The CISE-LOCEAN sea water isotopic database (1998–2021)

• Main Authors: 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, Le Goff, Hervé, Lherminier, Pascale, Lo Monaco, Claire, Mercier, Herlé, Metzl, Nicolas, Morisset, Simon, Naamar, Aïcha, Reynaud, Thierry, Sallée, Jean-Baptiste, Thierry, Virginie, Hartman, Susan, Mawji, Edward, Olafsdottir, Solveig, Kanzow, Torsten, Voelker, Antje, Yashayaev, Igor
• Other Authors: Processus et interactions de fine échelle océanique (PROTEO), 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), Cycles biogéochimiques marins : processus et perturbations (CYBIOM), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Instrumentation, Moyens analytiques, Observatoires en Géophysique et Océanographie (IMAGO), Marine and Freshwater Research Institute, Variabilité de l'Océan et de la Glace de mer (VOG), Développement Instrumental et Techniques Marines (DITM), Laboratoire d'Océanographie Physique et Spatiale (LOPS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Amundsen Science, Quebec, National Oceanography Centre Southampton (NOC), University of Southampton, Center for Marine Environmental Sciences Bremen (MARUM), Universität Bremen, Instituto Português de Investigação do Mar e da Atmosfera (IPMA), Centro de Ciências do Mar Faro (CCMAR), Universidade do Algarve (UAlg), Institut océanographique Bedford - Bedford Oceanographic Institute Dartmouth, Canada (IOB), ANR-13-BS06-0014,GEOVIDE,GEOVIDE, Une étude internationale GEOTRACES le long de la section OVIDE en Atlantique Nord et en Mer du Labrador(2013), European Project: 637770,H2020,ERC-2014-STG,WAPITI(2015)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: [SDE.MCG]Environmental Sciences/Global Changes; Indian; North Atlantic
• Online Access: https://hal.archives-ouvertes.fr/hal-03607291; https://hal.archives-ouvertes.fr/hal-03607291/document; https://hal.archives-ouvertes.fr/hal-03607291/file/essd-2022-34.pdf; https://doi.org/10.5194/essd-2022-34

International audience The characteristics of the CISE-LOCEAN sea water isotope data set (δ$^{18}$O, 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 δ$^{18}$O, 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 δ$^{18}$O 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 δ$^{18}$O and δD. Therefore, combining the two suggests a standard deviation of at most 0.05 / 0.25 ‰ for δ$^{18}$O / 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 δ$^{18}$O 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 ...