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

Digital.CSIC. Repositorio Institucional del CSIC
  • Vázquez Rodríguez, Marcos
  • Padín, X. A.
  • Pardo, Paula C.
  • Ríos, Aida F.
  • Pérez, Fiz F.
12 páginas, 6 figuras, 2 tablas.-- Proyecto Carbochange, The subsurface ocean layer (100–200 m deep) is suggested as a reference to parameterise preformed alkalinity
(AT°) and air–sea CO2 disequilibrium (ΔCdis) in the Atlantic. Results suggest that this domain retains thememory
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 year-round 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 pCO2 sampling during wintertime. The obtained AT° andΔCdis parameterisations
achieve uncertainties of±4.6 and±5.6 μmol kg−1, respectively, improving significantly the estimates
in previous works, particularly in the high latitudes. The AT° parameterisation 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 ΔCdis estimates in the upper layers are coherent
with air–sea ΔpCO2 data from Takahashi's climatology, thus tackling known important shortcomings and
biases of anthropogenic CO2 estimates in Atlantic waters., This study was developed and
funded by the European Commission within the 7th Framework Programme
(EU FP7-ENV-2010 CARBOCHANGE Collaborative Project, Contract
no. 264879), Ministerio de Educación y Ciencia (CTM2006-27116-
E/MAR), Xunta de Galicia (PGIDIT05PXIC40203PM), Acción Integrada
Hispano-Francesa (HF2006-0094) and the French research project
OVIDE. Marcos Vázquez-Rodríguez is funded by Consejo Superior de
Investigaciones Científicas (CSIC) I3P predoctoral grant programme
I3P-BPD2005, Peer reviewed
Proyecto: EC/FP7/264879




Anthropogenic carbon inventory in the Gulf of Cádiz

Digital.CSIC. Repositorio Institucional del CSIC
  • Flecha, Susana
  • Pérez, Fiz F.
  • Navarro, Gabriel
  • Ruiz Segura, Javier
  • Livé, I.
  • Rodríguez-Gálvez, Susana
  • Costas, Eduardo
  • Huertas, I. Emma
9 páginas, 2 tablas, 6 figuras.-- Proyecto Carbochange, The North Atlantic is the most important sink for atmospheric CO2 although there still remain uncertainties about the total amount stored by this region and the contribution of the anthropogenic CO2 (CANT) that is exchanged between the Mediterranean Sea and the Atlantic Ocean. During the P3A2 cruise performed in October 2008 throughout the oceanic area covered by the Gulf of Cádiz and the Strait of Gibraltar, which channelizes the water exchange between the Atlantic and the Mediterranean, extensive measurements of the carbon system parameters (pH, total alkalinity and total inorganic carbon) and others related (dissolved oxygen and nutrients) were carried out to analyze their distribution in the area. In order to study the CANT spatial variability, three observational methods for CANT concentration assessment (φCT°, ∆C* and TrOCA) were applied. The three water masses identified in the area, North Atlantic Central Water (NACW), North Atlantic Deep Water (NADW) and Mediterranean Outflow Water (MOW), were shown to contain different CANT concentration. NADW exhibited the lowest CANT levels whereas NACW was the most CANT enriched. Data also indicate a net import of CANT from the Atlantic towards the Mediterranean through Gibraltar. Specific CANT inventories showed that MOW contributes in 8–12% to the total specific CANT inventory of the Gulf of Cádiz., Funding for this work was provided by the European Projects CARBOOCEAN IP(511176GOCE) and CARBOCHANGE(264879) and by the Spanish Ministry of Sciences and Innovation through the projects and ., Peer reviewed
Proyecto: EC/FP7/264879




An update of anthropogenic CO2 storage rates in the western South Atlantic basin and the role of Antarctic Bottom Water

Digital.CSIC. Repositorio Institucional del CSIC
  • Ríos, Aida F.
  • Velo, A.
  • Pardo, Paula C.
  • Hoppema, Mario
  • Pérez, Fiz F.
7 páginas, 4 tablas, 3 figuras, 1 apéndice.-- Proyecto Carbochange, The western basin of the South Atlantic from 10°N to 55°S and from the coast to the Mid-Atlantic Ridge is a
region with large uncertainties as to the storage of anthropogenic CO2 (Cant). Our analysis of data of the last
three decades provides a Cant storage rate of 0.92±0.13 mol m−2 y−1, i.e., 13%–35% higher than previous
estimates in this area. The low but significant Cant concentrations ([Cant]) in the large volume of relatively
well ventilated Antarctic Bottom Water (AABW) may well be the underlying cause of this higher storage
rate. In fact, the significant contribution in terms of Cant of this ventilated AABW that enters the western
South Atlantic Ocean was calculated to be 0.055±0.02 Pg C y−1 or 0.20 mol m−2 y−1. Instead of being
based on the annual trend, the Cant specific inventory (in mol m−2) evolution is more consistently computed
as a function of the atmospheric xCO2 perturbation in ppm, (0.64 mol m−2 ppm−1). This methodology allows
improved projections of Cant storage rates over long periods., EU FP7 project CARBOCHANGE
“Changes in carbon uptake and emissions by oceans in a changing climate” which received funding from the European Community's Seventh
Framework Programme under grant agreement no. 264879, Peer reviewed
Proyecto: EC/FP7/264879




Interior carbon changes in the atlantic

Digital.CSIC. Repositorio Institucional del CSIC
  • Pérez, Fiz F.
  • Velo, A.
  • Mercier, Herlé
  • Ríos, Aida F.
  • Hoppema, Mario
Póster presentado en el congreso: THE OCEAN CARBON CYCLE AT A TIME OF CHANGE:
SYNTHESIS AND VULNERABILITIES
September 14 – 16, 2011, UNESCO, Paris.-- Proyecto Carbochange
Proyecto: EC/FP7/264879




An update of anthropogenic CO2 storage rates in the western South Atlantic basin and the role of Antarctic Bottom Water

Digital.CSIC. Repositorio Institucional del CSIC
  • Ríos, Aida F.
  • Velo, A.
  • Pardo, Paula C.
  • Hoppema, Mario
  • Pérez, Fiz F.
Póster presentado en el congreso: THE OCEAN CARBON CYCLE AT A TIME OF CHANGE: SYNTHESIS AND VULNERABILITIES September 14 – 16, 2011, UNESCO, Paris.-- Proyecto Carbochange, The western South Atlantic (WSA) basin is a region with large uncertainties as to the storage of anthropogenic CO2 (Cant). Our analysis of data of the last three decades provides a Cant storage rate of 0.92 ±0.13 mol m-2 y-1, i.e., 13/%-35/% higher than previous estimates in this area. The low but significant Cant concentrations in the large volume of relatively well ventilated Antarctic Bottom Water (AABW) may well be the underlying cause of this higher storage rate. In fact, the significant contribution in terms of Cant of this ventilated AABW that enters the WSA was calculated to be 0.055 ± 0.02 Pg C y-1 or 0.20 mol m-2 y-1. Instead of being based on the annual trend, the Cant specific inventory evolution is more consistently computed as a function of the atmospheric xCO2 perturbation (0.64 mol m-2 ppm-1). This methodology allows improved projections of Cant storage rates over long periods.
Proyecto: EC/FP7/264879




An update of anthropogenic CO2 storage rates in the western South Atlantic and the role of Antarctic Bottom Water

Digital.CSIC. Repositorio Institucional del CSIC
  • Ríos, Aida F.
  • Velo, A.
  • Pardo, Paula C.
  • Hoppema, Mario
  • Pérez, Fiz F.
Póster presentado al congreso: GEO-CARBON CONFERENCE: CARBON IN A CHANGING WORLD, 24-26 OCTOBER 2011, ROMA.-- Proyecto Carbochange, Re-evaluation of the CANT storage rates in the western South Atlantic and the role of the AABW using quality and quantity carbon measurements
Proyecto: EC/FP7/264879




Water masses distribution in the Southern Ocean: improvement of an extended OMP (eOMP) analysis

Digital.CSIC. Repositorio Institucional del CSIC
  • Pardo, Paula C.
  • Pérez, Fiz F.
  • Velo, A.
  • Gilcoto, Miguel
14 páginas, 9 figuras, 2 tablas.-- Proyecto Carbochange, The Southern Ocean (SO) is a major part of the global ocean circulation. The formation and mixing of
water masses in the SO cause changes in the northward flow of the Meridional Overturning Circulation
and as a consequence, in the Earth’s climate. There have been numerous studies of the SO but a
full understanding is difficult to achieve due to the complexity of the processes of formation and mixing
of the different water masses. This work aims to clarify some of these aspects through an
extended Optimum Multiparametric analysis, using data downloaded from the GLODAP and CARINA
databases. A total of 11 source water masses were selected accurately describe the physical and biochemical
properties of the SO. Shelf surface waters were included in order to accommodate the complex
shelf processes involved in the formation of Antarctic bottom Waters. The methodology here
developed takes into account the remineralisation of organic matter and as an improvement; the variability
of data related to the processes of dissolution of CaCO3 and opal. The results from this analysis
are accurate and reliable and led to very informative conclusions. Thus, a volumetric census is presented,
which confirms Circumpolar Deep Water (CDW; 53 ± 3% of the SO volume) as the most volumetrically
important water mass in the SO; followed by Antarctic Bottom Water (AABW;
17 ± 0.9%) and North Atlantic Deep Water (NADW; 13 ± 0.8%). AABW properties are the result of
the predefined combination of its three major types, i.e., 77% Weddell Sea Bottom Water, 20% Ross
Sea Bottom Water and 3% Adélie Bottom Water. CDW comprises 65% AABW, 30% NADW and 5% Antarctic
Intermediate Water, according to the relationship between their conservative properties (potential
temperature and salinity). Therefore, the volume occupied by AABW and NADW in the SO rises to
51 ± 2% and 28 ± 0.8%, respectively. The ratio between AABW and NADW is 1.79 ± 0.03, which is inside
the expected range of 1–3. Considering the Atlantic sector of the SO (70 W–80 E), which is the more
relevant in terms of AABW production (AABW represents 60 ± 0.2% of the volume of the sector), the
estimated ventilation time is approximately 250 years, the same period as for the whole SO. This
demonstrates the very important role of shelf processes in the quantity of AABW formed in the SO
and its crucial role in terms of global climate., This study was funded by the
7th Framework Programme (EU FP CARBOCHANGE, C_ENVIR/
0869) and by the Spanish Ministry of Education and Sciences
through the Projects CATARINA (CTM2010-17141/MAR)., Peer reviewed
Proyecto: EC/FP7/264879




