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2. The CISE-LOCEAN seawater isotopic database (1998–2021)

Author

Reverdin, Gilles, primary, Waelbroeck, Claire, additional, Pierre, Catherine, additional, Akhoudas, Camille, additional, Aloisi, Giovanni, additional, Benetti, Marion, additional, Bourlès, Bernard, additional, Danielsen, Magnus, additional, Demange, Jérôme, additional, Diverrès, Denis, additional, Gascard, Jean-Claude, additional, Houssais, Marie-Noëlle, additional, Le Goff, Hervé, additional, Lherminier, Pascale, additional, Lo Monaco, Claire, additional, Mercier, Herlé, additional, Metzl, Nicolas, additional, Morisset, Simon, additional, Naamar, Aïcha, additional, Reynaud, Thierry, additional, Sallée, Jean-Baptiste, additional, Thierry, Virginie, additional, Hartman, Susan E., additional, Mawji, Edward W., additional, Olafsdottir, Solveig, additional, Kanzow, Torsten, additional, Velo, Anton, additional, Voelker, Antje, additional, Yashayaev, Igor, additional, Haumann, F. Alexander, additional, Leng, Melanie J., additional, Arrowsmith, Carol, additional, and Meredith, Michael, additional

Published
2022
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4. The CISE-LOCEAN sea water isotopic database (1998–2021)

Author

Reverdin, Gilles, primary, Waelbroeck, Claire, additional, Pierre, Catherine, additional, Akhoudas, Camille, additional, Aloisi, Giovanni, additional, Benetti, Marion, additional, Bourlès, Bernard, additional, Danielsen, Magnus, additional, Demange, Jérôme, additional, Diverrès, Denis, additional, Gascard, Jean-Claude, additional, Houssais, Marie-Noëlle, additional, Le Goff, Hervé, additional, Lherminier, Pascale, additional, Lo Monaco, Claire, additional, Mercier, Herlé, additional, Metzl, Nicolas, additional, Morisset, Simon, additional, Naamar, Aïcha, additional, Reynaud, Thierry, additional, Sallée, Jean-Baptiste, additional, Thierry, Virginie, additional, Hartman, Susan E., additional, Mawji, Edward M., additional, Olafsdottir, Solveig, additional, Kanzow, Torsten, additional, Voelker, Antje, additional, and Yashayaev, Igor, additional

Published
2022
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5. The CISE-LOCEAN sea water isotopic database (1998-2021).

Author

Reverdin, Gilles, Waelbroeck, Claire, Pierre, Catherine, Akhoudas, Camille, Aloisi, Giovanni, Benetti, Marion, Bourlès, Bernard, Danielsen, Magnus, Demange, Jérôme, Diverrès, Denis, Gascard, Jean-Claude, Houssais, Marie-Noëlle, Goff, Hervé Le, Lherminier, Pascale, Monaco, Claire Lo, Mercier, Herlé, Metzl, Nicolas, Morisset, Simon, Naamar, Aïcha, and Reynaud, Thierry

Subjects
SEAWATER, CAVITY-ringdown spectroscopy, TIME series analysis, MASS spectrometry, TIMESTAMPS
Abstract

