Journal cover Journal topic
Earth System Science Data The Data Publishing Journal
Earth Syst. Sci. Data, 2, 133-155, 2010
© Author(s) 2010. This work is distributed under
the Creative Commons Attribution 3.0 License.
11 May 2010
CARINA data synthesis project: pH data scale unification and cruise adjustments
A. Velo1, F. F. Pérez1, X. Lin2, R. M. Key2, T. Tanhua3, M. de la Paz1, A. Olsen5,6, S. van Heuven4, S. Jutterström5, and A. F. Ríos1 1Instituto de Investigaciones Marinas, CSIC, Eduardo Cabello, 6, 36208 Vigo, Spain
2Atmospheric and Oceanic Sciences Program, Princeton University, Princeton, NJ, USA
3Leibniz-Institute für Meereswissenschaften, Marine Biogeochemie, Kiel, Germany
4Netherlands Institute for Sea Research, Texel, The Netherlands
5Institutionen för kemi, Göteborgs universitet, Göteborg, Sweden
6Bjerknes Centre for Climate Research, UNIFOB AS, Allégaten 55, 5007 Bergen, Norway
Abstract. Data on carbon and carbon-relevant hydrographic and hydrochemical parameters from 188 previously non-publicly available cruise data sets in the Artic Mediterranean Seas (AMS), Atlantic Ocean and Southern Ocean have been retrieved and merged to a new database: CARINA (CARbon IN the Atlantic Ocean).

These data have gone through rigorous quality control (QC) procedures to assure the highest possible quality and consistency. The data for most of the measured parameters in the CARINA database were objectively examined in order to quantify systematic differences in the reported values. Systematic biases found in the data have been corrected in the data products, three merged data files with measured, calculated and interpolated data for each of the three CARINA regions; AMS, Atlantic Ocean and Southern Ocean. Out of a total of 188 cruise entries in the CARINA database, 59 reported pH measured values. All reported pH data have been unified to the Sea-Water Scale (SWS) at 25 °C.

Here we present details of the secondary QC of pH in the CARINA database and the scale unification to SWS at 25 °C. The pH scale has been converted for 36 cruises. Procedures of quality control, including crossover analysis between cruises and inversion analysis are described. Adjustments were applied to the pH values for 21 of the cruises in the CARINA dataset. With these adjustments the CARINA database is consistent both internally as well as with the GLODAP data, an oceanographic data set based on the World Hydrographic Program in the 1990s. Based on our analysis we estimate the internal consistency of the CARINA pH data to be 0.005 pH units. The CARINA data are now suitable for accurate assessments of, for example, oceanic carbon inventories and uptake rates, for ocean acidification assessment and for model validation.

Citation: Velo, A., Pérez, F. F., Lin, X., Key, R. M., Tanhua, T., de la Paz, M., Olsen, A., van Heuven, S., Jutterström, S., and Ríos, A. F.: CARINA data synthesis project: pH data scale unification and cruise adjustments, Earth Syst. Sci. Data, 2, 133-155,, 2010.