234Th based POC Export

Investigators Ken Buesseler
Co-Investigators - none listed -
SMP Project Magnitude, variability and controls of particulate export in the upper ocean.
Product 234Th based POC Export estimates
Description The goal of this project was to compile a global database on upper ocean carbon export derived from thorium-234. Listed in the table are findings from the last 15 years investigating the relationship between carbon uptake and export. One major finding as a result of looking both globally and regionally at this relationship, is that there is large variability in space and time in this relationship that is not yet constrained by existing models. In general, regions with strong seasonal blooms, in particular those related to diatoms, were found to result in the highest flux of particulate organic carbon and associated elements out of the upper ocean Only a few regions have been studied where we have sufficient data to assess this relationship over an annual cycle. These results have a bearing on the global carbon cycle and climate change, since the ocean's "biological pump" provides a link between atmospheric CO2 uptake in the surface ocean, and sequestration of carbon in the deep ocean.
Submitted January 2004
e-Citation Excel file :
Buesseler, K. O.; U.S. JGOFS Synthesis & Modeling Project - Data. U.S. JGOFS. iPub: January 2004. 'date you accessed the data' http://usjgofs.whoi.edu/mzweb/data/Buesseler/world_ocean_export.xls
CSV file:
Buesseler, K. O.; U.S. JGOFS Synthesis & Modeling Project - Data. U.S. JGOFS. iPub: January 2004. 'date you accessed the data' http://usjgofs.whoi.edu/mzweb/data/Buesseler/world_ocean_export.csv
References

References cited in data files:

Amiel, D., J. K. Cochran, et al. (2002). "234Th/238U disequilibrium as an indicator of the seasonal export flux of particulate organic carbon in the North Water." Deep-Sea Research II 49: 5191-5209.

Baskaran, M., P. H. Santschi, et al. (1996). "234Th:238U disequilibria in the Gulf of Mexico: the importance of organic matter and particle concentration." Continental Shelf Research 16(3): 353-380.

Benitez-Nelson, C., K. O. Buesseler, et al. (2000). "Upper ocean carbon export, horizontal transport, and vertical eddy diffusivity in the southwestern Gulf of Maine." Continental Shelf Research 20: 707-736.

Benitez-Nelson, C., K. O. Buesseler, et al. (2001). "A time-series study of particular matter export in the North Pacific Subtropical Gyre based upon 234Th:238U disequilibrium." Deep-Sea Research 48(12): 2595-2611.

Buesseler, K. O., M. P. Bacon, et al. (1992). Carbon and nitrogen export during the JGOFS North Atlantic Bloom Experiment estimated from 234Th: 238U disequilibria. Deep-Sea Research I. 39: 1115-1137.

Buesseler, K. O., J. A. Andrews, et al. (1995). "Regional estimates of the export flux of particulate organic carbon derived from thorium-234 during the JGOFS EQPAC program." Deep-Sea Research II 42(2-3): 777-804.

Buesseler, K. O., L. Ball, et al. (1998). "Upper ocean export of particulate organic carbon in the Arabian Sea derived from thorium-234." Deep-Sea Research II 45(10-11): 2461-2487.

Buesseler, K. O., L. Ball, et al. (2001). "Upper ocean export of particulate organic carbon and biogenic silica in the Southern Ocean along 170°W." Deep-Sea Research II 48: 4275-4297.

Buesseler, K. O., R. T. Barber, et al. (2003). "The effect of marginal ice-edge dynamics on production and export in the Southern Ocean along 170°W." Deep-Sea Research II 50(3-4): 579-603.

Cai, P., Y. Huang, et al. (2002). "New production based on 228Ra-derived nutrient budgets and thorium-estimated POC export at the intercalibration station in the South China Sea." Deep-Sea Research I 49: 53-66.

Charette, M. (1999). "Thorium-234 as a tracer of the oceanic export of particulate organic carbon." Dissertation Abstracts International Part B: Science and Engineering 60(2): 539.

Cochran, J. K., K. Buesseler, et al. (2000). "Short-lived thorium isotopes (234Th, 228Th) as indicators of POC export and particle cycling in the Ross Sea, Southern Ocean." Deep-Sea Research II 47(15-16): 3451-3490.

Coppola, L., M. Roy-Barman, et al. (2002). "Calibration of sediment traps and particulate organic carbon export using 234Th in the Barents Sea." Marine Chemistry 80: 11-26.

Foster, J. M. and G. B. Shimmield (2002). "234Th as a tracer of particle flux and POC export in the northern North Sea during a coccolithophore bloom." Deep-Sea Research II 49: 2965-2977.

Guo, L., C.-C. Hung, et al. (2002). "234Th scavenging and its relationship to acid polysaccharide abundance in the Gulf of Mexico." Marine Chemistry 78: 103-119.

Hall, I. R., S. Schmidt, et al. (2000). "Particulate matter distribution and 234Th/238U disequilibrium along the Northern Iberian Margin: implications for particulate organic carbon export." Deep-Sea Research I 47: 557-582.

Moran, S. B. and J. N. Smith (2000). "Super(234)Th as a tracer of scavenging and particle export in the Beaufort Sea." Continental Shelf Research 20(2): 153-167.

Moran, S. B., S. E. Weinstein, et al. (2003). "Does 234Th/238U disequilibrium provide an accurate record of the export flux of particulate organic carbon from the upper ocean?" Limnology and Oceanography 48(3): 1018-1029.

Murray, J. W., J. N. Downs, et al. (1989). "Nutrient assimilation, export production and 234Th scavenging in the eastern equatorial Pacific." Deep-Sea Research 36(10): 1471-1489.

Murray, J. W., J. Young, et al. (1996). "Export flux of particulate organic carbon from the central equatorial Pacific determined using a combined drifting trap-234Th approach." Deep-Sea Research II 43: 1095-1132.

Nelson, D. M., R. F. Anderson, et al. (2002). "Vertical budgets for organic carbon and biogenic silica in the Pacific sector of the Southern Ocean, 1996-1998." Deep-Sea Research II 49(9-10): 1645-1674.

Rutgers van der Loeff, M. M., J. Friedrich, et al. (1997). "Carbon export during the Spring Bloom at the Antarctic Polar Front, determined with the natural tracer 234Th." Deep-Sea Research II 44(1-2): 457-478.

Santschi, P. H., L. Guo, et al. (1999). "Boundary exchange and scavenging of radionuclides in continental margin waters of the Middle Atlantic Bight: implications for organic carbon fluxes." Continental Shelf Research 19: 609-636.
Contact Steve Pike
Mail Stop 25
Department of Marine Chemistry and Geochemistry
Woods Hole Oceanographic Institution
Woods Hole, MA 02543
tel: 508-289-2350
fax: 508-457-2193
spike@whoi.edu