The characteristics of the CISE-LOCEAN sea water isotope data set (δ18O, δ²H, later designed as δD) are presented. This data set covers the time period from 1998 to 2021 and currently includes close to 8000 data entries, all with δ18O, three quarters of them also with δD, associated with a time and space stamp and usually a salinity measurement. Until 2010, samples were analysed by isotopic ratio mass spectrometry, and since then mostly by cavity ring-down spectroscopy (CRDS). Instrumental uncertainty on individual data in this dataset is usually with a standard deviation as low as 0.03 / 0.15 ‰ for δ18O and δD. An additional uncertainty is related to uncertain isotopic composition of the in-house standards that are used to convert daily data into the VSMOW scale. Different comparisons suggest that since 2010 the latter have remained within at most 0.03 / 0.20 ‰ for δ18O and δD. Therefore, combining the two suggests a standard deviation of at most 0.05 / 0.25 ‰ for δ18O / δD. Finally, for some samples, we find that there has been evaporation during collection and storage, requiring adjustment of the isotopic data produced by CRDS, based on d-excess. This adds an uncertainty on the adjusted data of roughly 0.05 / 0.10 ‰ on δ18O and δD. This issue of conservation of samples is certainly a strong source of quality loss for parts of the database, and 'small' effects may have remained undetected. The internal consistency of the database can be tested for subsets of the dataset, when time series can be obtained (such as in the southern Indian Ocean or North Atlantic subpolar gyre). These comparisons suggest that the overall uncertainty of the spatially (for a cruise) or temporally (over a year) averaged data is on the order of or less than 0.03 / 0.15 ‰ for δ18O / δD. On the other hand, 17 comparisons with duplicate sea water data analysed in other laboratories or with other data sets in deep regions suggest a larger scatter. When averaging the 17 comparisons done for δ18O, we find a difference close to the adjustment applied at LOCEAN to convert salty water data from the activity to the concentration scale. Such a difference is expected, but the scatter found suggests that care is needed when merging datasets from different laboratories. Examples of time series in the surface North Atlantic subpolar gyre illustrate the temporal changes in water isotope composition that can be detected with a carefully validated dataset. [ABSTRACT FROM AUTHOR]

Published
2022
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6. Constraining the Oceanic Uptake and Fluxes of Greenhouse Gases by Building an Ocean Network of Certified Stations: The Ocean Component of the Integrated Carbon Observation System, ICOS-Oceans

Author

Steinhoff, Tobias, Gkritzalis, Thanos, Lauvset, Siv K., Jones, Stephen D., Schuster, Ute, Olsen, Are, Becker, Meike, Bozzano, Roberto, Brunetti, Fabio, Cantoni, Carolina, Cardin, Vanessa, Diverrès, Denis, Fiedler, Björn, Fransson, Agneta, Giani, Michele, Hartman, Sue, Hoppema, Mario, Jeansson, Emil, Johannessen, Truls, Kitidis, Vassilis, Körtzinger, Arne, Landa, Camilla S., Lefèvre, Nathalie, Luchetta, Anna, Naudts, Lieven, Nightingale, Philip, Omar, Abdirahman M., Pensieri, Sara, Pfeil, Benjamin, Castaño-Primo, Rocío, Rehder, Gregor, Rutgersson, Anna, Sanders, Richard, Schewe, Ingo, Siena, Giuseppe, Skjelvan, Ingunn, Soltwedel, Thomas, Van Heuven, Steven M. A. C., Watson, Andrew J., Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Flanders Marine Institute, VLIZ, Bjerknes Centre for Climate Research (BCCR), Department of Biological Sciences [Bergen] (BIO / UiB), University of Bergen (UiB)-University of Bergen (UiB), College of Life and Environmental Sciences [Exeter], University of Exeter, University of Leeds, Instrumentation, Moyens analytiques, Observatoires en Géophysique et Océanographie (IMAGO), Norwegian Polar Institute, Istituto Nazionale di Geofisica e di Oceanografia Sperimentale (OGS), Meteorological Research Institute [Tsukuba] (MRI), Japan Meteorological Agency (JMA), Plymouth Marine Laboratory (PML), Austral, Boréal et Carbone (ABC), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Royal Belgian Institute of Natural Sciences (RBINS), University of Bergen (UiB), Department of Earth Sciences [Uppsala], Uppsala University, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Centre for Isotope Research [Groningen] (CIO), University of Groningen [Groningen], European Project: 654410,H2020,H2020-INFRAIA-2014-2015,JERICO-NEXT(2015), Plymouth Marine Laboratory, Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), GEOMAR - Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), University of Bergen (UIB), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Earth Sciences [ Uppsala], and NASA Ames Research Center (ARC)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], autonomous surface vehicle, Climate Research, ATC, dissolved inorganic, carbon portal, ocean observation, network design, Oceanografi, hydrologi och vattenresurser, flux maps, Klimatforskning, Oceanography, Hydrology and Water Resources, CO2 fluxes, Atmospheric Thematic Centre, DIC, CP, carbon sink, ComputingMilieux_MISCELLANEOUS, ASV
Abstract

