Start Submission Become a Reviewer

Reading: New early winter fCO2 data reveal continuous uptake of CO2 by the Weddell Sea

Download

A- A+
Alt. Display

Original Research Papers

New early winter fCO2 data reveal continuous uptake of CO2 by the Weddell Sea

Authors:

M. H. C. Stoll ,

Netherlands Institute for Sea Research, NL
X close

H. J. W. De Baar,

Netherlands Institute for Sea Research, NL
X close

M. Hoppema,

University of Bremen, FBI IUP, Dept. Tracer Oceanography, DE
X close

E. Fahrbach

Alfred Wegener Institute for Polar and Marine Research, DE
X close

Abstract

The Antarctic Ocean has been thought to be unimportant for the uptake of CO2 since upwelling of CO2-enriched deep waters would favour outgassing. Here we present the first direct fCO2 measurements obtained in early winter under the ice which, combined with estimated entrainment rates, show that the Weddell Sea, an area of intense upwelling manifested by the doming structure of the cyclonic gyre, has the capability to be almost continuously a sink for atmospheric CO2. A flux, effective after the ice cover disappears, is estimated to be — 0.74 ± 0.7 mmol/m-2 d-1. Combined with a flux estimate in late autumn (- 2.0 mmol m-2 d-1) integrated over the area of the central Weddell Gyre, a carbon uptake of 0.24 × 1013 gC y-1 (≈ 2.4× 10-3 GtC y-1 being ≈ 1‰ of global uptake) is computed, which is about a third of the strength of the biological pump of the Weddell Sea.

How to Cite: Stoll, M.H.C., De Baar, H.J.W., Hoppema, M. and Fahrbach, E., 1999. New early winter fCO2 data reveal continuous uptake of CO2 by the Weddell Sea. Tellus B: Chemical and Physical Meteorology, 51(3), pp.679–687. DOI: http://doi.org/10.3402/tellusb.v51i3.16460
  Published on 01 Jan 1999
 Accepted on 15 Aug 1998            Submitted on 21 Jan 1998

References

  1. Anderson , L. G. and Jones , E. P. 1991 . The transport of CO2 into the Arctic and Antarctic seas: Similarities and differences in the driving processes . J. Mar. Sys . 2 , 81 – 95 .  

  2. Anderson , L. G. , Holby , O. , Lindgren , R. and Ohlson , M. 1991 . The transport of anthropogenic carbon dioxide into the Weddell Sea . J. Geophys. Res . 96 ( C9 ), 16679 – 16687 .  

  3. Anonymous , 1985. Sea Ice Atlas (1). Antarctic NAVAIR 50-1C-540 . Naval Oceanography Command Detachment, Asheville , NC, USA .  

  4. Bakker , D. C. E. , De Baar , H. J. W. and Bathmann , U. 1997 . Changes of carbon dioxide in surface waters during spring in the Southern Ocean . Deep-Sea Res II . 44 , 91 – 127 .  

  5. Carmack , E. C. and Foster , T. D. 1975 . On the flow of water out of the Weddell Sea . Deep-Sea Res . 22 , 711 – 724 .  

  6. Chen , C.-T. A. 1982 . Carbonate chemistry during WEPOLEX-81 . Antarctic Journal 17 , 102 – 103 .  

  7. Chen T.-W. 1997 . Formation and transport of deep and bottom waters in the western Weddell Sea: a numerical modelling study . PhD thesis. Columbia University , USA .  

  8. Chisholm , S. W. and Morel , F. M. M. 1991 . What controls phytoplankton production in nutrientrich areas of the open sea. Limnol. Ocean . 36 , 1507 – 1970 with preface by the editors.  

  9. Conway. T. J. , Tans , P. P. , and Waterman , L. S. 1994 . Atmospheric CO2 records from sites in the NOAA/ CMDL air sampling network. In: Trends '93: A compendium of data on global change (eds. T. A. Boden , D. P. Kaiser , R. J. Sepanski and F. W. Stoss ). ORNL/ DIAC 65 , 41 – 119 .  

  10. Deacon , G. E. R. 1979. The Weddell Gyre . Deep-Sea Res . 26 , 81 – 95 .  

  11. El-Sayed , S. 1984 . Productivity of Antarctic waters: a reappraisal. In: Marine phytoplankton and productivity (eds. O. Holm-Hansen , L. Bolis and R. Gilles ). Springer , Berlin , 19 – 34 .  

