Project Funding: 2012 - 2014

NRA: 2011 NASA: Carbon Monitoring System   

Funded by NASA

Abstract:
Information about carbon fluxes in continental margins and linkages to terrestrial carbon cycles is key focus of NASA s Earth Science Research Program and a central aspect of NASA s Carbon Monitoring System. The uncertainties in coastal carbon fluxes are such that the net uptake of carbon in the coastal margins remains a poorly constrained term in global budgets. In particular, our ability to estimate current air-sea CO2 fluxes in continental margins is limited, and there is even less capability for predicting changes in the CO2 uptake capacity in coastal waters. The need to improve the understanding of coastal carbon dynamics and precision of estimates of coastal carbon fluxes has implications for attribution of land sources and sinks because atmospheric inversions are sensitive to uncertainties in coastal boundaries. Moreover, characterization of trends in carbon inventories reveal an increasing fraction of fossil fuel carbon is remaining in the atmosphere due to reductions in the efficiencies of ocean sinks and other sink processes not considered in current models. The proposed research will employ a combination of models and remotely-sensed and in situ observations to develop georeferenced products and associated uncertainties for land-ocean exchange of carbon, air-sea exchanges of carbon dioxide, and coastal to open ocean exchanges of carbon. Such information is critically needed to better constrain the contribution of coastal margins to carbon sources and sinks and improve capabilities to attribute sources and sinks to different regions as well as reducing uncertainties in estimates. The proposed effort will use a combination of observations and coupled terrestrial and ocean models to examine carbon processes and fluxes from the watershed to the continental margin. A major aspect of this proposed project will be to establish and populate geospatial portals for sharing and analysis of carbon datasets and products. The primary region of study will be the Mississippi River watershed and northern Gulf of Mexico. However, the model domain will also include the continental margins of Florida and the South Atlantic Bight. The region of study provides an excellent setting to carry out this work as there are a large number of supporting datasets and on-going programs that will complement this work. The proposed work is closely aligned with objectives of the NASA Carbon Monitoring System scoping effort and of the North American Carbon Program and will support National Climate Assessment activities. The effort will also contribute to NASA Coastal Carbon Synthesis effort and international efforts to develop a North American carbon budget (CarboNA). The unique nature of our approach, coupling models of terrestrial and ocean ecosystem dynamics and associated carbon processes, will allow for assessment of how societal and human-related LCLUC, as well as climate change, affects terrestrial carbon sources and sinks, export of materials to coastal margins, and associated carbon processes in the continental margins. Results would also benefit efforts to describe and predict how land cover and land use changes impact coastal water quality, including possible effects of coastal eutrophication, hypoxia, and ocean acidification.

Publications:

Chakraborty, S., Lohrenz, S. E., Gundersen, K. 2017. Photophysiological and light absorption properties of phytoplankton communities in the river-dominated margin of the northern G ulf of M exico. Journal of Geophysical Research: Oceans. 122(6), 4922-4938. DOI: 10.1002/2016JC012092

Lohrenz, S. E., Cai, W., Chakraborty, S., Huang, W., Guo, X., He, R., Xue, Z., Fennel, K., Howden, S., Tian, H. 2018. Satellite estimation of coastal pCO2 and air-sea flux of carbon dioxide in the northern Gulf of Mexico. Remote Sensing of Environment. 207, 71-83. DOI: 10.1016/j.rse.2017.12.039

Tian, H., Ren, W., Yang, J., Tao, B., Cai, W., Lohrenz, S. E., Hopkinson, C. S., Liu, M., Yang, Q., Lu, C., Zhang, B., Banger, K., Pan, S., He, R., Xue, Z. 2015. Climate extremes dominating seasonal and interannual variations in carbon export from the Mississippi River Basin. Global Biogeochemical Cycles. 29(9), 1333-1347. DOI: 10.1002/2014GB005068

Tian, H., Xu, R., Pan, S., Yao, Y., Bian, Z., Cai, W., Hopkinson, C. S., Justic, D., Lohrenz, S., Lu, C., Ren, W., Yang, J. 2020. Long-Term Trajectory of Nitrogen Loading and Delivery From Mississippi River Basin to the Gulf of Mexico. Global Biogeochemical Cycles. 34(5). DOI: 10.1029/2019GB006475

Zhang, B., Tian, H., Lu, C., Chen, G., Pan, S., Anderson, C., Poulter, B. 2017. Methane emissions from global wetlands: An assessment of the uncertainty associated with various wetland extent data sets. Atmospheric Environment. 165, 310-321. DOI: 10.1016/j.atmosenv.2017.07.001

Cai, W., Arthur Chen, C. T., Borges, A. 2013. Carbon dioxide dynamics and fluxes in coastal waters influenced by river plumes in: Biogeochemical Dynamics at Major River-Coastal Interfaces. Cambridge University Press, 155-173. DOI: 10.1017/CBO9781139136853.010

Lohrenz, S. E., Cai, W., Chakraborty, S., Gundersen, K., Murrell, M. C. 2013. Nutrient and carbon dynamics in a large river-dominated coastal ecosystem: the Mississippi-Atchafalaya River system in: Biogeochemical Dynamics at Major River-Coastal Interfaces. Cambridge University Press, 448-472. DOI: 10.1017/CBO9781139136853.023

Huang, W., Cai, W., Castelao, R. M., Wang, Y., Lohrenz, S. E. 2013. Effects of a wind-driven cross-shelf large river plume on biological production and CO2 uptake on the Gulf of Mexico during spring. Limnology and Oceanography. 58(5), 1727-1735. DOI: 10.4319/lo.2013.58.5.1727

