18 páginas, 8 figuras, 1 tabla, We discuss the distributions and transports of the main water masses in the North Atlantic Subpolar Gyre (NASPG) for the mean of the period 2002–2010 (OVIDE sections 2002–2010 every other year), as well as the inter-annual variability of the water mass structure from 1997 (4x and METEOR sections) to 2010. The water mass structure of the NASPG, quantitatively assessed by means of an Optimum MultiParameter analysis (with 14 water masses), was combined with the velocity fields resulting from previous studies using inverse models to obtain the water mass volume transports. We also evaluate the relative contribution to the Atlantic Meridional Overturning Circulation (AMOC) of the main water masses characterizing the NASPG, identifying the water masses that contribute to the AMOC variability. The reduction of the magnitude of the upper limb of the AMOC between 1997 and the 2000s is associated with the reduction in the northward transport of the Central Waters. This reduction of the northward flow of the AMOC is partially compensated by the reduction of the southward flow of the lower limb of the AMOC, associated with the decrease in the transports of Polar Intermediate Water and Subpolar Mode Water (SPMW) in the Irminger Basin. We also decompose the flow over the Reykjanes Ridge from the East North Atlantic Basin to the Irminger Basin (9.4 ± 4.7 Sv) into the contributions of the Central Waters (2.1 ± 1.8 Sv), Labrador Sea Water (LSW, 2.4 ± 2.0 Sv), Subarctic Intermediate Water (SAIW, 4.0 ± 0.5 Sv) and Iceland–Scotland Overflow Water (ISOW, 0.9 ± 0.9 Sv). Once LSW and ISOW cross over the Reykjanes Ridge, favoured by the strong mixing around it, they leave the Irminger Basin through the deep-to-bottom levels. The results also give insights into the water mass transformations within the NASPG, such as the contribution of the Central Waters and SAIW to the formation of the different varieties of SPMW due to air–sea interaction, The research leading to these results was supported through the EU FP7 project CARBOCHANGE, which received funding from the European Commission’s Seventh Framework Programme under grant agreement no. 264879. For this work M.I. García-Ibáñez was supported by the Spanish Ministry of Economy and Competitiveness (BES-2011-045614) through the CATARINA (CTM2010-17141) and BOCATS projects (CTM2013-41048-P) supported by the Spanish Government and co-funded by the Fondo Europeo de Desarrollo Regional 2007–2012 (FEDER); and this article is going to be part of her PhD that is attached to the framework of the doctoral program “Marine Science, Technology and Management” (DO*MAR) of the University of Vigo. P.C. Pardo, L.I. Carracedo, A.F. Rios and F.F. Pérez were supported by the Spanish National Research Council (CSIC); H. Mercier by the French National Centre for Scientific Research (CNRS); and P. Lherminier by the French Institute for Marine Science (Ifremer), Peer reviewed

17 páginas, 8 figuras, 5 tablas, The meridional transport of anthropogenic CO2 (Cant) in the tropical North Atlantic (TNA) is investigated using data from transoceanic sections along 7.5°N and 24.5°N, carried out in the early 1990s and 2010s. The net Cant transport across both sections is northward. At 7.5°N, this transport increased from 315 ± 47 kmol s−1 in 1993 to 493 ± 51 kmol s−1 in 2010; similarly, across 24.5°N it grew from 530 ± 46 kmol s−1 in 1992 to 662 ± 49 kmol s−1 in 2011. These changes result from modifications in the intermediate and deep circulation patterns, as well as from Cant increase within the thermocline waters. In deep waters, lateral advection causes a net Cant input of 112 ± 60 kmol s−1 (234 ± 65 kmol s−1) in 1992–1993 (2010–2011); within these deep waters, the storage rate of Cant is not statistically different from the net Cant input, 139 ± 21 kmol s−1 (188 ± 21 kmol s−1) in 1992–1993 (2010–2011). The Cant increase in deep waters is due to the large injection of Cant across the 24.5°N by the Deep Western Boundary Current and the northward recirculation of North Atlantic Deep Water along 7.5°N. In contrast, a large net Cant output in the upper layer is caused by the Florida Current. Despite this net Cant output, the Cant accumulates at a rate of 215 ± 24 kmol s−1 (291 ± 24 kmol s−1) referenced to year 1993 (2010). From the two Cant budgets, we infer a Cant air-sea flux of 0.23 ± 0.02 Pg yr−1in the TNA, much larger than previous estimates, The first author received a grant from the Tricontinental Atlantic Campus spending a 6 month period at the Universidad de Las Palmas de Gran Canaria where this study was carried out. This work has been performed under the projects MOC2 (CTM2008- 06438), Malaspina (CSD2008-00077), BOCATS (CTM2013-41048-P), and TIC-MOC (CTM2011-28867) supported by the Spanish Government and cofounded by the European Regional Development Fund (FEDER), Peer reviewed

9 páginas, 1 tabla, 2 figuras.-- Proyecto Carbochange.-- The OVIDE data analyzed in this study are available at the CLIVAR and Carbon Hydrographic Data Office (http://cchdo.ucsd.edu/search?q=Ovide) and at the Carbon Dioxide Information Analysis Center (http://cdiac.ornl.gov/oceans/RepeatSections/clivar_ovide.html). The climatology of Takahashi et al. was downloaded from http://www.ldeo.columbia.edu/res/pi/CO2/carbondioxide/pages/air_sea_flux_2000.html, The subpolar North Atlantic (SPNA) is important in the global carbon cycle because of the deep water ventilation processes that lead to both high uptake of atmospheric CO2 and large inventories of anthropogenic CO2 (Cant). Thus, it is crucial to understand its response to increasing anthropogenic pressures. In this work, the budgets of dissolved inorganic carbon (DIC), Cant and natural DIC (DICnat) in the eastern SPNA in the 2000s, are jointly analyzed using in situ data. The DICnat budget is found to be in steady state, confirming a long-standing hypothesis from in situ data for the first time. The biological activity is driving the uptake of natural CO2 from the atmosphere. The Cant increase in the ocean is solely responsible of the DIC storage rate which is explained by advection of Cant from the subtropics (65%) and Cant air-sea flux (35%). These results demonstrate that the Cant is accumulating in the SPNA without affecting the natural carbon cycle, This work is a contribution to the EU FP7 CARBOCHANGE project (264879) and the ANR GEOVIDE project (http://www.agence-nationale-recherche.fr/?Project=ANR-13-BS06-0014). For this work P. Zunino was funded by CARBOCHANGE and GEOVIDE projects as well as by IFREMER. The Tricontinental Atlantic Campus funded a 6 months contract for the first author at the Universidad de Las Palmas de Gran Canaria where part of this paper was written. P. Lherminier was supported by IFREMER, H. Mercier by the CNRS and the ATLANTOS GA 633211 H2020 project, and A. Padin by the Consejo Superior de Investigaciones Científicas (CSIC). A.F. Ríos and F.F. Pérez were supported by BOCATS (CTM2013-41048-P) project cofounded by the Spanish Government and the Fondo Europeo de Desarrollo Regional (FEDER), Peer reviewed

7 páginas, 1 tabla, 4 figuras, This study constituted the first attempt to measure dissolved calcium ([Ca2 +]meas) in the subtropical North Atlantic, during a zonal transoceanic cruise along 24.5°N (WOCE A05 section), in summer 1992. [Ca2 +]meas was obtained in 20 full-depth equidistant stations along the section, showing that their gradients are rather sensitive to horizontal and vertical water mass distribution. Deep waters along 24.5°N systematically show a positive calcium excess of 20 ± 14 μmol·kg− 1, i.e., more [Ca2 +] than expected by CaCO3 dissolution and organic matter oxidation (estimated by total alkalinity and nitrate). CaCO3 settling and benthic dissolution accounts for 70% and the North Atlantic plus Arctic riverine inputs of HCO3− for the remaining 30%. Combining [Ca2 +]meas and CO2 data sets, carbonate mineral saturation states distributions for aragonite and calcite can be obtained. The two solubility ratios resulted, on average, 0.5% smaller than if conservative behavior for Ca2 + was assumed (an approach widely followed when [Ca2 +]meas is unknown). As a result, shallower saturation horizon depths for both carbonate states (19 dbar for aragonite and 10 dbar for calcite) are yielded if [Ca2 +]meas is taken into account instead than estimated from salinity, This work has been performed under the project BOCATS (CTM2013-41048-P) supported by the Spanish Government and co-founded by the European Regional Development Fund (FEDER), Peer reviewed

9 páginas, 4 figuras, 1 tabla.-- This work is licensed under a Creative Commons Attribution 4.0 International License, The quantitative role of the Atlantic Meridional Overturning Circulation (AMOC) in dissolved organic carbon (DOC) export is evaluated by combining DOC measurements with observed water mass transports. In the eastern subpolar North Atlantic, both upper and lower limbs of the AMOC transport high-DOC waters. Deep water formation that connects the two limbs of the AMOC results in a high downward export of non-refractory DOC (197 Tg-C·yr−1). Subsequent remineralization in the lower limb of the AMOC, between subpolar and subtropical latitudes, consumes 72% of the DOC exported by the whole Atlantic Ocean. The contribution of DOC to the carbon sequestration in the North Atlantic Ocean (62 Tg-C·yr−1) is considerable and represents almost a third of the atmospheric CO2 uptake in the region, For this work M. Fontela was funded by the Spanish Ministry of Economy and Competitiveness (BES-2014-070449) through the BOCATS project (CTM2013-41048-P) supported by the Spanish Government and co-funded by the Fondo Europeo de Desarrollo Regional 2007–2012 (FEDER); and this article is going to be part of her PhD that is attached to the framework of the doctoral program “Marine Science, Technology and Management” (DO*MAR) of the University of Vigo. M.I. García-Ibáñez and F.F. Pérez were supported by the BOCATS project (CTM2013-41048-P) co-funded by the Spanish Government and the Fondo Europeo de Desarrollo Regional (FEDER). D.A. Hansell was supported by US National Science Foundation award OCE-1436748. H. Mercier was supported by the CNRS and the ATLANTOS project (GA 633211), Peer reviewed

