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Funded Research

Tidal Wetlands as Sources and Sinks of Carbon in a Changing world: Remote Sensing, Measurements and Modeling of Wetland-Ocean-Atmosphere Interactions

Tzortziou, Maria: CCNY City University of New York/ GSFC-NASA (Project Lead)
Canuel, Elizabeth: Virginia Inst Marine Science (Co-Investigator)
Hood, Raleigh: UMCES (Co-Investigator)
McDonald, Kyle: The City College of New York (Co-Investigator)
Megonigal, Patrick: SERC (Co-Investigator)
Long, Wen: PNNL (Institution Lead)
Neale, Patrick: SERC (Institution Lead)
Cao, Fang: CUNY-CCNY (Post-Doc)

Project Funding: 2014 - 2016

NRA: 2013 NASA: Carbon Cycle Science   

Funded by NASA

Serving as a link between the land and the ocean, tidal wetlands are exposed to a wide variety of anthropogenic and natural stressors. Among our most valuable natural resources, these rich in biodiversity and highly productive ecosystems are hot spots of biogeochemical exchanges and transformations. Despite recent advances in remote sensing observations and modeling of biogeochemical processes in terrestrial and ocean environments, large gaps remain in our understanding of key carbon processes in tidal wetland-estuarine systems at the land-ocean interface. As a result, there are many unknowns regarding the role these ecosystems play in regional and global carbon cycling, and their potential responses and services in a changing climate. This study will address this high priority research area by integrating advanced remote sensing observations of wetlands and coastal ocean color with new mechanistic carbon cycling modeling. Partnering with relevant stakeholders, the project aims at enhancing the capability of using remote sensing and modeling tools for adaptive resource management. Our proposed research is driven by three science objectives: (i) quantify carbon fluxes and exchanges (dissolved, particulate and gaseous CO2 and CH4 components) at the tidal wetland-estuarine-atmosphere interface, and assess the spatial extent of marsh influence on carbon quality along the continuum of wetlands, estuaries and the coastal ocean; (ii) quantify the relative importance of photochemistry as a key transformation process of marsh exported carbon in shallow-water terrestrial-aquatic interfaces, and its interaction with microbial transformations; (iii) assess the role of tidal wetland carbon fluxes and processes across a range of spatial and time scales. Potential influences of natural and anthropogenic pressures on these processes will be assessed under various environmental change scenarios (i.e., extreme flooding, sea-level rise, increased CO2, and nutrient enrichment). We will address these objectives through advanced remote sensing characterization of tidal wetland area extent, vegetation communities and inundation regimes (using Synthetic Aperture Radar, SMAP, Landsat, ASTER, UAVSAR), and refined retrievals of nearshore biogeochemical variables applied to almost two decades (1997-2016) of ocean color satellite imagery (SeaWiFS, MODIS, MERIS, VIIRS). Remote sensing will be integrated with rich field datasets and a novel coupled hydrodynamic-photochemical-biogeochemical model that we specifically designed to simulate key carbon processes along wetland-estuarine interfaces. Approaches and products from the proposed study will be applicable to tidal wetland ecosystems around the world that have been altered by growing anthropogenic pressures over the past century and are highly vulnerable to climate change and associated changes to the carbon cycle. The resulting field datasets and improved satellite retrievals will be made accessible to a variety of users. The models we develop will be disseminated as open-source code to the research and management communities through SourceForge, and so can be tailored and applied broadly to other systems around the world. Our study specifically addresses this solicitation's Theme 2 on: 'Carbon Dynamics along Terrestrial-Aquatic Interfaces', and is directly aligned with NASA, DOE and USDA objectives and strategic goals. It is also relevant to NASA's efforts to develop new applications for existing and future satellite missions, including improved environmental impact assessment and ecological forecasting. Through the proposed collaboration with relevant stakeholders, we will incorporate the remote sensing products and modeling tools developed here into enhanced decision support systems for predicting potential responses of wetlands to future pressures and assessing the services (regulating, provisioning, and cultural) these ecosystems may provide in a changing climate.


Cao, F., Tzortziou, M., Hu, C., Mannino, A., Fichot, C. G., Del Vecchio, R., Najjar, R. G., Novak, M. 2018. Remote sensing retrievals of colored dissolved organic matter and dissolved organic carbon dynamics in North American estuaries and their margins. Remote Sensing of Environment. 205, 151-165. DOI: 10.1016/j.rse.2017.11.014

Clark, J. B., Long, W., Tzortziou, M., Neale, P. J., Hood, R. R. 2017. Wind-Driven Dissolved Organic Matter Dynamics in a Chesapeake Bay Tidal Marsh-Estuary System. Estuaries and Coasts. DOI: 10.1007/s12237-017-0295-1

Nelson, N. G., Munoz-Carpena, R., Neale, P. J., Tzortziou, M., Megonigal, J. P. 2017. Temporal variability in the importance of hydrologic, biotic, and climatic descriptors of dissolved oxygen dynamics in a shallow tidal-marsh creek. Water Resources Research. 53(8), 7103-7120. DOI: 10.1002/2016WR020196

2015 NASA Carbon Cycle & Ecosystems Joint Science Workshop Poster(s)

  • Tidal wetlands as sources and sinks of carbon in a changing world: Remote Sensing, Measurements & Modeling of Wetland-Ocean-Atmosphere Interactions   --   (Maria A. Tzortziou, Elizabeth Ann Canuel, Patrick J. Neale, Patrick J. Megonigal, Raleigh Hood, Wen Long, Kyle McDonald, Blake Clark, Amanda knobloch, Fang Cao, Andrew Peresta)   [abstract]

More details may be found in the following project profile(s):