Xue, Z., He, R., Fennel, K., Cai, W., Lohrenz, S., Hopkinson, C. 2013. Modeling ocean circulation and biogeochemical variability in the Gulf of Mexico. Biogeosciences. 10(11), 7219-7234. DOI: 10.5194/bg-10-7219-2013

Liu, M., Tian, H., Yang, Q., Yang, J., Song, X., Lohrenz, S. E., Cai, W. 2013. Long-term trends in evapotranspiration and runoff over the drainage basins of the Gulf of Mexico during 1901-2008. Water Resources Research. 49(4), 1988-2012. DOI: 10.1002/wrcr.20180

Chen, G., Tian, H., Zhang, C., Liu, M., Ren, W., Zhu, W., Chappelka, A. H., Prior, S. A., Lockaby, G. B. 2012. Drought in the Southern United States over the 20th century: variability and its impacts on terrestrial ecosystem productivity and carbon storage. Climatic Change. 114(2), 379-397. DOI: 10.1007/s10584-012-0410-z

Guo, X., Cai, W., Huang, W., Wang, Y., Chen, F., Murrell, M. C., Lohrenz, S. E., Jiang, L., Dai, M., Hartmann, J., Lin, Q., Culp, R. 2011. Carbon dynamics and community production in the Mississippi River plume. Limnology and Oceanography. 57(1), 1-17. DOI: 10.4319/lo.2012.57.1.0001

Hopkinson, C. S., Cai, W., Hu, X. 2012. Carbon sequestration in wetland dominated coastal systems--a global sink of rapidly diminishing magnitude. Current Opinion in Environmental Sustainability. 4(2), 186-194. DOI: 10.1016/j.cosust.2012.03.005

Huang, W., Wang, Y., Cai, W. 2012. Assessment of sample storage techniques for total alkalinity and dissolved inorganic carbon in seawater. Limnology and Oceanography: Methods. 10(9), 711-717. DOI: 10.4319/lom.2012.10.711

Tian, H., Lu, C., Chen, G., Tao, B., Pan, S., Grosso, S. J. D., Xu, X., Bruhwiler, L., Wofsy, S. C., Kort, E. A., Prior, S. A. 2012. Contemporary and projected biogenic fluxes of methane and nitrous oxide in North American terrestrial ecosystems. Frontiers in Ecology and the Environment. 10(10), 528-536. DOI: 10.1890/120057

Tian, H., Chen, G., Zhang, C., Liu, M., Sun, G., Chappelka, A., Ren, W., Xu, X., Lu, C., Pan, S., Chen, H., Hui, D., McNulty, S., Lockaby, G., Vance, E. 2012. Century-Scale Responses of Ecosystem Carbon Storage and Flux to Multiple Environmental Changes in the Southern United States. Ecosystems. 15(4), 674-694. DOI: 10.1007/s10021-012-9539-x

Xu, X. F., Tian, H. Q., Chen, G. S., Liu, M. L., Ren, W., Lu, C. Q., Zhang, C. 2012. Multifactor controls on terrestrial N<sub>2</sub>O flux over North America from 1979 through 2010. Biogeosciences. 9(4), 1351-1366. DOI: 10.5194/bg-9-1351-2012

Zhang, C., Tian, H., Chen, G., Chappelka, A., Xu, X., Ren, W., Hui, D., Liu, M., Lu, C., Pan, S., Lockaby, G. 2012. Impacts of urbanization on carbon balance in terrestrial ecosystems of the Southern United States. Environmental Pollution. 164, 89-101. DOI: 10.1016/j.envpol.2012.01.020

Tian, H., Chen, G., Lu, C., Xu, X., Hayes, D. J., Ren, W., Pan, S., Huntzinger, D. N., Wofsy, S. C. 2014. North American terrestrial CO2 uptake largely offset by CH4 and N2O emissions: toward a full accounting of the greenhouse gas budget. Climatic Change. 129(3-4), 413-426. DOI: 10.1007/s10584-014-1072-9

Tao, B., Tian, H., Ren, W., Yang, J., Yang, Q., He, R., Cai, W., Lohrenz, S. 2014. Increasing Mississippi river discharge throughout the 21st century influenced by changes in climate, land use, and atmospheric CO2. Geophysical Research Letters. 41(14), 4978-4986. DOI: 10.1002/2014GL060361

Chen, G., Tian, H., Huang, C., Prior, S. A., Pan, S. 2013. Integrating a process-based ecosystem model with Landsat imagery to assess impacts of forest disturbance on terrestrial carbon dynamics: Case studies in Alabama and Mississippi. Journal of Geophysical Research: Biogeosciences. 118(3), 1208-1224. DOI: 10.1002/jgrg.20098

Wang, Z. A., Wanninkhof, R., Cai, W., Byrne, R. H., Hu, X., Peng, T., Huang, W. 2013. The marine inorganic carbon system along the Gulf of Mexico and Atlantic coasts of the United States: Insights from a transregional coastal carbon study. Limnology and Oceanography. 58(1), 325-342. DOI: 10.4319/lo.2013.58.1.0325

Xue, Z., He, R., Fennel, K., Cai, W., Lohrenz, S., Huang, W., Tian, H., Ren, W., Zang, Z. 2016. Modeling <i>p</i>CO<sub>2</sub> variability in the Gulf of Mexico. Biogeosciences. 13(15), 4359-4377. DOI: 10.5194/bg-13-4359-2016

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

• Ocean margins as an increasing sink for the atmospheric carbon dioxide   --   (Wei-Jun Cai, Goulven Laruelle, Xinping Hu, Pierre Regnier)   [abstract]

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

• NASA Ocean Biology & Biogeochemistry (OBB) Project Profile
• North American Carbon Program (NACP) Project Profile
• NASA Carbon Monitoring System (CMS) Project Profile