Dr. J. Blake Clark

Dr. J. Blake Clark

  • ASSOCIATE SCIENTIST
  • 301.286.3621
  • NASA/GSFC
  • Mail Code: 616.1
  • Greenbelt , MD 20771
  • Employer: UNIVERSITIES SPACE RESEARCH ASSOCIATION
  • Brief Bio

    I am an early career scientist with a focus on land-estuary-ocean biogeochemistry and carbon cycling. I completed my PhD in 2019 at the University of Maryland Center for Environmental Science, Horn Point Lab under the advice of Dr. Raleigh Hood. There, I worked on developing and applying a model that represented the processes of tidal inundation and marsh-estuary linkages and organic matter cycling. Upon graduation in 2019, I began a NASA Postdoctoral Program fellowship at Goddard in the Ocean Ecology Lab with Antonio Mannino as my advisor. My research focus shifted towards modeling and remote sensing of the coastal Arctic. I am now an associate scientist with USRA/GESTAR and hope to continue advancing our understanding of coastal environments and how the land and ocean carbon and nutrient cycles are linked via rivers and estuaries.

    Research Interests

    Coastal organic carbon cycling

    My research focuses on carbon cycling in the coastal ocean. I use process-based experiments to construct and inform biogeochemical models to investigate carbon cycling on multiple time and space skills. I have ongoing research in the Chesapeake Bay estimating organic matter cycling and fluxes in a tidal marsh influenced estuary, focusing on the export of dissolved organic matter from marshes and the role tidal marshes play in estuarine biogeochemistry. My current focus has shifted to the Arctic where I am taking my skills developed in Chesapeake Bay and applying them to study the organic carbon dynamics of the Yukon River plume.

    Biogeochemical model development

    Incorporating new and important processes into biogeochemical models requires precise field and laboratory measurements to inform mathematical models. Part of my work focuses on identifying current gaps in the biogeochemical modeling frameworks we use. Once identified, targeted sampling and experiments can build data sets that can be used to build a mathematical model. These mathematical models can be implemented on multiple scales to quantify the importance of any given process to elemental cycling as a whole.

    Positions/Employment

    3/2019 - 4/2021

    Postdoctoral Fellow

    Universities Space Research Association, NASA Goddard Space Flight Center
    4/2021 - Present

    Associate Scientist

    Universities Space Research Association/ GESTAR, Greenbelt

    Current Projects

    Arctic Ocean organic matter dynamics by integrating field and satellite observations into a three-dimensional hydrodynamic-biogeochemical model.

    The coastal Arctic Ocean is undergoing rapid changes due to increased warming, loss of sea ice, high rates of erosion and enhanced river discharge. Understanding these processes and the impact they have in the coastal ocean is key to predicting how Arctic water quality, carbon cycling and watershed-ocean interactions will change in the future. This research project aims to utilize data generated from ongoing field campaigns and satellite remote sensing (RS) products of chl a and dissolved and particulate organic matter (DOM & POM) in the coastal Arctic Ocean to estimate carbon fluxes using multiple combined hydrodynamic-biogeochemical modeling and RS techniques. First, predicted water transport from a newly built Yukon River regional hydrodynamic model (YukonFVCOM) will be combined with satellite ocean color organic matter (OM) concen-tration products to calculate OM fluxes near the Yukon river outflow and in Norton Sound. Second, the OM cycling model ICM-DOM-PD will be coupled with YukonFVCOM to corroborate and bolster estimates of OM distribution and fluxes in the Yukon River coastal region at multiple spatial and temporal scales. Model OM reaction kinetics will be re-parameterized to represent Arctic Ocean processes using data collected in the 2018 and 2019 field campaigns under a currently funded NASA Remote Sensing of Water Quality proposal, NNH16ZDA001N-RSWQ (PIs: Hernes, Mannino, Spencer and Tzortziou), in addition to relevant field data from the NASA SeaBASS archives. Specific locations along the river-delta-sea gradient where and timing when modeled OM undergoes rapid transformation will be identified, informing future large scale efforts such as the Arctic-COL-ORS project. Results from the RS and modeling efforts will be used to establish a baseline of current conditions to inform future studies and biogeochemical model forecasts that project how the Arctic carbon cycle will change in the future.

