The global ocean flux of particulate organic carbon: Areal distribution and magnitude

The magnitude and distribution of the particulate organic carbon (POC) rain rate to the seafloor in the Atlantic, Pacific and Indian Ocean basins between 61°N and 61°S has been estimated from benthic oxygen flux estimates (for water depths ≥ 1000 m only). The calculation utilizes the extensive data sets of sedimentary organic carbon, CaCO3, and accumulation rate to extrapolate between individual benthic flux measurement sites using an empirically-derived correlation between the seafloor oxygen flux and these parameters. The POC flux through the 1000 m depth horizon was then estimated from published correlations between sediment trap-determined fluxes and water depth. Total oxygen utilization in the deep ocean is estimated to be 1.2×1014 mol O2 yr−1, a value that agrees well with previous estimates which were based on surface water primary productivity, sediment trap, and depth relationships and with deep water respiration rates estimated from apparant oxygen utilization (AOU)-14C relationships. On the basis of the derived global ocean flux distribution, it is concluded that (1) dissolved organic carbon (DOC) inputs are not required to account for estimated deep water respiration rates; (2) the majority of the POC input to the deep ocean occurs within 30° of the equator; (3) the proportion of primary production that reaches the deep sea does not vary greatly with latitude; (4) gyre and continental margin regions contribute roughly equally to the deep POC flux with a relatively minor contribution from the equatorial divergence region; (5) of the estimated 7.2×1013 mol C yr−1 of POC that sinks below the 1000 m depth horizon, 45% (3.3×1013 mol C yr−1) reaches the seafloor where it is oxidized; (6) when normalized to basin area, average deep flux rates in the Atlantic and Pacific are similar while highest rates are observed in the Indian Ocean; and (7) the results can be fully reconciled only if the benthic flux of DOC is significantly less than the benthic O2 flux.

[1]  D. Burdige,et al.  The Role of Benthic Fluxes of Dissolved Organic Carbon in Oceanic and Sedimentary Carbon Cycling , 1992 .

[2]  W. Martin,et al.  Dissolved organic carbon concentrations in marine pore waters determined by high‐temperature oxidation , 1993 .

[3]  T. Platt,et al.  Basin-scale estimates of oceanic primary production by remote sensing - The North Atlantic , 1991 .

[4]  K. SmithJr..  Benthic community respiration in the N.W. Atlantic Ocean: in situ measurements from 40 to 5200 m , 1978 .

[5]  W. Reeburgh,et al.  Anaerobic mineralization of marine sediment organic matter: Rates and the role of anaerobic processes in the oceanic carbon economy , 1987 .

[6]  D. Hammond,et al.  Early oxidation of organic matter in pelagic sediments of the eastern equatorial Atlantic: suboxic diagenesis , 1979 .

[7]  C. Lambert,et al.  A whole‐core squeezer for interfacial pore‐water sampling1 , 1987 .

[8]  K. Turekian,et al.  Distribution of calcium carbonate in surface sediments of the Atlantic Ocean , 1976 .

[9]  R. Keir.  Recent increase in Pacific CaCo3 dissolution: A mechanism for generating old 14C ages , 1984 .

[10]  P. M. Williams,et al.  Reconciling particulate organic carbon flux and sediment community oxygen consumption in the deep North Pacific , 1992, Nature.

[11]  W. Martin,et al.  The Variability of Benthic Fluxes and Sedimentary Remineralization Rates in Response to Seasonally Variable Organic Carbon Rain Rates in the Deep Sea; a Modeling Study , 1988, American Journal of Science.

[12]  G. Jackson,et al.  The Spatial Distribution of Sea Floor Oxygen Consumption in The Atlantic and Pacific Oceans , 1992 .

[13]  Taro Takahashi,et al.  Redfield ratio based on chemical data from isopycnal surfaces , 1985 .

[14]  C. Reimers,et al.  Carbon fluxes and burial rates over the continental slope and rise off central California with impli , 1992 .

[15]  W. Martin,et al.  Benthic organic carbon degradation and biogenic silica dissolution in the central equatorial Pacific , 1991 .

[16]  Jorge L. Sarmiento,et al.  Redfield ratios of remineralization determined by nutrient data analysis , 1994 .

