NSF

The prediction of future atmospheric CO2 concentrations requires an in depth understanding of the feedbacks that operate between the physical, biological and chemical components of the global climate system.  One of the few means to study these feedbacks is the investigation of the observed variability in the past.  Variability in the marine carbon cycle has been studied most thoroughly in the tropical Pacific in connection with ENSO. By contrast, little is known about the contribution of the subtropical and subpolar gyres to atmospheric CO2 variations, despite the fact that these gyres cover more than half of the world's ocean.  This study addresses this gap and pursues the following goals:

1. to quantify the variability in the marine carbon cycle in the subtropical and subpolar gyres on the interannual to decadal time scale and to determine the role of these oceanic regions for the observed temporal and spatial variability in atmospheric CO2
2. to evaluate and quantify the contributions from biological and physical processes to the observed variability;
3. to work toward a better understanding of the complex feedbacks that operate between the physical, chemical and biological processes in the ocean.

Diagnostic box model results for seasonal and interannual variability of the oceanic carbon cycle at Stations BATS and ALOHA.

Papers:

Bates, N.R., 2002. Interannual variability in the global uptake of CO2, Geophysical Research Letters, 29(5), art.no. 1059, DOI 10.1029/2001GL013571.

Bates, N.R., A.C. Pequignet, R.J. Johnson and N. Gruber, 2002. A short-term sink for atmospheric CO2 in subtropical mode water of the North Atlantic Ocean, Nature, 420, 489-493. [PDF]

Bates, N.R., 2001. Regional testbeds: Interannual variability of the oceanic carbon cycle at the U.S. JGOFS Bermuda Atlantic Time-series Study (BATS) site. In WOCE International Project Office, Report of the WOCE/JGOFS Ocean Transport Workshop, WOCE Report No. 174/2001, pp. 43-46.

Brix, H., N. Gruber and C.D. Keeling, 2004. Interannual variability of the upper ocean carbon cycle at station ALOHA near Hawaii, Global Biogeochemical Cycles, 18, GBXXXX, doi:10.1029/2004GB002245. (in press). [Abstract]

Gruber, N., C.D. Keeling and N.R. Bates, 2002. Interannual Variability in the North Atlantic Ocean Carbon Sink, Science, 298, 2374-2378.

Karl, D.M., J.E. Dore, R. Lukas, A.F. Michaels, N.R. Bates and A. Knap, 2001. Building the Long-Term picture: The U.S. JGOFS Time-series Programs, Oceanography, 14(4), 6-17.

Keeling, C.D., H. Brix and N. Gruber, 2004. Seasonal and long-term dynamics of the upper ocean carbon cycle at station ALOHA near Hawaii, Global Biogeochemical Cycles, 18, GBXXXX, doi:10.1029/2004GB002227. (in press). [Abstract]

Abstracts:

Gruber, N., N. Bates, C.D. Keeling and C. LeQuere, Interannual Variability in the Extra Tropical Ocean Carbon Cycle: The Role of the North Atlantic. Sixth International Carbon Dioxide Conference, Extended abstracts, pp. 677-680, 2001.

Bates, N.R., A.C. Pequignet, and R.J. Johnson, 2002. Changes in the oceanic sink of CO2 in Subtropical Mode Water of the North Atlantic Ocean. ASLO/AGU Ocean Sciences Meeting, Hawaii, February 2002.

Gruber, N., C.D. Keeling, A. Dickson, P. Guenther, H. Brix, N. Bates and J. Dore, Interannual to decadal variability in the carbon cycle of the subtropical gyres: A comparative study between Station 'S'/BATS and HOT. ASLO/AGU Ocean Science Meeting, Hawaii, February 2002.

Lomas, M., and N.R. Bates, Fate of Oceanic Primary Production: A Potential Change in Sargasso Sea Ecosystem Functioning? Primary Productivity Meeting and Workshop. Bangor, North Wales, March 2002.

Bates, N.R., A.C. Pequignet, and R.J. Johnson, Changes in the oceanic sink of CO2 in Subtropical Mode Water of the North Atlantic Ocean. European Geophysical Society Meeting, Nice, France, April 2002.

Gruber, N., C.D. Keeling, A. Dickson, P. Guenther, H. Brix, N.R. Bates and J. Dore, Interannual to decadal variability in the carbon cycle of the subtropical gyres: A comparative study between Station 'S'/BATS and HOT, Eos. Trans. AGU, 83(4), Ocean Sciences Suppl. Abstract OS22P-01, 2002.

Brix, H, N. Gruber and C.D. Keeling, Seasonal and long-term dynamics of the upper ocean carbon cycle at station ALOHA near Hawaii, Eos. Trans. AGU, AGU Fall Meet. Suppl., abstract GC72B-0226, 2002.

LeQuere, C. and N. Gruber, Gaining insight into the interannual variability of air-sea CO2 flux using satellite observations, Eos. Trans. AGU, AGU Fall Meet. Suppl., abstract GC72B-0228, 2002.

Brix, H., N. Gruber, C.D. Keeling, and N. Bates, Interannual to decadal variability in the subtropical oceanic carbon cycle, Geophysical Research Abstracts, 5, 07063, 2003.

Brix, H., N.R. Bates, J.E. Dore, N. Gruber, D.M. Karl, C.D. Keeling, R. Lukas, and D.W.Sadler, Interannual to Decadal Variability in the Oceanic Carbon Cycle: Lessons from BATS and HOT, JGOFS, Open Science Conference Proceedings, 2003.

Quay, P.D., N. Gruber, and H. Brix, 13C/12C of Dissolved Inorganic Carbon: A means to close the carbon budgets at ALOHA and BATS , JGOFS, Open Science Conference Proceedings, 2003.

Brix, H., N. Gruber, C.D. Keeling, N. Bates, C. LeQuere, and G. McKinley, Interannual Variability and Trends in the Oceanic Carbon Cycle: From HOT and BATS to the Subtropical Ocean, Eos Trans. AGU, 84(46), Ocean Sci. Meet., Abstract OS31A-02, 2004.

Gruber; Sabine; Sonnerup; Bullister; Key "Global Assessment and Synthesis of Data Based Estimates of Anthropogenic CO2 in the Ocean"