Total alkalinity estimation using MLR and neural network techniques

Digital.CSIC. Repositorio Institucional del CSIC
  • Velo, A.
  • Pérez, Fiz F.
  • Tanhua, Toste
  • Gilcoto, Miguel
  • Ríos, Aida F.
  • Key, Robert M.
8 páginas, 2 tablas, 5 figuras.-- Proyecto Carbochange, During the last decade, two important collections of carbon relevant hydrochemical data have become available:
GLODAP and CARINA. These collections comprise a synthesis of bottle data for all ocean depths from many
cruises collected over several decades. For a majority of the cruises at least two carbon parameters were
measured. However, for a large number of stations, samples or even cruises, the carbonate system is
under-determined (i.e., only one or no carbonate parameterwas measured) resulting in data gaps for the carbonate
system in these collections. A method for filling these gaps would be very useful, as it would help with
estimations of the anthropogenic carbon (Cant) content or quantification of oceanic acidification. The aim of
this work is to apply and describe, a 3D moving window multilinear regression algorithm (MLR) to fill gaps in
total alkalinity (AT) of the CARINA and GLODAP data collections for the Atlantic. In addition to filling data gaps,
the estimated AT values derived from the MLR are useful in quality control of the measurements of the carbonate
system, as they can aid in the identification of outliers. For comparison, a neural network algorithm able to
performnon-linear predictionswas also designed. The goal herewas to design an alternative approach to accomplish
the sametask of filling AT gaps. Bothmethods return internally consistent results, thereby giving confidence
in our approach., This work and in particular T.T.
was supported through EU FP7 project CARBOCHANGE “Changes in
carbon uptake and emissions by oceans in a changing climate”, which
received funding from the European Community's Seventh Framework
Programme under grant agreement no. 264879., Peer reviewed
Proyecto: EC/FP7/264879




Cambios de CO2 en el océano Atlántico

Digital.CSIC. Repositorio Institucional del CSIC
  • Ríos, Aida F.
Conferencia invitada del ISMS12 International Symposium in Marine Sciences and XVI SIQM Seminario Ibérico de Química Marina, Universidad de Cádiz, 2012.-- Proyecto Carbochange, Peer reviewed
Proyecto: EC/FP7/264879




Mass, nutrient and oxygen budgets for the northeastern Atlantic Ocean

Digital.CSIC. Repositorio Institucional del CSIC
  • Maze, G.
  • Mercier, Herlé
  • Thierry, V.
  • Mémery, L.
  • Morin, Pascal
  • Pérez, Fiz F.
15 páginas, 4 figuras, 4 tablas, The northeast Atlantic is a key horizontal and vertical crossroads region for the meridional overturning circulation, but basic nutrient and oxygen fluxes are still poorly constrained by observations in the region. A surface to bottom northeast Atlantic Ocean budget for mass, nutrients (nitrate and phosphate) and oxygen is determined using an optimization method based on three surveys of the OVIDE transect (from Greenland to Portugal) completed with the World Ocean Atlas 2009. Budgets are derived for two communicating boxes representing the northeastern European basin (NEEB) and the Irminger Sea.

For the NEEB (Irminger) box, it is found that 30% of the mass import (export) across the OVIDE section reach (originate from) the Nordic Seas, while 70% are redistributed between both boxes through the Reykjanes Ridge (9.3 ± 0.7 × 109 kg s−1).

Net biological source/sink terms of nitrate point to both the Irminger and NEEB boxes as net organic matter production sites (consuming nitrate at a rate of –7.8 ± 6.5 kmol s−1 and –8.4 ± 6.6 kmol s−1, respectively). Using a standard Redfield ratio of C : N = 106 : 16, nitrate consumption rates indicate that about 40 TgC yr−1 of carbon is fixed by organic matter production between the OVIDE transect and the Greenland–Scotland Ridge. Nutrient fluxes also induce a net biological production of oxygen of 73 ± 60 kmol s−1 and 79 ± 62 kmol s−1 in the Irminger and NEEB boxes, which points to the region as being autotrophic.

The abiotic air–sea oxygen flux leads to an oceanic oxygen uptake in the two regions (264 ± 66 kmol s−1 in the north and 443 ± 70 kmol s−1 in the south). The abiotic flux is partitioned into a mixing and a thermal component. It is found that the Irminger Sea oceanic oxygen uptake is driven by an air–sea heat flux cooling increasing the ocean surface oxygen solubility. Over the northeastern European basin the mixing component is about half the thermal flux, presumably because of the oxygen minimum in the subtropical thermocline., G. Maze was co-funded by the GIS Europole
Mer, Ifremer and the CREST Argo project from the CPER Bretagne
2008–2013. The CREST Argo project is funded by Europe through
the FEDER program and by the Brittany Region, Brest Metropole
Oceane and CG29. Funding for this work was also provided by the
CARBOCHANGE FP7-ENV-2010 of the European Commission
(264879) and by the Spanish Ministry of Education and Sciences
through the CATARINA (CTM2010-17141/MAR). The OVIDE
survey is a project co-funded by IFREMER, CNRS-INSU and
LEFE. Contributions from H. Mercier and P. Morin were funded
by the CNRS and from V. Thierry by IFREMER., Peer reviewed
Proyecto: EC/FP7/264879




Short-term variability of surface carbon dioxide and sea-air CO2 fluxes in the shelf waters of the Galician coastal upwelling system

Digital.CSIC. Repositorio Institucional del CSIC
  • Cobo-Viveros, Alba Marina
  • Padín, X. A.
  • Otero, P.
  • Paz, M. de la
  • Ruiz-Villarreal, Manuel
  • Ríos, Aida F.
  • Pérez, Fiz F.
12 pages, 4 figures, 2 tables.-- Proyecto Carbochange.-- XV Seminario Ibérico de Química Marina, Vigo, 22-24 February 2010, [EN] Using data collected during the DYBAGA and ECO cruises, remote sensing chlorophyll-a estimations and the averaged upwelling index of the previous fortnight (Iw’), we studied the variability of the sea surface CO2 fugacity (fCO2) over the Galician continental shelf during three seasonal cycles. Sea surface salinity (SSS) distribution controlled fCO2 mainly in spring, while sea surface temperature (SST) did during periods of intense cooling in November and warming in June. The uptake of carbon by photosynthetic activity, which was more intense during spring and autumn, masked the surface increase of dissolved inorganic carbon concentration during upwelling events, especially during spring. Significant low correlation between fCO2 and Iw’ was found during spring and summer when upwelling events were observed, whereas no relationship was observed during the downwelling period. High fCO2 exceeding atmospheric values was only found during the summer stratification breakdown. Although sea-air CO2 fluxes showed a marked inter-annual variability, surface waters off the Galician coast were net sinks for atmospheric CO2 in every seasonal cycle, presenting a lower CO2 uptake (~65%) compared to previous published values. Marked inter-annual changes of the sea-air CO2 fluxes seem to be influenced by fresh water inputs on the continental shelf under different meteorological scenarios., [ES] Durante tres ciclos estacionales se estudió la variabilidad superficial de la fugacidad de CO2 (fCO2) en la plataforma continental gallega, utilizando datos recogidos durante los proyectos DYBAGA y ECO, así como estimaciones de clorofila-a a partir de datos de satélite, y promedios quincenales del índice de afloramiento (Iw’). Los cambios de salinidad controlaron la variabilidad de fCO2 en primavera, mientras que la temperatura lo hizo durante el máximo enfriamiento de Noviembre y máximo calentamiento de Junio. La captación de carbono por la actividad fotosintética, más intensa durante primavera y otoño, enmascaró el incremento superficial de carbono inorgánico durante los episodios de afloramiento, especialmente en primavera. Se observó una correlación significativa, aunque pequeña, entre fCO2 e Iw’ durante el período de afloramiento, mientras que no se encontró ninguna durante el hundimiento. Sólo se encontraron valores de fCO2 superiores a los atmosféricos durante la ruptura de la estratificación estival. Aunque el intercambio de CO2 océano-atmósfera mostró una marcada variabilidad interanual, la plataforma continental gallega fue un sumidero neto de CO2 atmosférico. Los valores encontrados son inferiores a otros publicados anteriormente (~65% menos). Estos cambios interanuales parecen estar influidos por los aportes de agua dulce en la plataforma continental bajo distintas condiciones 52 meteorológicas., This study 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 Community’s Seventh Framework Programme under grant agreement no. 264879. The experimental work was funded by the Spanish research project DYBAGA (CICYT. MAR1999-1039) and the ECO project (MCyT REN2002-00503/MAR). Alba Marina Cobo- Viveros is a PhD student financed by the Spanish National Research Council (CSIC) through the JAE-Predoc grants from the program “Junta de Ampliación de Estudios”, and cofinanced by the FSE (Fondo Social Europeo – European Social Fund). The co-author Mercedes de la Paz acknowledges the financial support of the CSIC post-doctoral program JAE-Doc, also co-financed by the FSE, No
Proyecto: EC/FP7/264879




Observed acidification trends in North Atlantic water masses

Digital.CSIC. Repositorio Institucional del CSIC
  • Vázquez Rodríguez, Marcos
  • Pérez, Fiz F.
  • Velo, A.
  • Ríos, Aida F.
  • Mercier, Herlé
14 páginas, 4 figuras, 3 tablas.-- Proyecto Carbochange, The lack of observational pH data has made it difficult
to assess recent rates of ocean acidification, particularly
in the high latitudes. Here we present a time series that
spans over 27 yr (1981–2008) of high-quality carbon system
measurements in the North Atlantic, which comprises fourteen
cruises and covers the important water mass formation
areas of the Irminger and Iceland Basins. We provide direct
quantification of acidification rates in upper and intermediate
North Atlantic waters. The highest rates were associated with
surface waters and with Labrador Sea Water (LSW). The
Subarctic Intermediate and Subpolar Mode Waters (SAIW
and SPMW) showed acidification rates of −0.0019±0.0001
and −0.0012±0.0002 yr−1, respectively. The deep convection
activity in the North Atlantic Subpolar Gyre injects surface
waters loaded with anthropogenic CO2 into lower layers,
provoking the remarkable acidification rate observed for
LSW in the Iceland Basin (−0.0016±0.0002 yr−1). An extrapolation
of the observed linear acidification trends suggests
that the pH of LSW could drop 0.45 units with respect
to pre-industrial levels by the time atmospheric CO2
concentrations reach 775 ppm. Under circulation conditions
and evolution of CO2 emission rates similar to those
of the last three decades, by the time atmospheric CO2
reaches 550 ppm, an aragonite undersaturation state could be
reached in the cLSW of the Iceland Basin, earlier than surface
SPMW., The research leading to these results was supported by
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; by the Spanish
Ministry of Science and Innovation and co-funded by Fondo
Eurpeo de Desarrollo Regional 2007–2012 (FEDER) through the
CATARINA Project (CTM2010-17141). The OVIDE research
project was co-funded by the IFREMER, CNRS/INSU and LEFE.
H.M. was supported by CNRS. M.V.R. was funded by CSIC I3P
Predoctoral Grant program (I3P-BPD2005)., Peer reviewed
Proyecto: EC/FP7/264879




Atlantic Ocean CO2 uptake reduced by weakening of the meridional overturning circulation