The European Research Infrastructure Consortium “Integrated Carbon Observation System” (ICOS) aims at delivering high quality greenhouse gas (GHG) observations and derived data products (e.g., regional GHG-flux maps) for constraining the GHG balance on a European level, on a sustained long-term basis. The marine domain (ICOS-Oceans) currently consists of 11 Ship of Opportunity lines (SOOP – Ship of Opportunity Program) and 10 Fixed Ocean Stations (FOSs) spread across European waters, including the North Atlantic and Arctic Oceans and the Barents, North, Baltic, and Mediterranean Seas. The stations operate in a harmonized and standardized way based on community-proven protocols and methods for ocean GHG observations, improving operational conformity as well as quality control and assurance of the data. This enables the network to focus on long term research into the marine carbon cycle and the anthropogenic carbon sink, while preparing the network to include other GHG fluxes. ICOS data are processed on a near real-time basis and will be published on the ICOS Carbon Portal (CP), allowing monthly estimates of CO2 air-sea exchange to be quantified for European waters. ICOS establishes transparent operational data management routines following the FAIR (Findable, Accessible, Interoperable, and Reusable) guiding principles allowing amongst others reproducibility, interoperability, and traceability. The ICOS-Oceans network is actively integrating with the atmospheric (e.g., improved atmospheric measurements onboard SOOP lines) and ecosystem (e.g., oceanic direct gas flux measurements) domains of ICOS, and utilizes techniques developed by the ICOS Central Facilities and the CP. There is a strong interaction with the international ocean carbon cycle community to enhance interoperability and harmonize data flow. The future vision of ICOS-Oceans includes ship-based ocean survey sections to obtain a three-dimensional understanding of marine carbon cycle processes and optimize the existing network design. publishedVersion

Published
2019
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7. Basin-scale estimate of the sea-air CO2 flux during the 2010 warm event in the Tropical North Atlantic

Author

Lefèvre, Nathalie, Veleda, D., Tyaquica, P., Perruche, C., Diverrès, Denis, and Ibanhez, J. S. P.

Abstract

Following the anomalous warming event occurring in the tropical North Atlantic in 2010, higher than usual surface fugacity of CO2 (fCO(2)) was observed. To evaluate the spatial extent of these anomalies and their drivers, and to quantify the sea-air CO2 flux at basin scale, the Mercator-Ocean model is used from 2006 to 2014 within the region 0-30 degrees N, 70-15 degrees W. Model outputs are generally in accordance with underway sea surface temperature, sea surface salinity, and surface fCO(2) recorded by two merchant ships. The anomalous warming of 2010 is well reproduced by the model and is the main driver of fCO(2) anomalies. The first coupled Empirical Orthogonal Function mode, between sea surface temperature and fCO(2), captures more than 70% of the total variance and is characterized by a basin-scale warming associated to positive fCO(2) anomalies. The corresponding principal components are correlated to the Tropical North Atlantic Index and identify 2010 as the year with the highest positive anomaly over 2006-2014. Exceptions to this general pattern are located near the African coast, where the weakening of the coastal upwelling causes negative inorganic carbon anomalies, and close to the Amazon River plume, where fCO(2) anomalies are primarily associated with sea surface salinity anomalies. Although the fCO(2) anomalies of 2010 appear mostly in spring, they affect the annual CO2 budget and lead to an increased CO2 outgassing twice as large (46.2 Tg C per year) as the mean annual flux over the 2006-2014 period (23.3 Tg C per year).

