith, G. Crane, and R. Baltes, 2013. The U.S. IOOS coastal and ocean modeling testbed. Journal of Geophysical Research: Oceans, 118, 6319-6328, doi:10.1002/2013JC008939. Open Access.
2012 and earlier

  • Luo, Y.-W., H. W. Ducklow, M.A.M. Friedrichs, M. J. Church, D. M. Karl, and S. C. Doney, 2012. Interannual variability of primary production and dissolved organic nitrogen storage in the North Pacific Subtropical Gyre. Journal of Geophysical Research: Biogeosciences, 117, G03019, doi:10.1029/2011JG001830. Open Access.
  • Saba, V.S.M.A.M. Friedrichs, and the PPARR team, 2011. An evaluation of ocean color model estimates of marine primary productivity in coastal and pelagic regions across the globe. Biogeosciences, 8, 489-503,doi: 10.5194/bg-8-489-2011. Open Access.
  • Hofmann, E.E., B. Cahill, K. Fennel, M.A.M. Friedrichs, K. Hyde, C. Lee, A. Mannino, R.G. Najjar, J.E. O'Reilly, J. Wilkin, J. Xue, 2011. Modeling the dynamics of continental shelf carbon. Annual Review of Marine Science, 3, 93-122. Online Access.
  • Druon, J-N, A. Mannino, C. McClain, M. Friedrichs, J. Wilkin, K. Fennel, 2010. Modeling the dynamics and export of dissolved organic matter in the Northeastern U.S. continental shelf. Estuarine, Coastal and Shelf Science, 88, 488-507. Online Access.
  • Saba, V.S.M.A.M. Friedrichs, M.-E. Carr and the PPARR team, 2010. Challenges of modeling depth-integrated marine primary productivity over multiple decades: A case study at BATS and HOT. Global Biogeochemical Cycles, 24, GB3020, doi:10.1029/2009GB003655. Open Access.
  • Ward, B.A., M.A.M Friedrichs, T.R. Anderson, A. Oschlies, 2010. Parameter optimisation techniques and the problem of underdetermination in marine biogeochemical models. Journal of Marine Systems 81, doi:10.1016/j.jmarsys.2009.12.005, 34-43. Online Access.
  • Luo, Y., M.A.M Friedrichs, S.C. Doney, M.J. Church, H.W. Ducklow, 2010. Oceanic heterotrophic bacterial nutrition by semilabile DOM as revealed by data assimilative modeling. Aquatic Microbial Ecology, 60, doi:10.3354/ame01427, 273-287. Online Access.
  • Friedrichs, M.A.M., Carr, M.-E., Barber, R., Scardi, M., Antoine, D., Armstrong, R.A., Asanuma,I., Behrenfeld, M.J., Buitenhuis, E.T., Chai, F., Christian, J.R., Ciotti, A.M., Doney, S.C., Dowell, M., Dunne, J., Gentili, B., Gregg, W., Hoepffner, N., Ishizaka, J., Kameda, T., Lima, I., Marra, J., Mélin, F., Moore, J.K., Morel, A., O'Malley, R.T., O'Reilly, J., Saba, V.S., Schmeltz, M., Smyth, T.J., Tjiputra, J., Waters, K., Westberry, T.K., Winguth, A., 2009. Assessing the uncertainties of model estimates of primary productivity in the tropical Pacific Ocean. Journal of Marine Systems, 76, doi:10.1016/j.jmarsys.2008.05.010. Online Access.
  • Gregg, W., M.A.M. Friedrichs, A. R. Robinson, K. Rose, R. Schlitzer, and K.R. Thompson, 2009. Skill assessment in ocean biological data assimilation. Journal of Marine Systems, 76, doi:10.1016/j.jmarsys.2008.05.006. Online Access. 
  • Jolliff, J., J.C. Kindle, I. Shulman, B. Penta, M.A.M.Friedrichs, R.Helber, R.A. Arnone, 2009. Summary diagrams for coupled hydrodynamic-ecosystem model skill assessment. Journal of Marine Systems, 76, doi:10.1016/j.jmarsys.2008.05.014. Online Access. 
  • Stow, C.A., J.K. Jolliff, D.J. McGillicuddy, Jr., S.C. Doney, M.A.M. Friedrichs, J.I. Allen, K.A Rose, and P. Wallhead, 2009. Skill Assessment for Coupled Biological/Physical Models of Marine Systems. Journal of Marine Systems, 76, doi:10.1016/j.jmarsys.2008.03.011. Online Access. 
  • Hofmann, E. E., J.-N. Druon, K. Fennel, M.A.M. Friedrichs, D. Haidvogel, C. Lee, A. Mannino, C. McClain, R. Najjar, J. Siewert, J. OReilly, D. Pollard, M. Previdi, S. Seitzinger, S. Signorini, J. Wilkin, 2008. Eastern U.S. Continental Shelf Carbon Budget: Integrating Models, Data Assimilation, and Analysis, Oceanography, 21 (1): 86-104. Download 
  • Friedrichs, M.A.M., J. Dusenberry, L. Anderson, R. Armstrong, F. Chai, J. Christian, S.C. Doney, J. Dunne, M. Fujii, R. Hood, D. McGillicuddy, K. Moore, M. Schartau, Y. H. Sptiz, J. Wiggert, 2007. Assessment of skill and portability in regional marine biogeochemical models: role of multiple phytoplankton groups. Journal of Geophysical Research, 112, CO8001, doi:10.1029/2006JC003852. Open Access.
  • Carr, M.-E., M.A.M. Friedrichs and the PPARR3 team, 2006. A comparison of global estimates of marine primary production from ocean color. Deep-Sea Research II, 53: 741-770. Download
  • Friedrichs, M.A.M., R. Hood, and J. Wiggert, 2006. Ecosystem model complexity versus physical forcing: Quantification of their relative impact with assimilated Arabian Sea data. Deep-Sea Research II, 53: 576-600. Download
  • Hood, R., E. Laws, K. Moore, R. Armstrong, N. Bates, C. Carlson, F. Chai, S. Doney, P. Falkowski, D. Feely,M. Friedrichs, M. Landry, R. Letelier, D. Nelson, T. Richardson, B. Salihoglu, J. Wiggert, and M. Schartau, 2006. Functional group modeling: progress, challenges and prospects. Deep-Sea Research II, 53: 459-512. Open Access.
  • Friedrichs, M.A.M., 2002. Assimilation of SeaWiFS and JGOFS EqPac data into a marine ecosystem model of the central equatorial Pacific. Deep-Sea Research II, 49: 289-319. Online Access.
  • Hofmann E.E., and M.A.M. Friedrichs, 2002. Predictive modeling for marine ecosystems. In: Robinson, A.R.; McCarthy, J.J.; Rothschild B.J. (eds.), The Sea, Volume 12: Biological-Physical Interactions in the Ocean, John Wiley and Sons, Inc., NY, pp. 537-565. 
  • Doney, S.C., I. Lima, K. Lindsay, J.K. Moore, S. Dutkiewicz, M.A.M. Friedrichs, and R. Matear, 2001. Marine biogeochemical modeling. Oceanography, 14 (4): 93-107. Open Access.
  • Friedrichs, M.A.M., 2001. A data-assimilative marine ecosystem model of the central equatorial Pacific: numerical twin experiments. Journal of Marine Research, 59: 859-894. Open Access.
  • Friedrichs, M.A.M., and E.E. Hofmann, 2001. Physical control of biological processes in the central equatorial Pacific. Deep-Sea Research I, 48: 1023-1069. Online Access.
  • Hofmann, E.E., and M.A.M. Friedrichs, 2001. Biogeochemical data assimilation. In: J.H. Steele, S.A. Thorpe, and K.K. Turekian (eds.) Encyclopedia of Ocean Sciences Vol. 1, pp. 302-308. London, UK: Academic Press.