15 páginas, 3 tablas, 6 figuras.-- Proyecto Carbochange.-- This work is distributed
under the Creative Commons Attribution 3.0 License, Repeated hydrographic sections provide critically needed data on and understanding of changes in basin-wide ocean CO2 chemistry over multi-decadal timescales. Here, high-quality measurements collected at twelve cruises carried out along the same track between 1991 and 2015 have been used to determine long-term changes in ocean CO2 chemistry and ocean acidification in the Irminger and Iceland basins of the North Atlantic Ocean. Trends were determined for each of the main water masses present and are discussed in the context of the basin-wide circulation. The pH has decreased in all water masses of the Irminger and Iceland basins over the past 25 years with the greatest changes in surface and intermediate waters (between −0.0010 ± 0.0001 and −0.0018 ± 0.0001 pH units yr−1). In order to disentangle the drivers of the pH changes, we decomposed the trends into their principal drivers: changes in temperature, salinity, total alkalinity (AT) and total dissolved inorganic carbon (both its natural and anthropogenic components). The increase in anthropogenic CO2 (Cant) was identified as the main agent of the pH decline, partially offset by AT increases. The acidification of intermediate waters caused by Cant uptake has been reinforced by the aging of the water masses over the period of our analysis. The pH decrease of the deep overflow waters in the Irminger basin was similar to that observed in the upper ocean and was mainly linked to the Cant increase, thus reflecting the recent contact of these deep waters with the atmosphere, The research leading to these results was supported
through the EU FP7 project CARBOCHANGE “Changes
in carbon uptake and emissions by oceans in a changing climate”,
which received funding from the European Commission’s Seventh
Framework Programme under grant agreement no. 264879. For this
work M. I. Garcia-Ibáñez, A. F. Rios and F. F. Pérez were supported
by the Spanish Ministry of Economy and Competitiveness through
the BOCATS (CTM2013-41048-P) project co-funded by the Fondo
Europeo de Desarrollo Regional 2007–2012 (FEDER). P. Zunino
was supported by the GEOVIDE project as well as by IFREMER.
L. I. Carracedo was funded by the University of Vigo, through
the Galician I2C Plan for postdoctoral research. H. Mercier was
supported by the French National Centre for Scientific Research
(CNRS). F. Fröb and A. Olsen were supported by a grant from the
Norwegian Research Council (SNACS, project 229756/E10), Peer reviewed

15 páginas, 4 tablas, 8 figuras, The variability of the turbulent kinetic energy dissipation due to internal waves is quantified using a finescale parameterization applied to the A25 Greenland–Portugal transect repeated every two years from 2002 to 2012. The internal wave velocity shear and strain are estimated for each cruise at 91 stations from full depth vertical profiles of density and velocity. The 2002–12 averaged dissipation rate 〈ε2002–2012〉 in the upper ocean lays in the range 1–10 × 10−10 W kg−1. At depth, 〈ε2002–2012〉 is smaller than 1 × 10−10 W kg−1 except over rough topography found at the continental slopes, the Reykjanes Ridge, and in a region delimited by the Azores–Biscay Rise and Eriador Seamount. There, the vertical energy flux of internal waves is preferentially oriented toward the surface and 〈ε2002–2012〉 is in the range 1–20 × 10−10 W kg−1. The interannual variability in the dissipation rates is remarkably small over the whole transect. A few strong dissipation rate events exceeding the uncertainty of the finescale parameterization occur at depth between the Azores–Biscay Rise and Eriador Seamount. This region is also marked by mesoscale eddying flows resulting in enhanced surface energy level and enhanced bottom velocities. Estimates of the vertical energy fluxes into the internal tide and into topographic internal waves suggest that the latter are responsible for the strong dissipation events. At Eriador Seamount, both topographic internal waves and the internal tide contribute with the same order of magnitude to the dissipation rate while around the Reykjanes Ridge the internal tide provides the bulk of the dissipation rate, The OVIDE
project was supported by IFREMER, CNRS/INSU
and the National Program LEFE. B. Ferron, H. Mercier,
and T. Huck were supported by the French National
Center for Scientific Research (CNRS), P.
Lherminier and V. Thierry by the French Institute for
Marine Science (Ifremer), and F. Kokoszka by the
European University of Brittany. Aida F. Ríos was
funded by the Spanish Ministry of Economy and Competitiveness
(BES-2014-070449) through the BOCATS
project (CTM2013-41048-P). The CATARINA cruise
was supported the Spanish Ministry of Sciences and Innovation
cofunded by the Fondo Europeo de Desarrollo
Regional 2007-2012 (FEDER) through the CATARINA
project (CTM2010-17141), Peer reviewed

17 páginas, 9 figuras, 3 tablas.-- Nathalie Daniault ... et al.-- Proyecto Carbochange, The decadal mean circulation in the northern North Atlantic was assessed for the early 21st century from repeated ship-based measurements along the Greenland-Portugal OVIDE line, from satellite altimetry and from earlier reported transports across 59.5°N and at the Greenland-Scotland sills. The remarkable quantitative agreement between all data sets allowed us to draw circulation pathways with a high level of confidence. The North Atlantic Current (NAC) system is composed of three main branches, referred to as the northern, central and southern branches, which were traced from the Mid-Atlantic Ridge (MAR), to the Irminger Sea, the Greenland-Scotland Ridge and the subtropical gyre. At OVIDE, the northern and central branches of the NAC fill the whole water column and their top-to-bottom integrated transports were estimated at 11.0 ± 3 Sv and 14.2 ± 6.4 Sv (1 Sv = 106 m3 s−1), respectively. Those two branches feed the cyclonic circulation in the Iceland Basin and the flow over the Reykjanes Ridge into the Irminger Sea. This cross-ridge flow was estimated at 11.3 ± 4.2 Sv westward, north of 58.5°N. The southern NAC branch is strongly surface-intensified and most of its top-to-bottom integrated transport, estimated at 16.6 ± 2 Sv, is found in the upper layer. It is composed of two parts: the northern part contributes to the flow over the Rockall Plateau and through the Rockall Trough toward the Iceland-Scotland Ridge; the southern part feeds the anticyclonic circulation toward the subtropical gyre. Summing over the three NAC branches, the top-to-bottom transport of the NAC across OVIDE was estimated at 41.8 ± 3.7 Sv. Because of the surface-intensification of the southern NAC branch, the intermediate water is transported to the northeast Atlantic mostly by the northern and central branches of the NAC (11.9 ± 1.8 Sv eastward). This water circulates cyclonically in the Iceland Basin and anticyclonically in the West European Basin, with similar transport intensities. In the deep layer of the Iceland Basin, Iceland-Scotland Overflow Water (ISOW) spreads southwestward along three pathways on the eastern flank of the Reykjanes Ridge. The associated transport was estimated at 3.2 ± 0.4 Sv. The two shallowest pathways turn around the Reykjanes Ridge toward the Irminger Sea where they head northward. A northeastward transport of deep water is observed in the deep extension of the northern and central branches of the NAC, east of the MAR. In the Irminger Sea our transport estimates for the Irminger Current, Irminger Gyre, East Greenland Irminger Current and Deep Western Boundary Current are in line with previous work, This research was supported by CNRS, by IFREMER, the French
national program LEFE coordinated by INSU, the EU FP7 project
CARBOCHANGE ‘‘Changes in carbon uptake and emissions by
oceans in a changing climate”, which received funding from the
European Commission Seventh Framework Programme under
grant agreement no. 264879. This research is a contribution to
the OVIDE project, OSNAP and CLIVAR. It benefited of support from
the French research infrastructure TGIR flotte (RV Thalassa). Herlé
156
N. Daniault et al./Progress in Oceanography 146 (2016) 142–158
Mercier was supported by CNRS. Artem Sarafanov and Anastasia
Falina were supported by the RSF Grant 14-50-00095 and the RFBR
Grants 15-05-03782, 15-05-02250. A.F. Rios and F.F. Pérez were
supported by the Consejo Superior de Investigaciones Científicas
(CSIC) and the Spanish Ministry of Economy and Competitiveness
(BES-2011-045614) through the CATARINA project (CTM2010-
17141) and BOCATS (CTM2013-41048-P) projects both cofunded
by the Fondo Europeo de Desarrollo Regional (FEDER)., Peer reviewed

27 páginas, 11 tablas, 9 figuras.-- Are Olsen ... et al.-- This work is distributed
under the Creative Commons Attribution 3.0 License.-- Proyecto Carbochange, Version 2 of the Global Ocean Data Analysis Project (GLODAPv2) data product is composed of data from 724 scientific cruises covering the global ocean. It includes data assembled during the previous efforts GLODAPv1.1 (Global Ocean Data Analysis Project version 1.1) in 2004, CARINA (CARbon IN the Atlantic) in 2009/2010, and PACIFICA (PACIFic ocean Interior CArbon) in 2013, as well as data from an additional 168 cruises. Data for 12 core variables (salinity, oxygen, nitrate, silicate, phosphate, dissolved inorganic carbon, total alkalinity, pH, CFC-11, CFC-12, CFC-113, and CCl4) have been subjected to extensive quality control, including systematic evaluation of bias. The data are available in two formats: (i) as submitted but updated to WOCE exchange format and (ii) as a merged and internally consistent data product. In the latter, adjustments have been applied to remove significant biases, respecting occurrences of any known or likely time trends or variations. Adjustments applied by previous efforts were re-evaluated. Hence, GLODAPv2 is not a simple merging of previous products with some new data added but a unique, internally consistent data product. This compiled and adjusted data product is believed to be consistent to better than 0.005 in salinity, 1 % in oxygen, 2 % in nitrate, 2 % in silicate, 2 % in phosphate, 4 µmol kg−1 in dissolved inorganic carbon, 6 µmol kg−1 in total alkalinity, 0.005 in pH, and 5 % for the halogenated transient tracers, The GLODAPv2 project itself received support from a number
of agencies and projects. Importantly, the EU-IP CARBOCHANGE
(FP7 264878) provided funding for A. Olsen, M. Hoppema, S. van
Heuven, and T. Tanhua as well as travel support for R. Key and
the project framework that instigated GLODAPv2. A. Olsen further
acknowledges generous support from the FRAM – High North Research
Centre for Climate and the Environment, the Centre for Climate
Dynamics at the Bjerknes Centre for Climate Research, the EU
AtlantOS (grant agreement no. 633211) project, and the Norwegian
Research Council project SNACS (229752). R. Key was supported
by KeyCrafts grant 2012-001, CICS grants NA08OAR4320752
and NA14OAR4320106, NASA grant NNX12AQ22G, NSF grants
OCE-0825163 (with a supplement via WHOI P.O. C119245) and
PLR-1425989, and Battelle contract #4000133565 to CDIAC.
A. Kozyr was supported by DOE contract DE-AC05-00OR2272 to
UT-Battelle, operators of CDIAC under ORNL. S. K. Lauvset and
E. Jeansson appreciate support from the Norwegian Research Council
(projects DECApH, 214513 and VENTILATE, 229791). The International
Ocean Carbon Coordination Project (IOCCP) also supported
this activity through the U.S. National Science Foundation
grant (OCE- 1243377) to the Scientific Committee on Oceanic Research.
A. Velo and F. F. Pérez acknowledge the support provided
by BOCATS project (CTM2013-41048-P) co-funded by the Spanish
Government and the Fondo Europeo de Desarrollo Regional
(FEDER), and the AtlantOS project (grant agreement no. 633211)
funded by EU H2020 research and innovation programme., Peer reviewed

