@article{fdi:010085237,
  title = {{T}he {CISE}-{LOCEAN} seawater isotopic database (1998-2021)},
  author = {{R}everdin, {G}. and {W}aelbroeck, {C}. and {P}ierre, {C}. and {A}khoudas, {C}. and {A}loisi, {G}. and {B}enetti, {M}. and {B}ourl{\`e}s, {B}ernard and {D}anielsen, {M}. and {D}emange, {J}. and {D}iverr{\`e}s, {D}enis and {G}ascard, {J}. {C}. and {H}oussais, {M}. {N}. and {L}e {G}off, {H}. and {L}herminier, {P}. and {L}o {M}onaco, {C}. and {M}ercier, {H}. and {M}etzl, {N}. and {M}orisset, {S}. and {N}aamar, {A}. and {R}eynaud, {T}. and {S}allee, {J}. {B}. and {T}hierry, {V}. and {H}artman, {S}. {E}. and {M}awji, {E}. {W}. and {O}lafsdottir, {S}. and {K}anzow, {T}. and {V}elo, {A}. and {V}oelker, {A}. and {Y}ashayaev, {I}. and {H}aumann, {F}. {A}. and {L}eng, {M}. {J}. and {A}rrowsmith, {C}. and {M}eredith, {M}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he characteristics of the {CISE}-{LOCEAN} seawater isotope dataset (delta {O}-18, delta {H}-2, referred to as delta {D}) are presented (https://doi.org/10.17882/71186; {W}aterisotopes-{CISE}-{LOCEAN}, 2021). {T}his dataset covers the time period from 1998 to 2021 and currently includes close to 8000 data entries, all with delta {O}-18, three-quarters of them also with delta {D}, associated with a date stamp, space stamp, and usually a salinity measurement. {U}ntil 2010, samples were analyzed by isotopic ratio mass spectrometry and since then mostly by cavity ring-down spectroscopy ({CRDS}). {I}nstrumental uncertainty in this dataset is usually as low as 0.03 parts per thousand for delta {O}-18 and 0.15 parts per thousand for delta {D}. {A}n additional uncertainty is related to the isotopic composition of the in-house standards that are used to convert data to the {V}ienna {S}tandard {M}ean {O}cean {W}ater ({VSMOW}) scale. {D}ifferent comparisons suggest that since 2010 the latter have remained within at most 0.03 parts per thousand for delta {O}-18 and 0.20 parts per thousand for delta {D}. {T}herefore, combining the two uncertainties suggests a standard deviation of at most 0.05 parts per thousand for delta {O}-18 and 0.25 parts per thousand for delta {D}. {F}or 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 (delta {D} - 8x delta {O}-18). {T}his adjustment adds an uncertainty in the respective data of roughly 0.05 parts per thousand for delta {O}-18 and 0.10 parts per thousand for delta {D}. {T}his 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. {T}he internal consistency of the database can be tested for subsets of the dataset when time series can be obtained (such as in the southern {I}ndian {O}cean or {N}orth {A}tlantic subpolar gyre). {T}hese comparisons suggest that the overall uncertainty of the spatially (for a cruise) or temporally (over a year) averaged data is less than 0.03 parts per thousand for delta {O}-18 and 0.15 parts per thousand for delta {D}. {H}owever, 18 comparisons with duplicate seawater data analyzed in other laboratories or with other datasets in the intermediate and deep ocean suggest a larger scatter. {W}hen averaging the 18 comparisons done for delta {O}-18, we find a difference of 0.082 parts per thousand with a standard error of 0.016 parts per thousand. {S}uch an average difference is expected due to the adjustments applied at {LOCEAN} to saline water data produced either by {CRDS} or isotope ratio mass spectrometry ({IRMS}), but the scatter found suggests that care is needed when merging datasets from different laboratories. {E}xamples of time series in the surface {N}orth {A}tlantic subpolar gyre illustrate the temporal changes in water isotope composition that can be detected with a carefully validated dataset.},
  keywords = {},
  booktitle = {},
  journal = {{E}arth {S}ystem {S}cience {D}ata},
  volume = {14},
  numero = {6},
  pages = {2721--2735},
  ISSN = {1866-3508},
  year = {2022},
  DOI = {10.5194/essd-14-2721-2022},
  URL = {https://www.documentation.ird.fr/hor/fdi:010085237},
}