Published
2019

8. Le Service national d'observation de la salinité de surface de la mer : 50 ans de mesures océaniques globales

Author

Alory, Gaël, primary, Téchiné, Philippe, additional, Delcroix, Thierry, additional, Diverrès, Denis, additional, Varillon, David, additional, Donguy, Jean-René, additional, Reverdin, Gilles, additional, Morrow, Rosemary, additional, Grelet, Jacques, additional, Gouriou, Yves, additional, Jacquin, Stéphane, additional, Kestenare, Elodie, additional, Bachelier, Céline, additional, and DiMattéo, Angelo, additional

Published
2020
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9. Winter weather controls net influx of atmospheric CO2 on the north-west European shelf

Author

Kitidis, Vassilis, primary, Shutler, Jamie D., additional, Ashton, Ian, additional, Warren, Mark, additional, Brown, Ian, additional, Findlay, Helen, additional, Hartman, Sue E., additional, Sanders, Richard, additional, Humphreys, Matthew, additional, Kivimäe, Caroline, additional, Greenwood, Naomi, additional, Hull, Tom, additional, Pearce, David, additional, McGrath, Triona, additional, Stewart, Brian M., additional, Walsham, Pamela, additional, McGovern, Evin, additional, Bozec, Yann, additional, Gac, Jean-Philippe, additional, van Heuven, Steven M. A. C., additional, Hoppema, Mario, additional, Schuster, Ute, additional, Johannessen, Truls, additional, Omar, Abdirahman, additional, Lauvset, Siv K., additional, Skjelvan, Ingunn, additional, Olsen, Are, additional, Steinhoff, Tobias, additional, Körtzinger, Arne, additional, Becker, Meike, additional, Lefevre, Nathalie, additional, Diverrès, Denis, additional, Gkritzalis, Thanos, additional, Cattrijsse, André, additional, Petersen, Wilhelm, additional, Voynova, Yoana G., additional, Chapron, Bertrand, additional, Grouazel, Antoine, additional, Land, Peter E., additional, Sharples, Jonathan, additional, and Nightingale, Philip D., additional

Published
2019
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11. Winter weather controls net influx of atmospheric CO2 on the north-west European shelf

Author

Kitidis, Vassilis, Shutler, Jamie D., Ashton, Ian, Warren, Mark, Brown, Ian, Findlay, Helen, Hartman, Sue E., Sanders, Richard, Humphreys, Matthew, Kivimäe, Caroline, Greenwood, Naomi, Hull, Tom, Pearce, David, McGrath, Triona, Stewart, Brian M., Walsham, Pamela, McGovern, Evin, Bozec, Yann, Gac, Jean-Philippe, van Heuven, Steven M. A. C., Hoppema, Mario, Schuster, Ute, Johannessen, Truls, Omar, Abdirahman, Lauvset, Siv K., Skjelvan, Ingunn, Olsen, Are, Steinhoff, Tobias, Körtzinger, Arne, Becker, Meike, Lefevre, Nathalie, Diverrès, Denis, Gkritzalis, Thanos, Cattrijsse, André, Petersen, Wilhelm, Voynova, Yoana G., Chapron, Bertrand, Grouazel, Antoine, Land, Peter E., Sharples, Jonathan, Nightingale, Philip D., Kitidis, Vassilis, Shutler, Jamie D., Ashton, Ian, Warren, Mark, Brown, Ian, Findlay, Helen, Hartman, Sue E., Sanders, Richard, Humphreys, Matthew, Kivimäe, Caroline, Greenwood, Naomi, Hull, Tom, Pearce, David, McGrath, Triona, Stewart, Brian M., Walsham, Pamela, McGovern, Evin, Bozec, Yann, Gac, Jean-Philippe, van Heuven, Steven M. A. C., Hoppema, Mario, Schuster, Ute, Johannessen, Truls, Omar, Abdirahman, Lauvset, Siv K., Skjelvan, Ingunn, Olsen, Are, Steinhoff, Tobias, Körtzinger, Arne, Becker, Meike, Lefevre, Nathalie, Diverrès, Denis, Gkritzalis, Thanos, Cattrijsse, André, Petersen, Wilhelm, Voynova, Yoana G., Chapron, Bertrand, Grouazel, Antoine, Land, Peter E., Sharples, Jonathan, and Nightingale, Philip D.

