ALBERT

Description: 〈jats:p〉Abstract. Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere in a changing climate is critical to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe and synthesize data sets and methodology to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (EFOS) are based on energy statistics and cement production data, while emissions from land-use change (ELUC), mainly deforestation, are based on land-use and land-use change data and bookkeeping models. Atmospheric CO2 concentration is measured directly, and its growth rate (GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) is estimated with global ocean biogeochemistry models and observation-based fCO2 products. The terrestrial CO2 sink (SLAND) is estimated with dynamic global vegetation models. Additional lines of evidence on land and ocean sinks are provided by atmospheric inversions, atmospheric oxygen measurements, and Earth system models. The resulting carbon budget imbalance (BIM), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and incomplete understanding of the contemporary carbon cycle. All uncertainties are reported as ±1σ. For the year 2022, EFOS increased by 0.9 % relative to 2021, with fossil emissions at 9.9±0.5 Gt C yr−1 (10.2±0.5 Gt C yr−1 when the cement carbonation sink is not included), and ELUC was 1.2±0.7 Gt C yr−1, for a total anthropogenic CO2 emission (including the cement carbonation sink) of 11.1±0.8 Gt C yr−1 (40.7±3.2 Gt CO2 yr−1). Also, for 2022, GATM was 4.6±0.2 Gt C yr−1 (2.18±0.1 ppm yr−1; ppm denotes parts per million), SOCEAN was 2.8±0.4 Gt C yr−1, and SLAND was 3.8±0.8 Gt C yr−1, with a BIM of −0.1 Gt C yr−1 (i.e. total estimated sources marginally too low or sinks marginally too high). The global atmospheric CO2 concentration averaged over 2022 reached 417.1±0.1 ppm. Preliminary data for 2023 suggest an increase in EFOS relative to 2022 of +1.1 % (0.0 % to 2.1 %) globally and atmospheric CO2 concentration reaching 419.3 ppm, 51 % above the pre-industrial level (around 278 ppm in 1750). Overall, the mean of and trend in the components of the global carbon budget are consistently estimated over the period 1959–2022, with a near-zero overall budget imbalance, although discrepancies of up to around 1 Gt C yr−1 persist for the representation of annual to semi-decadal variability in CO2 fluxes. Comparison of estimates from multiple approaches and observations shows the following: (1) a persistent large uncertainty in the estimate of land-use changes emissions, (2) a low agreement between the different methods on the magnitude of the land CO2 flux in the northern extra-tropics, and (3) a discrepancy between the different methods on the strength of the ocean sink over the last decade. This living-data update documents changes in methods and data sets applied to this most recent global carbon budget as well as evolving community understanding of the global carbon cycle. The data presented in this work are available at https://doi.org/10.18160/GCP-2023 (Friedlingstein et al., 2023). 〈/jats:p〉

Description: Underway data for dissolved oxygen, total dissolved gas pressure, fluorescence and turbidity have been collected along the track of the RV METEOR cruise M160 around the Cape Verde archipelago. Water was pumped from the moon pool at 5 m depth into an insulated box, where the sensors were located. Discrete samples for dissolved oxygen were taken from the water stream and analysed on board by Winkler titration to correct the sensor data. Salinity data used for corrections and conversions was taken from the shipside TSG measurements at 5m depth.

Description: Underway temperature and salinity data was collected along the cruise track with two autonomous thermosalinograph (TSG) systems, each consisting of a SBE21 TSG together with a SBE38 Thermometer. Both systems worked independent from each other throughout the cruise. While temperature is taken at the water inlet in about 5 m depth, salinity is estimated within the interior TSG from conductivity and interior temperature. Temperature and salinity were calibrated against CTD data from 5 m depth. For details to all processing steps see Data Processing Report.

