Virginia Institute of Marine Science
Friedrichs Home Page

Marjorie A.M. Friedrichs

Research Associate Professor of Marine Science

Email : [[marjy]]
Phone : (804) 684-7695
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 focuses on optimally combining mathematical models with observations of biological, physical and chemical properties of estuaries and coastal oceans. I have a wide variety of funded research projects currently underway, and am looking for additional personnel at the graduate student and post-doctoral level to assist in these efforts. Current projects 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
  • the assimilation of biological, physical and chemical data acquired from a remotely-operated glider in Antarctica into a marine ecosystem model
  • 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
  • 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)
  • Impacts of changing climate and land use on carbon cycling in the Chesapeake Bay and the coastal ocean margin (Funded by NASA)
  • Collaborative Research: Impacts of atmospheric nitrogen deposition on the biogeochemistry of oligotrophic coastal waters (Funded by NSF) 
  • Comparison of shallow-water models for use in supporting Chesapeake Bay management decision-making (Funded by EPA)
  • Synergistic impacts of population growth, urbanization and climate change on watersheds and coastal ecology of the northeastern United States (Funded by NASA)
  • Primary productivity algorithm round robin for the Arctic Ocean (PPARR; Funded by NASA)
Recent Publications
  • 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, doi:10.1002/2015JG002931. Download. 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, doi:10.1002/2014JG002763. Download.
  • 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, doi:10.1002/2014JG002760. Download. Open Access
  • Yang, Q., H. Tian, M.A.M. Friedrichs, M. Liu, L. Xia, and J. Yang, 2015. Hydrological responses to climate and land-use changes along the North American East Coast: A 110-year historical reconstruction. Journal of the American Water Resources Association, 47-67, doi:10.1111/jawr.12232. Download.
  • 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. Download.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. Download. 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. Download. 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. Download. 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. Download. 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. Download. 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. Download. Open Access.
  • 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. Download. 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. Download. 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. Download
  • 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. Download
  • 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. Download. 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.
  • 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.
  • 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.marsys.2008.05.010. Download 
  • 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.marsys.2008.05.010. Download 
  • 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.marsys.2008.05.014. Download 
  • 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.marsys.2008.03.011. Download 
  • 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. Download. 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. Download.Open 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. Download. 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. Download. 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. Download. Open 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.

Major Advisor:

   Currently enrolled:

  • Ph.D. Danny Kaufman (entered  2011)
  • Ph.D. Isaac Irby (entered  2012)
  • Ph.D. Kelsey Fall (entered 2013)
  • Ph.D. Julia Moriarty (entered  2013)


  • Ph.D. Yongjin Xiao (2013)
  • M.S. Kelsey Fall (2012)

Current Student Committees:

  • Steven Baer, Ph.D. (VIMS, entered fall 2007)
  • Gabrielle Saluta, M.S. (VIMS, entered fall 2008)

Past Student Committees:

  • Xiao Liu, M.S. Virginia Institute of Marine Science, 2011. "Ecological, Physiological, and Bio-optical Characteristics of Phaeocystis globosa in Coastal Waters of South Central Vietnam."
  • Tian Tian, M.S. Old Dominion University, 2011. "Model-Based Analyses of Nitrogen Cycling on the Mid-Atlantic Bight Continental Shelf."
  • Aaron Bever, Ph.D. Virginia Institute of Marine Science, College of William and Mary, 2010. "Integrating Space- and Time-Scales of Sediment Transport for Poverty Bay, New Zealand."
  • David Elliot, Ph.D. Virginia Institute of Marine Science, College of William and Mary, 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. Old Dominion University, 2005. "Modeling the Effects of Physical and Biogeochemical Processes on Phytoplankton Species and Carbon Production in the Equatorial Pacific Ocean."
Post-doctoral investigators

Current post-docs: 

  • Dr. Cathy Feng
  • Dr. Pierre St. Laurent

Past post-docs: 

  • Dr. Aaron Bever, currently at Delta Modeling Associates
  • Dr. Jianhong Xue, currently at University of Texas
  • Dr. Vincent Saba, currently at Princeton University