Net and gross oxygen production from O2/Ar, 17O/16O and 18O/16O ratios

Luz, Boaz; Barkan, Eugeni

doi:10.3354/ame01296

Cited by 85 publications

(159 citation statements)

References 36 publications

Supporting

Mentioning

151

Contrasting

Order By: Relevance

“…One of the studies in the 8 to 9 ppm-cluster found an 18 δ sat value that is about 0.06 ‰ lower than the parameterisation (Reuer et al, 2007); the other study in the same cluster did not report 18 δ sat (Stanley et al, 2010). Interestingly, the 17 sat value derived from Reuer et al (2007) for 11 • C (row 4a) is close to that of Luz and Barkan (2009) for 12 • C (row 5b), even though the same two studies disagree near room temperature (rows 4b and 5c).…”

Section: Gas Exchangementioning

confidence: 91%

“…If s were greater than 2 %, this would lead to an enhancement of the 18 δ sat value by more than 0.07 ‰, which cannot be reconciled with the published data. Luz and Barkan (2009) have also reported a temperature dependence of the 17 O excess at saturation, i.e. 17 # sat (λ = 0.518)/ppm = 0.6 ϑ/ • C + 1.8.…”

Section: Gas Exchangementioning

confidence: 99%

“…Compare this with the approximation given by Luz and Barkan (2009) in their Eq. (5) (re-written for a single depth and corrected for two errors in the numerator -the index of their second term should be "in" -here replaced by index "0" -and the third term should be subtracted rather than added):…”

Section: Production Below the Mixed Layermentioning

confidence: 99%

“…28). By measuring temporal changes in the isotope composition of dissolved O 2 , it is possible to determine gross production (Luz and Barkan, 2009 …”

Section: Production Below the Mixed Layermentioning

confidence: 99%

“…They will be used to estimate the systematic uncertainty in g. I focus on parameters appropriate for the marine mixed layer because this is where the oxygen triple isotope technique has found the widest application. However, with appropriate adjustments of the parameters, the same technique can also be used for freshwater environments (Luz and Barkan, 2009). …”

Section: Input Parametersmentioning

confidence: 99%

See 4 more Smart Citations

Technical note: Consistent calculation of aquatic gross production from oxygen triple isotope measurements

Kaiser

2011

Biogeosciences

144

View full text Add to dashboard Cite

Abstract. Oxygen triple isotope measurements can be used to calculate aquatic gross oxygen production rates. Past studies have emphasised the appropriate definition of the 17 O excess and often used an approximation to derive production rates from the 17 O excess. Here, I show that the calculation can be phrased more consistently and without any approximations using the relative 17 O/ 16 O and 18 O/ 16 O isotope ratio differences (delta values) directly. I call this the "dual delta method". The 17 O excess is merely a mathematical construct and the derived production rate is independent of its definition, provided all calculations are performed with a consistent definition. I focus on the mixed layer, but also show how time series of triple isotope measurements below the mixed layer can be used to derive gross production.In the calculation of mixed layer productivity, I explicitly include isotopic fractionation during gas invasion and evasion, which requires the oxygen supersaturation s to be measured as well. I also suggest how bubble injection could be considered in the same mathematical framework. I distinguish between concentration steady state and isotopic steady state and show that only the latter needs to be assumed in the calculation. It is even possible to derive an estimate of the net production rate in the mixed layer that is independent of the assumption of concentration steady state.I review measurements of the parameters required for the calculation of gross production rates and show how their systematic uncertainties as well as the use of different published calculation methods can cause large variations in the production rates for the same underlying isotope ratios. In particular, the 17 O excess of dissolved O 2 in equilibrium with atmospheric O 2 and the 17 O excess of photosynthetic O 2 need to be re-measured. Because of these uncertainties, all calculaCorrespondence to: J. Kaiser (j.kaiser@uea.ac.uk) tion parameters should always be fully documented and the measured relative isotope ratio differences as well as the oxygen supersaturation should be permanently archived, so that improved measurements of the calculation parameters can be used to retrospectively improve production rates.