Description: Discrete samples for dissolved oxygen (DO), nutrients, dissolved inorganic carbon (DIC) and total alkalinity (TA) were taken from CTD rosette casts during the RV METEOR cruise M160 in the Cape Verde region. This cruise was part of the REEBUS project focusing on researching oceanic eddies generated in the Mauritanian upwelling system. Therefore, the majority of the samples were either taken within or in close proximity to oceanic eddies. Dissolved oxygen, determined via Winkler titration, and nutrient samples, analysed with a SEAL Analytical QuAAtro AutoAnalyzer, were both measured on the vessel within 24 hours of sampling. Samples for DIC and TA analysis were taken in Duran glass bottles, poisoned with Mercury(II) chloride and stored to be analysed at GEOMAR using a SOMMA and VINDTA 3S respectively.

Description: Raw multibeam bathymetry data were recorded on RV Meteor during M68/3 using a Kongsberg EM710 multibeam echosounder. The cruise took place between 12.7.2006 – 6.8.2006 (Mindelo, Cape Verde – Las Palmas, Gran Canary) in the Atlantic Ocean. Data were recorded within the Cape Verde and Mauritanian EEZ with an approximate average depth of around 600m. For beam raytracing, sound velocity profiles (SVP) profiles were taken from CTD casts to improve MBES data accuracy. There are no extra SVP files provided in this publication. Data are unprocessed and can therefore contain incorrect depth measurements (artifacts) if not further processed. Note that refraction errors can be expected due to the lack of proper SVP. M68/3 was carried out in the programmatic frame of the international "Surface Ocean Lower Atmosphere Study" (SOLAS) and presents the 2nd German SOLAS Cruise. It combined a wide spectrum of biological, chemical and physical oceanography as well as atmospheric chemistry under a regional focus on the Mauritanian Upwelling. The data are archived at the Federal Maritime and Hydrographic Agency of Germany (Bundesamt für Seeschifffahrt und Hydrographie, BSH) and provided to PANGAEA database for data curation and publication. Data publication is accomplished within work package 2 of the EU Horizon 2020 project iAtlantic- Integrated Assessment of Atlantic Marine Ecosystem in Space and Time (https://www.iatlantic.eu/).

Description: Raw multibeam bathymetry data were recorded on RV Meteor during M68/3 using a Kongsberg EM120 multibeam echosounder. The cruise took place between 12.7.2006 – 6.8.2006 (Mindelo, Cape Verde – Las Palmas, Gran Canary) in the Atlantic Ocean. Data were recorded throughout the whole time spend outside EEZs as well as within the Cape Verde and Mauritanian EEZ with an approximate average depth of around 3100m. For beam raytracing, sound velocity profiles (SVP) profiles were taken from CTD casts to improve MBES data accuracy. There are no extra SVP files provided in this publication. Data are unprocessed and can therefore contain incorrect depth measurements (artifacts) if not further processed. Note that refraction errors can be expected due to the lack of proper SVP. M68/3 was carried out in the programmatic frame of the international "Surface Ocean Lower Atmosphere Study" (SOLAS) and presents the 2nd German SOLAS Cruise. It combined a wide spectrum of biological, chemical and physical oceanography as well as atmospheric chemistry under a regional focus on the Mauritanian Upwelling. The data are archived at the Federal Maritime and Hydrographic Agency of Germany (Bundesamt für Seeschifffahrt und Hydrographie, BSH) and provided to PANGAEA database for data curation and publication. Data publication is accomplished within work package 2 of the EU Horizon 2020 project iAtlantic- Integrated Assessment of Atlantic Marine Ecosystem in Space and Time (https://www.iatlantic.eu/).

Description: This dataset compiles all available ship-based biogeochemical measurements at the Cape Verde Ocean Observatory (CVOO) into one merged dataset. The irregular measurements at CVOO started in 2006 and are still ongoing aiming at increasing data coverage in a key region for air-sea interaction. The station has a bottom depth of 3600 m and lies in the center of the Cape Verde Fontal Zone, resulting in large variations of the present oligotrophic water masses as well as an oxygen-poor layer between 400 m to 500 m. The dataset includes oxygen, nutrients, dissolved inorganic carbon, total alkalinity, and particulate organic matter measurements, and ancillary ctd-data are also included. The research vessels used and the exact measurement methods as well as the laboratories varied on a cruise-to-cruise basis, accordingly the data has undergone additional quality-control checks. The checks included flier detection (WOCE-flagging) and crossover-analysis that resulted in bias corrections.