Abstract

Shelf seas play an important role in the global carbon cycle, absorbing atmospheric carbon dioxide (CO2) and exporting carbon (C) to the open ocean and sediments. The magnitude of these processes is poorly constrained, because observations are typically interpolated over multiple years. Here, we used 298500 observations of CO2 fugacity (fCO2) from a single year (2015), to estimate the net influx of atmospheric CO2 as 26.2 ± 4.7 Tg C yr−1 over the open NW European shelf. CO2 influx from the atmosphere was dominated by influx during winter as a consequence of high winds, despite a smaller, thermally-driven, air-sea fCO2 gradient compared to the larger, biologically-driven summer gradient. In order to understand this climate regulation service, we constructed a carbon-budget supplemented by data from the literature, where the NW European shelf is treated as a box with carbon entering and leaving the box. This budget showed that net C-burial was a small sink of 1.3 ± 3.1 Tg C yr−1, while CO2 efflux from estuaries to the atmosphere, removed the majority of river C-inputs. In contrast, the input from the Baltic Sea likely contributes to net export via the continental shelf pump and advection (34.4 ± 6.0 Tg C yr−1).

Published
2019

12. Basin‐Scale Estimate of the Sea‐Air CO2 Flux During the 2010 Warm Event in the Tropical North Atlantic

Author

European Commission, Lefèvre, Nathalie [0000-0002-1126-5528], Veleda, Doris [0000-0003-2103-5950], Perruche, Coralie [0000-0003-1307-049X], Ibánhez, J. Severino P. [0000-0001-6093-3054], Lefèvre, Nathalie, Veleda, Doris, Tyaquiçã, Pedro, Perruche, Coralie, Diverrès, Denis, Ibánhez, J. Severino P., European Commission, Lefèvre, Nathalie [0000-0002-1126-5528], Veleda, Doris [0000-0003-2103-5950], Perruche, Coralie [0000-0003-1307-049X], Ibánhez, J. Severino P. [0000-0001-6093-3054], Lefèvre, Nathalie, Veleda, Doris, Tyaquiçã, Pedro, Perruche, Coralie, Diverrès, Denis, and Ibánhez, J. Severino P.

Abstract

Following the anomalous warming event occurring in the tropical North Atlantic in 2010, higher than usual surface fugacity of CO2 (fCO2) was observed. To evaluate the spatial extent of these anomalies and their drivers, and to quantify the sea‐air CO2 flux at basin scale, the Mercator‐Ocean model is used from 2006 to 2014 within the region 0–30°N, 70–15°W. Model outputs are generally in accordance with underway sea surface temperature, sea surface salinity, and surface fCO2 recorded by two merchant ships. The anomalous warming of 2010 is well reproduced by the model and is the main driver of fCO2 anomalies. The first coupled Empirical Orthogonal Function mode, between sea surface temperature and fCO2, captures more than 70% of the total variance and is characterized by a basin‐scale warming associated to positive fCO2 anomalies. The corresponding principal components are correlated to the Tropical North Atlantic Index and identify 2010 as the year with the highest positive anomaly over 2006–2014. Exceptions to this general pattern are located near the African coast, where the weakening of the coastal upwelling causes negative inorganic carbon anomalies, and close to the Amazon River plume, where fCO2 anomalies are primarily associated with sea surface salinity anomalies. Although the fCO2 anomalies of 2010 appear mostly in spring, they affect the annual CO2 budget and lead to an increased CO2 outgassing twice as large (46.2 Tg C per year) as the mean annual flux over the 2006–2014 period (23.3 Tg C per year)

Published
2019

13. North Atlantic subpolar gyre along predetermined ship tracks since 1993 : a monthly data set of surface temperature, salinity, and density

Author

Reverdin, G., Valdimarsson, H., Alory, Gaël, Diverrès, Denis, Bringas, F., Goni, G., Heilmann, L., Chafik, L., Szekely, T., and Friedman, A. R.

Abstract

We present a binned product of sea surface temperature, sea surface salinity, and sea surface density data in the North Atlantic subpolar gyre from 1993 to 2017 that resolves seasonal variability along specific ship routes (

Published
2018

14. Basin‐Scale Estimate of the Sea‐Air CO2 Flux During the 2010 Warm Event in the Tropical North Atlantic.

Author

Lefèvre, Nathalie, Veleda, Doris, Tyaquiçã, Pedro, Perruche, Coralie, Diverrès, Denis, and Ibánhez, J. Severino P.

