Articles | Volume 8, issue 2
Earth Syst. Sci. Data, 8, 297–323, 2016
Earth Syst. Sci. Data, 8, 297–323, 2016
15 Aug 2016
15 Aug 2016

The Global Ocean Data Analysis Project version 2 (GLODAPv2) – an internally consistent data product for the world ocean

Are Olsen1, Robert M. Key2, Steven van Heuven3, Siv K. Lauvset1,4, Anton Velo5, Xiaohua Lin2, Carsten Schirnick6, Alex Kozyr7, Toste Tanhua6, Mario Hoppema8, Sara Jutterström9, Reiner Steinfeldt10, Emil Jeansson4, Masao Ishii11, Fiz F. Pérez5, and Toru Suzuki12 Are Olsen et al.
  • 1Geophysical Institute, University of Bergen and Bjerknes Centre for Climate Research, Allègaten 70, 5007 Bergen, Norway
  • 2Atmospheric and Oceanic Sciences, Princeton University, 300 Forrestal Road, Sayre Hall, Princeton, NJ 08544, USA
  • 3Royal Netherlands Institute for Sea Research (NIOZ), Marine Geology and Chemical Oceanography, P.O. Box 59, 1790 AB Den Burg, the Netherlands
  • 4Uni Research Climate, Bjerknes Centre for Climate Research, Nygårdsgaten 112, 5007 Bergen, Norway
  • 5Instituto de Investigaciones Marinas – CSIC, Eduardo Cabello 6, 36208 Vigo, Spain
  • 6GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105 Kiel, Germany
  • 7Carbon Dioxide Information Analysis Center, Environmental Sciences Division, Oak Ridge National Laboratory, U.S. Department of Energy, Building 4500N, Mail Stop 6290, Oak Ridge, TN 37831-6290, USA
  • 8Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bussestrasse 24, 27570 Bremerhaven, Germany
  • 9IVL Swedish Environmental Research Institute, Ascheberggatan 44, 411 33 Gothenburg, Sweden
  • 10University of Bremen, Institute of Environmental Physics, Otto-Hahn-Allee, 28359 Bremen, Germany
  • 11Oceanography and Geochemistry Research Department, Meteorological Research Institute, Japan Meteorological Agency, 1-1 Nagamine, Tsukuba, 305-0052, Japan
  • 12Marine Information Research Center, Japan Hydrographic Association, 1-6-6-6F, Hanedakuko, Ota-ku, Tokyo, 144-0041, Japan

Abstract. Version 2 of the Global Ocean Data Analysis Project (GLODAPv2) data product is composed of data from 724 scientific cruises covering the global ocean. It includes data assembled during the previous efforts GLODAPv1.1 (Global Ocean Data Analysis Project version 1.1) in 2004, CARINA (CARbon IN the Atlantic) in 2009/2010, and PACIFICA (PACIFic ocean Interior CArbon) in 2013, as well as data from an additional 168 cruises. Data for 12 core variables (salinity, oxygen, nitrate, silicate, phosphate, dissolved inorganic carbon, total alkalinity, pH, CFC-11, CFC-12, CFC-113, and CCl4) have been subjected to extensive quality control, including systematic evaluation of bias. The data are available in two formats: (i) as submitted but updated to WOCE exchange format and (ii) as a merged and internally consistent data product. In the latter, adjustments have been applied to remove significant biases, respecting occurrences of any known or likely time trends or variations. Adjustments applied by previous efforts were re-evaluated. Hence, GLODAPv2 is not a simple merging of previous products with some new data added but a unique, internally consistent data product. This compiled and adjusted data product is believed to be consistent to better than 0.005 in salinity, 1 % in oxygen, 2 % in nitrate, 2 % in silicate, 2 % in phosphate, 4 µmol kg−1 in dissolved inorganic carbon, 6 µmol kg−1 in total alkalinity, 0.005 in pH, and 5 % for the halogenated transient tracers.

The original data and their documentation and doi codes are available at the Carbon Dioxide Information Analysis Center ( This site also provides access to the calibrated data product, which is provided as a single global file or four regional ones – the Arctic, Atlantic, Indian, and Pacific oceans – under the doi:10.3334/CDIAC/OTG.NDP093_GLODAPv2. The product files also include significant ancillary and approximated data. These were obtained by interpolation of, or calculation from, measured data. This paper documents the GLODAPv2 methods and products and includes a broad overview of the secondary quality control results. The magnitude of and reasoning behind each adjustment is available on a per-cruise and per-variable basis in the online Adjustment Table.

Short summary
The GLODAPv2 data product collects data from more than 700 hydrographic cruises into a global and internally calibrated product. It provides access to the data from almost all ocean carbon cruises carried out since the 1970s and is a unique resource for marine science, in particular regarding the ocean carbon cycle. GLODAPv2 will form the foundation for future routine synthesis of hydrographic data of the same sort.