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

Are Olsen,Alex Kozyr,Toru Suzuki,Emil Jeansson,Siv K Lauvset,Reiner Steinfeldt,Masao Ishii,Steven Van Heuven,Mario Hoppema,Fiz F Pérez,Toste Tanhua,Carsten Schirnick,Sara Jutterström,Anton Velo,Xiaohua Lin,Robert M Key

doi:10.5194/essd-8-297-2016

Abstract

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 (http://cdiac.ornl.gov/oceans/GLODAPv2/). 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.

Highlights

% 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
This paper summarizes sources of data for GLODAPv2 (Sect. 2), describes the primary and secondary quality control (QC) procedures (Sect. 3) and results (Sect. 4), introduces the GLODAPv2 data products and access (Sect. 5), provides recommendations for use (Sect. 6), and concludes with a summary of lessons learned during the preparation of this product
All individual cruise data files used for GLODAPv1.1, CARINA, and PACIFICA existed in the required WOCE exchange format and had been subjected to primary QC during the preparation of these products

Summary

Introduction

% 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. All individual cruise data files used for GLODAPv1.1, CARINA, and PACIFICA existed in the required WOCE exchange format and had been subjected to primary QC during the preparation of these products. – pH data were not included in the GLODAPv1.1 product files per se but were used in combination with TCO2 to calculate TAlk whenever that was missing and pH available.

Results

Conclusion