  12. Fahrbach , E. 1997 . The expedition ANTARKTIS XIII/ 4-5 of the Research Vessel “Polarstern” in 1996 . Ber. Polarforsch . 239 , pp. 134 .  

  13. Fahrbach , E. , Rohardt , G. , Schröder , M. and Strass , V. 1994 . Transport and structure of the Weddell Gyre . Ann. Geophysicae 12 , 840 – 855 .  

  14. Gordon , A. L. and Huber , B. A. 1990 . Southern Ocean winter mixed layer . J. Geophys. Res . 95 ( C ), 11655 – 11672 .  

  15. Goyet , C. and A. Poisson , 1989 . New determination of carbonic acid dissociation constants in seawater as a function of temperature and salinity . Deep-Sea Res . 36 , 1635 – 1654 .  

  16. Hoppema , M. , Fahrbach , E. , Schröder , M. , Wisotzki , A. and De Baar , H. J. W. 1995 . Winter-summer differences of carbon dioxide and oxygen in the Weddell Sea surface layer . Mar. Chem . 51 , 177 – 192 .  

  17. Hoppema , M. , Fahrbach , E. , Stoll , M. H. C. and De Baar , H. J. W. 1998a . Increase of carbon dioxide in the bottom water of the Weddell Sea, Antarctica . Mar. Chem . 59 , 201 – 210 .  

  18. Hoppema , M. , Fahrbach , E. , Stoll , M. H. C. and De Baar , H. J. W. 1998b . Annual uptake of atmospheric CO2 by the Weddell Sea derived from a surface layer balance, including estimations of entrainment and new production. J. Mar. Sys . 18 , in press .  

  19. Keeling , R. F. and Shertz , S. R. 1993 . Seasonal and interannual variations in atmospheric oxygen and implications for the global carbon cycle . Nature 358 , 723 – 727 .  

  20. Lemke , P. 1994 . The expedition ANTARKTIS X/4 of Research Vessel “Polarstern” in 1992 . Ber. Polarforsch . 140 , pp. 90 .  

  21. Levitus , S. 1988 . Ekman volume fluxes for the world ocean and individual ocean basins . J. Phys. Oceanogr . 18 , 271 – 289 .  

  22. Louanchi , F. , Hoppema , M. , Bakker , D. C. E. , Poisson , A. , Stoll , M. H. C. , De Baar , H. J. W. , Schauer , B. , Ruiz-Pino , D. P. and Wolf-Gladrow , D. 1999 . Modelled and observed sea surface fcoz in the Southern Ocean: a comparative study. Tellus 51B , in press.  

  23. Mantyla , A. W. and Reid , J.L. 1983. Abyssal characteristics of the World Ocean waters. Deep-Sea Res. 3e , 805 – 833 .  

  24. Metzl , N. , Beauverger , C. , Bruner , C. , Goyet , C. and Poisson , A. 1991 . Surface water carbon dioxide in the southwest Indian sector of the southern Ocean: a highly variable CO2 source/sink region in summer . Mar. Chem . 35 , 85 – 95 .  

  25. Millero , F. J. , Lee , K. and Roche , M. 1998 . Distribution of alkalinity in the surface waters of the major oceans . Mar. Chem . 60 , 111 – 130 .  

  26. Murphy , P. P. , Feely , R. A. , Gammon , R. H. , Harrison , D. E. , Kelly , K. C. and Waterman , L. S. 1991a . Assessment of the air-sea exchange of CO2 in the south Pacific during the Austral autumn . J. Geophys. Res . 96 , 20455 – 20465 .  

  27. Murphy , P. P. , Feely , R. A. , Gammon , R. H. , Kelly , K. C. and Waterman , L. S. 1991b . Autumn air-sea disequilibrium of CO2 in the South Pacific Ocean . Mar. Chem . 35 , 77 – 84 .  

  28. Murray , J. W. , Johnson , E. and Garside , C. 1995 . A U.S. JGOFS Process Study in the equatorial Pacific (EqPac): Introduction . Deep-Sea-Res. II 42 , 275 – 293 .  

  29. Orsi , A. H , Nowlin Jr., W. D. and Whitworth III, T. 1993. On the circulation and stratification of the Wed-dell Gyre. Deep-Sea Res . 40 , 169 – 203 .  

  30. Poisson , A. and Chen , C.-T. A. 1987 . Why is there little anthropogenic CO2 in the Antarctic Bottom Water? Deep-Sea Res . 34 , 1255 – 1275 .  