    Education

    Doctor of Philosophy. Marine Estuary Environmental Science: Focus in Biogeochemistry and Oceanography. Horn Point Laboratory, University of Maryland Center for Environmental Science, Cambridge, MD. September 2014 – May 2019. Advisor: Professor Raleigh Hood

    Bachelor of Science, Aquatic Biology. University of California at Santa Barbara, Santa Barbara, CA. September 2008 - September 2012. Advisor: Professor Craig Carlson
     

    Professional Societies

    American Society of Limnology and Oceanography, 2017 - Present
    Community Surface Dynamics Modeling System, 2015 - Present
    American Geophysical Union, 2019 - Present

    Professional Service

    Chesapeake Bay Program Scientific and Technical Advisory Committee (STAC) “Assessing the environment in outcome units” workshop. Invited Participant Annapolis, MD. March 20-21, 2019.

    Chesapeake Bay Program Scientific and Technical Advisory Committee (STAC) “Chesapeake Bay Program Climate Change Modeling 2.0 workshop.” Invited Participant Annapolis, MD. September 24-25, 2018

    Awards

    NASA Postdoctoral Fellowship. Universities Space Research Association. 2 Years fully funded. 

    University of Maryland College of Computer, Mathematical and Natural Science Merit fellowship- $5000

    Horn Point Laboratory Graduate Student Research Fellowship - 2 Years of stipend and tuition

    University of Maryland Graduate School Dean’s Fellowship -$5000
     

    Publications

    Refereed

    Clark, J. B., and A. Mannino. 2021. "Preferential loss of Yukon River delta colored dissolved organic matter under nutrient replete conditions." Limnology and Oceanography, lno.11706 [10.1002/lno.11706]

    Clark, J. B., W. Long, and R. R. Hood. 2020. "A Comprehensive Estuarine Dissolved Organic Carbon Budget Using an Enhanced Biogeochemical Model." Journal of Geophysical Research: Biogeosciences, 125 (5): [10.1029/2019jg005442]

    Clark, J. B., P. Neale, M. Tzortziou, F. Cao, and R. R. Hood. 2019. "A mechanistic model of photochemical transformation and degradation of colored dissolved organic matter." Marine Chemistry, 214: 103666 [10.1016/j.marchem.2019.103666]

    Clark, J. B., W. Long, and R. R. Hood. 2017. "Estuarine Sediment Dissolved Organic Matter Dynamics in an Enhanced Sediment Flux Model." Journal of Geophysical Research: Biogeosciences, 122 (10): 2669-2682 [10.1002/2017jg003800]

    Clark, J. B., W. Long, M. Tzortziou, P. J. Neale, and R. R. Hood. 2017. "Wind-Driven Dissolved Organic Matter Dynamics in a Chesapeake Bay Tidal Marsh-Estuary System." Estuaries and Coasts, 41 (3): 708-723 [10.1007/s12237-017-0295-1]

    Testa, J. M., J. B. Clark, W. C. Dennison, et al. E. C. Donovan, A. W. Fisher, W. Ni, M. Parker, D. Scavia, S. E. Spitzer, A. M. Waldrop, V. M. Vargas, and G. Ziegler. 2017. "Ecological Forecasting and the Science of Hypoxia in Chesapeake Bay." BioScience, 67 (7): 614-626 [10.1093/biosci/bix048]

    Talks, Presentations and Posters

    Invited

    Estimating the fluxes and controls of estuarine organic matter: a case study of the Rhode River, MD. Invited Seminar. GCReW Symposium. Smithsonian Environmental Research, Edgewater, MD.

    3 / 28 / 2019

    Estimates of wetland-estuary organic matter cycling using a new biogeochemical modeling system. Invited Seminar. Virginia Institute of Marine Science, College of William and Mary, Gloucester, VA. 

    8 / 22 / 2018

    Modeling organic carbon at the wetland estuary interface – A small model with large insights. Invited Seminar. Smithsonian Environmental Research Center, Edgewater, MD

    12 / 11 / 2017

    Progress and challenges in up-scaling carbon modeling to a regionally significant wetland-estuary system. Lightning talk. Ocean Carbon and Biogeochemistry Workshop, Woods Hole, MA. 

    6 / 24 / 2017

    Other

    Modeling of complex flow patterns across a large wetland-estuarine complex in Southern Dorchester Co, MD. Oral Presentation. Chesapeake Research and Modeling Symposium. Annapolis, MD.

    6 / 14 / 2018

    Modeling of complex flow patterns across a large wetland-estuarine complex in Southern Dorchester Co, MD. Oral Presentation. Atlantic Estuarine Research Society Biennial Meeting. Rehoboth, DE

    4 / 6 / 2018

    Development and application of a mechanistic model of the photochemical degradation of colored dissolved organic matter. Oral presentation. Ocean Sciences Meeting, Portland, OR.

