Abstract
The relationship between age and oxygen is one that is often assumed in oceanography to be relatively simple. Because oxygen utilization rates are difficult to directly measure in the ocean, it is commonly assumed that the apparent oxygen utilization divided by the water age is a good representation of respiration. Likewise, because of limited transient tracer observations and difficulties constraining water age, it has been suggested that oxygen could be a useful proxy for age. In this paper, we explore the relationship between age and oxygen using observations from Line W, a repeat hydrography cruise track which crosses the Gulf Stream, extending from Cape Cod to Bermuda, and an Earth System Model simulation. In both the observations and the model, the assumed positive linear relationship between apparent oxygen utilization (AOU) and mean age is not found within and directly below the ventilated thermocline at the end of Line W. In the Earth System Model decoupling of age and AOU is found in gyre centers, in some coastal upwelling zones, and downstream of mode water formation regions that show large variability in isopycnal depth. In all three regions, differences in the spatial distribution of sources of age and AOU become critically important, producing offset maxima in the gyre centers, and different time variability of sources in the other two areas.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Andres M, Toole J, Torres D, Smethie W, Joyce T, Curry R (2016) Stirring by deep cyclones and the evolution of denmark strait overflow water observed at line w. Deep-Sea Res Pt I 109:10–26. doi:https://doi.org/10.1016/j.dsr.2015.12.011
Armstrong R, Lee C, Hedges JI, Honjo S, Wakeham S (2002) A new, mechanistic model for organic carbon fluxes in the ocean based on the quantitative association of poc with ballast minerals. Deep-Sea Res Pt II 49:219–236. doi:https://doi.org/10.1016/S0967-0645(01)00101-1
Bahl AA, Gnanadesikan A, Pradal MA (2019) Variations in ocean deoxygenation across Earth System Models: Isolating the role of parameterized lateral mixing. Global Biogeochem Cy 33:703–724. doi:https://doi.org/10.1029/2018GB006121
Brennan CE, Matear RJ, Keller K (2008) Measuring oxygen concentrations to improve the detection capabilities of an ocean circulation observation array. J Geophys Res-Oceans 113(C2): C02019. doi:https://doi.org/10.1029/2007JC004113
Burd AB, Hansell DA, Steinberg DK, Anderson TR, Arístegui J, Baltar F, Beaupré SR, Buesseler KO, DeHairs F, Jackson GA, Kadko DC, Koppelmann R, Lampitt RS, Nagata T, Reinthaler T, Robinson C, Robison BH, Tamburini C, Tanaka T (2010) Assessing the apparent imbalance between geochemical and biochemical indicators of meso- and bathypelagic biological activity: What the @$#! is wrong with present calculations of carbon budgets? Deep-Sea Res Pt II 57(16):1557–1571. doi:https://doi.org/10.1016/j.dsr2.2010.02.022
Deutsch C, Emerson S, Thompson L (2005) Fingerprints of climate change in North Pacific oxygen. Geophys Res Lett 32:L16604. doi:https://doi.org/10.1029/2005GL023190
Dunne JP, John JG, Adcroft AJ, Griffies SM, Hallberg RW, Shevliakova E, Stouffer RJ, Cooke W, Dunne KA, Harrison MJ, Krasting JP, Malyshev SL, Milly PCD, Phillipps PJ, Sentman LT, Samuels BL, Spelman MJ, Winton M, Wittenberg AT, Zadeh N (2012) GFDL’s ESM2 global coupled climate-carbon Earth System Models. Part I: Physical formulation and baseline simulation characteristics. J Climate 25(19):6646-6665. doi:https://doi.org/10.1175/JCLID-11-00560.1
Emerson S, Hedges J (2011) Chemical oceanography and the marine carbon cycle. Cambridge University Press, Cambridge, 146 p
Galbraith ED, Gnanadesikan A, Dunne JP, Hiscock MR (2010) Regional impacts of iron-light colimitation in a global biogeochemical model. Biogeosciences 7(3):1043–1064. doi:https://doi.org/10.5194/bg-7-1043-2010
Galbraith ED, Kwon EY, Gnanadesikan A, Rodgers KB, Griffies SM, Bianchi D, Sarmiento JL, Dunne JP, Simeon J, Slater RD, Wittenberg AT, Held IM (2011) Climate variability and radiocarbon in the CM2Mc Earth System Model. J Climate 24(16):4230–4254. doi:https://doi.org/10.1175/2011JCLI3919.1
