An updated version of the global interior ocean biogeochemical data product, GLODAPv2.2020

Abstract

Abstract. The Global Ocean Data Analysis Project (GLODAP) is a synthesis effort providing regular compilations of surface-to-bottom ocean biogeochemical data, with an emphasis on seawater inorganic carbon chemistry and related variables determined through chemical analysis of seawater samples. GLODAPv2.2020 is an update of the previous version, GLODAPv2.2019. The major changes are data from 106 new cruises added, extension of time coverage to 2019, and the inclusion of available (also for historical cruises) discrete fugacity of CO2 (fCO2) values in the merged product files. GLODAPv2.2020 now includes measurements from more than 1.2 million water samples from the global oceans collected on 946 cruises. The data for the 12 GLODAP core variables (salinity, oxygen, nitrate, silicate, phosphate, dissolved inorganic carbon, total alkalinity, pH, CFC-11, CFC-12, CFC-113, and CCl4) have undergone extensive quality control with a focus on systematic evaluation of bias. The data are available in two formats: (i) as submitted by the data originator but updated to WOCE exchange format and (ii) as a merged data product with adjustments applied to minimize bias. These adjustments were derived by comparing the data from the 106 new cruises with the data from the 840 quality-controlled cruises of the GLODAPv2.2019 data product using crossover analysis. Comparisons to empirical algorithm estimates provided additional context for adjustment decisions; this is new to this version. The adjustments are intended to remove potential biases from errors related to measurement, calibration, and data-handling practices without removing known or likely time trends or variations in the variables evaluated. The 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, 4 µmol kg−1 in total alkalinity, 0.01–0.02 in pH (depending on region), and 5 % in the halogenated transient tracers. The other variables included in the compilation, such as isotopic tracers and discrete fCO2, were not subjected to bias comparison or adjustments. The original data and their documentation and DOI codes are available at the Ocean Carbon Data System of NOAA NCEI (https://www.nodc.noaa.gov/ocads/oceans/GLODAPv2_2020/, last access: 20 June 2020). This site also provides access to the merged data product, which is provided as a single global file and as four regional ones – the Arctic, Atlantic, Indian, and Pacific oceans – under https://doi.org/10.25921/2c8h-sa89 (Olsen et al., 2020). These bias-adjusted product files also include significant ancillary and approximated data. These were obtained by interpolation of, or calculation from, measured data. This living data update documents the GLODAPv2.2020 methods and provides a broad overview of the secondary quality control procedures and results.

Water masses in the Atlantic Ocean: characteristics and distributions

“…The formation process of AABW is a mixture of another two original water masses, CDW and WSBW, which are referred to as southern water masses, in the Weddell Sea region, consistent with Orsi et al (1999) andvan Heuven et al (2011). The CDW, with relatively warm temperature (CT > 0.4 • C), is advected with the ACC from the north, while the extremely cold shelf water (CT < −0.7 • C) comes as WSBW from the south (Fig.…”

“…south of 63 • S in the Weddell Sea (Fig. 5), with neutral density (γ ) larger than 28.27 kg m −3 (Weiss et al, 1979;Orsi et al, 1999). As an additional constraint, AABW is defined as water samples with silicate higher than 120 µmol kg −1 to distinguish it from other water masses in this region, as high silicate is a trademark property of AABW (Table 2).…”

Coastal Ocean Data Analysis Product in North America (CODAP-NA) – an internally consistent data product for discrete inorganic carbon, oxygen, and nutrients on the North American ocean margins

“…Anthropogenic ocean acidification (OA) refers to the process by which the ocean's uptake of excess anthropogenic atmospheric carbon dioxide (CO 2 ) reduces ocean pH and calcium carbonate mineral saturation states (Feely et al, 2004;Orr et al, 2005;Jiang et al, 2019;IPCC, 2011). OA is making it more difficult for marine calcifiers to build shells and skeletal structures and is endangering coral reefs and other marine ecosystems (Gattuso and Hanson, 2011;Doney et al, 2020).…”

Contrasting drivers and trends of ocean acidification in the subarctic Atlantic

“…From 1983 to present, the Icelandic Marine Research Institute (MRI) in cooperation with Lamont-Doherty Earth Observatory (LDEO) monitored hydrographic conditions quarterly at two stations located in the Iceland Sea (IS-TS; 68.0°N, 12.67°W) and in the Irminger Sea (IRM-TS; 64.33°N, 28.0°W). This large, high-quality database included in GLODAPv2 29 has allowed the study of the variability in the marine carbonate system and the assessment of OA trends 10,30,31 . The surface waters at IS-TS are under the influence of the low-salinity Schematic diagram of the large-scale circulation is adapted from Våge et al 34 and Lherminier et al 36 .…”