    2 / 14 / 2018

    Modeling of photodegradation and biogeochemical cycling in a wetland-estuary system. Oral. Coastal and Estuarine Research Federation Biennial Conference, Providence, RI.

    11 / 7 / 2017

    Insights gained from a wetland-estuary dissolved organic matter modeling system. Poster. Ocean Carbon and Biogeochemistry Workshop, Woods Hole, MA.

    6 / 26 / 2017

    Modeling of estuarine sediment organic matter remineralization with a dissolved organic matter intermediate state variable. Oral. Aquatic Sciences Meeting, Honolulu, HI

    3 / 1 / 2017

    Mass conservative modeling of dissolved organic matter photochemistry and biogeochemical cycling. Poster. Ocean Carbon and Biogeochemistry Workshop, Woods Hole, MA.

    7 / 27 / 2016

    Modeling the marsh-estuary organic carbon cycle in the Rhode River, MD. Oral. Chesapeake Modeling Symposium, Williamsburg, VA. 

    6 / 1 / 2016

    Atmospheric forcing and marsh dissolved organic matter fluxes: modeling and observations from a Chesapeake Bay tidal marsh-estuary ecosystem. Poster. Ocean Sciences Meeting, New Orleans, LA. 

    2 / 25 / 2016

    Three-dimensional modeling of a Chesapeake Bay tidal marsh Ecosystem, Oral Finite Volume Community Ocean Model (FVCOM) User workshop. Bedford Institute of Oceanography, Halifax, NS, CAN. 

    10 / 21 / 2015

    Three-dimensional modeling of a Chesapeake Bay tidal marsh Ecosystem. Poster Community Surface Dynamic Modeling Systems (CSDMS) Annual Meeting. National Center for Atmospheric Research, Boulder, CO.

    5 / 27 / 2015

    Brief Bio

    I am an early career scientist with a focus on land-estuary-ocean biogeochemistry and carbon cycling. I completed my PhD in 2019 at the University of Maryland Center for Environmental Science, Horn Point Lab under the advice of Dr. Raleigh Hood. There, I worked on developing and applying a model that represented the processes of tidal inundation and marsh-estuary linkages and organic matter cycling. Upon graduation in 2019, I began a NASA Postdoctoral Program fellowship at Goddard in the Ocean Ecology Lab with Antonio Mannino as my advisor. My research focus shifted towards modeling and remote sensing of the coastal Arctic. I am now an associate scientist with USRA/GESTAR and hope to continue advancing our understanding of coastal environments and how the land and ocean carbon and nutrient cycles are linked via rivers and estuaries.

    Publications

    Refereed

    Clark, J. B., and A. Mannino. 2021. "Preferential loss of Yukon River delta colored dissolved organic matter under nutrient replete conditions." Limnology and Oceanography lno.11706 [10.1002/lno.11706]

    Clark, J. B., W. Long, and R. R. Hood. 2020. "A Comprehensive Estuarine Dissolved Organic Carbon Budget Using an Enhanced Biogeochemical Model." Journal of Geophysical Research: Biogeosciences 125 (5): [10.1029/2019jg005442]

    Clark, J. B., P. Neale, M. Tzortziou, F. Cao, and R. R. Hood. 2019. "A mechanistic model of photochemical transformation and degradation of colored dissolved organic matter." Marine Chemistry 214 103666 [10.1016/j.marchem.2019.103666]

    Clark, J. B., W. Long, and R. R. Hood. 2017. "Estuarine Sediment Dissolved Organic Matter Dynamics in an Enhanced Sediment Flux Model." Journal of Geophysical Research: Biogeosciences 122 (10): 2669-2682 [10.1002/2017jg003800]

    Clark, J. B., W. Long, M. Tzortziou, P. J. Neale, and R. R. Hood. 2017. "Wind-Driven Dissolved Organic Matter Dynamics in a Chesapeake Bay Tidal Marsh-Estuary System." Estuaries and Coasts 41 (3): 708-723 [10.1007/s12237-017-0295-1]

    Testa, J. M., J. B. Clark, W. C. Dennison, et al. E. C. Donovan, A. W. Fisher, W. Ni, M. Parker, D. Scavia, S. E. Spitzer, A. M. Waldrop, V. M. Vargas, and G. Ziegler. 2017. "Ecological Forecasting and the Science of Hypoxia in Chesapeake Bay." BioScience 67 (7): 614-626 [10.1093/biosci/bix048]

                                                                                                                                                                                            
    NASA Logo, National Aeronautics and Space Administration