Galbraith ED, Dunne JP, Gnanadesikan A, Slater RD, Sarmiento JL, Dufour CO, de Souza GF, Bianchi D, Claret M, Rodgers KB, Marvasti SS (2015) Complex functionality with minimal computation: Promise and pitfalls of reduced-tracer ocean biogeochemistry models. J Adv Model Earth Sy 7(4):2012–2028. doi:https://doi.org/10.1002/2015MS000463
Haine TWN, Hall TM (2002) A generalized transport theory: Watermass composition and age. J Phys Oceanogr 32(6):1932–1946. doi:https://doi.org/10.1175/1520-0485
Ito T, Follows MJ, Boyle EA (2004) Is AOU a good measure of respiration in the oceans? Geophys Res Lett 31(17):L17305. doi:https://doi.org/10.1029/2004GL020900
Jenkins WJ (1982) Oxygen utilization rates in North Atlantic subtropical gyre and primaryproduction in oligotrophic systems. Nature 300:246–248
Klaas C, Archer DE (2002) Association of sinking organic matter with various types of mineral ballast in the deep sea: Implications for the rain ratio. Global Biogeochem Cy 16(4):63-1–63-14. doi:https://doi.org/10.1029/2001GB001765
Koeve W, Köhler P (2016) Oxygen utilization rate (our) underestimates ocean respiration: A model study. Global Biogeochem Cy 30(8):1166–1182. doi:https://doi.org/10.1002/2015GB005354
Kwon EY, Deutsch C, Xie S-P, Schmidtko S, Cho Y-K (2016) The North Pacific oxygen uptake rates over the past half century. J Climate 29(1):61–76. doi:https://doi.org/10.1175/JCLI-D-14-00157.1
Maximenko N, Niiler P, Centurioni L, Rio M, Melnichenko O, Chambers D, Zlotnicki V, Galperin B (2009) Mean dynamic topography of the ocean derived from satellite and drifting buoy data using three different techniques. J Atmos Ocean Tech 26:1910–1919. doi:https://doi.org/10.1175/2009JTECHO672.1
Millard RC, Yang K (1993) CTD calibration and processing methods used at Woods Hole Oceanographic Institution. Woods Hole Oceanographic Institution, WHOI-93-44, 101 p
Sarmiento JL, Gruber N (2006) Ocean biogeochemical dynamics. Princeton University Press, Princeton, 528 p
Shao AE, Mecking S, Thompson L, Sonnerup RE (2016) Evaluating the use of 1-d transit time distributions to infer the mean state and variability of oceanic ventilation. J Geophys Res-Oceans 121(9):6650–6670. doi:https://doi.org/10.1002/2016JC011900
Stanley RH, Doney SC, Jenkins WJ, Lott DE (2012) Apparent oxygen utilization rates calculated from tritium and helium-3 profiles at the Bermuda Atlantic time-series study site. Biogeosciences 9:1969–1983. doi:https://doi.org/10.5194/bg-9-1969-2012
Thiele G, Sarmiento JL (1990) Tracer dating and ocean ventilation. J Geophys Res-Oceans 95(C6):9377–9391. doi:https://doi.org/10.1029/JC095iC06p09377
Wanninkhof R (1992) Relationship between wind speed and gas exchange over the ocean. J Geophys Res-Oceans 97(C5):7373–7382
Waugh DW, Haine TW, Hall TM (2004) Transport times and anthropogenic carbon in the subpolar North Atlantic ocean. Deep-Sea Res Pt I 51(11):1475–1491. doi:https://doi.org/10.1016/j.dsr.2004.06.011
Waugh DW, Hall TM, Mcneil BI, Key R, Matear RJ (2006) Anthropogenic CO2 in the oceans estimated using transit time distributions. Tellus B 58(5):376–389. doi:https://doi.org/10.1111/j.1600-0889.2006.00222.x
Acknowledgments
This work was supported by the National Science Foundation under NSF proposal FESD-1338814 and the National Oceanic and Atmospheric Administration under grant NA16OAR4310174. Line W repeat hydrography data can be found at the Woods Hole Oceanographic Institute website (http://www.whoi.edu/science/PO/linew/download_data.php). The model output will be archived using the Johns Hopkins dataverse archive (https://archive.data.jhu.edu/).
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher’s Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Thomas, J.L., Waugh, D.W. & Gnanadesikan, A. Relationship between Age and Oxygen along Line W in the Northwest Atlantic Ocean. Ocean Sci. J. 55, 203–217 (2020). https://doi.org/10.1007/s12601-020-0019-5
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12601-020-0019-5