Anthropogenic CO<sub>2</sub> in the Southern Ocean: Distribution and inventory at the Indian‐Atlantic boundary (World Ocean Circulation Experiment line I6)

Monaco, Claire Lo

doi:10.1029/2004jc002643

Cited by 66 publications

(97 citation statements)

References 80 publications

(191 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Such practice has misleadingly prone researchers in the past to consider C ant -void waters where there were actually low concentrations of this tracer, above determination uncertainties (Orsi et al, 2002;Lo Monaco et al, 2005;Waugh et al, 2006;Vázquez-Rodríguez et al, 2009). In sum, setting inappropriate C ant =0 references in the C* method for old water masses yields less negative ΔC dis estimates that introduce positive systematic biases in (Coatanoan et al, 2001).…”

Section: Accepted M Manuscriptmentioning

confidence: 99%

“…16 therefore lower uptake of dissolved CO 2 and O 2 production, which leaves signs of apparent aging in tracer data that are accounted for in and SSL DC dis t but not in and; b) the ice cap hindrance of air-sea gas exchanges in the Southern Ocean constraints the oceanic uptake of O 2 from the atmosphere by the old, C T rich and oxygen undersaturated upwelled NADW (Lo Monaco et al, 2005). Concurrently, the ice sheets encumber CO 2 outgasing in this region that has been catalogued as a CO 2 source to the atmosphere ( >0; Takahashi et al, 2009).…”

Section: Accepted M Manuscriptmentioning

confidence: 99%

See 1 more Smart Citation

The subsurface layer reference to calculate preformed alkalinity and air–sea CO2 disequilibrium in the Atlantic Ocean

Vázquez-Rodríguez

Pad́ın

Pardo

et al. 2012

Journal of Marine Systems

View full text Add to dashboard Cite

The subsurface ocean layer (100-200 m deep) is suggested as a reference to parameterize preformed alkalinity (A T º) and air-sea CO 2 disequilibrium (C dis ) in the Atlantic. Results suggest that this domain retains the memory of water mass formation (WMF) conditions over annual periods and avoids the large, short-term variability of the uppermost layers. Its thermohaline variability also encompasses and represents all water masses that outcrop in the Atlantic. Subsurface data also avoids the scarcity of late wintertime surface observations and benefit from the larger availability of yearround measurements, thus enhancing their representativeness and application coverage.This last feature is most relevant in high Atlantic latitudes, where WMF typically occurs and the widespread ice sheets often preclude surface pCO 2 sampling during wintertime.The obtained A T º and C dis parameterizations achieve uncertainties of 4.6 and 5.6 mol kg -1 , respectively, improving significantly the estimates in previous works, particularly in the high latitudes. The A T º parameterization is well correlated with observations and is coherent with the latitudinal subsurface distribution of silicate, particularly in the northern subpolar region, where previous studies showed discrepancies. The C dis estimates in the upper layers are coherent with air-sea ∆pCO 2 data from Takahashi´s climatology, thus tackling known important shortcomings and biases of anthropogenic CO 2 estimates in Atlantic waters.

show abstract

Section: Accepted M Manuscriptmentioning

confidence: 99%

Section: Accepted M Manuscriptmentioning

confidence: 99%

The subsurface layer reference to calculate preformed alkalinity and air–sea CO2 disequilibrium in the Atlantic Ocean

Vázquez-Rodríguez

Pad́ın

Pardo

et al. 2012

Journal of Marine Systems

View full text Add to dashboard Cite

show abstract

“…Away from the surface, respiration will change individual oxygen/phosphate concentrations but not 'PO' through use of a standard remineralization ratio, thus making it a useful sub-surface tracer of water types of different surface origin. In this case, the remineralization ratio is from [57], having previously been applied in the Weddell Gyre [58][59][60][61][62]. Surface ocean oxygen saturation can fluctuate as biological activity, upwelling and sea-ice coverage impact air-sea gas exchange and oxygen's ability to reach equilibrium with the atmosphere [63][64][65].…”

Section: (D) Determination Of Freshwater Sourcesmentioning

confidence: 99%

Freshwater fluxes in the Weddell Gyre: results from δ ¹⁸ O

Brown

Meredith

Jullion

et al. 2014

Phil. Trans. R. Soc. A.