16 páginas, 14 figuras, 3 tablas.-- Siv K. Lauvset ... et al.-- This work is distributed
under the Creative Commons Attribution 3.0 License.-- Proyecto Carbochange, We present a mapped climatology (GLODAPv2.2016b) of ocean biogeochemical variables based on the new GLODAP version 2 data product (Olsen et al., 2016; Key et al., 2015), which covers all ocean basins over the years 1972 to 2013. The quality-controlled and internally consistent GLODAPv2 was used to create global 1°  ×  1° mapped climatologies of salinity, temperature, oxygen, nitrate, phosphate, silicate, total dissolved inorganic carbon (TCO2), total alkalinity (TAlk), pH, and CaCO3 saturation states using the Data-Interpolating Variational Analysis (DIVA) mapping method. Improving on maps based on an earlier but similar dataset, GLODAPv1.1, this climatology also covers the Arctic Ocean. Climatologies were created for 33 standard depth surfaces. The conceivably confounding temporal trends in TCO2 and pH due to anthropogenic influence were removed prior to mapping by normalizing these data to the year 2002 using first-order calculations of anthropogenic carbon accumulation rates. We additionally provide maps of accumulated anthropogenic carbon in the year 2002 and of preindustrial TCO2. For all parameters, all data from the full 1972–2013 period were used, including data that did not receive full secondary quality control. The GLODAPv2.2016b global 1°  ×  1° mapped climatologies, including error fields and ancillary information, are available at the GLODAPv2 web page at the Carbon Dioxide Information Analysis Center (CDIAC; doi:10.3334/CDIAC/OTG.NDP093_GLODAPv2), The work of S. K. Lauvset was funded by
the Norwegian Research Council through the projects DECApH
(214513/F20). The EU-IP CARBOCHANGE (FP7 264878) project
provided funding for A. Olsen, S. van Heuven, T. Tanhua, R. Steinfeldt,
and M. Hoppema and is the project framework that instigated
GLODAPv2. A. Olsen additionally acknowledges generous
support from the FRAM – High North Research Centre for
Climate and the Environment, the Centre for Climate Dynamics
at the Bjerknes Centre for Climate Research, the EU AtlantOS
(grant agreement no. 633211) project, and the Norwegian Research
Council project SNACS (229752). Emil Jeansson appreciates support
from the Norwegian Research Council project VENTILATE
(229791). R. Key was supported by KeyCrafts grant 2012-001,
CICS grants NA08OAR4320752 and NA14OAR4320106, NASA
grant NNX12AQ22G, NSF grants OCE-0825163 (with a supplement
via WHOI P.O. C119245) and PLR-1425989, and Battelle
contract #4000133565 to CDIAC. A. Kozyr acknowledges funding
from the US Department of Energy. M. Ishii acknowledges
the project MEXT 24121003. A. Velo and F. F. Pérez were supported
by the BOCATS (CTM20134410484P) project cofounded
by the Spanish government and the Fondo Europeo de Desarrollo
Regional (FEDER). The International Ocean Carbon Coordination
Project (IOCCP) partially supported this activity through the U.S.
National Science Foundation grant (OCE- 1243377) to the Scientific
Committee on Oceanic Research.
The research leading to the last developments of DIVA has
received funding from the European Union Seventh Framework
Programme (FP7/2007-2013) under grant agreement no. 283607,
SeaDataNet 2, and from the project EMODNET (MARE/2012/10
– Lot 4 Chemistry – SI2.656742) from the Directorate-General for
Maritime Affairs and Fisheries, Peer reviewed

16 páginas, 6 figuras, The extent to which water mass mixing and ocean ventilation contribute to nitrous oxide (N2O) distribution at the scale of oceanic basins is poorly constrained. We used novel N2O and chlorofluorocarbon measurements along with multiparameter water mass analysis to evaluate the impact of water mass mixing and Atlantic Meridional Overturning Circulation (AMOC) on N2O distribution along the Observatoire de la variabilité interannuelle et décennale en Atlantique Nord (OVIDE) section, extending from Portugal to Greenland. The biological N2O production has a stronger impact on the observed N2O concentrations in the water masses traveling northward in the upper limb of the AMOC than those in recently ventilated cold water masses in the lower limb, where N2O concentrations reflect the colder temperatures. The high N2O tongue, with concentrations as high as 16 nmol kg−1, propagates above the isopycnal surface delimiting the upper and lower AMOC limbs, which extends from the eastern North Atlantic Basin to the Iceland Basin and coincides with the maximum N2O production rates. Water mixing and basin-scale remineralization account for 72% of variation in the observed distribution of N2O. The mixing-corrected stoichiometric ratio N2O:O2 for the North Atlantic Basin of 0.06 nmol/μmol is in agreement with ratios of N2O:O2 for local N2O anomalies, suggesting than up to 28% of N2O production occurs in the temperate and subpolar Atlantic, an overlooked region for N2O cycling. Overall, our results highlight the importance of taking into account mixing, O2 undersaturation when water masses are formed and the increasing atmospheric N2O concentrations when parameterizing N2O:O2 and biological N2O production in the global oceans, Financial support for this work came from the Consejo Superior de Investigaciones Científicas (CSIC) and the Spanish Ministry of Economy and Competitiveness through the CATARINA project (CTM2010-17141) and BOCATS (CTM2013-41048-P) projects both cofounded by the Fondo Europeo de Desarrollo Regional (FEDER) and also from the Ingos EU Project (grant agreement 284274) and from Xunta de Galicia through the OSIMON project (09MDS035402PR), Peer reviewed

1 file.-- This dataset compiles information obtained during the cruise BOCATS 2016, This dataset gathers discrete measurements of CO2 (pH and alkalinity) and hydrographic variables (salinity, temperature, dissolved oxygen, nitrate, phosphate and silicate) obtained during the cruise BOCATS carried out along the OVIDE section from 17 June to 31 July 2016.
pH was measured spectrophotometrically following the Clayton and Byrne (1993). This method consists on adding a dye solution to the seawater sample, so that the ratio between two absorbances at two different wavelengths is proportional to the sample pH.
Alkalinity was measured using an automatic potentiometric titrator Titrando 809 Metrohm, with a Metrohm 6.0232.100 combination glass electrode and a Pt-1000 probe for temperature measurement following the methodology given by Pérez and Fraga (1987).
Dissolved oxygen was analyzed following the widely applied Winkler method.
Determinations of nitrate, phosphate and silicate were carried out following methods described by Hansen and Grassoff (1983)
Salinity and Temperature were recorded with a CTD probe, BOCATS (CTM2013-41048-P), Peer reviewed

103 páginas, 28 figuras, The objectives of the BOCATS cruise are fulfilled in spite of the problems derived from
the installation of the new signal transmission cable. This operation delayed the departure by one
week. However, this delay was recovered thanks to the speed of the ship, the constant adaptation
of the cruise planning to the weather forecasts and the excellent reliability of the CTD and boxcorer
operations. A total of 138 CTD stations and 66 sediment sampling were done. In addition,
the recovery and new deployment of two ASFAR-ARGO systems were done, as well as the
deployment of five meteorological floats and nine ARGO floats, Project funded by MINECO, Ref. CTM2013-41048-P, Peer reviewed

20 pages, 12 figures, 1 table.-- This work is distributed under the Creative Commons Attribution 4.0 License, The GEOVIDE cruise was carried out in the subpolar
North Atlantic (SPNA) along the OVIDE section and
across the Labrador Sea in May–June 2014. It was planned
to clarify the distribution of the trace elements and their isotopes
in the SPNA as part of the GEOTRACES international
program. This paper focuses on the state of the circulation
and distribution of thermohaline properties during the cruise.
In terms of circulation, the comparison with the 2002–2012
mean state shows a more intense Irminger Current and also
a weaker North Atlantic Current, with a transfer of volume
transport from its northern to its central branch. However,
those anomalies are compatible with the variability already
observed along the OVIDE section in the 2000s. In terms
of properties, the surface waters of the eastern SPNA were
much colder and fresher than the averages over 2002–2012.
In spite of negative temperature anomalies in the surface waters,
the heat transport across the OVIDE section estimated
at 0.56 0.06PW was the largest measured since 2002. This
relatively large value is related to the relatively strong Meridional
Overturning Circulation measured across the OVIDE
section during GEOVIDE (18.7 3.0 Sv). By analyzing the
air–sea heat and freshwater fluxes over the eastern SPNA
in relation to the heat and freshwater content changes observed
during 2013 and 2014, we concluded that on a short
timescale these changes were mainly driven by air–sea heat
and freshwater fluxes rather than by ocean circulation, Patricia Zunino was supported by CNRS and
IFREMER within the framework of the projects AtlantOS (European
Union Horizon 2020, grant no. 633211) and GEOVIDE
(ANR-13-BS06-0014-02). H. Mercier was financed by CNRS,
Pascale Lherminier by Ifremer, and Nathalie Daniault by the
University of Western Brittany, Brest. Maribel I. García-Ibáñez and
Fiz F. Pérez were supported by the Spanish Ministry of Economy
and Competitiveness through the BOCATS (CTM2013-41048-P)
project co-funded by the Fondo Europeo de Desarrollo Regional
2014–2020 (FEDER), Peer reviewed

22 pages, 10 figures, 3 tables.-- This work is distributed under the Creative Commons Attribution 3.0 License, The subpolar region in the North Atlantic is a ma-
jor sink for anthropogenic carbon. While the storage rates
show large interannual variability related to atmospheric
forcing, less is known about variability in the natural dis-
solved inorganic carbon (DIC) and the combined impact
of variations in the two components on the total DIC in-
ventories. Here, data from 15 cruises in the Irminger Sea
covering the 24-year period between 1991 and 2015 were
used to determine changes in total DIC and its natural and
anthropogenic components. Based on the results of an ex-
tended optimum multiparameter analysis (eOMP), the in-
ventory changes are discussed in relation to the distribu-
tion and evolution of the main water masses. The inventory
of DIC increased by 1.43
±
0.17 mol m
−
2
yr
−
1
over the pe-
riod, mainly driven by the increase in anthropogenic carbon
(1.84
±
0.16 mol m
−
2
yr
−
1
) but partially offset by a loss of
natural DIC (
−
0.57
±
0.22 mol m
−
2
yr
−
1
). Changes in the
carbon storage rate can be driven by concentration changes
in the water column, for example due to the ageing of wa-
ter masses, or by changes in the distribution of water masses
with different concentrations either by local formation or ad-
vection. A decomposition of the trends into their main drivers
showed that variations in natural DIC inventories are mainly
driven by changes in the layer thickness of the main water
masses, while anthropogenic carbon is most affected by con-
centration changes. The storage rates of anthropogenic car-
bon are sensitive to data selection, while changes in DIC in-
ventory show a robust signal on short timescales associated
with the strength of convection, Friederike Fröb and Are Olsen appreciate funding from the
SNACS project (229752), which is part of the KLIMAFORSK
programme of the Norwegian Research Council. Emil Jeansson
and Siv K. Lauvset received funding from the NRC project
VENTILATE (229791). Fiz F. Pérez and Maribel I. García-Ibáñez
were supported by the Spanish Ministry of Economy and Com-
petitiveness through the BOCATS (CTM2013-41048-P) project
co-funded by the Fondo Europeo de Desarrollo Regional 2007–
2012 (FEDER), Peer reviewed