Digital.CSIC. Repositorio Institucional del CSIC
  • Pérez, Fiz F.
  • Mercier, Herlé
  • Vázquez Rodríguez, Marcos
  • Lherminier, Pascale
  • Velo, A.
  • Pardo, Paula C.
  • Rosón, Gabriel
  • Ríos, Aida F.
7 páginas, 4 figuras.-- Proyecto Carbochange, Uptake of atmospheric carbon dioxide in the subpolar North Atlantic Ocean declined rapidly between 1990 and 2006. This reduction in carbon dioxide uptake was related to warming at the sea surface, which—according to model simulations—coincided with a reduction in the Atlantic meridional overturning circulation. The extent to which the slowdown of this circulation system—which transports warm surface waters to the northern high latitudes, and cool deep waters south—contributed to the reduction in carbon uptake has remained uncertain. Here, we use data on the oceanic transport of volume, heat and carbon dioxide to track carbon dioxide uptake in the subtropical and subpolar regions of the North Atlantic Ocean over the past two decades. We separate anthropogenic carbon from natural carbon by assuming that the latter corresponds to a pre-industrial atmosphere, whereas the remaining is anthropogenic. We find that the uptake of anthropogenic carbon dioxide—released by human activities—occurred almost exclusively in the subtropical gyre. In contrast, natural carbon dioxide uptake—which results from natural Earth system processes—dominated in the subpolar gyre. We attribute the weakening of contemporary carbon dioxide uptake in the subpolar North Atlantic to a reduction in the natural component. We show that the slowdown of the meridional overturning circulation was largely responsible for the reduction in carbon uptake, through a reduction of oceanic heat loss to the atmosphere, and for the concomitant decline in anthropogenic CO2 storage in subpolar waters., This work was supported by the Spanish Ministry of Sciences and Innovation and
co-funded by the Fondo Europeo de Desarrollo Regional 2007 2012 (FEDER)
through the CATARINA project (CTM2010-17141) and through 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 EU under grant agreement no. 264879. The OVIDE research project, Peer reviewed
Proyecto: EC/FP7/264879




Net sea-air CO2 flux uncertainties in the Bay of Biscay based on the choice of wind speed products and gas transfer parameterizations

Digital.CSIC. Repositorio Institucional del CSIC
  • Otero, P.
  • Padín, X. A.
  • Ruiz-Villarreal, Manuel
  • García-García, L. M.
  • Ríos, Aida F.
  • Pérez, Fiz F.
25 páginas, 4 figuras, 1 tabla, The estimation of sea-air CO2 fluxes are largely dependent on wind speed through the gas transfer velocity parameterization. In this paper, we quantify uncertainties in the estimation of the CO2 uptake in the Bay of Biscay resulting from using different sources of wind speed such as three different global reanalysis meteorological models (NCEP/NCAR 1, NCEP/DOE 2 and ERA-Interim), one regional high-resolution forecast model (HIRLAM-AEMet) and QuikSCAT winds, in combination with some of the most widely used gas transfer velocity parameterizations. Results show that net CO2 flux estimations during an entire seasonal cycle may differ up to 240% depending on the wind speed product and the gas exchange parameterization. The comparison of satellite and model derived winds with observations at buoys advises against the systematic overestimation of NCEP-2 and the underestimation of NCEP-1. In this region, QuikSCAT has the best performing, although ERA-Interim becomes the best choice in areas near the coastline or when the time resolution is the constraint., This work was developed and funded by the
ECO project (MCyT REN2002-00503/MAR) and EU FP7 project CARBOCHANGE “Changes
5 in carbon uptake and emissions by oceans in a changing climate” under agreement no. 264879, Peer reviewed
Proyecto: EC/FP7/264879




Key controls on the seasonal and interannual variations of the carbonate system and air-sea CO2 flux in the Northeast Atlantic (Bay of Biscay)

Digital.CSIC. Repositorio Institucional del CSIC
  • Jiang, Zong-Pei
  • Hydes, David J.
  • Tyrrell, Toby
  • Hartman, Susan E.
  • Hartmam, Mark C.
  • Dumousseaud, Cynthia
  • Padín, X. A.
  • Skjelvan, Ingunn
  • González-Pola, C.
16 páginas, 4 tablas, 9 figuras, Biogeochemical variations of surface water in the Northeast Atlantic (Bay of Biscay) were examined using high-frequency underway measurements combined with monthly sampling of carbon-related variables. The mechanisms controlling seasonal CO2 variability were investigated by distinguishing the contributions of biological and physical processes to the monthly changes in dissolved inorganic carbon (DIC) and partial pressure of CO2 (pCO2). The seasonality of DIC (47–81 µmol kg−1) had a single peak with a winter maximum primarily driven by vertical mixing and a summer minimum driven by spring biological removal. Non-Redfield C:N uptake was observed in the nutrient-depleted summer but not during the spring bloom. In the North Atlantic, pCO2 seasonality shows a latitudinal transition: from the temperature-dominated oligotrophic subtropical gyre to the subpolar region where pCO2 is dominated by changing concentrations of DIC. In the midlatitude Bay of Biscay, the annual cycle of pCO2 (61–75 µatm) showed a double-peak distribution. The summer pCO2 peak was mainly driven by temperature increase, while the winter peak resulted from the dominant effect of entrainment of subsurface water. Interannual variations of DIC were more pronounced in winter and were driven by the changes in the strength of winter mixing. Higher wintertime concentrations and seasonal amplitudes of DIC were observed in cold years when the mixed-layer depths were deeper, which appears to be associated with negative phases of the North Atlantic Oscillation. The Bay of Biscay shows a decrease of CO2 uptake in 2008–2010 (−0.97 and −0.75 mol m−2 yr−1) compared to 2002–2004 (−1.47 and −1.68 mol m−2 yr−1)., This work was supported by the UK
DEFRApH, the EU EPOCA projects, and the EU FP7 project CARBO-
CHANGE “Changes in carbon uptake and emissions by oceans in a chang-
ing climate”
funded by the European Community’s Seventh Framework
Programme (no. 264879). Swire Education Trust is thanked for providing
Zong-Pei Jiang’s scholarship, Peer reviewed
Proyecto: EC/FP7/264879




El CO2 antrópico en el oceáno austral

Digital.CSIC. Repositorio Institucional del CSIC
  • Pardo, Paula C.
180 páginas.-- Proyecto Carbochange, El crecimiento acelerado de los niveles de dióxido de carbono (CO2) en la atmósfera a lo largo de los últimos siglos y su impacto en la temperatura media del planeta son, desde hace tiempo, unas de las grandes preocupaciones político-científicas de mayor repercusión. Las principales causas del rápido incremento de los niveles atmosféricos de CO2 son: la utilización de combustibles fósiles, la deforestación y el cambio en los usos del suelo, todos ellos consecuencia de la industrialización. La biosfera y, principalmente, el océano captan buena parte del CO2 atmosférico, mitigando su tasa de incremento. Sin embargo, estimaciones recientes indican que el porcentaje de CO2 que el océano es capaz de absorber está disminuyendo. Por ello, es necesario cuantificar la captación y distribución del CO2 en el océano, y, en especial, su componente antrópica (CANT), la parte del CO2 que se debe a la actividad humana. Además, el aumento del CO2 en el océano trae como consecuencia la progresiva acidificación del mismo, lo que supone condiciones más agresivas y, de continuar esta tendencia, letales en los ecosistemas.
La absorción y acumulación de CO2 en el océano está controlada por la circulación y la mezcla de las masas de agua y, además, por la bomba biológica. La acción del fitoplancton a través de la fotosíntesis, así como la oxidación de componentes orgánicos y la disolución de las estructuras duras de carbonato cálcico de algunos animales regulan la cantidad de CO2 disuelto en el agua.
El principal problema a la hora de cuantificar la capacidad del océano de captar CANT es la imposibilidad de medir esta cantidad directamente. Además, la tarea se complica debido a la dificultad de separar la señal antrópica (del orden de un 3%) en las medidas de carbono inorgánico total. Desde hace más de 30 años se han desarrollado varios métodos (para la medición indirecta de CANT) muy competitivos. Dentro de estos, las técnicas de back-calculation son las más extendidas y están basadas en medidas de carbono. La estimación de CANT a través de estas técnicas se realiza mediante la substracción, en el carbono inorgánico total medido, de los cambios biogeoquímicos ocurridos desde que la masa de agua se formó en superficie y del carbono preformado pre-industrial. La técnica de back-calculation considerada como referencia es la denominada ΔC*, desarrollada por Nicolas Gruber en 1996 y cuyas incertidumbres y errores siguen siendo discutidas en la bibliografía. Este método se ha utilizado en importantes estudios, tales como cálculos globales de CANT, que se encuentran actualmente incluidos en la base de datos global Global Ocean Data Analysis (GLODAP1, Análisis de Datos del Océano Global), para la estimación de flujos globales de CO2 entre el océano y la atmósfera y de transportes de CANT a escala global y para la evaluación de modelos oceánicos., Peer reviewed
Proyecto: EC/FP7/264879




Global ocean storage of anthropogenic carbon

Digital.CSIC. Repositorio Institucional del CSIC
  • Khatiwala, S.
  • Ríos, Aida F.
48 páginas, 7 figuras, 7 tablas. -- S. Kathiwala ... et al.-- Proyecto Carbochange, The global ocean is a significant sink for anthropogenic carbon (Cant), 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 Cant 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 Cant 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 Cant 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 Cant with numerical ocean circulation models. Such methods are especially useful for estimating the air-sea flux and interior transport of Cant, 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 Cant. Our review also highlights the importance of repeat measurements of hydrographic and biogeochemical parameters to estimate the storage of Cant on decadal timescales in the presence of the variability in circulation that is neglected by other approaches. Data-based Cant estimates provide important constraints on ocean forward models, which exhibit both broad similarities and regional errors relative to the observational fields. A compilation of inventories of Cant gives us a "best" estimate of the global ocean inventory of anthropogenic carbon in 2010 of 155 Pg C with an uncertainty of ±20%. 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., Peer reviewed
Proyecto: EC/FP7/264879




Anthropogenic carbon changes in the Irminger Basin (1981–2006): Coupling δ13CDIC and DIC observations

