Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Biogeosciences, 10, 7723-7738, 2013
https://doi.org/10.5194/bg-10-7723-2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
28 Nov 2013
A novel estimate of ocean oxygen utilisation points to a reduced rate of respiration in the ocean interior
O. Duteil1, W. Koeve1, A. Oschlies1, D. Bianchi2, E. Galbraith2, I. Kriest1, and R. Matear3 1GEOMAR, Helmholtz Center for Ocean Research Kiel, Düsternbrooker Weg 20, 24103 Kiel, Germany
2Department of Earth and Planetary Science, McGill University, Montreal, QC, Canada
3CSIRO Marine and Atmosphere Research, Hobart, TAS, Australia
Abstract. The Apparent Oxygen Utilisation (AOU) is a classical measure of the amount of oxygen respired in the ocean's interior. We show that AOU systematically overestimates True Oxygen Utilisation (TOU) in 6 coupled circulation-biogeochemical ocean models. This is due to atmosphere–ocean oxygen disequilibria in the subduction regions, consistent with previous work. We develop a simple, new, observationally-based approach which we call Evaluated Oxygen Utilisation (EOU). In this approach, we take into account the impact of the upper ocean oxygen disequilibria into the interior, considering that transport takes place predominantly along isopycnal surfaces. The EOU approximates the TOU with less than half of the bias of AOU in all 6 models despite large differences in the physical and biological components of the models. Applying the EOU approach to a global observational dataset yields an oxygen consumption rate 25% lower than that derived from AOU-based estimates, for a given ventilation rate.

Citation: Duteil, O., Koeve, W., Oschlies, A., Bianchi, D., Galbraith, E., Kriest, I., and Matear, R.: A novel estimate of ocean oxygen utilisation points to a reduced rate of respiration in the ocean interior, Biogeosciences, 10, 7723-7738, https://doi.org/10.5194/bg-10-7723-2013, 2013.
Publications Copernicus
Download
Share