15 pages, 3 tables, 9 figures, Since the Industrial Revolution, the North Atlantic Ocean has been accumulating anthropogenic carbon dioxide (CO2) and experiencing ocean acidification1, that is, an increase in the concentration of hydrogen ions (a reduction in pH) and a reduction in the concentration of carbonate ions. The latter causes the ‘aragonite saturation horizon’—below which waters are undersaturated with respect to a particular calcium carbonate, aragonite—to move to shallower depths (to shoal), exposing corals to corrosive waters2,3. Here we use a database analysis to show that the present rate of supply of acidified waters to the deep Atlantic could cause the aragonite saturation horizon to shoal by 1,000–1,700 metres in the subpolar North Atlantic within the next three decades. We find that, during 1991–2016, a decrease in the concentration of carbonate ions in the Irminger Sea caused the aragonite saturation horizon to shoal by about 10–15 metres per year, and the volume of aragonite-saturated waters to reduce concomitantly. Our determination of the transport of the excess of carbonate over aragonite saturation (xc[CO32−])—an indicator of the availability of aragonite to organisms—by the Atlantic meridional overturning circulation shows that the present-day transport of carbonate ions towards the deep ocean is about 44 per cent lower than it was in preindustrial times. We infer that a doubling of atmospheric anthropogenic CO2 levels—which could occur within three decades according to a ‘business-as-usual scenario’ for climate change4—could reduce the transport of xc[CO32−] by 64–79 per cent of that in preindustrial times, which could severely endanger cold-water coral habitats. The Atlantic meridional overturning circulation would also export this acidified deep water southwards, spreading corrosive waters to the world ocean, The OVIDE research project was co-funded by the Institut Français de Recherche pour l’Exploitation de la Mer (IFREMER) and CNRS/Institut National des Sciences de l’Univers (INSU)/Les Enveloppes Fluides et l’Environnement (LEFE). H.M. was supported by CNRS. This is a contribution to the AtlantOS project funded by the European Union’s Horizon 2020 research and innovation programme under grant agreement 633211. This study is also a contribution to the BOCATS project (CTM2013-41048-P) supported by the Spanish Ministry of Economy and Competitiveness and co-funded by the Fondo Europeo de Desarrollo Regional 2014–2020 (FEDER), Peer reviewed

9 pages, 4 figures, 1 table, Climatology-based storage rate of anthropogenic CO2 (Cant, referred to year 2000) in the North-East Atlantic (53 ± 9 kmol s−1, 0.020 ± 0.003 Pg-C yr−1) is described on annual mean terms. Cant advection (32 ± 14 kmol s−1) occurs mostly in the upper 1800 m and contributes to 60% of the Cant storage rate. The Azores and Portugal Currents act as ‘Cant streams’ importing 389 ± 90 kmol s−1, most of which recirculates southwards with the Canary Current (−214 ± 34 kmol s−1). The Azores Counter Current (−79 ± 36 kmol s−1) and the northward-flowing Mediterranean Water advective branch (−31 ± 12 kmol s−1) comprise secondary Cant export routes. By means of Cant transport decomposition, we find horizontal circulation to represent 11% of the Cant storage rate, while overturning circulation is the main driver (48% of the Cant storage rate). Within the domain of this study, overturning circulation is a key mechanism by which Cant in the upper layer (0–500 dbar) is drawdown (74 ± 14 kmol s−1) to intermediate levels (500–2000 dbar), and entrained (37 ± 7 kmol s−1) into the Mediterranean Outflow Water to form Mediterranean Water. This newly formed water mass partly exports Cant to the North Atlantic at a rate of −39 ± 9 kmol s−1 and partly contributes to the Cant storage in the North-East Atlantic (with up to 0.015 ± 0.006 Pg-C yr−1). Closing the Cant budget, 40% of the Cant storage in the North-East Atlantic is attributable to anthropogenic CO2 uptake from the atmosphere (21 ± 10 kmol s−1)., This work was funded by the Spanish National Research Council (CSIC), through the EU H2020 project AtlantOS (“Optimizing and Enhancing the Integrated Atlantic Ocean Observing Systems Research”, RIA), financed by the European Commission’s H2020 Framework Programme under grant agreement no. 633211. The first author is being funded by the University of Vigo, through the Galician I2C Plan for postdoctoral research. F.F. Pérez and G. Rosón were supported by the Spanish Ministry of Economy through the CATARINA (CTM2010-17141) and BOCATS (CTM2013-41048-P) projects, both co-funded by the Fondo Europeo de Desarrollo Regional (FEDER), Peer reviewed

6 pages, 3 figures, 1 table, The Labrador Sea links the Arctic and North Atlantic oceans and constitutes one of the main entrances of atmospheric inputs into the Ocean's interior. We report here the first high-resolution Hg distribution pattern along a transect from Greenland to Labrador coasts sampled after the 2014 winter convection. Total Hg concentrations in unfiltered (HgTUNF) samples ranged from 0.25 pmol L− 1 to 0.67 pmol L− 1 averaging 0.44 ± 0.10 pmol L− 1 (n = 113, 1σ). Concentrations in filtered samples (HgTF, < 0.45 μm) represented from 62 to 92% of the HgTUNF and exhibited a similar distribution. High HgTUNF concentrations were found (i) in the waters of the Labrador Current, which receive desalted waters from the Canadian Arctic Archipelago, and (ii) in the waters over the Labrador shelf and rise. In the Labrador Sea Waters formed during the 2014 winter convection, HgTUNF concentrations were low (0.38 ± 0.05 pmol L− 1, n = 23), and increased gradually with depth (up to > 0.5 pmol L− 1) in the Northeast Atlantic Deep Waters. HgTF correlates with apparent oxygen utilization implying that atmospheric deposition, biological uptake, and microbial respiration control the Hg distribution in the Labrador Sea. Subtracting the amount of Hg released during organic matter remineralization allows us to identify a Hg and organic matter enriched fraction, which originates from fluvial sources in the Canadian Arctic Archipelago waters. This fraction is transferred southward, in surface waters with the Labrador Current, and at depth with the lower limb of the Atlantic Meridional Overturning Circulation. Climate warming, which will increase the mobilization of Hg from thawing permafrost, would consequently increase the Arctic export of Hg initially associated with organic matter, This research was funded by the French National Research Agency (ANR-13-BS06-0014), the French National Center for Scientific Research (Cnrs-Lefe-Cyber), the Global Mercury Observation System (GMOS, N°265113 European Union project), and the European Research Council (ERC-2010-StG-20091028). For this work M.I. García-Ibáñez and F.F. Pérez were supported by the Spanish Ministry of Economy and Competitiveness through the BOCATS (CTM2013-41048-P) project co-funded by the Fondo Europeo de Desarrollo Regional 2014-2020 (FEDER), Peer reviewed

16 pages, 6 figures, 1 table.-- This work is distributed under the Creative Commons Attribution 4.0 License, We present the distribution of water masses along the GEOTRACES-GA01 section during the GEOVIDE cruise, which crossed the subpolar North Atlantic Ocean and the Labrador Sea in the summer of 2014. The water mass structure resulting from an extended optimum multiparameter (eOMP) analysis provides the framework for interpreting the observed distributions of trace elements
and their isotopes. Central Waters and Subpolar Mode Waters (SPMW) dominated the upper part of the GEOTRACESGA01 section. At intermediate depths, the dominant water mass was Labrador Sea Water, while the deep parts of the section were filled by Iceland–Scotland Overflow Water (ISOW) and North-East Atlantic Deep Water. We also evaluate the water mass volume transports across the 2014 OVIDE line (Portugal to Greenland section) by combining the water mass fractions resulting from the eOMP analysis with the absolute geostrophic velocity field estimated through a box inverse model. This allowed us to assess the relative contribution of each water mass to the transport across the section. Finally, we discuss the changes in the distribution and transport of water masses between the 2014
OVIDE line and the 2002–2010 mean state. At the upper and intermediate water levels, colder end-members of the water masses replaced the warmer ones in 2014 with respect to 2002–2010, in agreement with the long-term cooling of the North Atlantic Subpolar Gyre that started in the mid-2000s. Below 2000 dbar, ISOW increased its contribution in 2014 with respect to 2002–2010, with the increase being consistent with other estimates of ISOWtransports along 58–59 N.We also observed an increase in SPMW in the East Greenland Irminger Current in 2014 with respect to 2002–2010, which
supports the recent deep convection events in the Irminger Sea. From the assessment of the relative water mass contribution to the Atlantic Meridional Overturning Circulation (AMOC) across the OVIDE line, we conclude that the larger AMOC intensity in 2014 compared to the 2002–2010 mean
was related to both the increase in the northward transport of Central Waters in the AMOC upper limb and to the increase in the southward flow of Irminger Basin SPMW and ISOW in the AMOC lower limb., For this work Maribel I. García-Ibáñez and Fiz F. Pérez were supported by the Spanish Ministry of Economy and Competitiveness through the BOCATS (CTM2013-41048-P) project, co-funded by the
Fondo Europeo de Desarrollo Regional 2014–2020 (FEDER). Maribel I. García-Ibáñez was also supported by the Centre for Climate Dynamics at the Bjerknes Centre. Pascale Lherminier
was supported by IFREMER. Patricia Zunino was supported by CNRS and IFREMER, within the framework of the projects AtlantOS (H2020-633211) and GEOVIDE (ANR-13-BS06-0014-02). Herlé Mercier was supported by CNRS and the AtlantOS H2020 project under grant number 633211. Paul Tréguer was supported by the LABEX-Mer (French Government “Investissement d’Avenir” programme, ANR-10-LABX-19-01), Peer reviewed