Digital.CSIC. Repositorio Institucional del CSIC
  • Racapé, V.
  • Pierre, C.
  • Metzl, Nicolas
  • Lo Monaco, Claire
  • Reverdin, Gilles
  • Olsen, Are
  • Morin, Pascal
  • Vázquez Rodríguez, Marcos
  • Ríos, Aida F.
  • Pérez, Fiz F.
9 páginas, 8 figuras, 2 tablas.-- Proyecto Carbochange, The North Atlantic subpolar gyre is considered to be one of the strongest marine anthropogenic CO2 sinks, a consequence of extensive deep convection occurring during winter. Observations collected in this region since 1981 have shown large changes in Dissolved Inorganic Carbon (DIC) concentrations in intermediate and deep waters, which have been attributed to both anthropogenic CO2 penetration and natural variability in the ocean carbon cycle (Wanninkhof et al., 2010). In this context, we describe new δ13CDIC observations obtained in the Irminger Basin during two OVIDE cruises (2002 and 2006) which we compare to historical data (TTO-NAS 1981) in order to estimate the oceanic 13C Suess Effect over the more than twenty years that separates these surveys. The data reveal a significant decrease in δ13CDIC, of between − 0.3‰ and − 0.4‰ from 1981 to 2006. The anthropogenic change, extracted by using the extended Multi Linear Regression (eMLR) approach, explains 75% of this signal for oldest water mass and 90% for youngest. The reminding signal is due to the natural processes, such as remineralization and vertical mixing. The eMLR method was also applied to DIC measurements which i) reveal strong relationships between the increase of anthropogenic CO2 and the oceanic 13C Suess Effect over the whole water column during the 25-year period and ii) support the hypothesis of change in the Cant storage rate in the Irminger Basin between 1981 and 2006., The OVIDE project was and is still supported by French research institutions, IFREMER and CNRS/INSU, and by the EU FP6 project CARBOOCEAN (511176) and EU FP7 project CARBOCHANGE (264879). This study is also a contribution to the international IMBER/SOLAS projects. The 13C analyses have been also supported by CNRS/INSU (LEFE/OCEANS-C13 project)., Peer reviewed
Proyecto: EC/FP7/264879




Observed trends of carbon storage, acidification and calcium carbonate saturation along the ovide section

Digital.CSIC. Repositorio Institucional del CSIC
  • García-Ibáñez, Maribel I.
  • Fajar, Noelia
  • Ríos, Aida F.
  • Mercier, Herlé
  • Pérez, Fiz F.
1 póster.-- 9th International Carbon Dioxide Conference, 3-7 June 2013, Beijing, China.-- Proyecto Carbochange
Proyecto: EC/FP7/264879




A uniform, quality controlled Surface Ocean CO2 Atlas (SOCAT)

Digital.CSIC. Repositorio Institucional del CSIC
  • Pfeil, Benjamin
  • Padín, X. A.
  • Pérez, Fiz F.
  • Ríos, Aida F.
19 páginas, 6 tablas, 4 figuras.-- B. Pfeil ... et al.-- Proyecto Carbochange.-- Distribuido bajo licencia Creative Commons, A well-documented, publicly available, global
data set of surface ocean carbon dioxide (CO2) parameters
has been called for by international groups for nearly two
decades. The Surface Ocean CO2 Atlas (SOCAT) project was
initiated by the international marine carbon science community
in 2007 with the aim of providing a comprehensive, publicly
available, regularly updated, global data set of marine
surface CO2, which had been subject to quality control (QC).
Many additional CO2 data, not yet made public via the Carbon
Dioxide Information Analysis Center (CDIAC), were retrieved
from data originators, public websites and other data
centres. All data were put in a uniform format following a
strict protocol. Quality control was carried out according to
clearly defined criteria. Regional specialists performed the
quality control, using state-of-the-art web-based tools, specially
developed for accomplishing this global team effort.
SOCAT version 1.5 was made public in September 2011 and holds 6.3 million quality controlled surface CO2 data
points from the global oceans and coastal seas, spanning four
decades (1968–2007). Three types of data products are available:
individual cruise files, a merged complete data set and
gridded products. With the rapid expansion of marine CO2
data collection and the importance of quantifying net global
oceanic CO2 uptake and its changes, sustained data synthesis
and data access are priorities., Bjerknes
Centre for Climate Research, University of Bergen, Uni
Research (Norway), US National Oceanic and Atmospheric
Administration, University of Washington, Oak Ridge National
Laboratory (US), University of East Anglia (UEA, UK), PANGAEA, Peer reviewed
Proyecto: EC/FP7/264879




Anthropogenic CO2 estimates in the Southern Ocean: Storage partitioning in the different water masses

Digital.CSIC. Repositorio Institucional del CSIC
  • Pardo, Paula C.
  • Pérez, Fiz F.
  • Khatiwala, S.
  • Ríos, Aida F.
The role of the Southern Ocean (SO) remains a key issue in our understanding of the global carbon cycle and for predicting future climate change. A number of recent studies suggest that 30 to 40% of ocean uptake of anthropogenic carbon (CANT) occurs in the SO, accompanied by highly efficient transport of CANT by intermediate-depth waters out of that region. In contrast, storage of CANT in deep and bottom layers is still an open question. Significant discrepancies can be found between results from several indirect techniques and ocean models. Even though reference methodologies state that CANT concentrations in deep and bottom layers of the SO are negligible, recent results from tracer-based methods and ocean models as well as accurate measurements of 39Ar, CCl4 and CFCs along the continental slope and in the Antarctic deep and bottom waters contradict this conclusion. The role of the SO in the uptake, storage and transport of CANT has proved to be really important for the global ocean and there is a need for agreement between the different techniques. A CO2-data-based (>back-calculation>) method, the CT0 method, was developed with the aim of obtaining more accurate CANT concentration and inventory estimates in the SO region (south of 45°S). Data from the GLODAP (Global Ocean Data Analysis Project) and CARINA databases were used. The CT0 method tries to reduce at least two of the main caveats attributed to the back-calculation methods: the need for a better definition of water mass mixing and, most importantly, the unsteady state of the air-sea CO2 disequilibrium (δCdis) term. Water mass mixing was computed on the basis of results from an extended Optimum Multi-Parametric (eOMP) analysis applied to the main water masses of the SO. Recently published parameterizations were used to obtain more reliable values of δCdis and also of preformed alkalinity. The variability of the δCdis term (δCdis) was approximated using results from an ocean carbon cycle model. Results from the CT0 method are compared with those from the δC* method, the TrOCA method, and two different tracer-based approaches, the transit-time distribution (TTD) and Green's function (GF) methods. We find that the TTD, GF and CT0 methods give very similar estimates for the SO's inventory (with reference to the year 1994) of 30±2, 22±2, 29±3 PgC, respectively. Importantly, Antarctic Bottom Water shows CANT concentrations of 9±1, 3±0.3, 6±1μmolkg-1, contributing 6-12% of the SO's inventory. The δC* and TrOCA methods seem to underestimate and overestimate, respectively, both the total CANT inventory and CANT concentrations in deep and bottom layers. Results from the CT0 method suggest that deep and bottom layers of the water column in the SO contain, in general, low concentrations of CANT compared with subsurface and intermediate layers but higher than those recorded in the global databases. It is important to note that, as deep and bottom layers in the SO fill two of the most voluminous water masses of the global ocean, even these relatively low values of CANT can be of considerable importance when computing the inventories in the water column, mostly in the SO but also in outer regions where bottom waters spread. © 2013 Elsevier Ltd., The research leading to these results was supported through EU FP7 project CARBOCHANGE “Changes in carbon uptake and emissions by oceans in a changing climate” which received funding form the European Commission’s Seventh Framework under grant agreement no. 264879 and by the Spanish Ministry of Sciences and Innovation, and was co-founded by the Fondo Europeo de Desarrollo Regional 2007–2012 (FEDER) through the CATARINA Project (CTM2010-17141/MAR)., Peer Reviewed
Proyecto: EC/FP7/264879




An assessment of the Atlantic and Arctic sea–air CO2 fluxes, 1990–2009

Digital.CSIC. Repositorio Institucional del CSIC
  • Schuster, Ute
  • Ríos, Aida F.
  • Watson, Andrew J.
Schuster, Ute at al., The Atlantic and Arctic Oceans are critical components of the global carbon cycle. Here we quantify the net sea–air CO2 flux, for the first time, across different methodologies for consistent time and space scales for the Atlantic and Arctic basins. We present the long-term mean, seasonal cycle, interannual variability and trends in sea–air CO2 flux for the period 1990 to 2009, and assign an uncertainty to each. We use regional cuts from global observations and modeling products, specifically a pCO2-based CO2 flux climatology, flux estimates from the inversion of oceanic and atmospheric data, and results from six ocean biogeochemical models. Additionally, we use basin-wide flux estimates from surface ocean pCO2 observations based on two distinct methodologies. Our estimate of the contemporary sea–air flux of CO2 (sum of anthropogenic and natural components) by the Atlantic between 40° S and 79° N is −0.49 ± 0.05 Pg C yr−1, and by the Arctic it is −0.12 ± 0.06 Pg C yr−1, leading to a combined sea–air flux of −0.61 ± 0.06 Pg C yr−1 for the two decades (negative reflects ocean uptake). We do find broad agreement amongst methodologies with respect to the seasonal cycle in the subtropics of both hemispheres, but not elsewhere. Agreement with respect to detailed signals of interannual variability is poor, and correlations to the North Atlantic Oscillation are weaker in the North Atlantic and Arctic than in the equatorial region and southern subtropics. Linear trends for 1995 to 2009 indicate increased uptake and generally correspond between methodologies in the North Atlantic, but there is disagreement amongst methodologies in the equatorial region and southern subtropics., U. Schuster has been supported by
EU grants IP 511176-2 (CARBOOCEAN), 212196 (COCOS), and
264879 (CARBOCHANGE), and UK NERC grant NE/H017046/1
(UKOARP). G. A. McKinley and A. Fay thank NASA for support
(NNX08AR68G, NNX11AF53G). P. Landsch
̈
utzer has been
supported by EU grant 238366 (GREENCYCLESII). N. Metzl
acknowledges the French national funding program LEFE/INSU.
Support for N. Gruber has been provided by EU grants 264879
(CARBOCHANGE) and 283080 (GEO-CARBON) S. Doney
acknowledges support from NOAA (NOAA-NA07OAR4310098).
T. Takahashi is supported by NOAA (NAO80AR4320754)., Peer reviewed
Proyecto: EC/FP7/264879




Picophytoplankton biomass distribution in the global ocean

Digital.CSIC. Repositorio Institucional del CSIC
  • Buitenhuis, Erik
  • Macías, Diego
  • McManus, B.
Buitenhuis, Erik et al., The smallest marine phytoplankton, collectively termed picophytoplankton, have been routinely enumerated by flow cytometry since the late 1980s during cruises throughout most of the world ocean. We compiled a database of 40 946 data points, with separate abundance entries for Prochlorococcus, Synechococcus and picoeukaryotes. We use average conversion factors for each of the three groups to convert the abundance data to carbon biomass. After gridding with 1° spacing, the database covers 2.4% of the ocean surface area, with the best data coverage in the North Atlantic, the South Pacific and North Indian basins, and at least some data in all other basins. The average picophytoplankton biomass is 12 ± 22 μg C l−1 or 1.9 g C m−2. We estimate a total global picophytoplankton biomass of 0.53–1.32 Pg C (17–39% Prochlorococcus, 12–15% Synechococcus and 49–69% picoeukaryotes), with an intermediate/best estimate of 0.74 Pg C. Future efforts in this area of research should focus on reporting calibrated cell size and collecting data in undersampled regions., We thank Claude Belzile, Jacques Neveux and Genevieve Tremblay for their comments on a draft manuscript, the EU (CarboChange, contract 264879) for financial support to ETB, and the Networks of Centres of Excellence of Canada-ArcticNet for financial support to MG., Peer Reviewed
Proyecto: EC/FP7/264879