Subjects
FUGACITY, SALINITY, ORTHOGONAL functions, PRECIPITATION anomalies
Abstract

Following the anomalous warming event occurring in the tropical North Atlantic in 2010, higher than usual surface fugacity of CO2 (fCO2) was observed. To evaluate the spatial extent of these anomalies and their drivers, and to quantify the sea‐air CO2 flux at basin scale, the Mercator‐Ocean model is used from 2006 to 2014 within the region 0–30°N, 70–15°W. Model outputs are generally in accordance with underway sea surface temperature, sea surface salinity, and surface fCO2 recorded by two merchant ships. The anomalous warming of 2010 is well reproduced by the model and is the main driver of fCO2 anomalies. The first coupled Empirical Orthogonal Function mode, between sea surface temperature and fCO2, captures more than 70% of the total variance and is characterized by a basin‐scale warming associated to positive fCO2 anomalies. The corresponding principal components are correlated to the Tropical North Atlantic Index and identify 2010 as the year with the highest positive anomaly over 2006–2014. Exceptions to this general pattern are located near the African coast, where the weakening of the coastal upwelling causes negative inorganic carbon anomalies, and close to the Amazon River plume, where fCO2 anomalies are primarily associated with sea surface salinity anomalies. Although the fCO2 anomalies of 2010 appear mostly in spring, they affect the annual CO2 budget and lead to an increased CO2 outgassing twice as large (46.2 Tg C per year) as the mean annual flux over the 2006–2014 period (23.3 Tg C per year). Key Points: Underway fCO2 observations of 2010, collected on two merchant ships, compare well with the Mercator‐Ocean model simulationsThe fCO2 anomalies observed in Spring 2010 in the tropical North Atlantic are mostly driven by the sea surface temperature anomaliesThe resulting outgassing of CO2 for the year 2010 is twice as large as the mean sea‐air CO2 flux over the 2006 to 2014 period [ABSTRACT FROM AUTHOR]

Published
2019
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15. Seasonal and interannual variability of sea-air CO2 fluxes in the tropical Atlantic affected by the Amazon River plume

Author

Ibanhez, J. S. P., Diverrès, Denis, Araujo, M., and Lefèvre, Nathalie

Abstract

CO2 fugacities obtained from a merchant ship sailing from France to French Guyana were used to explore the seasonal and interannual variability of the sea-air CO2 exchange in the western tropical North Atlantic (TNA; 5-14 degrees N, 41-52 degrees W). Two distinct oceanic water masses were identified in the area associated to the main surface currents, i.e., the North Brazil Current (NBC) and the North Equatorial Current (NEC). The NBC was characterized by permanent CO2 oversaturation throughout the studied period, contrasting with the seasonal pattern identified in the NEC. The NBC retroflection was the main contributor to the North Equatorial Counter Current (NECC), thus spreading into the central TNA, the Amazon River plume, and the CO2-rich waters probably originated from the equatorial upwelling. Strong CO2 undersaturation was associated to the Amazon River plume. Total inorganic carbon drawdown due to biological activity was estimated to be 154 mu mol kg(-1) within the river plume. As a consequence, the studied area acted as a net sink of atmospheric CO2 (from -72.2 +/- 10.2 mmol m(-2) month(-1) in February to 14.3 +/- 4.5 mmol m(-2) month(-1) in May). This contrasted with the net CO2 efflux estimated by the main global sea-air CO2 flux climatologies. Interannual sea surface temperature changes in the TNA caused by large-scale climatic events could determine the direction and intensity of the sea-air CO2 fluxes in the NEC. Positive temperature anomalies observed in the TNA led to an almost permanent CO2 outgassing in the NEC in 2010.

