The δ18O of dissolved O2 as a tracer of mixing and respiration in the mesopelagic ocean
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.
Suggested CitationGlobal Biogeochemical Cycles 23 (2009): GB1006
Showing items related by title, author, creator and subject.
Mesopelagic respiration near the ESTOC (European Station for Time-Series in the Ocean, 15.5°W, 29.1°N) site inferred from a tracer conservation model Fernández Castro, Bieito; Arístegui, Javier; Anderson, Lawrence A.; Montero, Maria F.; Hernández-León, Santiago; Marañón, Emilio; Mourino-Carballido, Beatriz (2016-05-23)Remineralization of organic matter in the mesopelagic zone (ca. 150–700 m) is a key controlling factor of carbon export to the deep ocean. By using a tracer conservation model applied to climatological data of oxygen, ...
Time series measurements of transient tracers and tracer-derived transport in the Deep Western Boundary Current between the Labrador Sea and the subtropical Atlantic Ocean at Line W Smith, John N.; Smethie, William M.; Yashayaev, Igor; Curry, Ruth G.; Azetsu-Scott, Kumiko (John Wiley & Sons, 2016-11-10)Time series measurements of the nuclear fuel reprocessing tracer 129I and the gas ventilation tracer CFC-11 were undertaken on the AR7W section in the Labrador Sea (1997–2014) and on Line W (2004–2014), located over the ...
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. ...