Surface Ocean CO2 Atlas (SOCAT) gridded data products

Digital.CSIC. Repositorio Institucional del CSIC
  • Sabine, Christopher L.
  • Pérez, Fiz F.
  • Ríos, Aida F.
  • Yoshikawa-Inoue, H.
Sabine, C. L. et al., As a response to public demand for a well-documented, quality controlled, publically available, global surface ocean carbon dioxide (CO2) data set, the international marine carbon science community developed the Surface Ocean CO2 Atlas (SOCAT). The first SOCAT product is a collection of 6.3 million quality controlled surface CO2 data from the global oceans and coastal seas, spanning four decades (1968–2007). The SOCAT gridded data presented here is the second data product to come from the SOCAT project. Recognizing that some groups may have trouble working with millions of measurements, the SOCAT gridded product was generated to provide a robust, regularly spaced CO2 fugacity (fCO2) product with minimal spatial and temporal interpolation, which should be easier to work with for many applications. Gridded SOCAT is rich with information that has not been fully explored yet (e.g., regional differences in the seasonal cycles), but also contains biases and limitations that the user needs to recognize and address (e.g., local influences on values in some coastal regions)., SOCAT is promoted by IOCCP, the Sur-
face Ocean Lower Atmosphere Study, and the Integrated Marine
Biogeochemistry and Ecosystem Research program. Douglas
Wallace (Dalhousie University, Canada and former SOLAS chair)
has strongly encouraged SOCAT. Support has been received from
the University of Bergen (Norway), the Bjerknes Centre for Cli-
mate Research (Norway), the National Oceanic and Atmospheric
Administration (United States), the University of Washington
(United States), Oak Ridge National Laboratory (United States),
the University of East Anglia (United Kingdom), PANGAEA –
Data Publisher for Earth & Environmental data (Germany), the
Alfred Wegener Institute for Polar and Marine Research (Ger-
many), the Centre National de la Recherche Scientifique (France),
the CarboOcean (Norway, GOCE 511176-1) and CarboChange
(Norway, FP7 264879) projects of the European Union, the US
National Science Foundation (United States, OCE-1068958), the
international Scientific Committee on Oceanic Research (SCOR,
United States, OCE-0938349), and 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 A
ff
airs). Support for SOCAT meetings has been received
from IOCCP, IMBER, the European Cooperation in Science and
Technology (COST) Action 735 (United Kingdom), Geomar
(Germany), the National Institute for Environmental Studies
(Japan), and the Commonwealth Scientific and Industrial Research
Organisation (Australia)., Peer reviewed
Proyecto: EC/FP7/264879




An update to the surface ocean CO2 atlas (SOCAT version 2)

Digital.CSIC. Repositorio Institucional del CSIC
  • Bakker, D. C. E.
  • Ríos, Aida F.
22 páginas, 9 figuras, 10 tablas.-- D. C. E. Bakker ... et al.-- This work is distributed
under the Creative Commons Attribution 3.0 License.-- Proyecto Carbochange, The Surface Ocean CO2 Atlas (SOCAT), an activity of the international marine carbon research community, provides access to synthesis and gridded fCO2 (fugacity of carbon dioxide) products for the surface oceans. Version 2 of SOCAT is an update of the previous release (version 1) with more data (increased from 6.3 million to 10.1 million surface water fCO2 values) and extended data coverage (from 1968–2007 to 1968–2011). The quality control criteria, while identical in both versions, have been applied more strictly in version 2 than in version 1. The SOCAT website (http://www.socat.info/) has links to quality control comments, metadata, individual data set files, and synthesis and gridded data products. Interactive online tools allow visitors to explore the richness of the data. Applications of SOCAT include process studies, quantification of the ocean carbon sink and its spatial, seasonal, year-to-year and longerterm variation, as well as initialisation or validation of ocean carbon models and coupled climate-carbon models, Support for
SOCAT has been received from the University of East Anglia (UK),
the Bjerknes Centre for Climate Research, the Geophysical Institute
at the University of Bergen (Norway), the Climate Observation
Division of the Climate Program Office of the US National Oceanic
and Atmospheric Administration, the University of Washington,
Oak Ridge National Laboratory (USA), PANGAEA
®
Data Publisher for Earth and Environmental Data (Germany), the Alfred
Wegener Institute Helmholtz Centre for Polar and Marine Research
(Germany), the National Institute for Environmental Studies
(Japan), the Korean Institute of Ocean Science and Technology, the
European Union projects CarboChange (FP7 264879) and GEO-
CARBON (FP7 283080), 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), the
Research Council of Norway (CARBON-HEAT), the Scientific
Committee on Oceanic Research (SCOR, US, OCE-0938349),
the US National Science Foundation (OCE-1068958), Swedish
Research Council projects (2009–2994; 2008–6228; 2009–2994)
and the Swedish National Space Board (RESCUE project; REmote
Sensing ocean Carbon UptakE)., Peer reviewed
Proyecto: EC/FP7/264879




Variability of the transport of anthropogenic CO2 at the Greenland–Portugal OVIDE section: controlling mechanisms

Digital.CSIC. Repositorio Institucional del CSIC
  • Zunino, P.
  • García-Ibáñez, Maribel I.
  • Lherminier, Pascale
  • Mercier, Herlé
  • Ríos, Aida F.
  • Pérez, Fiz F.
15 páginas, 7 figuras, 2 tablas.-- Proyecto Carbochange.-- CC Attribution 3.0 License, The interannual to decadal variability in the transport of anthropogenic CO2 (Cant) across the subpolar North Atlantic (SPNA) is investigated, using summer data of the FOUREX and OVIDE high-resolution transoceanic sections, from Greenland to Portugal, occupied six times from 1997 to 2010. The transport of Cant across this section, Tcant hereafter, is northward, with a mean value of 254 ± 29 kmol s−1 over the 1997–2010 period. We find that Tcant undergoes interannual variability, masking any trend different from 0 for this period. In order to understand the mechanisms controlling the variability of Tcant across the SPNA, we propose a new method that quantifies the transport of Cant caused by the diapycnal and isopycnal circulation. The diapycnal component yields a large northward transport of Cant (400 ± 29 kmol s−1) that is partially compensated by a southward transport of Cant caused by the isopycnal component (−171 ± 11 kmol s−1), mainly localized in the Irminger Sea. Most importantly, the diapycnal component is found to be the main driver of the variability of Tcant across the SPNA. Both the Meridional Overturning Circulation (computed in density coordinates, MOCσ) and the Cant increase in the water column have an important effect on the variability of the diapycnal component and of Tcant itself. Based on this analysis, we propose a simplified estimator for the variability of Tcant based on the intensity of the MOCσ and on the difference of Cant between the upper and lower limb of the MOCσ (ΔCant). This estimator shows a good consistency with the diapycnal component of Tcant, and help to disentangle the effect of the variability of both the circulation and the Cant increase on the Tcant variability. We find that ΔCant keeps increasing over the past decade, and it is very likely that the continuous Cant increase in the water masses will cause an increase in Tcant across the SPNA at long timescale. Nevertheless, at the timescale analyzed here (1997–2010), the MOCσ controls the Tcant variability, blurring any Tcant trend. Extrapolating the observed ΔCant increase rate and considering the predicted slow-down of 25% of the MOCσ, Tcant across the SPNA is expected to increase by 430 kmol s−1 during the 21st century. Consequently, an increase in the storage rate of Cant in the SPNA could be envisaged., The research leading to these results was
supported through the EU FP7 CARBOCHANGE “Changes in
carbon uptake and emissions by oceans in a changing climate”
project, which received funding from the European Commission’s
Seventh Framework Programme under grant agreement no. 264879.
For this work P. Zunino was supported by the former project and
by the Ifremer postdoctoral program. M. I. Garcia-Ibáñez was
supported by the Spanish Ministry of Economy and Competitiveness
(BES-2011-045614) through the CATARINA project
(CTM2010-17141) co-funded by the Fondo Europeo de Desarrollo
Regional 2007-2012 (FEDER); this article is going to be part of
her PhD that is attached to the framework of the “Marine Science,
Technology and Management” (DO*MAR) doctoral program of
the University of Vigo. P. Lherminier was supported by the French
Institute for Marine Science (Ifremer), H. Mercier by the French
National Center for Scientific Research (CNRS), and A. F. Rios and
F. F. Pérez by the Consejo Superior de Investigaciones Científicas
(CSIC), Peer reviewed
Proyecto: EC/FP7/264879




Optimización de métodos numéricos en la determinación de la acidificación en los océanos

Digital.CSIC. Repositorio Institucional del CSIC
  • Velo, A.
214 páginas, 4 apéndices.-- Proyecto Carbochange, Durante las dos últimas décadas se ha intensificado la observación del
océano por diferentes motivaciones científicas auspiciadas por distintos programas
nacionales e internacionales. Con ello, se han acumulado una importante
cantidad de medidas del sistema del carbóonico en agua de mar con
diferentes niveles de calidad. El carbono inorgánico total (CT), la alcalinidad
total (AT) y el pH han sido las variables del sistema del carbónico que con
mayor frecuencia se han determinado en la columna de agua. Todas estas
medidas necesitan de una evaluación de su calidad, así como de una homogeneización debido a que las medidas de pH se han realizado con escalas y
temperaturas diferentes. El objetivo final es conseguir una base de datos homogénea que permita evaluar y 'censar' los cambios en el CT y pH durante
las últimas décadas debido al incremento de CO2 atmosférico
Dado que para determinar el sistema del carbonato en agua de mar son
necesarios únicamente dos parámetros de este sistema, se busca obtener una
base de datos general lo más extensa posible que incluya un registro tanto
temporal como espacial de la variabilidad del pH y del CO2 de origen antropogénico. Las bases de datos origen deben ser homogeneizadas y complementadas
con la ayuda de diversas metodologías numéricas como paso previo para
integrarse en una gran base de datos general., Es necesario, por lo tanto, elaborar algoritmos que permitan detectar sesgos
y valores anómalos en las bases de datos originales. Utilizando diversas
técnicas multilineales aplicadas a la variabilidad de parámetros o magnitudes oceanográficas como temperatura, salinidad, oxígeno y nutrientes, hemos podido
discriminar gran parte de la variabilidad real de la generada por los sesgos
producidos por errores en las metodologías analíticas. Finalmente, desarrollando
nuevos algoritmos de interpolación se ha propagado de forma optimizada la
información disponible, originalmente sin estructura geográfica homogénea, a
una red geográfica regular para generar un producto que facilite la evaluación
regional del almacenamiento de CO2 y de la variabilidad del pH en el océano, Peer reviewed
Proyecto: EC/FP7/264879