show abstract

Section: Gas Exchangementioning

confidence: 91%

Section: Gas Exchangementioning

confidence: 99%

Section: Production Below the Mixed Layermentioning

confidence: 99%

“…28). By measuring temporal changes in the isotope composition of dissolved O 2 , it is possible to determine gross production (Luz and Barkan, 2009 …”

Section: Production Below the Mixed Layermentioning

confidence: 99%

Section: Input Parametersmentioning

confidence: 99%

See 3 more Smart Citations

Technical note: Consistent calculation of aquatic gross production from oxygen triple isotope measurements

Kaiser

2011

Biogeosciences

144

View full text Add to dashboard Cite

show abstract

The triple oxygen isotope tracer of primary productivity in a dynamic ocean model

Nicholson

Stanley

Doney

2014

Global Biogeochemical Cycles

View full text Add to dashboard Cite

The triple oxygen isotopic composition of dissolved oxygen ( 17 Δ dis ) was added to the ocean ecosystem and biogeochemistry component of the Community Earth System Model, version 1.1.1. Model simulations were used to investigate the biological and physical dynamics of 17 Δ dis and assess its application as a tracer of gross photosynthetic production (gross oxygen production (GOP)) of O 2 in the ocean mixed layer. The model reproduced large-scale patterns of 17 Δ dis found in observational data across diverse biogeographical provinces. Mixed layer model performance was best in the Pacific and had a negative bias in the North Atlantic and a positive bias in the Southern Ocean. Based on model results, the steady state equation commonly used to calculate GOP from tracer values overestimated the globally averaged model GOP by 29%. Vertical entrainment/mixing and the time rate of change of 17 Δ dis were the two largest sources of bias when applying the steady state method to calculate GOP. Entrainment/mixing resulted in the largest overestimation in midlatitudes and during summer and fall and almost never caused an underestimation of GOP. The tracer time rate of change bias resulted both in underestimation of GOP (e.g., during spring blooms at high latitudes) and overestimation (e.g., during the summer following a bloom). Seasonally, bias was highest in the fall (September-October-November in the Northern Hemisphere, March-April-May in the Southern), overestimating GOP by 62%, globally averaged. Overall, the steady state method was most accurate in equatorial and low-latitude regions where it estimated GOP to within ±10%. Field applicable correction terms are derived for entrainment and mixing that capture 86% of model vertical bias and require only mixed layer depth history and triple oxygen isotope measurements from two depths.

show abstract

Net community production in the North Atlantic Ocean derived from Volunteer Observing Ship data

Ostle

Johnson

Landschützer

et al. 2015

Global Biogeochemical Cycles

View full text Add to dashboard Cite

The magnitude of marine plankton net community production (NCP) is indicative of both the biologically driven exchange of carbon dioxide between the atmosphere and the surface ocean and the export of organic carbon from the surface ocean to the ocean interior. In this study the seasonal variability in the NCP of five biogeochemical regions in the North Atlantic was determined from measurements of surface water dissolved oxygen and dissolved inorganic carbon (DIC) sampled from a Volunteer Observing Ship (VOS). The magnitude of NCP derived from dissolved oxygen measurements (NCP O 2 ) was consistent with previous geochemical estimates of NCP in the North Atlantic, with an average annual NCP O 2 of 9.5 ± 6.5 mmol O 2 m −2 d −1 . Annual NCP O 2 did not vary significantly over 35• of latitude and was not significantly different from NCP derived from DIC measurements (NCP DIC ). The relatively simple method described here is applicable to any VOS route on which surface water dissolved oxygen concentrations can be accurately measured, thus providing estimates of NCP at higher spatial and temporal resolution than currently achieved.

show abstract

Net and gross oxygen production from O2/Ar, 17O/16O and 18O/16O ratios

Cited by 85 publications

References 36 publications

Technical note: Consistent calculation of aquatic gross production from oxygen triple isotope measurements

Technical note: Consistent calculation of aquatic gross production from oxygen triple isotope measurements

The triple oxygen isotope tracer of primary productivity in a dynamic ocean model

Net community production in the North Atlantic Ocean derived from Volunteer Observing Ship data

Contact Info

Product

Resources

About