  31. Poisson , A. , Metzl , N. , Brunet , C. , Schauer , B. , Bres , B. , Ruiz-Pino , D. and Louanchi , F. 1994 . Variability of sources and sinks of CO2 in the Western Indian and Southern Oceans during the year 1991 . J. Geophys. Res . 98 , 22759 – 22778 .  

  32. Quay , P. D. , Tilbrook , B. and Wong , C. S. 1992 . Oceanic uptake of fossil fuel CO2: carbon-13 evidence . Science 256 , 74 – 79 .  

  33. Reid , J. L. and Lynn , R. J. 1971 . On the influence of the Norwegian-Greenland and Weddell seas upon the bottom waters of the Indian and Pacific oceans . Deep-Sea Res . 18 , 1063 – 1088 .  

  34. Robertson , J. E. , Watson , A. J. , Langdon , C. , Ling , R. D. and Wood , J. W. 1993 . Diurnal variation in surface pCO2 and 02 at 60°N, 20°W in the North Atlantic . Deep-Sea Res. II 40 , 409 – 422 .  

  35. Robertson , J. E. and Watson , A. J. 1995 . A summertime sink for atmospheric carbon dioxide in the Southern Ocean between 88°W and 80°E . Deep-Sea Res. II 42 , 1081 – 1091 .  

  36. Roy , R. N. , Roy , L. N. , Vogel , K. M. , Porter-Moore , C. , Pearson , T. , Good , C. E. , Millero , F. J. and Campbell , D. M. 1993 . The dissociation constants of carbonic acid in seawater at salinities 5 to 45 and temperatures 0 to 45°C . Mar. Chem . 44 , 249 – 267 .  

  37. Sarmiento , J. L. , Orr , J. C. and Siegenthaler , U. 1992 . A perturbation simulation of CO2 uptake in an Ocean General Circulation Model . J. Geophys. Res . 97 ( C3 ), 3621 – 3645 .  

  38. Schlosser , P. , Roether , W. and Rohardt , G. 1987 . Helium-3 balance of the upper layers of the north-western Weddell Sea . Deep-Sea Res . 34 , 365 – 377 .  

  39. Siegenthaler , U. and Sarmiento , J. L. 1993 . Atmospheric carbon dioxide and the ocean . Nature 365 , 119 – 125 .  

  40. Stoll , M. H. C. , Rommets , J. W. and De Baar , H. J. W. 1993 . Effect of selected calculation routines and dissociation constants on the determination of total carbon dioxide in seawater . Deep-Sea Res . 40 , 1307 – 1322 .  

  41. Stoll , M. H. C. , Van Aken , H. M. , De Baar , H. J. W. and De Boer , C. J. 1996 . Meridional carbon dioxide transport in the northern North Atlantic . Mar. Chem . 55 , 205 – 216 .  

  42. Takahashi , T. , Olafsson , J. , Goddard , J. G. , Chipman , D. W. and Sutherland , S. C. 1993 . Seasonal variation of CO2 and nutrients in the high-latitude surface oceans: a comparative study . Global Biogeochem. Cycles 7 , 843 – 878 .  

  43. Tans , P. P. , Fung , I. Y. and Takahashi , T. 1990 . Observational constraints on the global atmospheric CO2 budget . Science 247 , 1431 – 1438 .  

  44. Volk , T. and Hoffert , M. I. 1985 . Ocean carbon pumps: analysis of relative strengths and efficiencies in ocean-driven atmopsheric CO2 changes . Geophys. Monogr . 32 , 99 – 110 .  

  45. Wanninkhof , R. 1992 . Relationship between wind speed and gas exchange over the ocean . .1. Geophys. Res . 97 ( C5 ), 7373 – 7382 .  

  46. Wanninkhof , R. H. and Thoning , K. 1993 . Measurement of fugacity of CO2 in surface water using continuous and discrete sampling methods . Mar. Chem . 44 , 183 – 204 .  

  47. Weiss , R. F. 1974 . Carbon dioxide in water and seawater: the solubility of a non-ideal gas . Mar. Chem . 2 , 203 – 205 .  

  48. Weppemig , R. , Schlosser , P. , Khatiwala , S. and Fair-banks , R. G. 1996 . Isotope data from Station Weddell: implications for deep water formation in the Weddell Sea. J . Geophys. Res . 101 ( C10 ), 25723 – 25739 .  

comments powered by Disqus