Ocean acidification along the 24.5°N section in the subtropical North Atlantic

Digital.CSIC. Repositorio Institucional del CSIC
  • Fernández-Guallart, E.
  • Fajar, Noelia
  • Padín, X. A.
  • Vázquez Rodríguez, Marcos
  • Calvo, Eva María
  • Ríos, Aida F.
  • Hernández Guerra, Alonso
  • Pelejero, Carles
  • Pérez, Fiz F.
9 páginas, 4 figuras.-- Proyecto Carbochange, Ocean acidification is directly related to increasing atmospheric CO2 levels due to human activities and the active role of the global ocean in absorbing part of this anthropogenic CO2. Here we present an assessment of the pH changes that have occurred along 24.5°N in the subtropical North Atlantic through comparison of pH observations conducted in 1992 and 2011. It reveals an overall decline in pH values in the first 1000 dbar of the water column. The deconvolution of the temporal pH differences into anthropogenic and nonanthropogenic components reveals that natural variability, mostly owed to a decrease in oxygen levels in particular regions of the section, explains the vertical distribution of the larger pH decreases (up to −0.05 pH units), which are found within the permanent thermocline. The detection of long-term trends in dissolved oxygen in the studied region gains importance for future pH projections, as these changes modulate the anthropogenically derived acidification. The anthropogenic forcing explains significant acidification deeper than 1000 dbar in the western basin, within the Deep Western Boundary Current., We acknowledge funding from
the Spanish Ministry of Economy and
Competitiveness through grants
CSD2008-00077 (Circumnavigation
Expedition MALASPINA 2010 Project),
CTM2009-08849 (ACDC Project), and
CTM2012-32017 (MANIFEST Project)
and from the Seventh Framework
Programme FP7 CARBOCHANGE (grant
agreement 264879). E.F. Guallart was
funded by CSIC through a JAE-Pre grant., Peer reviewed
Proyecto: EC/FP7/264879




Trends in anthropogenic CO2 in water masses of the Subtropical North Atlantic Ocean

Digital.CSIC. Repositorio Institucional del CSIC
  • Fernández-Guallart, E.
  • Schuster, Ute
  • Fajar, Noelia
  • Legge, O.
  • Brown, Peter J.
  • Pelejero, Carles
  • Messias, M. J.
  • Calvo, Eva María
  • Watson, Andrew J.
  • Ríos, Aida F.
  • Pérez, Fiz F.
12 páginas, 4 figuras,1 tabla.-- Proyecto Carbochange, The variability in the storage of the oceanic anthropogenic CO2 (Cant) on decadal timescales is evaluated within the main water masses of the Subtropical North Atlantic along 24.5°N. Inorganic carbon measurements on five cruises of the A05 section are used to assess the changes in Cant between 1992 and 2011, using four methods (ΔC∗, TrOCA, φCT0, TTD). We find good agreement between the Cant distribution and storage obtained using chlorofluorocarbons and CO2 measurements in both the vertical and horizontal scales. Cant distribution shows higher concentrations and greater decadal storage rates in the upper layers with both values decreasing with depth. The greatest enrichment is obserbed in the central water masses, with their upper limb showing a mean annual accumulation of about 1 μmol kg−1 yr−1 and the lower limb showing, on average, half that value. We detect zonal gradients in the accumulation of Cant. This finding is less clear in the upper waters, where greater variability exists between methods. In accordance with data from time series stations, greater accumulation of Cant is observed in the upper waters of the western basin of the North Atlantic Subtropical Gyre. In intermediate and deep layers, the zonal gradient in the storage of Cant is more robust between methods. The much lower mean storage rates found along the section (<0.25 μmol kg−1 yr−1) become more obvious when longitudinal differences in the Cant accumulation are considered. In particular, west of 70°W the ventilation by the Labrador Sea Water creates a noticeable accumulation rate up to ∼0.5 μmol kg−1 yr−1 between 1000 and 2500 dbar. If a Transient Stationary State of the Cant distributions is considered, significant bi-decadal trends in the Cant storage rates in the deepest North Atlantic waters are detected, in agreement with recent estimations., We acknowledge funding from the Spanish Ministry of Economy and Competitiveness through Grants CSD2008-00077 (Circumnavigation Expedition MALASPINA 2010 Project), CTM2009-08849 (ACDC Project) and CTM2012-32017 (MANIFEST Project). We also acknowledge funding from the EU FP7 project CARBOCHANGE under Grant Agreement No. 264879 and by the Marine Biogeochemistry and Global Change research group (Generalitat de Catalunya, 2014SGR1029). E.F. Guallart was funded through a JAE-Pre grant that was financed by the Spanish National Research Council Agency (Consejo Superior de Investigaciones Científicas, CSIC) and by the European Social Fund., Peer reviewed
Proyecto: EC/FP7/264879




Anthropogenic CO2 changes in the Equatorial Atlantic Ocean

Digital.CSIC. Repositorio Institucional del CSIC
  • Fajar, Noelia
  • Fernández-Guallart, E.
  • Steinfeldt, Reiner
  • Ríos, Aida F.
  • Pelegrí, Josep Lluís
  • Pelejero, Carles
  • Calvo, Eva María
  • Pérez, Fiz F.
15 páginas, 4 tablas, 5 figuras, 3 apéndices.-- Proyecto Carbochange, Methods based on CO2 and chlorofluorocarbon (CFC) data are used to describe and evaluate the anthropogenic CO2 (Cant) concentrations, Cant specific inventories, and Cant storage rates in the Equatorial Atlantic Ocean. The Cant variability in the water masses is evaluated from the comparison of two hydrographic sections along 7.5°N carried out in 1993 and 2010. During both cruises, high Cant concentrations are detected in the upper layers, with values decreasing progressively towards the deep layers. Overall, the Cant concentrations increase from 1993 to 2010, with a large increment in the upper North Atlantic Deep Water layer of about 0.18 ± 0.03 μmol kg−1 y−1. In 2010, the Cant inventory along the whole section amounts to 58.9 ± 2.2 and 45.1 ± 2.0 mol m−2 using CO2 and CFC based methods, respectively, with most Cant accumulating in the western basin. Considering the time elapsed between the two cruises, Cant storage rates of 1.01 ± 0.18 and 0.75 ± 0.17 mol m−2 y−1 (CO2 and CFC based methods, respectively) are obtained. Below ∼1000 m, these rates follow the pace expected from a progressive increase of Cant at steady state; above ∼1000 m, Cant increases faster, mainly due to the retreat of the Antarctic Intermediate Waters, This work was funded by the 7th Framework Programme (EU FP7 CARBOCHANGE, under grand agreement no. 264879) and by the Spanish Ministry of Economy and Competitiveness through Projects GHGMOC (CTM2009-07574-E), MOC2 (CTM2008-06438-C02-01/MAR) and ESCLAT (CTM2009-07405-E/MAR) and by the Deutsche Forschungsgemeinschaft (DFG) (M. Rhein, grant Rh25/36-1). FFP and AFR were supported by the Spanish Government and co-founded by the European Regional Development Fund (CTM2013-41048-P)., Peer reviewed
Proyecto: EC/FP7/264879




Discrete measurements of CO2 and hydrographic data during the GIFT Time Series cruises (Strait of Gibraltar 2005-2007)

Digital.CSIC. Repositorio Institucional del CSIC
  • Huertas, I. Emma
  • Ríos, Aida F.
This dataset gathers discrete measurements of CO2 (pH and alkalinity) and hydrographic variables (salinity, temperature, dissolved oxygen, nitrate, phosphate and silicate) in 10 cruises between 2005 and 2007 in the GIFT Time Series Stations located at the Strait of Gibraltar, 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 794 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, The item is made of 11 files, of which 1 is the dataset and the other 10 files include detailed descriptions of the data per month of gathering, Dataset contributed to the project Carbochange, CARBOOCEAN, Data are part of the EC-funded Integrated Project CARBOOCEAN - Marine carbon sources and sinks assessment Contract no. 511176 (GOCE), more details available at http://www.carboocean.org/, No
Proyecto: EC/FP7/264879




Structure, transports and transformations of the water masses in the Atlantic Subpolar Gyre

Digital.CSIC. Repositorio Institucional del CSIC
  • García-Ibáñez, Maribel I.
  • Pardo, Paula C.
  • Carracedo, L.
  • Mercier, Herlé
  • Lherminier, Pascale
  • Ríos, Aida F.
  • Pérez, Fiz F.
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




Decadal acidification in the water masses of the Atlantic Ocean

Digital.CSIC. Repositorio Institucional del CSIC
  • Ríos, Aida F.
  • Resplandy, Laure
  • García-Ibáñez, Maribel I.
  • Fajar, Noelia
  • Velo, A.
  • Padín, X. A.
  • Wanninkhof, Rik
  • Steinfeldt, Reiner
  • Rosón, Gabriel
  • Pérez, Fiz F.
6 páginas, 5 figuras, 1 tabla.-- Proyecto Carbochange.-- Open access, Global ocean acidification is caused primarily by the ocean’s uptake of CO2 as a consequence of increasing atmospheric CO2 levels. We present observations of the oceanic decrease in pH at the basin scale (50°S–36°N) for the Atlantic Ocean over two decades (1993–2013). Changes in pH associated with the uptake of anthropogenic CO2 (ΔpHCant) and with variations caused by biological activity and ocean circulation (ΔpHNat) are evaluated for different water masses. Output from an Institut Pierre Simon Laplace climate model is used to place the results into a longer-term perspective and to elucidate the mechanisms responsible for pH change. The largest decreases in pH (∆pH) were observed in central, mode, and intermediate waters, with a maximum ΔpH value in South Atlantic Central Waters of −0.042 ± 0.003. The ΔpH trended toward zero in deep and bottom waters. Observations and model results show that pH changes generally are dominated by the anthropogenic component, which accounts for rates between −0.0015 and −0.0020/y in the central waters. The anthropogenic and natural components are of the same order of magnitude and reinforce one another in mode and intermediate waters over the time period. Large negative ΔpHNat values observed in mode and intermediate waters are driven primarily by changes in CO2 content and are consistent with (i) a poleward shift of the formation region during the positive phase of the Southern Annular Mode in the South Atlantic and (ii) an increase in the rate of the water mass formation in the North Atlantic, This research was supported by the Spanish
Ministry of Sciences and Innovation and was cofunded by the European Regional
Development Fund 2007–2012 (FEDER) through the Carbon Transport
and Acidification Rates in the North Atlantic Project (CTM2010-17141/MAR),
by the European Union Seventh Framework Programme CARBOCHANGE
project under Grant Agreement 264879, and by the Office of Atmospheric
and Oceanic Research of the NOAA, Peer reviewed
Proyecto: EC/FP7/264879