[17]  D. Canfield,et al.  Sulfate reduction and oxic respiration in marine sediments: implications for organic carbon preservation in euxinic environments. , 1989, Deep-sea research. Part A, Oceanographic research papers.

[18]  O. Pfannkuche.  Benthic response to the sedimentation of particulate organic matter at the BIOTRANS station, 47°N, 20°W , 1993 .

[19]  J. Patching,et al.  Abyssal benthic oxygen-consumption in the northeastern atlantic - measurements using the suspended core technique , 1986 .

[20]  D. Archer,et al.  Dissolution of calcite in deep-sea sediments: pH and O2 microelectrode results , 1989 .

[21]  M. Bender,et al.  Fate of organic carbon reaching the deep sea floor: a status report☆ , 1984 .

[22]  Kenneth L. Smith.  Food energy supply and demand: A discrepancy between particulate organic carbon flux and sediment community oxygen consumption in the deep ocean1 , 1987 .

[23]  J. Toggweiler,et al.  Downward transport and fate of organic matter in the ocean: Simulations with a general circulation model , 1992 .

[24]  A. Bé,et al.  Calcium carbonate distribution in the surface sediments of the Indian Ocean , 1976 .

[25]  W. Berger,et al.  Distribution of carbonate in surface sediments of the Pacific Ocean , 1976 .

[26]  Xiaomei Xu,et al.  Benthic fluxes and pore water studies from sediments of the central equatorial north Pacific: Nutrient diagenesis , 1990 .

[27]  D. Cwienk.  Recent and Glacial Age Organic Carbon and Biogenic Silica Accumulation in Marine Sediments , 1986 .

[28]  D. Archer,et al.  Benthic recycling of biogenic debris in the eastern tropical Atlantic Ocean , 1989 .

[29]  W. Broecker,et al.  The Influence of CaCO3 Dissolution on Core Top Radiocarbon Ages for Deep‐Sea Sediments , 1991 .

[30]  H. W. Menard,et al.  Hypsometry of ocean basin provinces , 1966 .

[31]  J. Walsh,et al.  The nature and distribution of organic matter in the surface sediments of world oceans and seas , 1982 .

[32]  J. Cullen,et al.  Organic carbon oxidation and preservation in NW Atlantic continental margin sediments , 1987, Geological Society, London, Special Publications.

[33]  E. Druffel,et al.  Radiocarbon in dissolved organic matter in the central North Pacific Ocean , 1987, Nature.

[34]  R. Jahnke.  Ocean flux studies: A status report , 1990 .

[35]  Bernard P. Boudreau,et al.  On a reactive continuum representation of organic matter diagenesis , 1991 .

[36]  D. Archer,et al.  Respiration and dissolution in the sediments of the western North Atlantic: estimates from models of in situ microelectrode measurements of porewater oxygen and pH , 1994 .

[37]  C. Reimers,et al.  A closer look at nitrification in pelagic sediments , 1980 .

[38]  J. Bauer,et al.  14C activity of dissolved organic carbon fractions in the north-central Pacific and Sargasso Sea , 1992, Nature.

[39]  T. Platt,et al.  An estimate of global primary production in the ocean from satellite radiometer data , 1995 .

[40]  R. Jahnke,et al.  The influence of organic matter diagenesis on CaCO3 dissolution at the deep-sea floor , 1994 .

[41]  K. Hinga.  Evidence for a higher average primary productivity in the Pacific than in the Atlantic Ocean , 1985 .

[42]  C. Reimers,et al.  Organic carbon dynamics and preservation in deep-sea sediments , 1985 .

[43]  Steven Emerson,et al.  A model of oxygen reduction, denitrification, and organic matter mineralization in marine sediments1 , 1982 .

[44]  F. Sayles,et al.  Response of benthic oxygen demand to particulate organic carbon supply in the deep sea near Bermuda , 1994, Nature.

[45]  R. J. Thompson,et al.  Bacterial responses to temperature and substrate concentration during the Newfoundland spring bloom , 1991 .

[46]  R. Merewether,et al.  Oxygen microprofiles measured in situ in deep ocean sediments , 1986, Nature.

[47]  C. Reimers,et al.  Intensification of recycling of organic matter at the sea floor near ocean margins , 1990, Nature.

[48]  J. Murray,et al.  Aerobic respiration in pelagic marine sediments , 1982 .