Search for: All records

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 the 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 the 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 National Centers for Environmental Information (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.

 

We report marine dissolved organic carbon (DOC) concentrations, and DOC Δ¹⁴C and δ¹³C in seawater collected from the West Indian Ocean during the GO‐SHIP I07N cruise in 2018. We find bomb¹⁴C in DOC from the upper 1,000 m of the water column. There is no significant change in ∆¹⁴C of DOC in deep water northward, unlike that of dissolved inorganic carbon (DIC), suggesting that transport of deep water northward is not controlling the¹⁴C age of DOC. Variability of DOC ∆¹⁴C, including high values in the deep waters, is more pronounced than in other oceans, suggesting that dissolution of surface derived particulate organic carbon is a source of modern carbon to deep DOC in the West Indian Ocean. Low δ¹³C are present at two of the five stations studied, suggesting a source of low δ¹³C DOC, or additional microbial utilization of deep DOC.

 

Abstract. The Global Ocean Data Analysis Project (GLODAP) is asynthesis effort providing regular compilations of surface-to-bottom oceanbiogeochemical bottle data, with an emphasis on seawater inorganic carbonchemistry and related variables determined through chemical analysis ofseawater samples. GLODAPv2.2022 is an update of the previous version,GLODAPv2.2021 (Lauvset et al., 2021). The major changes are as follows: datafrom 96 new cruises were added, data coverage was extended until 2021, andfor the first time we performed secondary quality control on all sulfurhexafluoride (SF6) data. In addition, a number of changes were made todata included in GLODAPv2.2021. These changes affect specifically theSF6 data, which are now subjected to secondary quality control, andcarbon data measured on board the RV Knorr in the Indian Ocean in 1994–1995 whichare now adjusted using certified reference material (CRM) measurements made at the time. GLODAPv2.2022includes measurements from almost 1.4 million water samples from the globaloceans collected on 1085 cruises. The data for the now 13 GLODAP corevariables (salinity, oxygen, nitrate, silicate, phosphate, dissolvedinorganic carbon, total alkalinity, pH, chlorofluorocarbon-11 (CFC-11), CFC-12, CFC-113, CCl4,and SF6) have undergone extensive quality control with a focus onsystematic evaluation of bias. The data are available in two formats: (i) assubmitted by the data originator but converted to World Ocean CirculationExperiment (WOCE) exchange format and (ii) as a merged data product withadjustments applied to minimize bias. For the present annual update,adjustments for the 96 new cruises were derived by comparing those data withthe data from the 989 quality-controlled cruises in the GLODAPv2.2021 dataproduct using crossover analysis. SF6 data from all cruises wereevaluated by comparison with CFC-12 data measured on the same cruises. Fornutrients and ocean carbon dioxide (CO2) chemistry comparisons toestimates based on empirical algorithms provided additional context foradjustment decisions. The adjustments that we applied are intended to removepotential biases from errors related to measurement, calibration, and datahandling practices without removing known or likely time trends orvariations in the variables evaluated. The compiled and adjusted dataproduct 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−1in total alkalinity, 0.01–0.02 in pH (depending on region), and 5 % inthe halogenated transient tracers. The other variables included in thecompilation, 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 theOcean Carbon and Acidification Data System of NOAA NCEI (https://www.ncei.noaa.gov/access/ocean-carbon-acidification-data-system/oceans/GLODAPv2_2022/, last access: 15 August 2022). This site also provides access to themerged data product, which is provided as a single global file and as fourregional ones – the Arctic, Atlantic, Indian, and Pacific oceans –under https://doi.org/10.25921/1f4w-0t92 (Lauvset et al.,2022). These bias-adjusted product files also include significant ancillaryand approximated data, which were obtained by interpolation of, orcalculation from, measured data. This living data update documents theGLODAPv2.2022 methods and provides a broad overview of the secondary qualitycontrol procedures and results.

 

Abstract. The Global Ocean Data Analysis Project (GLODAP) is asynthesis effort providing regular compilations of surface-to-bottom oceanbiogeochemical data, with an emphasis on seawater inorganic carbon chemistryand related variables determined through chemical analysis of seawatersamples. GLODAPv2.2020 is an update of the previous version, GLODAPv2.2019.The major changes are data from 106 new cruises added, extension of timecoverage to 2019, and the inclusion of available (also for historicalcruises) discrete fugacity of CO2 (fCO2) values in the mergedproduct files. GLODAPv2.2020 now includes measurements from more than 1.2 million water samples from the global oceans collected on 946 cruises. Thedata 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 afocus on systematic evaluation of bias. The data are available in twoformats: (i) as submitted by the data originator but updated to WOCEexchange format and (ii) as a merged data product with adjustments appliedto minimize bias. These adjustments were derived by comparing the data fromthe 106 new cruises with the data from the 840 quality-controlled cruises ofthe GLODAPv2.2019 data product using crossover analysis. Comparisons toempirical algorithm estimates provided additional context for adjustmentdecisions; this is new to this version. The adjustments are intended toremove potential biases from errors related to measurement, calibration, anddata-handling practices without removing known or likely time trends orvariations in the variables evaluated. The compiled and adjusted dataproduct 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−1in total alkalinity, 0.01–0.02 in pH (depending on region), and 5 % inthe halogenated transient tracers. The other variables included in thecompilation, such as isotopic tracers and discrete fCO2, were notsubjected to bias comparison or adjustments. The original data and their documentation and DOI codes are available at theOcean Carbon Data System of NOAA NCEI(https://www.nodc.noaa.gov/ocads/oceans/GLODAPv2_2020/, lastaccess: 20 June 2020). This site also provides access to the merged dataproduct, 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). Thesebias-adjusted product files also include significant ancillary andapproximated data. These were obtained by interpolation of, or calculationfrom, measured data. This living data update documents the GLODAPv2.2020methods and provides a broad overview of the secondary quality controlprocedures and results. 

Large volumes of cool water are drawn up to the surface in the tropical oceans. A companion paper shows that the cool water reaches the surface in or near the upwelling zones off northern and southern Africa and Peru. The cool water has a subantarctic origin and spreads extensively across the Atlantic and Pacific basins after it reaches the surface. Here, we look at the spreading in two low‐resolution ocean general circulation models and find that the spreading in the models is much less extensive than observed. The problem seems to be the way the upwelling and the spreading are connected (or not connected) to the ocean's large‐scale overturning. As proposed here, the cool upwelling develops when warm buoyant water in the western tropics is drawn away to become deep water in the North Atlantic. The “drawing away” shoals the tropical thermocline in a way that allows cool subantarctic water to be drawn up to the surface along the eastern margins. The amounts of upwelling produced this way exceed the amounts generated by the winds in the upwelling zones by as much as 4 times. Flow restrictions make it difficult for the warm buoyant water in our models to be drawn away.

 

We report marine dissolved organic carbon (DOC) concentrations, and DOC Δ¹⁴C and δ¹³C values in seawater collected from the Southern Ocean and eastern Pacific GOSHIP cruise P18 in 2016/2017. The aging of¹⁴C in DOC in circumpolar deep water northward from 69°S to 20°N was similar to that measured in dissolved inorganic carbon in the same samples, indicating that the transport of deep waters northward is the primary control of¹⁴C in DIC and DOC. Low DOC ∆¹⁴C and δ¹³C measurements between 1,200 and 3,400 m depth may be evidence of a source of DOC produced in nearby hydrothermal ridge systems (East Pacific Rise).