Discrete measurements of CO2 and hydrographic data during the R/V Hesperides P3A2 cruise in Gulf of Cadiz and Strait of Gibraltar (October 6 - 12, 2008), Producción Pelágica en la Plataforma Atlántico-Andaluza

Digital.CSIC. Repositorio Institucional del CSIC
  • Huertas, I. Emma
  • Ríos, Aida F.
The item is made of 2 files, of which 1 is the dataset and the other includes a small description of the measured variables.-- Dataset contributed to the Project Carbochange, 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 P3A22008. carried out in the Strait of Gibraltar from 6 to 12 October 2008, 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 794 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, Proyecto CARBOOCEAN (511176GOCE), y proyectos del Ministerio de Ciencia e Innovación (CTM2005/01091-MAR y CTM2008-05680-C02-01), No
Proyecto: EC/FP7/264879




Nitrous oxide and methane in Atlantic and Mediterranean waters in the Strait of Gibraltar: Air-sea fluxes and inter-basin exchange

Digital.CSIC. Repositorio Institucional del CSIC
  • Paz, M. de la
  • Huertas, I. Emma
  • Flecha, Susana
  • Ríos, Aida F.
  • Pérez, Fiz F.
14 páginas, 7 figuras, 2 tablas.-- Proyecto Carbochange, The global ocean plays an important role in the overall budget of nitrous oxide (N2O) and methane (CH4), as both gases are produced within the ocean and released to the atmosphere. However, for large parts of the open and coastal oceans there is little or no spatial data coverage for N2O and CH4. Hence, a better assessment of marine emissions estimates is necessary. As a contribution to remedying the scarcity of data on marine regions, N2O and CH4 concentrations have been determined in the Strait of Gibraltar at the ocean Fixed Time series (GIFT). During six cruises performed between July 2011 and November 2014 samples were collected at the surface and various depths in the water column, and subsequently measured using gas chromatography. From this we were able to quantify the temporal variability of the gas air-sea exchange in the area and examine the vertical distribution of N2O and CH4 in Atlantic and Mediterranean waters. Results show that surface Atlantic waters are nearly in equilibrium with the atmosphere whereas deeper Mediterranean waters are oversaturated in N2O, and a gradient that gradually increases with depth was detected in the water column. Temperature was found to be the main factor responsible for the seasonal variability of N2O in the surface layer. Furthermore, although CH4 levels did not reveal any feature clearly associated with the circulation of water masses, vertical distributions showed that higher concentrations are generally observed in the Atlantic layer, and that the deeper Mediterranean waters are considerably undersaturated (by up to 50%). Even though surface waters act as a source of atmospheric N2O during certain periods, on an annual basis the net N2O flux in the Strait of Gibraltar is only 0.35 ± 0.27 μmol m−2 d−1, meaning that these waters are almost in a neutral status with respect to the atmosphere. Seasonally, the region behaves as a slight sink for atmospheric CH4 in winter and as a source in spring and fall. Approximating the circulation pattern in the Strait to a bi-layer scheme, N2O exchange between basins was also calculated, and a net export from the Mediterranean Sea to the Atlantic Ocean equivalent to 39 μmol m−2 d−1 was found, Funding for this work was provided by the INGOS (Grant Agreement 284274), CARBOCHANGE IP (264879GOCE) and PERSEUS of the European Commission, the CATARINA Project supported by the MICINN and co-funded by FEDER (CTM2010-17141/MAR) and OSIMON project funded by the Regional Government of Galicia (Xunta de Galicia, 09MDS035402PR), Peer reviewed
Proyecto: EC/FP7/264879




Carbon Data Obtained During the R/V Sarmiento de Gamboa CAIBOX-2009 Cruise in the Atlantic Ocean (25 July - 13 August, 2009)

Digital.CSIC. Repositorio Institucional del CSIC
  • Gilcoto, Miguel
  • Pérez, Fiz F.
  • Ríos, Aida F.
  • Pardo, Paula C.
  • Carracedo, L.
  • Vieitez dos Santos, Vanesa
  • Paz, M. de la
The item is made of 2 files, of which 1 is the dataset and the other include a small description of the measured variables.-- Dataset contributed to the Project Carbochange, 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 CAIBOX 2009 carried out from 25 July to 13 August 2009.
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, Spanish Project CAIBEX supported by Ministerio de Eduación y Ciencia (CTM2007–66408–C02–01/MAR), CARBOOCEAN (511176GOCE), No
Proyecto: EC/FP7/264879




Carbon Data Obtained During the R/V Hesperides Cruise in the Atlantic Ocean on CLIVAR Repeat Hydrography Section A06, (5 April - 16 May, 2010)

Digital.CSIC. Repositorio Institucional del CSIC
  • Ríos, Aida F.
  • Pérez, Fiz F.
  • Pelegrí, Josep Lluís
  • Fajar, Noelia
The item is made of 2 files, of which 1 is the dataset and the other include detailed information about measures realized.-- Dataset contributed to the Project Carbochange, 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 MOC2EQ carried out from 5 April to 16 May 2010.
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, Spanish Projects GHG4MOC (CTM2009-07574-E) and MOC2 (CTM2008-06438-C02-01/MAR) supported by Ministerio de Ciencia e Innovación, and CARBOCHANGE (264879), No
Proyecto: EC/FP7/264879




Carbon Dioxide and Hydrographic Data Obtained During the R/V Hesperides Cruise in the South Atlantic Ocean on CLIVAR Repeat Hydrography Section A21 (8 February - 10 March, 2010)

Digital.CSIC. Repositorio Institucional del CSIC
  • Pérez, Fiz F.
  • Ríos, Aida F.
  • Velo, A.
  • Castaño, Mónica
  • Movilla, J.
  • Hernández Guerra, Alonso
  • Escánez, José
  • Domínguez-Yanes, J.F.
The item is made of 2 files, of which 1 is the dataset and the other include a small description of the measured variables.-- Dataset contributed to the Project Carbochange, 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 MOC2Austral carried out from 8 February to 10 March 2010.
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, Spanish Projects GHG4MOC (CTM2009-07574-E) and MOC2 (CTM2008-06438-C02-02/MAR) supported by Ministerio de Ciencia e Innovación, and CARBOCHANGE (264879), No
Proyecto: EC/FP7/264879




High spatial resolution Alkalinity and pH measurements by IIM-CSIC group along 24.5°N during the R/V Hesperides WOCE Section A05 cruise (July 14 - August 15, 1992)

Digital.CSIC. Repositorio Institucional del CSIC
  • Fernández-Guallart, E.
  • Pérez, Fiz F.
  • Rosón, Gabriel
  • Ríos, Aida F.
Dataset contributed to the Project Carbochange.-- More information in http://hdl.handle.net/10261/93331, 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 WOCE Section A05 carried out from 14 July to 15 August 1992.
The pH was measured potentiometrically in the NBS scale with a combined glass electrode associated to a thermo-compensator and referred to 15ºC (Perez and Fraga, 1987a). The method had a shipboard precision of 0.005 units, based on 184 replicate analysis corresponding to two different oceanographic bottles fired at the same depth at each station (Ríos and Rosón, 1996).
AT measurements were made by titration of seawater with potentiometric endpoint detection (Perez and Fraga, 1987b), reaching a precision of ±1 µmol kg-1.
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, Instituto Español de Oceanografía y Comisión Interministerial de Ciencia y Tecnología (CICYT), No
Proyecto: EC/FP7/264879




FICARAM-15 Cruise Report 20th March – 22nd May 2013 on board BIO Hespérides by the Group FICARAM

Digital.CSIC. Repositorio Institucional del CSIC
  • Ríos, Aida F.
  • Marrasé, Cèlia
  • Rodríguez-Marroyo, Rocío
  • Paz, M. de la
  • Padín, X. A.
  • Velo, A.
  • Gasser, Marc
  • Ramírez, Sergio
  • Aparicio, Francisco Luis
  • Borrull, Encarnación
  • Rodríguez Giner, Caterina
  • Llinás, Joaquim
  • Agudo, Gustavo
  • Vallo, Javier
  • Paredes, Manuel
  • Sandoval, Antonio
  • Pérez, Fiz F.
  • Peña-Izquierdo, Jesús
  • Alonso Pérez, Fernando
  • García-Ibáñez, Maribel I.
  • Royo, Elena
  • Llanillo, P. J.
  • Romero, Estela
  • Afonso, Dulce
  • González-Anleo, Alberto
  • Hernández Jiménez, Alberto
  • Gómez López, Camilo
  • López Rodríguez, Iago
54 páginas, 19 figuras, 3 anexos, The FICARAM-15 is the fifteenth repetition of a section conducted in 1994. This section is part
of the international program GOSHIP (http://www.go-ship.org/CruisePlans.html) to develop a
globally coordinated network of sustained hydrographic sections as part of the global
ocean/climate observing system.
The objective of the FICARAM-15 cruise is to investigate the temporal evolution of the
anthropogenic carbon and evaluate the CO2 absorption capacity of the South Atlantic region, the
Equatorial zone, and the subtropical region of Azores-Gibraltar in the North Atlantic. This cruise
is supported by the CATARINA project funded by the Ministry of Economy and
Competitiveness (CTM2010-17141) and is part of the European Union FP7 project
CARBOCHANGE (http://carbochange.b.uib.no/). The objective of FICARAM-15 cruise is
framed in the CATARINA project conducted by the tasks I.2.1 (air-sea CO2 exchange) I.3
(ventilation of water masses), I.4.1 (zonal variability of N2O and CH4), I.4.2 (anthropogenic
carbon storage), I.4.4 (saturation horizon of calcium carbonate along the section) and I.5.4
(evolution of the acidification rates).
Another component of the FICARAM-15 cruise aims to examine the biological and
biogeochemical mechanisms that hinder total dissolved organic carbon (DOC) remineralisation
in marine systems, taking a multidisciplinary perspective and applying many different
approaches. This is the global objective of the Spanish project DOREMI (CTM2012-34294) that
joins this FICARAM-15 cruise., During the FICARAM cruise the physical oceanography group was responsible for collecting the
following data sets: CTD and XBT data; vessel-mounted ADCP and lowered ADCP; continuous
thermosalinograph. Physical oceanographers participated in the cruise financed through Project
“Tipping Corners in the Meridional Overturning Circulation” (TIC-MOC), CTM2011-28867.
The FICARAM-15 cruise was organized in two phases with a common sampling.
LEG 1: From Punta Arenas (Chile) to Recife (Brazil): 62 stations.
Chief Scientist: Aida F. Ríos, PI of CATARINA project
LEG 2: From Recife (Brazil) to Cartagena (Spain): 46 stations
Chief Scientist: Celia Marrasé, PI of DOREMI project
This report contains the sampling of all the variables at each station along the FICARAM
section, as well as the analysis of the biogeochemical variables and the preliminary results. The
principal investigator of the DOREMI project produced another report with the common
sampling section, showing the analysis and results of the experiments on dissolved organic
matter carried out on board., This cruise
is supported by the CATARINA project funded by the Ministry of Economy and
Competitiveness (CTM2010-17141) and is part of the European Union FP7 project
CARBOCHANGE (http://carbochange.b.uib.no/), Peer reviewed
Proyecto: EC/FP7/264879