Published
2015

16. Seasonal and interannual variability of sea-air CO2 fluxes in the tropical Atlantic affected by the Amazon River plume

Author

Ibánhez, J. Severino P., Diverrès, Denis, Araujo, Moacyr, Lefèvre, Nathalie, IRD Lago Sul, Brazil, Instrumentation, Moyens analytiques, Observatoires en Géophysique et Océanographie (IMAGO), Universidade Federal de Pernambuco [Recife] (UFPE), Austral, Boréal et Carbone (ABC), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636))

Subjects
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2015
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17. Basin‐Scale Estimate of the Sea‐Air CO2Flux During the 2010 Warm Event in the Tropical North Atlantic

Author

Lefèvre, Nathalie, Veleda, Doris, Tyaquiçã, Pedro, Perruche, Coralie, Diverrès, Denis, and Ibánhez, J. Severino P.

Abstract

Following the anomalous warming event occurring in the tropical North Atlantic in 2010, higher than usual surface fugacity of CO2(fCO2) was observed. To evaluate the spatial extent of these anomalies and their drivers, and to quantify the sea‐air CO2flux at basin scale, the Mercator‐Ocean model is used from 2006 to 2014 within the region 0–30°N, 70–15°W. Model outputs are generally in accordance with underway sea surface temperature, sea surface salinity, and surface fCO2recorded by two merchant ships. The anomalous warming of 2010 is well reproduced by the model and is the main driver of fCO2anomalies. The first coupled Empirical Orthogonal Function mode, between sea surface temperature and fCO2, captures more than 70% of the total variance and is characterized by a basin‐scale warming associated to positive fCO2anomalies. The corresponding principal components are correlated to the Tropical North Atlantic Index and identify 2010 as the year with the highest positive anomaly over 2006–2014. Exceptions to this general pattern are located near the African coast, where the weakening of the coastal upwelling causes negative inorganic carbon anomalies, and close to the Amazon River plume, where fCO2anomalies are primarily associated with sea surface salinity anomalies. Although the fCO2anomalies of 2010 appear mostly in spring, they affect the annual CO2budget and lead to an increased CO2outgassing twice as large (46.2 Tg C per year) as the mean annual flux over the 2006–2014 period (23.3 Tg C per year). Underway fCO2observations of 2010, collected on two merchant ships, compare well with the Mercator‐Ocean model simulationsThe fCO2anomalies observed in Spring 2010 in the tropical North Atlantic are mostly driven by the sea surface temperature anomaliesThe resulting outgassing of CO2for the year 2010 is twice as large as the mean sea‐air CO2flux over the 2006 to 2014 period

Published
2019
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22. Seasonal and interannual variability of sea-air CO2 fluxes in the tropical Atlantic affected by the Amazon River plume.

Author

Ibánhez, J. Severino P., Diverrès, Denis, Araujo, Moacyr, and Lefèvre, Nathalie

Subjects
SEA air, CARBON dioxide, MERCHANT ships, WATER masses, SURFACE temperature, REGIONS of freshwater influence
Abstract

CO2 fugacities obtained from a merchant ship sailing from France to French Guyana were used to explore the seasonal and interannual variability of the sea-air CO2 exchange in the western tropical North Atlantic (TNA; 5-14°N, 41-52°W). Two distinct oceanic water masses were identified in the area associated to the main surface currents, i.e., the North Brazil Current (NBC) and the North Equatorial Current (NEC). The NBC was characterized by permanent CO2 oversaturation throughout the studied period, contrasting with the seasonal pattern identified in the NEC. The NBC retroflection was the main contributor to the North Equatorial Counter Current (NECC), thus spreading into the central TNA, the Amazon River plume, and the CO2-rich waters probably originated from the equatorial upwelling. Strong CO2 undersaturation was associated to the Amazon River plume. Total inorganic carbon drawdown due to biological activity was estimated to be 154 µmol kg−1 within the river plume. As a consequence, the studied area acted as a net sink of atmospheric CO2 (from −72.2 ± 10.2 mmol m−2 month−1 in February to 14.3 ± 4.5 mmol m−2 month−1 in May). This contrasted with the net CO2 efflux estimated by the main global sea-air CO2 flux climatologies. Interannual sea surface temperature changes in the TNA caused by large-scale climatic events could determine the direction and intensity of the sea-air CO2 fluxes in the NEC. Positive temperature anomalies observed in the TNA led to an almost permanent CO2 outgassing in the NEC in 2010. [ABSTRACT FROM AUTHOR]

