Abstract. Global climatologies of the seawater CO2 chemistry variables are necessary to assess the marine carbon cycle in depth. The seasonal variability should be adequately captured in them to properly address issues such as ocean acidification. Total alkalinity (AT) is one variable of the seawater CO2 chemistry system involved in ocean acidification and frequently measured during campaigns assessing the marine carbon cycle. We took advantage of the data product Global Ocean Data Analysis Project version 2 (GLODAPv2) to extract the relations between the drivers of the AT variability and this variable using a neural network to generate a monthly climatology. 99% of the GLODAPv2 dataset used was modelled by the network with a root-mean-squared error (RMSE) of 5.1 µmol kg-1. The validation carried out using independent datasets revealed the good generalization of the network. Five ocean time-series stations used as an independent test showed an acceptable RMSE in the range of 3.1-6.2 µmol kg-1. The successful modeling of the monthly variability of AT in the time-series makes our network a good candidate to generate a monthly climatology. It was obtained passing the climatologies of the World Ocean Atlas 2013 (WOA13) through the network. The spatiotemporal resolution of the climatology is determined by the one of WOA13: 1ºx1º in the horizontal, 102 depth levels (0-5500m) in the vertical, and 12 months. We offer the product as a service to the scientific community at the data repository of the Spanish National Research Council (CSIC; doi: http://dx.doi.org/10.20350/digitalCSIC/8564) with the purpose to contribute to a continuous improvement of the understanding of the global carbon cycle.
During the 1990s, ocean sampling expeditions were carried out as part of the World Ocean Circulation Experiment (WOCE), the Joint Global Ocean Flux Study (JGOFS), and the Ocean Atmosphere Carbon Exchange Study (OACES). Subsequently, a group of U.S. scientists synthesized the data into easily usable and readily available products. This collaboration is known as the Global Ocean Data Analysis Project (GLODAP). Results were merged into a common format data set, segregated by ocean. For comparison purposes, each ocean data set includes a small number of high‐quality historical cruises. The data were subjected to rigorous quality control procedures to eliminate systematic data measurement biases. The calibrated 1990s data were used to estimate anthropogenic CO 2 , potential alkalinity, CFC watermass ages, CFC partial pressure, bomb‐produced radiocarbon, and natural radiocarbon. These quantities were merged into the measured data files. The data were used to produce objectively gridded property maps at a 1° resolution on 33 depth surfaces chosen to match existing climatologies for temperature, salinity, oxygen, and nutrients. The mapped fields are interpreted as an annual mean distribution in spite of the inaccuracy in that assumption. Both the calibrated data and the gridded products are available from the Carbon Dioxide Information Analysis Center. Here we describe the important details of the data treatment and the mapping procedure, and present summary quantities and integrals for the various parameters.
This data documentation discusses the procedures and methods used to measure total carbon dioxide (TCO2), total alkalinity (TALK), and radiocarbon (delta 14C), at hydrographic stations, as well as the underway partial pressure of CO2 (pCO2) during the R/V Thomas G. Thompson oceanographic cruise in the Pacific Ocean (Section P10). Conducted as part of the World Ocean Circulation Experiment (WOCE), the cruise began in Suva, Fiji, on October 5, 1993, and ended in Yokohama, Japan, on November 10, 1993. Measurements made along WOCE Section P10 included pressure, temperature, salinity [measured by conductivity temperature, and depth sensor (CTD)], bottle salinity, bottle oxygen, phosphate, nitrate, silicate, chlorofluorocarbons (CFC-11, CFC-12), TCO2, TALK, delta 14C, and underway pCO2.
Abstract. The Global Ocean Data Analysis Project (GLODAP) is a synthesis effort providing regular compilations of surface-to-bottom ocean biogeochemical bottle data, with an emphasis on seawater inorganic carbon chemistry and related variables determined through chemical analysis of seawater samples. GLODAPv2.2023 is an update of the previous version, GLODAPv2.2022 (Lauvset et al., 2022). The major changes are as follows: data from 23 new cruises were added. In addition, a number of changes were made to data included in GLODAPv2.2022. GLODAPv2.2023 includes measurements from more than 1.4 million water samples from the global oceans collected on 1108 cruises. The data for the now 13 GLODAP core variables (salinity, oxygen, nitrate, silicate, phosphate, dissolved inorganic carbon, total alkalinity, pH, chlorofluorocarbon-11 (CFC-11), CFC-12, CFC-113, CCl4, and SF6) 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 converted to World Ocean Circulation Experiment (WOCE) exchange format and (ii) as a merged data product with adjustments applied to minimize bias. For the present annual update, adjustments for the 23 new cruises were derived by comparing those data with the data from the 1085 quality-controlled cruises in the GLODAPv2.2022 data product using crossover analysis. SF6 data from all cruises were evaluated by comparison with CFC-12 data measured on the same cruises. For nutrients and ocean carbon dioxide (CO2) chemistry comparisons to estimates based on empirical algorithms provided additional context for adjustment decisions. The adjustments that we applied 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 CO2 fugacity (fCO2), were not subjected to bias comparison or adjustments. The original data, their documentation and DOI codes are available at the Ocean Carbon and Acidification Data System of NOAA NCEI, which also provides access to the merged data product. This 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/zyrq-ht66 (Lauvset et al., 2023). These bias-adjusted product files also include significant ancillary and approximated data, which were obtained by interpolation of, or calculation from, measured data. This living data update documents the GLODAPv2.2023 methods and provides a broad overview of the secondary quality control procedures and results.