Carbon Data Obtained During the R/V Hesperides Cruise in the Atlantic Ocean on CLIVAR Repeat Hydrography Section A17, FICARAM XV (March 20 - May 2, 2013)

Digital.CSIC. Repositorio Institucional del CSIC
  • Ríos, Aida F.
  • Pérez, Fiz F.
  • Pelegrí, Josep Lluís
  • Paz, M. de la
  • Alonso Pérez, Fernando
  • Royo, Elena
  • Velo, A.
  • García-Ibáñez, Maribel I.
  • Padín, X. A.
The item is made of 2 files, of which 1 is the dataset and the other include a small description of the measured variables.-- Dataset contributed to the Project Carbochange.-- Related item http://hdl.handle.net/10261/125339, 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 FICARAM-XV carried out along the A17 section from 20 March to 2 May 2013.
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, Ministry of Economy and Competitiveness, CATARINA project (CTM2010-17141); European Commission, project Carbochange, No
Proyecto: EC/FP7/264879




Carbon Dioxide, Hydrographic, and Chemical Data Obtained During the R/V Merian Cruise in the North Atlantic Ocean on CLIVAR Repeat Hydrography Section OVIDE-2006 (May 23 - June 28, 2006)

Digital.CSIC. Repositorio Institucional del CSIC
  • Pérez, Fiz F.
  • Mercier, Herlé
  • Morin, Pascal
  • Lherminier, Pascale
The item is made of 2 files, of which 1 is the dataset and the other include a small description of the measured variables.-- Dataset contributed to the Project Carbochange.-- More information in http://hdl.handle.net/10261/115854, 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 OVIDE 2006 carried out from 23 May to 26 June 2006.
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, Spanish Project (CTM2007-28896-E), French OVIDE Project supported by CNRS, and CARBOOCEAN (511176GOCE), No
Proyecto: EC/FP7/264879




Carbon Dioxide, Hydrographic, and Chemical Data Obtained During the R/V Thalassa Cruise in the North Atlantic Ocean on CLIVAR Repeat Hydrography Section OVIDE-2008 (June 6 - July 11, 2008)

Digital.CSIC. Repositorio Institucional del CSIC
  • Ríos, Aida F.
  • Vázquez Rodríguez, Marcos
  • Castaño, Mónica
  • Mercier, Herlé
  • Ferron, B.
  • Branellec, Pierre
  • Lherminier, Pascale
The item is made of 2 files, of which 1 is the dataset and the other include a small description of the measured variables.-- Dataset contributed to the Project Carbochange, 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 OVIDE 2008 carried out from 6 June to 11 July 2008.
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, French OVIDE Project supported by CNRS, and CARBOOCEAN (511176GOCE), No
Proyecto: EC/FP7/264879




Carbon Dioxide, Hydrographic, and Chemical Data Obtained During the R/V Thalassa Cruise in the North Atlantic Ocean on CLIVAR Repeat Hydrography Section OVIDE-2010 (June 08 - 30, 2010)

Digital.CSIC. Repositorio Institucional del CSIC
  • Ríos, Aida F.
  • Ribas, Mariana
  • Vázquez Rodríguez, Marcos
  • Castaño, Mónica
  • Fajar, Noelia
  • Pérez, Fiz F.
  • Mercier, Herlé
  • Thierry, V.
  • Branellec, Pierre
  • Lherminier, Pascale
  • Morin, Pascal
The item is made of 2 files, of which 1 is the dataset and the other include a small description of the measured variables.-- Dataset contributed to the Project Carbochange.-- More information in http://hdl.handle.net/10261/115861, 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 OVIDE 2010 carried out from 8 to 30 June 2010.
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, French OVIDE Project supported by CNRS, and CARBOCHANGE, No
Proyecto: EC/FP7/264879




Carbon Dioxide, Hydrographic, and Chemical Data Obtained During the R/V Sarmiento de Gamboa Cruise in the North Atlantic Ocean on CLIVAR Repeat Hydrography Section OVIDE-2012 (June 23 - July 20, 2012)

Digital.CSIC. Repositorio Institucional del CSIC
  • Ríos, Aida F.
  • Pérez, Fiz F.
  • García-Ibáñez, Maribel I.
  • Fajar, Noelia
  • Gilcoto, Miguel
  • Alonso Pérez, Fernando
  • Paz, M. de la
  • Castaño, Mónica
  • Velo, A.
The item is made of 2 files, of which 1 is the dataset and the other include a small description of the measured variables.-- Aida F. Ríos ... et al.-- Dataset contributed to the Project Carbochange, 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 CATARINA carried out along the OVIDE section from 23 June to 20 July 2012.
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, CATARINA (CTM2010-17141), CARBOCHANGE, No
Proyecto: EC/FP7/264879




R/V Sarmiento de Gamboa 24N_Malaspina_2011 cruise carbon data from the CLIVAR/GO_SHIP Repeat Section A5_2011 (Jan. 28 - Mar. 14, 2011)

Digital.CSIC. Repositorio Institucional del CSIC
  • Hernández Guerra, Alonso
  • Pérez, Fiz F.
  • Ríos, Aida F.
  • Fernández-Guallart, E.
  • Padín, X. A.
  • Vázquez Rodríguez, Marcos
The item is made of 2 files, of which 1 is the dataset and the other include a small description of the measured variables.-- Dataset contributed to the Project Carbochange, 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 24N_Malaspina carried out from 28 January to 14 March 2011.
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, Project MALASPINA (CSD2008-00077) supported by Ministerio de Ciencia e Innovación, and project CARBOCHANGE (264879) supported by European Commission, No
Proyecto: EC/FP7/264879




Trends of pH decrease in the Mediterranean Sea through high frequency observational data: indication of ocean acidification in the basin

Digital.CSIC. Repositorio Institucional del CSIC
  • Flecha, Susana
  • Pérez, Fiz F.
  • García-Lafuente, Jesús
  • Sammartino, Simone
  • Ríos, Aida F.
  • Huertas, I. Emma
14 páginas, 4 figuras.-- This work is licensed under a Creative Commons Attribution 4.0 International License.-- Proyecto Carbochange, A significant fraction of anthropogenic carbon dioxide (CO2) released to the atmosphere is absorbed by the oceans, leading to a range of chemical changes and causing ocean acidification (OA). Assessing the impact of OA on marine ecosystems requires the accurate detection of the rate of seawater pH change. This work reports the results of nearly 3 years of continuous pH measurements in the Mediterranean Sea at the Strait of Gibraltar GIFT time series station. We document a remarkable decreasing annual trend of −0.0044 ± 0.00006 in the Mediterranean pH, which can be interpreted as an indicator of acidification in the basin based on high frequency records. Modeling pH data of the Mediterranean outflow allowed to discriminate between the pH values of its two main constituent water masses, the Levantine Intermediate Water (LIW) and the Western Mediterranean Deep Water (WMDW). Both water masses also exhibited a decline in pH with time, particularly the WMDW, which can be related to their different biogeochemical nature and processes occurring during transit time from formation sites to the Strait of Gibraltar, Funding
for this work was provided by the European Commission through the projects CARBOCHANGE (FP7-
264879), and PERSEUS (FP7-287600) and by the Spanish Ministry of Economy and Competitiveness
(CTM2010-21229). SF was supported by a JAE PREDOCTORAL scholarship, part-funded by the
European Commission (European Social Fund, ESF2007-2013) and the Spanish Ministry for Economy
and Competitiveness., Peer reviewed
Proyecto: EC/FP7/264879




Dissolved inorganic carbon budgets in the eastern subpolar North Atlantic in the 2000s from in situ data

Digital.CSIC. Repositorio Institucional del CSIC
  • Zunino, P.
  • Lherminier, Pascale
  • Mercier, Herlé
  • Padín, X. A.
  • Ríos, Aida F.
  • Pérez, Fiz F.
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




On the mediterranean water composition

Digital.CSIC. Repositorio Institucional del CSIC
  • Carracedo, L.
  • Pardo, Paula C.
  • Flecha, Susana
  • Pérez, Fiz F.
20 páginas, 5 tablas, 6 figuras, 1 apéndice.-- Proyecto Carbochange, The Mediterranean Outflow Water (MOW) spills from the Mediterranean Sea (east North Atlantic basin)
west off the Strait ofGibraltar.AsMOWoutflows, it entrains eastern NorthAtlantic CentralWaters (ENACW)
and IntermediateWaters to formthe neutrally buoyantMediterraneanWater (MW) that can be traced over the
entire NorthAtlantic basin. Its high salinity content influences the thermohaline properties of the intermediate–
deepwater column in theNorthAtlantic and its dynamics.Here, the composition ofMWin its source region (the
Gulf of Cádiz, west off Strait of Gibraltar) is investigated on the basis of an optimum multiparameter analysis.
The results obtained indicate that mixing of MOW (34.1% 6 0.3%) occurs mainly with overlying ENACW
(57.1% 6 0.8%) in a process broadly known as central water entrainment. A diluted form (80% of dilution) of
the Antarctic Intermediate Water (AAIW) reaches the region and also takes part in MW formation (8.3% 6
0.5%). Finally, the underlying Labrador Sea Water (LSW) also contributes (0.4%6 0.1%) to the characteristics
ofMW. Fromthese results and considering 0.74 Sverdrups (Sv; 1 Sv[ 106m3 s21) as themean outflow ofMOW,
the MW exportation rate was inferred (2.2 Sv), which, decomposing MW, means that the MOW outflow is
accompanied by 1.24 Sv of entrained ENACW, 0.18 Sv of AAIW, and ,0.01 Sv of LSW., The research
was supported through the Seventh Framework Program
(EU FP7 Project CARBOCHANGE, ‘‘Changes in carbon
uptake and emissions by oceans in a changing climate,’’
C_ENVIR/0869). All the authors were funded by the
Spanish Research Council (CSIC). The first author was
also partly financed by the Regional Government of
Galicia through a specific program for short stays abroad,
cofounded by the European Social Fund (FSE) 2011–15
and now is being funded by the University of Vigo,
through the Galician I2C Plan for postdoctoral research, Peer reviewed
Proyecto: EC/FP7/264879




Ocean acidification in the subpolar North Atlantic: rates and mechanisms controlling pH changes

Digital.CSIC. Repositorio Institucional del CSIC
  • García-Ibáñez, Maribel I.
  • Zunino, P.
  • Fröb, Friederike
  • Carracedo, L.
  • Ríos, Aida F.
  • Mercier, Herlé
  • Olsen, Are
  • Pérez, Fiz F.
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