15 pages, 2 tables, 6 figures.-- Daniel cossa ... et al.-- This work is distributed under
the Creative Commons Attribution 4.0 License, We report here the results of total mercury (HgT) determinations along the 2014 Geotraces Geovide cruise (GA01 transect) in the North Atlantic Ocean (NA) from Lisbon (Portugal) to the coast of Labrador (Canada). HgT concentrations in unfiltered samples (HgTUNF) were log-normally distributed and ranged between 0.16 and 1.54 pmol L−1, with a geometric mean of 0.51 pmol L−1 for the 535 samples analysed. The dissolved fraction (< 0.45 µm) of HgT (HgTF), determined on 141 samples, averaged 78 % of the HgTUNF for the entire data set, 84 % for open seawaters (below 100 m) and 91 % if the Labrador Sea data are excluded, where the primary production was high (with a winter convection down to 1400 m). HgTUNF concentrations increased eastwards and with depth from Greenland to Europe and from subsurface to bottom waters. The HgTUNF concentrations were similarly low in the subpolar gyre waters ( ∼  0.45 pmol L−1), whereas they exceeded 0.60 pmol L−1 in the subtropical gyre waters. The HgTUNF distribution mirrored that of dissolved oxygen concentration, with highest concentration levels associated with oxygen-depleted zones. The relationship between HgTF and the apparent oxygen utilization confirms the nutrient-like behaviour of Hg in the NA. An extended optimum multiparameter analysis allowed us to characterize HgTUNF concentrations in the different source water types (SWTs) present along the transect. The distribution pattern of HgTUNF, modelled by the mixing of SWTs, show Hg enrichment in Mediterranean waters and North East Atlantic Deep Water and low concentrations in young waters formed in the subpolar gyre and Nordic seas. The change in anthropogenic Hg concentrations in the Labrador Sea Water during its eastward journey suggests a continuous decrease in Hg content in this water mass over the last decades. Calculation of the water transport driven by the Atlantic Meridional Overturning Circulation across the Portugal–Greenland transect indicates northward Hg transport within the upper limb and southward Hg transport within the lower limb, with resulting net northward transport of about 97.2 kmol yr−1., This
research was funded by the French National Research Agency
(ANR-13-BS06-0014, ANR-12-PDOC-0025-01), the French
National Center for Scientific Research (CNRS-LEFE-CYBER), the
LabexMER (ANR-10-LABX-19), the Global Mercury Observation
System (GMOS, no. 265113 European Union project), and the
European Research Council (ERC-2010-StG-20091028). For this
work Maribel I. García-Ibáñez and Fiz F. Pérez were supported by
the Spanish Ministry of Economy and Competitiveness through the
BOCATS (CTM2013-41048-P) project, co-funded by the Fondo
Europeo de Desarrollo Regional 2014–2020 (FEDER), Peer reviewed

19 pages, 4 tables, 10 figures.-- Nolwenn Lemaitre ... et al.-- This work is distributed under
the Creative Commons Attribution 4.0 License, The remineralisation of sinking particles by prokaryotic heterotrophic activity is important for controlling oceanic carbon sequestration. Here, we report mesopelagic particulate organic carbon (POC) remineralisation fluxes in the North Atlantic along the GEOTRACES-GA01 section (GEOVIDE cruise; May–June 2014) using the particulate biogenic barium (excess barium; Baxs) proxy. Important mesopelagic (100–1000 m) Baxs differences were observed along the transect depending on the intensity of past blooms, the phytoplankton community structure, and the physical forcing, including downwelling. The subpolar province was characterized by the highest mesopelagic Baxs content (up to 727 pmol L−1), which was attributed to an intense bloom averaging 6 mg chl a m−3 between January and June 2014 and by an intense 1500 m deep convection in the central Labrador Sea during the winter preceding the sampling. This downwelling could have promoted a deepening of the prokaryotic heterotrophic activity, increasing the Baxs content. In comparison, the temperate province, characterized by the lowest Baxs content (391 pmol L−1), was sampled during the bloom period and phytoplankton appear to be dominated by small and calcifying species, such as coccolithophorids. The Baxs content, related to oxygen consumption, was converted into a remineralisation flux using an updated relationship, proposed for the first time in the North Atlantic. The estimated fluxes were of the same order of magnitude as other fluxes obtained using independent methods (moored sediment traps, incubations) in the North Atlantic. Interestingly, in the subpolar and subtropical provinces, mesopelagic POC remineralisation fluxes (up to 13 and 4.6 mmol C m−2 d−1, respectively) were equalling and occasionally even exceeding upper-ocean POC export fluxes, deduced using the 234Th method. These results highlight the important impact of the mesopelagic remineralisation on the biological carbon pump of the studied area with a near-zero, deep (> 1000 m) carbon sequestration efficiency in spring 2014., This work was funded by the Flanders Research Foundation
(project G071512N), the Vrije Universiteit Brussel (strategy research program: project SRP-2), the French National Research
Agency (ANR-13-BS06-0014 and ANR-12-PDOC-0025-01),
the French National Center for Scientific Research (CNRSLEFE-
CYBER), IFREMER, and the “Laboratoire d’Excellence”
Labex-Mer (ANR-10-LABX-19). For this work, Maribel I. Garcia-
Ibáñez was supported by the Centre for Climate Dynamics at
the Bjerknes Centre and by the Spanish Ministry of Economy
and Competitiveness through the BOCATS (CTM2013-41048-P)
project co-funded by the Fondo Europeo de Desarrollo Regional
2014–2020 (FEDER)., Peer reviewed

22 pages, 10 figures.-- Emilie Le Roy ... et al.-- This work is distributed under
the Creative Commons Attribution 4.0 License, We report detailed sections of radium-226 (226Ra, T1∕2 =  1602 years) activities and barium (Ba) concentrations determined in the North Atlantic (Portugal–Greenland–Canada) in the framework of the international GEOTRACES program (GA01 section – GEOVIDE project, May–July 2014). Dissolved 226Ra and Ba are strongly correlated along the section, a pattern that may reflect their similar chemical behavior. Because 226Ra and Ba have been widely used as tracers of water masses and ocean mixing, we investigated their behavior more thoroughly in this crucial region for thermohaline circulation, taking advantage of the contrasting biogeochemical patterns existing along the GA01 section. We used an optimum multiparameter (OMP) analysis to distinguish the relative importance of physical transport (water mass mixing) from nonconservative processes (sedimentary, river or hydrothermal inputs, uptake by particles and dissolved–particulate dynamics) on the 226Ra and Ba distributions in the North Atlantic. Results show that the measured 226Ra and Ba concentrations can be explained by conservative mixing for 58 and 65 % of the samples, respectively, notably at intermediate depth, away from the ocean interfaces. 226Ra and Ba can thus be considered conservative tracers of water mass transport in the ocean interior on the space scales considered here, namely, on the order of a few thousand kilometers. However, regions in which 226Ra and Ba displayed nonconservative behavior and in some cases decoupled behaviors were also identified, mostly at the ocean boundaries (seafloor, continental margins and surface waters). Elevated 226Ra and Ba concentrations found in deepwater in the West European Basin suggest that lower Northeast Atlantic Deep Water (NEADWl) accumulates 226Ra and Ba from sediment diffusion and/or particle dissolution during transport. In the upper 1500 m of the West European Basin, deficiencies in 226Ra and Ba are likely explained by their incorporation in planktonic calcareous and siliceous shells, or in barite (BaSO4) by substitution or adsorption mechanisms. Finally, because Ba and 226Ra display different source terms (mostly deep-sea sediments for 226Ra and rivers for Ba), strong decoupling between 226Ra and Ba were observed at the land–ocean boundaries. This is especially true in the shallow stations near the coasts of Greenland and Newfoundland where high 226Ra ∕ Ba ratios at depth reflect the diffusion of 226Ra from sediment and low 226Ra ∕ Ba ratios in the upper water column reflect the input of Ba associated with meteoric waters, The present research and Emilie Le Roy’s
fellowship are co-funded by the European Union and the Région Occitanie-Pyrénées-Méditerranée (European Regional Development
Fund). The GEOVIDE project is co-funded by the
French national program LEFE/INSU (GEOVIDE), ANR Blanc
(GEOVIDE, ANR-13-BS06-0014) and RPDOC (ANR-12-PDOC-
0025-01), LabEX MER (ANR-10-LABX-19) and IFREMER. This work was
also co-funded by the French national program LEFE/INSU
“REPAP” (PI Stéphanie H. M Jacquet) and the US National
Science Foundation (PI Matthew A. Charette, OCE-1458305;
OCE-1232669). For this work Maribel I. García-Ibáñez and
Fiz F. Pérez were supported by the Spanish Ministry of Economy
and Competitiveness through the BOCATS (CTM2013-41048-P)
project co-funded by the Fondo Europeo de Desarrollo Regional
2014–2020 (FEDER), Peer reviewed

1 poster.-- 2018 Ocean Sciences Meeting, 11-16 February, Portland, Oregon, USA, Funding for this work was provided by the European Projects INGOS (Grant agreement 284274) by the
Spanish funded CATARINA Project (CTM2010-17141/MAR), and BOCATS (CTM 2013-41048-P). M. de la Paz is
funded by the project INICIO (CTM-75510-JIN) funded by the Spanish Ministry of Economy and
Competitiviness and cofounded by the Fondo Eurpeo de Desarrollo regional (FEDER), Peer reviewed