Abstract. Internally consistent, quality-controlled (QC) data products play an important role in promoting regional-to-global research efforts to understand societal vulnerabilities to ocean acidification (OA). However, there are currently no such data products for the coastal ocean, where most of the OA-susceptible commercial and recreational fisheries and aquaculture industries are located. In this collaborative effort, we compiled, quality-controlled, and synthesized 2 decades of discrete measurements of inorganic carbon system parameters, oxygen, and nutrient chemistry data from the North American continental shelves to generate a data product called the Coastal Ocean Data Analysis Product in North America (CODAP-NA). There are few deep-water (>â1500âm) sampling locations in the current data product. As a result, crossover analyses, which rely on comparisons between measurements on different cruises in the stable deep ocean, could not form the basis for cruise-to-cruise adjustments. For this reason, care was taken in the selection of data sets to include in this initial release of CODAP-NA, and only data sets from laboratories with known quality assurance practices were included. New consistency checks and outlier detections were used to QC the data. Future releases of this CODAP-NA product will use this core data product as the basis for cruise-to-cruise comparisons. We worked closely with the investigators who collected and measured these data during the QC process. This version (v2021) of the CODAP-NA is comprised of 3391 oceanographic profiles from 61 research cruises covering all continental shelves of North America, from Alaska to Mexico in the west and from Canada to the Caribbean in the east. Data for 14 variables (temperature; salinity; dissolved oxygen content; dissolved inorganic carbon content; total alkalinity; pH on total scale; carbonate ion content; fugacity of carbon dioxide; and substance contents of silicate, phosphate, nitrate, nitrite, nitrate plus nitrite, and ammonium) have been subjected to extensive QC. CODAP-NA is available as a merged data product (Excel, CSV, MATLAB, and NetCDF; https://doi.org/10.25921/531n-c230, https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0219960.html, last access: 15 May 2021) (Jiang et al., 2021a). The original cruise data have also been updated with data providers' consent and summarized in a table with links to NOAA's National Centers for Environmental Information (NCEI) archives (https://www.ncei.noaa.gov/access/ocean-acidification-data-stewardship-oads/synthesis/NAcruises.html).
This report discusses the procedures and methods used to measure total carbon dioxide (TCO2), total alkalinity (TALK), and partial pressure of CO2 (pCO2) at hydrographic stations during the cruise of research vessel (R/V) Nathaniel B. Palmer in the Southern Indian Ocean on the S04I Section as a part of the Joint Global Ocean Flux Study (JGOFS)/World Ocean Circulation Experiment (WOCE). The carbon-related measurements were sponsored by the U.S. Department of Energy (DOE). The expedition started in Cape Town, South Africa, on May 3, 1996, and ended in Hobart, Australia, on July 4, 1996. Instructions for accessing the data are provided. The TCO2 was measured in discrete water samples using the Lamont-Doherty Earth Observatory (LDEO) coulomteric system with an overall precision of ±1.7 μmol/kg. TALK was determined by potentiometric titration with an overall precision of ±1.7 μmol/kg. During the S04I cruise pCO2 was also measured using the LDEO equilibrator-gas chromatograph system with a precision of 0.5% (including the station-to-station reproducibility) at a constant temperature of 4.0ºC. The R/V Nathaniel B. Palmer S04I data set is available free of charge as a numeric data package (NDP) from the Carbon Dioxide Information Analysis Center. The NDP consists of the oceanographic data files and this printed documentation, which describes the contents and format of all files as well as the procedures and methods used to obtain the data.
