Articles | Volume 1, issue 1
Earth Syst. Sci. Data, 1, 63–75, 2009

Special issue: CARINA: a consistent carbon-relevant data base for the Arctic,...

Earth Syst. Sci. Data, 1, 63–75, 2009

  08 Dec 2009

08 Dec 2009

Consistency of cruise data of the CARINA database in the Atlantic sector of the Southern Ocean

M. Hoppema1, A. Velo2, S. van Heuven3, T. Tanhua4, R. M. Key5, X. Lin5, D. C. E. Bakker6, F. F. Perez2, A. F. Ríos2, C. Lo Monaco7, C. L. Sabine8, M. Álvarez9, and R. G. J. Bellerby10 M. Hoppema et al.
  • 1Alfred Wegener Institute for Polar and Marine Research, Climate Sciences, Postfach 120161, 27515 Bremerhaven, Germany
  • 2Instituto de Investigaciones Marinas – CSIC, Eduardo Cabello 6, 36208 Vigo, Spain
  • 3University of Groningen, Department of Ocean Ecosystems, Biological Center, P.O.Box 14, 9750 AA Groningen, The Netherlands
  • 4Leibniz Institute for Marine Sciences, Marine Biogeochemistry, Kiel, Germany
  • 5Atmospheric and Oceanic Sciences Program, Princeton University, Princeton, NJ 08544, USA
  • 6School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK
  • 7LOCEAN-IPSL, Université Pierre et Marie Curie, Paris, France
  • 8NOAA Pacific Marine Environmental Laboratory, 7600 Sand Point Way NE, Seattle, WA 98115, USA
  • 9IMEDEA (CSIC-UIB), Miquel Marqués 21, E-07190 Esporles, Spain
  • 10Bjerknes Centre for Climate Research, University of Bergen, Allegaten 55, 5007 Bergen, and Geophysical Institute, University of Bergen, Allegaten 70, 5007 Bergen, Norway

Abstract. Initially a North Atlantic project, the CARINA carbon synthesis was extended to include the Southern Ocean. Carbon and relevant hydrographic and geochemical ancillary data from cruises all across the Arctic Mediterranean Seas, Atlantic and Southern Ocean were released to the public and merged into a new database as part of the CARINA synthesis effort. Of a total of 188 cruises, 37 cruises are part of the Southern Ocean, including 11 from the Atlantic sector. The variables from all Southern Ocean cruises, including dissolved inorganic carbon (TCO2), total alkalinity, oxygen, nitrate, phosphate and silicate, were examined for cruise-to-cruise consistency in one collective effort. Seawater pH and chlorofluorocarbons (CFCs) are also part of the database, but the pH quality control (QC) is described in another Earth System Science Data publication, while the complexity of the Southern Ocean physics and biogeochemistry prevented a proper QC analysis of the CFCs. The area-specific procedures of quality control, including crossover analysis between stations and inversion analysis of all crossover data (i.e. secondary QC), are briefly described here for the Atlantic sector of the Southern Ocean. Data from an existing, quality controlled database (GLODAP) were used as a reference for our computations – however, the reference data were included into the analysis without applying the recommended GLODAP adjustments so the corrections could be independently verified. The outcome of this effort is an internally consistent, high-quality carbon data set for all cruises, including the reference cruises. The suggested corrections by the inversion analysis were allowed to vary within a fixed envelope, thus accounting for natural variability. The percentage of cruises adjusted ranged from 31% (for nitrate) to 54% (for phosphate) depending on the variable.