20 pages, 6 figures, 1 table.-- This work is distributed under
the Creative Commons Attribution 4.0 License, Pathways and timescales of water mass transport in the subpolar North Atlantic Ocean (SPNA) have been investigated by many studies due to their importance for the meridional overturning circulation and thus for the global ocean. In this sense, observational data on geochemical tracers provide complementary information to improve the current understanding of the circulation in the SPNA. To this end, we present the first simultaneous distribution of artificial 129I and 236U in 14 depth profiles and in surface waters along the GEOVIDE section covering a zonal transect through the SPNA in spring 2014. Our results show that the two tracers are distributed following the water mass structure and that their presence is largely influenced by the global fallout (GF) and liquid effluents discharged to north-western European coastal waters by the Sellafield and La Hague nuclear reprocessing plants (NRPs). As a result, 129I concentrations and 236U∕238U atom ratios and 129I∕236U atom ratios display a wide range of values: (0.2–256) × 107atkg−1 (40–2350) × 10−12 and 0.5–200, respectively. The signal from NRPs, which is characterised by higher 129I concentrations and 129I∕236U atom ratios compared to GF, is transported by Atlantic Waters (AWs) into the SPNA, notably by the East Greenland Current (EGC)/Labrador Current (LC) at the surface and by waters overflowing the Greenland–Scotland passage at greater depths. Nevertheless, our results show that the effluents from NRPs may also directly enter the surface of the eastern SPNA through the Iceland–Scotland passage or the English Channel/Irish Sea. The use of the 236U∕238U and 129I∕236U dual tracer approach further serves to discern Polar Intermediate Water (PIW) of Canadian origin from that of Atlantic origin, which carries comparably higher tracer levels due to NRPs (particularly 129I). The cascading of these waters appears to modify the water mass composition in the bottom of the Irminger and Labrador seas, which are dominated by Denmark Strait Overflow Water (DSOW). Indeed, PIW–Atlantic, which has a high level of 129I compared to 236U, appears to contribute to the deep Irminger Sea increasing the 129I concentrations in the realm of DSOW. A similar observation can be made for 236U for PIW entering through the Canadian Archipelago into the Labrador Sea. Several depth profiles also show an increase in 129I concentrations in near bottom waters in the Iceland and the West European basins that are very likely associated with the transport of the NRP signal by the Iceland–Scotland Overflow Water (ISOW). This novel result would support current modelling studies indicating the transport of ISOW into the eastern SPNA. Finally, our tracer data from 2014 are combined with published 129I data for the deep central Labrador Sea between 1993 and 2013. The results obtained from comparing simulated and measured 129I concentrations support the previously suggested two major transport pathways for the AWs in the SPNA, i.e. a short loop through the Nordic seas into the SPNA and a longer loop, which includes recirculation of the AWs in the Arctic Ocean before it enters the western SPNA, The GEOVIDE
cruise was funded by the French National Research Agency
(ANR-13-BS06-0014, ANR-12-PDOC-0025-01), the French
National Center for Scientific Research (CNRS LEFE CYBER),
the LabexMER (ANR-10-LABX-19), and Ifremer. This work was
funded by the Ministerio de Economía y Competitividad of Spain
(MDM2015-0552), the Generalitat de Catalunya (MERS 2017
SGR-1588) and consortium partners of the ETH Zurich Laboratory
of Ion Beam Physics (EAWAG, EMPA, and PSI). Maxi Castrillejo
was funded by a FPU PhD studentship (AP-2012-2901) from
the Ministerio de Educación, Cultura y Deporte of Spain and the
ETH Zurich Postdoctoral Fellowship Programme (17-2 FEL-30),
co-funded by the Marie Curie Actions for People COFUND
Programme. Núria Casacuberta’s research was funded by the
AMBIZIONE grant (PZ00P2_154805) from the Swiss National
Science Foundation. Maribel I. García-Ibáñez was supported by
the Spanish Ministry of Economy and Competitiveness through the
BOCATS (CTM2013-41048-P) project co-funded by the Fondo Europeo de Desarrollo Regional 2014–2020 (FEDER), Peer reviewed

14 pages, 6 figures, 3 tables.-- This work is distributed under
the Creative Commons Attribution 4.0 License, The stable isotope composition of dissolved silicon
in seawater ( 30SiDSi) was examined at 10 stations along
the GEOVIDE section (GEOTRACES GA-01), spanning the
North Atlantic Ocean (40–60 N) and Labrador Sea. Variations
in 30SiDSi below 500m were closely tied to the distribution
of water masses. Higher 30SiDSi values are associated
with intermediate and deep water masses of northern Atlantic
or Arctic Ocean origin, whilst lower 30SiDSi values are associated
with DSi-rich waters sourced ultimately from the
Southern Ocean. Correspondingly, the lowest 30SiDSi values
were observed in the deep and abyssal eastern North Atlantic,
where dense southern-sourced waters dominate. The
extent to which the spreading of water masses influences
the 30SiDSi distribution is marked clearly by Labrador Sea
Water (LSW), whose high 30SiDSi signature is visible not
only within its region of formation within the Labrador and
Irminger seas, but also throughout the mid-depth western
and eastern North Atlantic Ocean. Both 30SiDSi and hydrographic
parameters document the circulation of LSW into the
eastern North Atlantic, where it overlies southern-sourced
Lower DeepWater. The GEOVIDE 30SiDSi distribution thus
provides a clear view of the direct interaction between subpolar/
polar water masses of northern and southern origin, and
allow examination of the extent to which these far-field signals
influence the local 30SiDSi distribution, This work was supported by the “Laboratoire d’Excellence”
LabexMER (ANR-10-LABX-19) and co-funded by a grant from
the French government under the program “Investissements
d’Avenir”, and by a grant from the Regional Council of Brittany
(SAD programme). The GEOVIDE project was funded by
CNRS-INSU (programme LEFE-CYBER), the French National
Research Agency (ANR-13-BS06-0014, ANR-12-PDOC-0025-01)
and “RPDOC” BITMAP (ANR-12-PDOC-0025), the LabexMER
ANR-10-LABX-19) and Ifremer. The GEOVIDE project was also
supported for logistics by DT-INSU and GENAVIR. Gregory de
Souza was supported by a Marie Skłodowska-Curie Research
Fellowship under EU Horizon 2020 (SOSiC; no. 708407). Maribel
I. Garcia-Ibáñez was supported by the Spanish Ministry of
Economy and Competitiveness through the BOCATS (CTM2013-
41048-P) project co-funded by the Fondo Europeo de Desarrollo
Regional 2014–2020 (FEDER)., Peer reviewed

31 pages, 5 figures., Evaluation of biogeochemical processes in Anthropocene deep-sea sediments require accurate dating techniques. Here we show the results of an approach using high resolution low level background gamma spectrometry with two simultaneous hyper-pure germanium (HPGe) detectors. The quantitative role of the deepest zones (>3000 m depth) of the Irminger Basin (Subpolar North Atlantic Ocean) as a carbon sink during the Anthropocene is evaluated combining a chronology based in the natural radionuclide 210Pb with sedimentological analysis and elemental composition. The average sedimentation rate of the central Irminger is 1.28 ± 0.18 mm·yr−1, with a mean weighted flux to the sediment for inorganic and organic carbon of 46 ± 15 g·Cinorg·m−2·yr−1 and 8 ± 1 g·Corg·m−2·yr−1. The biogenic fraction of the mass flux is increased since the XXth century. The contribution of the deepest zones of the Irminger Basin to the Anthropocene carbon sequestration in the North Atlantic Ocean is considerable at basin-scale., For this work M. Fontela was funded by the Spanish Ministry of Economy and Competitiveness through the BOCATS project supported by the Spanish Government., Peer reviewed

7 pages, 5 figures, 3 tables, In order to establish the chronology of deep-sea sediments from high-resolution 210Pb-dating, the determination of 210Pb and 226Ra activity concentrations needs to be improved. Gamma spectrometry allows determining simultaneously both radionuclides. However, spectrum background is still an issue to obtain high sensitivity. Four deep-sea sediment cores were dated using Mazinger, a gamma spectrometer with high-efficiency and very low-background, and the Constant Rate and Supply model was applied to obtain recent ages, For this work M. Fontela was funded by the Spanish Ministry of Economy and Competitiveness (BES-2014-070449) through the BOCATS Project (CTM2013-41048-P) supported by the Spanish Government and co-funded by the Fondo Europeo de Desarrollo Regional 2007–2012 (FEDER). F.F. Pérez were supported by the BOCATS Project (CTM2013-41048-P) co-funded by the Spanish Government and the Fondo Europeo de Desarrollo Regional (FEDER), Peer reviewed

XX Seminario Ibérico de Química Marina, SIQUIMAR 2020, Barcelona (Spain), 1st-3rd July 2020, Ocean acidification decreases the excess carbonate, that is, the amount of carbonate available for marine calcifiers. Here, the chemical status of the Northeast Atlantic and its cold-water corals (CWC) communities is examined by means of a high-quality database of carbon variables based on the GO-SHIP A25 section. The database covers a two-decade period (1997-2018), where the mean annual atmospheric carbon dioxide (CO2) increased from 364 to 409 parts per million of volume. The running out of excess carbonate, that is, the progression of undersaturation with respect to aragonite, could compromise the conservation of the habitats and ecosystem services developed by CWC communities. We find that the anthropogenic perturbation in the ocean carbon cycle is significantly decreasing the concentration of excess carbonate in the waters surrounding CWC communities at a rate of -0.17±0.02 μmol kg-1·ppm-1. The optimal chemical conditions for development of CWC communities in the Northeast Atlantic are maintained by the interplay between the northward spreading of recently conveyed Mediterranean Water with excess of carbonate available and the arrival of subpolar-origin waters close to undersaturation. Given the current acidification rate, the living CWC communities would be exposed to undersaturated waters before the end of the century, if atmospheric CO2 concentration reached ~700 ppm. Therefore, the future of the CWC communities in the Northeast Atlantic is closely linked to the accomplishment of global climate policies to limit global warming below 1.5-2ºC, which would preserve chemically optimal conditions of CWC growth in this particular oceanic region, For this work M. Fontela was funded by the Spanish Ministry of Economy and Competitiveness (BES-2014-070449) supported by the Spanish Government and co-funded by the Fondo Europeo de Desarrollo Regional 2007–2012 (FEDER) and by Portuguese national funds from FCT - Foundation for Science and Technology through project UIDB/04326/2020 and CEECINST/00114/2018. F.F. Pérez were supported by the BOCATS Project (CTM2013-41048-P) and ARIOS project (CTM2016-76146-C3-1-R) both co-funded by the Spanish Government and the Fondo Europeo de Desarrollo Regional (FEDER). This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 820989 (project COMFORT, Our common future ocean in the Earth system – quantifying coupled cycles of carbon, oxygen, and nutrients for determining and achieving safe operating spaces with respect to tipping points).”, No

