Continuous shipboard measurements of oceanic δ18O, δD and δ1
Details of Research
TitleContinuous shipboard measurements of oceanic δ18O, δD and δ13CDIC along a transect from New Zealand to Antarctica using cavity ring-down isotope spectrometryAbstractCavity ring-down spectrometers, with automated sampling interfaces, were deployed to allow measurements of water isotopes (δ18O, δD) and dissolved inorganic carbon (δ13CDIC) stable isotope ratios at high temporal resolution along a transect from New Zealand to the Antarctic continental shelf. Measurements every 10min for δ18O and δD, 15min for DIC yielded 2499 and 2289 discrete measurements respectively. High resolution data enabled the delineation of water mass boundaries as well as revealing insights into surface hydrological and biological processes. δ18O, δD, and δ13CDIC decreased southwards, dropping by approximately 1.0†Degrees, 7.0†Degrees, and 0.5†Degrees, respectively. Though the decline in δ13CDIC with latitude was generally linear, the drop in δ18O and δD was punctuated by areas of rapid, significant change corresponding to the Sub-Tropical, Sub-Antarctic and Polar Fronts. North of the Sub-Antarctic Front (approx. 54.5 deg S) the dominant control on water and DIC isotopes was the precipitation-evaporation balance and the contribution of upwelling waters, respectively. Further south, in close proximity to the sea ice and on the Antarctic shelf, water isotope values were more variable and predominantly influenced by the melting/freezing of sea-ice coupled to inputs from glacial/snow melt water. Local increases in δ13CDIC were likely due to photosynthetic enrichment of the DIC pool. Using this new instrumentation has provided one of the most comprehensive oceanic transect data sets yet achieved and illustrates the potential of these methods to delineate discrete water masses and advance our knowledge of both water and inorganic carbon cycling processes in the ocean. This methodology, combining high-resolution isotopic measurements with hydrographic data, has significant benefits in modelling water mixing in locations with multiple sources and controlling processes. Copyright 2014 Elsevier B.V.AcknowledgementsWe thank the Captain and crew of the RV Tangaroa for their assistance, Rob Smith for extracting the sea surface temperature data, and Sergei Sokolov for extracting the front positions from sea surface height data. This study was supported in part by the Cooperative Research Centre program of the Australian Government, through the Antarctic Climate and Ecosystems Cooperative Research Centre and by the Australian Government Department of the Environment, the Bureau of Meteorology and CSIRO through the Australian Climate Change Science Program, and the National Institute of Water and Atmospheric Research through its government funded core research (COPR1304 and CLCS1301). Additional funding was provided by an Australian Research Council grant (LE130100159). Insightful reviews from two anonymous reviewers greatly improved this manuscript.
Details
1st AuthorBass, A.AuthorBass, A.Munksgaard, N.OGÌrady, D.Williams, M.Bostock, H.Rintoul, S.Bird, M.Year2014JournalJournal of Marine SystemsVolume137Pages21-27DOI10.1016/j.jmarsys.2014.04.003URLhttps://www.scopus.com/inward/recor.....92105aa4e48e8d6025f130bc1KeywordsCarbonDissolved oxygenIsotopesOceanographySea iceCarbonDissolved oxygenHydrographic surveysIceIsotopesLight measurementOceanographySea ice, AntarcticaDissolved inorganic carbonHydrogen isotopeOxygen isotopesPolar FrontSouthern oceanSub-Antarctic frontSub-tropical front, Process controlProcess control, automationcarbon cyclecarbon isotopecontinental shelfdissolved inorganic carbonevaporationhydrogen isotopehydrographmixing ratiooxygen isotopephotosynthesispolar frontprecipitation (climatology)sea iceshipborne measurementsnowmeltspectrometrystable isotopetransectupwellingwater mass, New ZealandSouthern Ocean, rank1Author KeywordsAntarcticaDissolved inorganic carbonHydrogen isotopesOxygen isotopesPolar frontSea-iceSouthern oceanSub-Antarctic frontSub-tropical front
Other
TypeArticleCitationBass, A., Munksgaard, N., O'Grady, D., Williams, M., Bostock, H., Rintoul, S. and Bird, M. (2014). Continuous shipboard measurements of oceanic δ18O, δD and δ13CDIC along a transect from New Zealand to Antarctica using cavity ring-down isotope spectrometry. Journal of Marine Systems, 137: 21-27 IdentifierBass2014Relevancerank1
Bird, M., Continuous shipboard measurements of oceanic δ18O, δD and δ1 , [Bass2014]. Antarctica NZ, accessed 24/06/2025, https://adam.antarcticanz.govt.nz/nodes/view/63389, 10.1016/j.jmarsys.2014.04.003