We quantify the oceanic sink for anthropogenic carbon dioxide (CO2) over the period 1994 to 2007 by using observations from the global repeat hydrography program and contrasting them to observations from the 1990s. Using a linear regression-based method, we find a global increase in the anthropogenic CO2 inventory of 34 ± 4 petagrams of carbon (Pg C) between 1994 and 2007. This is equivalent to an average uptake rate of 2.6 ± 0.3 Pg C year-1 and represents 31 ± 4% of the global anthropogenic CO2 emissions over this period. Although this global ocean sink estimate is consistent with the expectation of the ocean uptake having increased in proportion to the rise in atmospheric CO2, substantial regional differences in storage rate are found, likely owing to climate variability-driven changes in ocean circulation.
This paper presents a comprehensive analysis of the basin‐wide inventory of anthropogenic CO 2 in the Atlantic Ocean based on high‐quality inorganic carbon, alkalinity, chlorofluorocarbon, and nutrient data collected during the World Ocean Circulation Experiment (WOCE) Hydrographic Program, the Joint Global Ocean Flux Study (JGOFS), and the Ocean‐Atmosphere Carbon Exchange Study (OACES) surveys of the Atlantic Ocean between 1990 and 1998. Anthropogenic CO 2 was separated from the large pool of dissolved inorganic carbon using an extended version of the ΔC* method originally developed by Gruber et al. [1996] . The extension of the method includes the use of an optimum multiparameter analysis to determine the relative contributions from various source water types to the sample on an isopycnal surface. Total inventories of anthropogenic CO 2 in the Atlantic Ocean are highest in the subtropical regions at 20°–40°, whereas anthropogenic CO 2 penetrates the deepest in high‐latitude regions (>40°N). The deeper penetration at high northern latitudes is largely due to the formation of deep water that feeds the Deep Western Boundary Current, which transports anthropogenic CO 2 into the interior. In contrast, waters south of 50°S in the Southern Ocean contain little anthropogenic CO 2 . Analysis of the data collected during the 1990–1998 period yielded a total anthropogenic CO 2 inventory of 28.4 ± 4.7 Pg C in the North Atlantic (equator‐70°N) and of 18.5 ± 3.9 Pg C in the South Atlantic (equator‐70°S). These estimated basin‐wide inventories of anthropogenic CO 2 are in good agreement with previous estimates obtained by Gruber [1998] , after accounting for the difference in observational periods. Our calculation of the anthropogenic CO 2 inventory in the Atlantic Ocean, in conjunction with the inventories calculated previously for the Indian Ocean [ Sabine et al. , 1999 ] and for the Pacific Ocean [ Sabine et al. , 2002 ], yields a global anthropogenic CO 2 inventory of 112 ± 17 Pg C that has accumulated in the world oceans during the industrial era. This global oceanic uptake accounts for approximately 29% of the total CO 2 emissions from the burning of fossil fuels, land‐use changes, and cement production during the past 250 years.
This report presents methods, and analytical and quality control procedures for salinity, oxygen, nutrients, total carbon dioxide (TCO2), total alkalinity (TALK), pH, discrete CO2 partial pressure (pCO2), dissolved organic carbon (DOC), chlorofluorocarbons (CFCs), radiocarbon, δ13C, and underway carbon measurements performed during the P16S-2005 (9 January - 19 February 2005) and P16N-2006 (13 February - 30 March, 2006) cruises in the Pacific Ocean. The research vessel (R/V) Roger Revelle departed Papeete, Tahiti, on January 9, 2005 for the Repeat Section P16S, nominally along 150°W, ending in Wellington, New Zealand, on February 19. During this cruise, samples were taken from 36 depths at 111 CTD stations between 16°S and 71°S. The Repeat Section P16N, nominally along 152°W, consisted of two legs. Leg 1 started on February 13, 2006 in Papeete, Tahiti, and finished on March 3, in Honolulu, Hawaii. The R/V Thomas G. Thompson departed Honolulu for Leg 2 on March 10, 2006 and arrived in Kodiak, Alaska, on March 30. During the P16N cruises, samples were taken from 34 or 36 depths at 84 stations between 17°S and 56.28°N. The research conducted on these cruises was part of a series of repeat hydrography sections jointly funded by the National Oceanic and Atmospheric Administration (NOAA) and the National Science Foundation (NSF) as part of the Climate Variability Program (CLIVAR)/CO2 Repeat Hydrography Program. The P16S and P16N data sets are available free of charge as a numeric data package (NDP) from the Carbon Dioxide Information Analysis Center (CDIAC). The NDP consists of the oceanographic data files and this printed documentation, which describes the procedures and methods used to obtain the data.