10 pages, 6 figures, 1 table.-- This article is licensed under a Creative Commons Attribution 4.0 International License, The oceanic uptake of atmospheric carbon dioxide (CO 2) emitted by human activities alters the seawater carbonate system. Here, the chemical status of the Northeast Atlantic is examined by means of a high-quality database of carbon variables based on the GO-SHIP A25 section (1997–2018). The increase of atmospheric CO 2 leads to an increase in ocean anthropogenic carbon (Cant) and a decrease in carbonate that is unequivocal in the upper and mid-layers (0–2,500 m depth). In the mid-layer, the carbonate content in the Northeast Atlantic is maintained by the interplay between the northward spreading of recently conveyed Mediterranean Water with excess of carbonate and the arrival of subpolar-origin waters close to carbonate undersaturation. In this study we show a progression to undersaturation with respect to aragonite that could compromise the conservation of the habitats and ecosystem services developed by benthic marine calcifiers inhabiting that depth-range, such as the cold-water corals (CWC) communities. For each additional ppm in atmospheric pCO2 the waters surrounding CWC communities lose carbonate at a rate of − 0.17 ± 0.02 μmol kg−1 ppm−1. The accomplishment of global climate policies to limit global warming below 1.5–2 ℃ will avoid the exhaustion of excess carbonate in the Northeast Atlantic., For this work M. Fontela was funded by the Spanish Ministry of Economy and Competitiveness (BES-2014-070449) supported by the Spanish Government and co-funded by the Fondo Europeo de Desarrollo Regional 2007–2012 (FEDER) and by Portuguese national funds from FCT Foundation for Science and Technology through project UID/Multi/04326/2019 and CEECINST/00114/2018. F.F. Pérez was supported by the BOCATS Project (CTM2013-41048-P) and ARIOS project (CTM2016-76146-C3-1-R) both co-funded by the Spanish Government and the Fondo Europeo de Desarrollo Regional (FEDER). This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 820989 (COMFORT, Our common future ocean in the Earth system—quantifying coupled cycles of carbon, oxygen, and nutrients for determining and achieving safe operating spaces with respect to tipping points)., Peer reviewed

48 pages, 9 figures, 10 tables.--Project Carbochange, Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and a methodology to quantify all major components of the global carbon budget, including their uncertainties, based on the combination of a range of data, algorithms, statistics, and model estimates and their interpretation by a broad scientific community. We discuss changes compared to previous estimates as well as consistency within and among components, alongside methodology and data limitations. CO2 emissions from fossil fuels and industry (EFF) are based on energy statistics and cement production data, while emissions from land-use change (ELUC), mainly deforestation, are based on combined evidence from land-cover-change data, fire activity associated with deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the annual changes in concentration. The mean ocean CO2 sink (SOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. The variability in SOCEAN is evaluated with data products based on surveys of ocean CO2 measurements. The global residual terrestrial CO2 sink (SLAND) is estimated by the difference of the other terms of the global carbon budget and compared to results of independent dynamic global vegetation models forced by observed climate, CO2, and land-cover change (some including nitrogen–carbon interactions). We compare the mean land and ocean fluxes and their variability to estimates from three atmospheric inverse methods for three broad latitude bands. All uncertainties are reported as ±1σ, reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. For the last decade available (2005–2014), EFF was 9.0 ± 0.5 GtC yr−1, ELUC was 0.9 ± 0.5 GtC yr−1, GATM was 4.4 ± 0.1 GtC yr−1, SOCEAN was 2.6 ± 0.5 GtC yr−1, and SLAND was 3.0 ± 0.8 GtC yr−1. For the year 2014 alone, EFF grew to 9.8 ± 0.5 GtC yr−1, 0.6 % above 2013, continuing the growth trend in these emissions, albeit at a slower rate compared to the average growth of 2.2 % yr−1 that took place during 2005–2014. Also, for 2014, ELUC was 1.1 ± 0.5 GtC yr−1, GATM was 3.9 ± 0.2 GtC yr−1, SOCEAN was 2.9 ± 0.5 GtC yr−1, and SLAND was 4.1 ± 0.9 GtC yr−1. GATM was lower in 2014 compared to the past decade (2005–2014), reflecting a larger SLAND for that year. The global atmospheric CO2 concentration reached 397.15 ± 0.10 ppm averaged over 2014. For 2015, preliminary data indicate that the growth in EFF will be near or slightly below zero, with a projection of −0.6 [range of −1.6 to +0.5] %, based on national emissions projections for China and the USA, and projections of gross domestic product corrected for recent changes in the carbon intensity of the global economy for the rest of the world. From this projection of EFF and assumed constant ELUC for 2015, cumulative emissions of CO2 will reach about 555 ± 55 GtC (2035 ± 205 GtCO2) for 1870–2015, about 75 % from EFF and 25 % from ELUC. This living data update documents changes in the methods and data sets used in this new carbon budget compared with previous publications of this data set (Le Quéré et al., 2015, 2014, 2013). All observations presented here can be downloaded from the Carbon Dioxide Information Analysis Center (doi:10.3334/CDIAC/GCP_2015)., NERC provided funding to C. Le Quéré, R. Moriarty, and the GCP through their International Opportunities Fund specifically to support this publication (NE/103002X/1). G. P. Peters and R. M. Andrew were supported by the Norwegian Research Council (236296). J. G. Canadell was supported by the Australian Climate Change Science Programme. S. Sitch was supported by EU FP7 for funding through projects LUC4C (GA603542). R. J. Andres was supported by US Department of Energy, Office of Science, Biological and Environmental Research (BER) programmes under US Department of Energy contract DE-AC05-00OR22725. T. A. Boden was supported by US Department of Energy, Office of Science, Biological and Environmental Research (BER) programmes under US Department of Energy contract DE-AC05-00OR22725.J. I. House was supported by the Leverhulme foundation and the EU FP7 through project LUC4C (GA603542). P. Friedlingstein was supported by the EU FP7 for funding through projects LUC4C (GA603542) and EMBRACE (GA282672). A. Arneth was supported by the EU FP7 for funding through LUC4C (603542), and the Helmholtz foundation and its ATMO programme. D. C. E. Bakker was supported by the EU FP7 for funding through project CARBOCHANGE (284879), the UK Ocean Acidification Research Programme (NE/H017046/1; funded by the Natural Environment Research Council, the Department for Energy and Climate Change and the Department for Environment, Food and Rural Affairs). L. Barbero was supported by NOAA’s Ocean Acidification Program and acknowledges support for this work from the National Aeronautics and Space Administration (NASA) ROSES Carbon Cycle Science under NASA grant 13-CARBON13_2-0080. P. Ciais acknowledges support from the European Research Council through Synergy grant ERC-2013-SyG-610028 “IMBALANCE-P”. M. Fader was supported by the EU FP7 for funding through project LUC4C (GA603542). J. Hauck was supported by the Helmholtz Postdoc Programme (Initiative and Networking Fund of the Helmholtz Association). R. A. Feely and A. J. Sutton were supported by the
Climate Observation Division, Climate Program Office, NOAA, US Department of Commerce. A. K. Jain was supported by the US National Science Foundation (NSF AGS 12-43071) the US Department of Energy, Office of Science and BER programmes (DOE DE-SC0006706) and NASA LCLUC programme (NASA NNX14AD94G). E. Kato was supported by the ERTDF (S-10) from the Ministry of Environment, Japan. K. Klein Goldewijk was supported by the Dutch NWO VENI grant no. 863.14.022. S. K. Lauvset was supported by the project “Monitoring ocean acidification in Norwegian waters” from the Norwegian Ministry of Climate and Environment. V. Kitidis was supported by the EU FP7 for funding through project CARBOCHANGE (264879). C. Koven was supported by the Director, Office of Science, Office of Biological and Environmental Research of the US Department of Energy under contract no. DE-AC02-05CH11231 as part of their Regional and Global Climate Modeling Program. P. Landschützer was supported by GEOCarbon. I. T. van der Lann-Luijkx received financial support from OCW/NWO for ICOS-NL and computing time from NWO (SH-060-13). I. D. Lima was supported by the US National Science Foundation (NSF AGS-1048827). N. Metzl was supported by Institut National des Sciences de l’Univers (INSU) and Institut Paul Emile Victor (IPEV) for OISO cruises. D. R. Munro was supported by the US National Science Foundation (NSF PLR-1341647 and NSF AOAS-0944761). J. E. M. S. Nabel was supported by the German Research Foundation’s Emmy Noether Programme (PO1751/1-1) and acknowledges Julia Pongratz and Kim Naudts for their contributions. Y. Nojiri and S. Nakaoka were supported by the Global Environment Research Account for National Institutes (1432) by the Ministry of Environment of Japan. A. Olsen appreciates support from the Norwegian Research Council (SNACS, 229752). F. F. Pérez were supported by BOCATS (CTM2013-41048-P) project co-founded by the Spanish government and the Fondo Europeo de Desarrollo Regional (FEDER). B. Pfeil was supported through the European Union’s Horizon 2020 research and innovation programme AtlantOS under grant agreement no. 633211. D. Pierrot was supported by NOAA through the Climate Observation Division of the Climate Program Office. B. Poulter was supported by the EU FP7 for funding through GEOCarbon. G. Rehder was supported by BMBF (Bundesministerium für Bildung und Forschung) through project ICOS, grant no. 01LK1224D. U. Schuster was supported by NERC UKOARP (NE/H017046/1), NERC RAGANRoCC (NE/K002473/1), the European Space Agency (ESA) OceanFlux Evolution project, and EU FP7 CARBOCHANGE (264879). T. Steinhoff was supported by ICOS-D (BMBF FK 01LK1101C) and EU FP7 for funding through project CARBOCHANGE (264879). J. Schwinger was supported by the Research Council of Norway through project EVA (229771). T. Takahashi was supported by grants from NOAA and the Comer Education and Science Foundation. B. Tilbrook was supported by the Australian Department of Environment and the Integrated Marine Observing System. B. D. Stocker was supported by the Swiss National Science Foundation and FP7 funding through project EMBRACE (282672). S. van Heuven was supported by the EU FP7 for funding through project CARBOCHANGE (264879). G. R. van der Werf was supported by the European Research Council (280061). A. Wiltshire was supported by the Joint UK DECC/Defra Met Office Hadley Centre Climate Programme (GA01101) and EU FP7 Funding through project LUC4C (603542). S. Zaehle was supported by the European Research Council (ERC) under the Eu ropean Union’s Horizon 2020 research and innovation programme (QUINCY; grant agreement no. 647204). ISAM (PI: Atul K. Jain) simulations were carried out at the National Energy Research Scientific Computing Center (NERSC), which is supported by the US DOE under contract DE-AC02-05CH11231. Contributions from the Scripps Institution of Oceanography were supported under DoE grant DE-SC0012167 and by Schmidt Philanthropies. This is NOAA-PMEL contribution number 4400., Peer reviewed

