Air-Sea CO2 Flux and Carbon Budget Synthesis and Modeling in the Entire Gulf of Mexico

Sponsor:  National Aeronautics and Space Administration


USGS: Lisa Robbins (lead PI)
University of Delaware: Wei-Jun Cai
NOAA: Rik Wanninkhof, Leticia Barbero
Dalhousie University: Katja Fennel, Arnaud Laurent
North Carolina State University: Ruoying He, Haibo Zong
Universidad Autonoma de Baja California: Jose Martin Hernandez-Ayon
National Sun Yat-sen University: Wei-Jen Huang

Funding period

September 2014 -June 2017


The Gulf of Mexico is a large semi-enclosed subtropical/tropical sea shared almost equally by the U.S. and Mexico. Fed by more than 150 rivers, the drainage basin to the Gulf of Mexico is comprised of 33 major river systems, and extends over approximately 40% of the landmass. Among the many rivers, the Mississippi and Atchafalaya River System is largest, carrying about 65% of all freshwater to the Gulf. The estuarine system that rims the Gulf also plays a large role. River-dominated estuaries characterize the northern Gulf, large marine-dominated bays occur to the east, and to the south, coastal lagoons dominate. As such, the Gulf of Mexico is distinctive in terms of its river and estuarine-dominated shelves.
The importance of constraining CO2 fluxes in the Gulf is evident in the modulation and estimation of continental (atmospheric) CO2 concentrations. Large variability between marine air concentrations impacted by sea-air CO2 fluxes from the Gulf of Mexico and continental air masses can introduce significant errors into continental CO2 fluxes calculation by atmospheric inversion methods, particularly at regional scales. The drainage basins upstream of the Gulf have also experienced great climate and anthropogenic changes. These changes have influenced and will continue to influence carbon cycle in the Gulf of Mexico. Thus the current status of a poorly known air-sea CO2 flux represents a big knowledge gap that is critical to our understanding of the carbon cycle and budget in North America and how it may respond to climate and anthropogenic changes in the future. Our research goal is to improve our understanding of the sinks and sources of CO2 by delineating their distribution through synthesis and modeling efforts.


The web site Air-Sea Carbon Dioxide Flux in the Gulf of Mexico Project has been created to inform the public about the project and its products.


Huang, W-J., Cai, W-J., Wang, Y., Hu, X., Chen, B., Lohrenz, S.E., Chakraborty, S., He, R., Brandes, J., and C.S. Hopkinson. 2015. The response of inorganic carbon distributions and dynamics to upwelling-favorable winds on the northern Gulf of Mexico during summer, Continental Shelf Research, 111(2015) 211-222, doi: 10.1016/j.csr.2015.08.020.

Huang, W-J., Cai, W-J., Wang, Y., Lohrenz, S.E., and Murrell, M.C. 2015. The carbon dioxide (CO2) system on the Mississippi River–dominated continental shelf in the northern Gulf of Mexico – I: Distribution and air-sea CO2 flux, Journal of Geophysical Research-Oceans. 120, 1429–1445, doi:10.1002/2014JC010498.

Laurent, A., Fennel, K., Cai, W.-J., Huang, W.-J., Barbero, L., and Wanninkhof, R. 2017. Eutrophication-induced acidification of coastal waters in the northern Gulf of Mexico: Results from a coupled physical-biogeochemical model, Geophysical Research Letters, 44, doi: :10.1002/2016GL071881

Ledwell, J.R., He, R., Xue, Z., DiMarco, S.F., Spencer, L., and Chapman, P. 2016. Dispersion of a tracer in the deep Gulf of Mexico, Journal of Geophysical Research – Oceans, 121, doi: 10.1002/2015JC011405

Patsavas, M.C., Byrne, R.H., Wanninkhof, R., Feely, R.A., and Cai, W.-J. 2015. Internal consistency of marine carbonate system measurements of aragonite saturation state: Insights from two U.S. coastal cruises, Marine Chemistry, 176:9-20, doi:10.1016/j.marchem.2015.06.022

Patsavas, M.C., Byrne, R.H., Yang, B., Easley, R.A., Wanninkhof, R., and Liu, X. 2015. Procedures for direct spectrophotometric measurements of carbonate ion concentrations: Measurements in US Gulf of Mexico and East Coast waters, Marine Chemistry 168, 80-85, doi:10.1016/j.marchem.2014.10.015

Ren, W., Tian, H., Cai, W-J, Lohrenz, S.E., Huang, W.-J., Yang, J., Tao, B., Pan, S., and He, R. 2016. Century-long increasing trend and variability of dissolved organic carbon export from the Mississippi River basin driven by natural and anthropogenic forcing, Global Biogeochemical Cyclesdoi: 10.1002/2016GB005395

Ren, W., Tian, H., Tao, B., Yang, J., Pan, S., Cai, W-J, Lohrenz, S.E., He, R., and Hopkinson, C.S. 2015. Large increase in dissolved inorganic carbon flux from the Mississippi River to Gulf of Mexico due to climatic and anthropogenic changes over the 21st century, Journal of Geophysical Research – Biogeosciences, 120, doi: 10.1002/2014JG002761.

