The δ18O of dissolved O2 as a tracer of mixing and respiration in the mesopelagic ocean
Levine, Naomi M.
Bender, Michael L.
Doney, Scott C.
MetadataShow full item record
The isotopic composition of dissolved oxygen in the mesopelagic ocean is a unique tracer of respiration and transport. New δ 18O of O2 data from the tropical South Atlantic oxygen minimum zone are presented and compared to global δ 18O data. The δ 18O variability in oxygen poor waters is attributed to differences in physical and biogeochemical processes. Simple respiration-transport models show that both isopycnal diffusion and advection must be properly considered when interpreting oxygen isotope signatures along an isopycnal surface. We estimate rates of respiration and oxygen isotope fractionation for the study region using a two-dimensional (2-D) isopycnal and 1-D diapycnal model. Estimated respiration rates are consistent with previous studies. However, to account for observed δ 18O values at low [O2], model solutions need to invoke either very low [O2] that have not been observed in the South Atlantic or an isotope effect that is lower than values measured in the laboratory or euphotic zone.
Author Posting. © American Geophysical Union, 2009. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Global Biogeochemical Cycles 23 (2009): GB1006, doi:10.1029/2007GB003162.
Showing items related by title, author, creator and subject.
Chapin, F. Stuart; Woodwell, G. M.; Randerson, James T.; Rastetter, Edward B.; Lovett, G. M.; Baldocchi, Dennis D.; Clark, D. A.; Harmon, Mark E.; Schimel, David S.; Valentini, R.; Wirth, C.; Aber, J. D.; Cole, Jonathan J.; Goulden, Michael L.; Harden, J. W.; Heimann, M.; Howarth, Robert W.; Matson, P. A.; McGuire, A. David; Melillo, Jerry M.; Mooney, H. A.; Neff, Jason C.; Houghton, Richard A.; Pace, Michael L.; Ryan, M. G.; Running, Steven W.; Sala, Osvaldo E.; Schlesinger, William H.; Schulze, E.-D. (2006-01-06)Recent patterns and projections of climatic change have focused increased scientific and public attention on patterns of carbon (C) cycling and its controls, particularly the factors that determine whether an ecosystem is ...
Variability in the carbon isotopic composition of foliage carbon pools (soluble carbohydrates, waxes) and respiration fluxes in southeastern U.S. pine forests Mortazavi, Behzad; Conte, Maureen H.; Chanton, Jeffrey P.; Weber, John C.; Martin, Timothy A.; Cropper, Wendell P. (American Geophysical Union, 2012-04-19)We measured the δ13C of assimilated carbon (foliage organic matter (δCOM), soluble carbohydrates (δCSC), and waxes (δCW)) and respiratory carbon (foliage (δCFR), soil (δCSR) and ecosystem 13CO2 (δCER)) for two years at ...
Mixing in the North Atlantic Tracer Release Experiment : observations and numerical simulations of Lagrangian particles and passive tracer Sundermeyer, Miles A. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1995-09)Mixing and stirring of passive tracer and Lagrangian particles in the open ocean was studied through comparison of observations from the North Atlantic Tracer Release Experiment, a numerical model, and existing theory. ...