View full text Add to dashboard Cite

Full-depth measurements of δ 18 O from 2008 to 2010 enclosing the Weddell Gyre in the Southern Ocean are used to investigate the regional freshwater budget. Using complementary salinity, nutrients and oxygen data, a four-component mass balance was applied to quantify the relative contributions of meteoric water (precipitation/glacial input), sea-ice melt and saline (oceanic) sources. Combination of freshwater fractions with velocity fields derived from a box inverse analysis enabled the estimation of gyre-scale budgets of both freshwater types, with deep water exports found to dominate the budget. Surface net sea-ice melt and meteoric contributions reach 1.8% and 3.2%, respectively, influenced by the summer sampling period, and −1.7% and +1.7% at depth, indicative of a dominance of sea-ice production over melt and a sizable contribution of shelf waters to deep water mass formation. A net meteoric water export of approximately 37 mSv is determined, commensurate with local estimates of ice sheet outflow and precipitation, and the Weddell Gyre is estimated to be a region of net sea-ice production. These results constitute the first synoptic benchmarking of sea-ice and meteoric exports from the Weddell Gyre, against which future change associated with an accelerating hydrological cycle, ocean climate change and evolving Antarctic glacial mass balance can be determined.

show abstract

“…The C • IPSL method (Lo Monaco et al, 2005b) is based on the original C • method described by Brewer (1978) and Chen and Millero (1979), and was further updated by Körtzinger et al (1998). This scheme allows for air-sea oxygen disequilibrium in the surface ocean; it uses different relationships of A • T and DIC • for southern and northern Atlantic waters based on observations collected in their source regions (Körtzinger et al, 1998), and a mixing model based on optimum multi-parameter (OMP) analysis to constrain their relative contributions.…”

Section: S Khatiwala Et Al: Ocean Anthropogenic Carbon 2171mentioning

confidence: 99%

Global ocean storage of anthropogenic carbon

et al. 2013

View full text Add to dashboard Cite

The global ocean is a significant sink for anthropogenic carbon (C_ant), absorbing roughly a third of human CO₂ emitted over the industrial period. Robust estimates of the magnitude and variability of the storage and distribution of C_ant in the ocean are therefore important for understanding the human impact on climate. In this synthesis we review observational and model-based estimates of the storage and transport of C_ant in the ocean. We pay particular attention to the uncertainties and potential biases inherent in different inference schemes. On a global scale, three data-based estimates of the distribution and inventory of C_ant are now available. While the inventories are found to agree within their uncertainty, there are considerable differences in the spatial distribution. We also present a review of the progress made in the application of inverse and data assimilation techniques which combine ocean interior estimates of C_ant with numerical ocean circulation models. Such methods are especially useful for estimating the air–sea flux and interior transport of C_ant, quantities that are otherwise difficult to observe directly. However, the results are found to be highly dependent on modeled circulation, with the spread due to different ocean models at least as large as that from the different observational methods used to estimate C_ant. Our review also highlights the importance of repeat measurements of hydrographic and biogeochemical parameters to estimate the storage of C_ant on decadal timescales in the presence of the variability in circulation that is neglected by other approaches. Data-based C_ant estimates provide important constraints on forward ocean models, which exhibit both broad similarities and regional errors relative to the observational fields. A compilation of inventories of C_ant gives us a "best" estimate of the global ocean inventory of anthropogenic carbon in 2010 of 155 ± 31 PgC (±20% uncertainty). This estimate includes a broad range of values, suggesting that a combination of approaches is necessary in order to achieve a robust quantification of the ocean sink of anthropogenic CO₂

show abstract

Anthropogenic CO₂ in the Southern Ocean: Distribution and inventory at the Indian‐Atlantic boundary (World Ocean Circulation Experiment line I6)

Cited by 66 publications

References 80 publications

The subsurface layer reference to calculate preformed alkalinity and air–sea CO2 disequilibrium in the Atlantic Ocean

The subsurface layer reference to calculate preformed alkalinity and air–sea CO2 disequilibrium in the Atlantic Ocean

Freshwater fluxes in the Weddell Gyre: results from δ ¹⁸ O

Global ocean storage of anthropogenic carbon

Contact Info

Product

Resources

About

Anthropogenic CO2 in the Southern Ocean: Distribution and inventory at the Indian‐Atlantic boundary (World Ocean Circulation Experiment line I6)

Cited by 66 publications

References 80 publications

The subsurface layer reference to calculate preformed alkalinity and air–sea CO2 disequilibrium in the Atlantic Ocean

The subsurface layer reference to calculate preformed alkalinity and air–sea CO2 disequilibrium in the Atlantic Ocean

Freshwater fluxes in the Weddell Gyre: results from δ 18 O

Global ocean storage of anthropogenic carbon

Contact Info

Product

Resources

About

Anthropogenic CO₂ in the Southern Ocean: Distribution and inventory at the Indian‐Atlantic boundary (World Ocean Circulation Experiment line I6)

Freshwater fluxes in the Weddell Gyre: results from δ ¹⁸ O