Shropshire, T., Y. Li, and R. He (2016) Storm impact on sea surface temperature and chlorophyll a in the Gulf of Mexico and Sargasso Sea based on daily cloud-free satellite data reconstructions, Geophysical Research Letters, 43, doi: 10.1002/2016GL071178

Wanninkhof, R., Barbero, L., Byrne, R., Cai, W.-J., Huang, W.-J., Zhang, J.-Z., Baringer, M., and Langdon, C. 2015. Ocean acidification along the Gulf Coast and East Coast of the USA. Continental Shelf Research 98 (2015): 54-71. doi:10.1016/j.csr.2015.02.008

Xue, Z., He, R., Fennel, K., Cai, W-J, Huang, W-J., Tian, H., Ren, W., and Zang, Z. 2016. Modeling pCO2 variability in the Gulf of Mexico. Biogeosciences, 13, 4359-4377, doi: 10.5194/bg-13-4359-2016

Xue, Z., J. Zambon, Z. Yao, Y. Liu, and R. He. 2015 An integrated ocean circulation, wave, atmosphere, and marine ecosystem prediction system for the South Atlantic Bight and Gulf of Mexico, Journal of Operational Oceanographydoi:10.1080/1755876X.2015.1014667

Yang, B., Byrne, R.H., and Wanninkhof, R. 2015. Subannual variability of total alkalinity distributions in the northeastern Gulf of Mexico. Journal of Geophysical Research 120. doi:10.1002/2015JC010780

Zeng, X., Li, Y., and He, R. 2015. Predictability of the Loop Current variation and eddy shedding process in the Gulf of Mexico using an artificial neural network approach. Journal of Atmospheric and Oceanic Technologydoi: 10.1175/JTECH-D-14-00176.1

Zeng, X., Li, Y., He, R. and Yin, Y. 2015. Clustering of the Loop Current patters based on satellite observed sea surface height and self-organizing map. Remote Sensing Letters 6:1, 11-19, doi: 10.1080/2150704X.2014.998347


Barbero, L. Resultados de colaboraciones entre México y Estados Unidos en el ámbito del carbono en el océano, Programa Mexicano del Carbono. Presented at the VI International Symposium on Carbon in Mexico, Villahermosa, Tabasco, Mexico in May 2015. See PMC2015_BarberoReducedSize.pdf for a downloadable pdf file.

He, R. and A.C. Todd. Age and Residence Time of Terrestrial Source Water in the Western Atlantic Ocean and Gulf of Mexico. Ocean Sciences meeting, 2016, New Orleans, LA.

Laurent, A., K. Fennel, W.-J. Cai, W.-J. Huang, L. Barbero, and R. Wanninkhof. Processes Controlling Eutrophication-Induced Acidification in the Northern Gulf of Mexico: Results from a Coupled Physical-Biogeochemical Model. ASLO Aquatic Sciences Meeting, 22-27 Feb. 2015, Granada, Spain.  See ASLO2015_v2.pdf for a downloadable PDF file.

Shay, N., R. He, K. Fennel, and P. Furze. Three Dimensional Circulation and Biogeochemical Processes Using State-of-the-Art Profiling Floats and Data Assimilative Ocean Models. Gulf Oil spill and Science Meeting, 2015, Tampa, FL.


Barbero, L., R. Wanninkhof, L. Robbins, W.-J. Cai, R. He, and K. Fennel. The CO2 System in the Gulf of Mexico, a Synthesis and Modeling Effort. Presented at the Fifth North American Carbon Program Meeting, Washington, D.C., January 2015. See NACP2015_Barberoreducedsize.pdf for a downloadable pdf file.

Cai, Wei-Jun. Sea surface pCO2 distribution, variability and trend in coastal oceans and their potential impacts on regional and global carbon budgets. Presented at the Fifth North American Carbon Program Meeting, Washington, D.C., January 2015.

Huang, Wei-Jen, Wei-Jun Cai, Yongchen Wang, Xinping Hu, Baoshan Chen, Steven Lohrenz, Sumit Chakraborty, Ruoying He, Austin Todd, Jay Brandes, and Charles Hopkinson. The response of inorganic carbon distributions and dynamics to upwelling-favorable winds on the northern Gulf of Mexico during summer. Presented at the Fifth North American Carbon Program Meeting, Washington, D.C., January 2015.

Robbins, L., L. Barbero, R. Wanninkhof, R. He, W.-J. Cai, and K. Fennel. Carbon Fluxes on the West Florida Shelf. Presented at the Fifth North American Carbon Program Meeting, Washington, D.C., January 2015. See NACP airsea flux poster.pdf for a downloadable pdf file.

Tian, H., J. Yang, B. Zhang, S. Lohrenz, W-J Cai, R. He, Z. Xue, C. Lu, W. Ren, W-J Huang, and Y. Yao. Anthropogenic and Climactic Controls on Carbon and Nitrogen Exports from Mississippi River Basins to the Gulf of Mexico During 1800-2100: Implications for Hypoxia and Ocean Acidification. Ocean Sciences Meeting, New Orleans, LA, 2016.

Todd, A. C and R. He. Age and Residence Time of Terrestrial Source Water in the Gulf of Mexico.  Gulf of Mexico Oil Spill & Ecosystem Conference, Houston, TX, 2015.

Todd, A. C and R. He. Age and Residence Time of Terrestrial Source Water in the Western Atlantic Ocean and Gulf of Mexico. Gordon Research Conference, Portland, ME 2015.

Xue, Z., R. He, K. Fennel, W-J Cai, S. Lohrenz, W-J Huang, and W. Ren. Connecting the Mississippi River with Carbon Variability in the Gulf of Mexico. Ocean Sciences Meeting, New Orleans, LA,  2016.

Zambon, J. B., R. He, K. Fennel, W-J Cai, S. Lohrenz, W-J Huang, and W. Ren. A Coupled Ocean Circulation, Wave, Atmosphere, and Marine Ecosystem Prediction System for the Northwest Atlantic Ocean. Marine Environmental Monitoring, Modeling, and Prediction, Ocean Sciences Meeting, New Orleans, LA, 2016.