17 pages, 4 tables, 8 figures, The aragonite saturation state (ΩAr) in the subpolar North Atlantic was derived using new regional empirical algorithms. These multiple regression algorithms were developed using the bin-averaged GLODAPv2 data of commonly observed oceanographic variables [temperature (T), salinity (S), pressure (P), oxygen (O2), nitrate (NO−3 ), phosphate (PO3−4 ), silicate (Si(OH)4), and pH]. Five of these variables are also frequently observed using autonomous platforms, which means they are widely available. The algorithms were validated against independent shipboard data from the OVIDE2012 cruise. It was also applied to time series observations of T, S, P, and O2 from the K1 mooring (56.5°N, 52.6°W) to reconstruct for the first time the seasonal variability of ΩAr. Our study suggests: (i) linear regression algorithms based on bin-averaged carbonate system data can successfully estimate ΩAr in our study domain over the 0–3,500 m depth range (R2 = 0.985, RMSE = 0.044); (ii) that ΩAr also can be adequately estimated from solely non-carbonate observations (R2 = 0.969, RMSE = 0.063) and autonomous sensor variables (R2 = 0.978, RMSE = 0.053). Validation with independent OVIDE2012 data further suggests that; (iii) both algorithms, non-carbonate (MEF = 0.929) and autonomous sensors (MEF = 0.995) have excellent predictive skill over the 0–3,500 depth range; (iv) that in deep waters (>500 m) observations of T, S, and O2 may be sufficient predictors of ΩAr (MEF = 0.913); and (iv) the importance of adding pH sensors on autonomous platforms in the euphotic and remineralization zone (<500 m). Reconstructed ΩAr at Irminger Sea site, and the K1 mooring in Labrador Sea show high seasonal variability at the surface due to biological drawdown of inorganic carbon during the summer, and fairly uniform ΩAr values in the water column during winter convection. Application to time series sites shows the potential for regionally tuned algorithms, but they need to be further compared against ΩAr calculated by conventional means to fully assess their validity and performance., MD was supported by an NSERC Discovery Grant, and SKL was supported by the EU H2020 research and innovation project AtlantOS (grant agreement no 633211). The OVIDE-12 cruise and the contribution of FA-P and FP were supported by the Spanish Ministry of Economy and Competitiveness
through the project CTM2013-41048-P co-funded by the Fondo Europeo de Desarrollo Regional 2014-2020 (FEDER). K1 mooring is an Oceansites site supported by the EU Horizon 2020 research and innovation program AtlantOS (grant agreement no 633211). LDEO contribution no 8169., Peer reviewed

This dataset reports for the classical rosette bottle data for the following Essential Ocean Variables: salinity, dissolved oxygen, total alkalinity, pH, nitrates and silicic acid. It also reports on the measurements of the CTD-O2 probe at the bottle levels: pressure, temperature, salinity and dissolved oxygen, The GEOVIDE cruise was carried out coast to coast between Portugal and Newfoundland via the south tip of Greenland, following the OVIDE line in the eastern part and crossing the Labrador Sea in the western part. The classical hydrographic rosette was cast 163 times at 78 different geographical positions called stations. While the CTD-O2 probe acquired continuous profiles of the “physical” variables (pressure, temperature, salinity and dissolved oxygen), 22 Niskin bottles were closed at different levels during the upcast to provide samples for biogeochemical analysis. After calibration, we find precisions for pressure, temperature, salinity and dissolved oxygen that fit the GO-SHIP international quality requirements. In parallel, but not simultaneously, a trace-metal rosette (TMR) was cast 53 times, also acquiring profiles of physical variables, and equipped with 24 Go-Flo bottles adapted for the sampling of trace metals. Depending on the number of operations, stations were identified as “Short” (one single CTD cast), “Large” (3 CTD casts), “XLarge” (up to 6) and “Super” (up to 11). All along the track of the ship, current magnitude and direction was measured by Ship Acoustic Doppler Current Profilers, down to 1000m depth, Spanish Ministry of Economy and Competitiveness through the BOCATS (CTM2013-41048-P) project, co-funded by the Fondo Europeo de Desarrollo Regional 2014–2020 (FEDER). CNRS and the AtlantOS H2020 project under grant number 633211. LABEX-Mer (French Government “Investissement d’Avenir” programme, ANR-10-LABX-19-01), No

1 file, LOCEAN has been in charge of analyzing the isotopic composition of the dissolved inorganic carbon (DIC) in sea water collected during a series of cruises or ships of opportunity mostly in the southern Indian Ocean , the North Atlantic, and the equatorial Atlantic, but also in the Mediterranean Sea and in the equatorial Pacific.

The LOCEAN sea-water samples for δ13CDIC were collected in 125/25 ml glass bottles until 2022/since then and poisoned with HgCl2 (1 ml of saturated solution) before storage in a dark room à 4°C until their measurement. The DIC was extracted from the seawater by acidification with phosphoric acid (H3PO4 85%) and CO2 gas that was produced was collected in a vacuum system following the procedure described by Kroopnick (1974). The isotopic composition of CO2 was determined using a dual inlet-isotopic ratio mass spectrometer (SIRA9-VG) by comparing the 13C/12C ratio of the sample to the 13C/12C ratio of a reference material, the Vienna-Pee Dee Belemnite (V-PDB). The isotopic composition is expressed in the δ-unit defined by Craig (1957)(method type 2). Experience showed that samples older than 3-4 years are likely to have experienced conservation issues and have been dismissed. The mass spectrometer has worked very well until 2014-2015. Afterwards, its aging as well as the aging of the preparation line resulted in more data loss, and often less accurate results. The preparation line was renovated in 2019, and analyses in 2020 were run manually, often repeating the measurement a second time for each sample.

Up to 2007-2008, δ13CDIC values have a precision of±0.01 ‰ (Vangriesheim et al.,2009) and a reproducibility of±0.02 ‰. After an interlaboratory comparison exercise led by Claire Normandeau (Dalhousie University), results suggest that recent LOCEAN samples have a slightly poorer reproducibility (±0.04 ‰ ) as well as an offset of -0.13‰ (details available in Reverdin et al., ESSD 2018) that is confirmed by Becker et al. 2016 work by comparison with other cruises after removing the anthropogenic signal. Recent comparisons in early May 2021 with Orsay GEOPS facility samples suggest that the current offset is much smaller and might be +0.03‰.

LOCEAN has installed in 2021 a new measurement device by coupling a Picarro G2131-I cavity ring down spectrometer (CRDS) with a CO2 extractor (Apollo SciTech) that will measure at the same time DIC (method type 3) (Leseurre, 2022). Since then, all water samples have been analyzed on this device.

Part of the data set, as well as a scientific context and publications are also presented on the WEB site https://www.locean-ipsl.upmc.fr/oceans13c

Individual files correspond to regional subsets of the whole dataset. The file names are based on two letters for the region followed by (-) the cruise or project name (see below) followed by –DICisotopes, followed by either -s (surface data) or -b (subsurface data), and a version number (-V0, …): example SI-OISO-DICisotopes-s-V0; the highest version number corresponds to the latest update of the cruise/project data set, and can be directly downloaded. Earlier versions can be obtained on request, but are not recommended, Support by OSU ECCE Terra, by LOCEAN, and by various French national institutes and programs is gratefully acknowledged (including INSU/CNRS, IFREMER, IRD, IPEV, LEFE program, ANR GEOVIDE, IPSL), as well as support of different French ‘Services nationaux d’Observation’, such as PIRATA, SSS and OISO/CARAUS. Many of the data originate from cruises on French Research vessels: R.V. Noroit, Suroit, Thalassa, Atalante, Marion Dufresne 2. Some data were collected during research cruises on non-French vessels, such as BOCATS in 2016 on the Spanish R/V Sarmiento de Gamboa. The SURATLANT data were collected on merchant vessels with support of EIMSKIP in Iceland., Peer reviewed

Poster.-- VI International Symposium on Marine Sciences, Vigo (Spain), 20-22th June 2018, During the BOCATS 2016 cruise an exhaustive sampling of superficial sediments were done across the transect of the OVIDE/A25 transoceanic section in the North Atlantic. OVIDE section spans from subtropical to subpolar latitudes, crossing several ocean basins where presumably different pelagic-sedimentation processes take place. Here, we report the carbon elemental composition for box-corer samples from the subpolar basins Irminger and Iceland. Quantitative analysis of the carbon composition has been done on dried sub-samples with a LECO CN system analyzer. After a first determination of total carbon, the aliquot is heated under 400ºC during 3h in order to remove the organic fraction prior to a second analysis. The second determination represents the total inorganic carbon fraction. Total organic carbon is the difference between the two measurements. Carbon elemental composition was obtained at centimetric resolution from top to bottom.
The preliminary results show that as a general rule, the amount of total carbon is dominated by the inorganic fraction. In all the cores, the organic fraction is always less than 1% in mass. While the carbon composition is consistent between nearby cores, there are also inter-basin differences. The inter-basin differences are mainly based in the relative contribution of the inorganic carbon, with the Iceland Basin showing the greatest fractions. The inter-basin differences remains in the inorganic:organic ratios. This basin-scale preliminary analysis suggest that significant relationships between the inorganic:organic ratio and the location of the samples exists. In the Iceland Basin the inorganic:organic ratio is statistically significant with the depth. In both subpolar basins the existence of strong western boundary bottom currents is hypothesized as a main factor underlying the inorganic:organic ratio distribution, This study is a contribution to the BOCATS project (CTM2013-41048-P) funded by the Ministerio de Economía y Competitividad (MINECO, BES-2014-07044) and co-funded by the Fondo Europeo de Desarrollo Regional 2007-2012 (FEDER), Peer reviewed

Evaluation of biogeochemical processes in Anthropocene deep-sea sediments require accurate dating techniques. Here we show the results of an approach using high resolution low level background gamma spectrometry with two simultaneous hyper-pure germanium (HPGe) detectors. The quantitative role of the deepest zones (>3000 m depth) of the Irminger Basin (Subpolar North Atlantic Ocean) as a carbon sink during the Anthropocene is evaluated combining a chronology based in the natural radionuclide 210 Pb with sedimentological analysis and elemental composition. The average sedimentation rate of the central Irminger is 1.28 ± 0.18 mm·yr −1 , with a mean weighted flux to the sediment for inorganic and organic carbon of 46 ± 15 g·C inorg ·m −2 ·yr −1 and 8 ± 1 g·C org ·m −2 ·yr −1 . The biogenic fraction of the mass flux is increased since the XXth century. The contribution of the deepest zones of the Irminger Basin to the Anthropocene carbon sequestration in the North Atlantic Ocean is considerable at basin-scale., Ministerio de Economía y Competitividad | Ref. CTM2013-41048-P, Ministerio de Economía y Competitividad | Ref. BES-2014-070449

In order to establish the chronology of deep-sea sediments from high-resolution 210Pb-dating, the determination of 210Pb and 226Ra activity concentrations needs to be improved. Gamma spectrometry allows determining simultaneously both radionuclides. However, spectrum background is still an issue to obtain high sensitivity. Four deep-sea sediment cores were dated using Mazinger, a gamma spectrometer with high-efficiency and very low-background, and the Constant Rate and Supply model was applied to obtain recent ages., Ministerio de Economía y Competitividad | Ref. BES-2014-070449, Ministerio de Economía y Competitividad | Ref. CTM2013-41048-P