Current students:

Current Student Committees:

  • Cassidy Peterson, Ph.D. (VIMS)
  • Dan Crear, Ph.D. (VIMS)
  • Jackie Friedman, Bypass (VIMS)
  • Liese Carlton, Bypass (VIMS)
  • Qubin Qin, Ph.D. (VIMS)
  • Sarah Pease, Ph.D. (VIMS)
  • Danielle Tarpley Smith, Ph.D. (VIMS)

Graduated students:

  • Ph.D. Julia Moriarty (2017)
  • Ph.D. Ike Irby (2017)
  • Ph.D. Danny Kaufman (2017)
  • Ph.D. Yongjin Xiao (2013)
  • M.S. Kelsey Fall (2012)

Former post-docs:

  • Dr. Danny Kaufman, currently at Chesapeake Research Consortium, Inc.
  • Dr. Aaron Bever, currently at Anchor, QEA, LLC
  • Dr. Jianhong Xue, currently at University of Texas
  • Dr. Vincent Saba, currently at NOAA NMFS
  • Dr. Pierre St. Laurent, currently Assistant Research Scientist at VIMS
  • Dr. Yang (Cathy) Feng

Past Student Committees:

  • Fei Ye, Ph.D. VIMS, 2017. “Developing efficient high-order transport schemes for cross-scale coupled estuary-ocean modeling.”
  • Mark Stratton, Ph.D. VIMS, 2017. ”Spatiotemporal abundance patterns and ecological drivers of a nearshore U.S. Atlantic fish and invertebrate assemblage.“
  • Bianca Santos, M.S. VIMS, 2017. ”Integrating empirical data and ocean drift models to better understand sea turtle strandings in Virginia."
  • Randy Jones, M.S. VIMS, 2015. "The influence of short-term events on the hydrographic and biological structure of the southwestern Ross Sea."
  • Lela Schlenker, M.S. VIMS, 2014. “Evaluating post-release mortality of white marlin caught in the recreational fishery.”
  • Dan Tomaso, M.S. Penn State University, 2013. “Salt, freshwater and oxygen budgets of the Delaware Bay”
  • Steven Baer, Ph.D. VIMS, 2013. “Seasonal Nitrogen Uptake and Regeneration in the Water Column and Sea-Ice of the Western Coastal Arctic”
  • Gabby Saluta, M.S. VIMS, 2012. “Spatial distribution of overwintering blue crabs in Chesapeake Bay.”
  • Xiao Liu, M.S. VIMS, 2011. "Ecological, Physiological, and Bio-optical Characteristics of Phaeocystis globosa in Coastal Waters of South Central Vietnam."
  • Tian Tian, M.S. ODU, 2011. "Model-Based Analyses of Nitrogen Cycling on the Mid-Atlantic Bight Continental Shelf."
  • Mehara Kidston, Ph.D. CSIRO, Australia, 2010. “Southern Ocean ecosystem modeling using data assimilation.”
  • Aaron Bever, Ph.D. VIMS, 2010. "Integrating Space- and Time-Scales of Sediment Transport for Poverty Bay, New Zealand."
  • David Elliot, Ph.D. VIMS, 2010. "The Occurrence of Carcasses, Mortality and Population Dynamics of Copepods in the Lower Chesapeake Bay." 
  • Wayne Luo, Ph.D. Marine Biological Laboratory/Brown University, 2009. "A Data Assimilating Model of the Microbial Ecosystem in the Open Ocean."
  • Baris Salihoglu, Ph.D. ODU, 2005. "Modeling the Effects of Physical and Biogeochemical Processes on Phytoplankton Species and Carbon Production in the Equatorial Pacific Ocean."