Published
2015
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24. Impact of physical processes on the seasonal distribution of the fugacity of CO2in the western tropical Atlantic

Author

Lefèvre, Nathalie, Urbano, Domingos F., Gallois, Francis, and Diverrès, Denis

Abstract

The fugacity of CO2(fCO2) has been measured underway during three quasi‐synoptic cruises in the western tropical Atlantic in March/April 2009 and July/August 2010 in the region 6°S–15°N, 52°W–24°W. The distribution of fCO2is related to the main features of the ocean circulation. Temperature exerts a dominant control on the distribution of fCO2in March/April whereas salinity plays an important role in July/August due to the more developed North Equatorial Countercurrent (NECC) carrying Amazon water and to the high precipitation associated with the presence of the Intertropical Convergence Zone (ITCZ). The main surface currents are characterized by different fCO2. Overall, the NECC carries less saline waters with lower fCO2compared to the South Equatorial Current (SEC). The North Equatorial Current (NEC) is usually characterized by CO2undersaturation in winter and supersaturation in summer. Using empirical fCO2‐SST‐SSS relationships, two seasonal maps of fCO2are constructed for March 2009 and July 2010. The region is a sink of CO2of 0.40 mmol m−2d−1in March, explained by the winter cooling in the northern hemisphere, whereas it is a source of CO2of 1.32 mmol m−2d−1in July. The equatorial region is a source of CO2throughout the year due to the upwelling supplying CO2‐rich waters to the surface. However, the evolution of fCO2over time, determined from all the available cruises in a small area, 1°S–1°N, 32°W–28°W, suggests that the source of CO2has decreased in February‐March from 1983 to 2011 or has remained constant in October‐November from 1991 to 2010. Seasonal CO2maps from synoptic cruises are producedSurface fCO2is mainly driven by temperature and salinityThe equatorial source of CO2is decreasing or constant over time

Published
2014
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25. Winter weather controls net influx of atmospheric CO 2 on the north-west European shelf.

Author

Kitidis V, Shutler JD, Ashton I, Warren M, Brown I, Findlay H, Hartman SE, Sanders R, Humphreys M, Kivimäe C, Greenwood N, Hull T, Pearce D, McGrath T, Stewart BM, Walsham P, McGovern E, Bozec Y, Gac JP, van Heuven SMAC, Hoppema M, Schuster U, Johannessen T, Omar A, Lauvset SK, Skjelvan I, Olsen A, Steinhoff T, Körtzinger A, Becker M, Lefevre N, Diverrès D, Gkritzalis T, Cattrijsse A, Petersen W, Voynova YG, Chapron B, Grouazel A, Land PE, Sharples J, and Nightingale PD

Abstract

Shelf seas play an important role in the global carbon cycle, absorbing atmospheric carbon dioxide (CO 2 ) and exporting carbon (C) to the open ocean and sediments. The magnitude of these processes is poorly constrained, because observations are typically interpolated over multiple years. Here, we used 298500 observations of CO 2 fugacity (fCO 2 ) from a single year (2015), to estimate the net influx of atmospheric CO 2 as 26.2 ± 4.7 Tg C yr -1 over the open NW European shelf. CO 2 influx from the atmosphere was dominated by influx during winter as a consequence of high winds, despite a smaller, thermally-driven, air-sea fCO 2 gradient compared to the larger, biologically-driven summer gradient. In order to understand this climate regulation service, we constructed a carbon-budget supplemented by data from the literature, where the NW European shelf is treated as a box with carbon entering and leaving the box. This budget showed that net C-burial was a small sink of 1.3 ± 3.1 Tg C yr -1 , while CO 2 efflux from estuaries to the atmosphere, removed the majority of river C-inputs. In contrast, the input from the Baltic Sea likely contributes to net export via the continental shelf pump and advection (34.4 ± 6.0 Tg C yr -1 ).

Published
2019
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