ALBERT

Description: This dataset contains abiotic and biotic data from sediment samples from nine sites in the Weddell Sea (mostly South-Eastern). Data are provided for sediment pigments (chlorophyll a and phaeopigment content through fluorometry), total organic carbon (TOC), total nitrogen (TN), stable isotope values of carbon and nitrogen (δ13C, δ15N) and grain size (silt&clay 〈 32 µm, very fine sand 63–125 µm sand, fine sand 125–250 µm, medium sand 250–500 µm, coarse sand 500–1000 µm, larger coarse sand 〉 1000 µm). Before the TOC and carbon isotope analysis the sediment samples were acidified to eliminate inorganic carbon. A minimum of three replicate samples (cores) were collected using a MUC10 multicorer or giant box corer. Sediment cores were subsampled with a 60-ml syringe (inner diameter 2.7 cm) for stations 017, 026, 061, 072, and with a 10-ml syringe (inner diameter 1 cm) for stations 001, 037, 048, 104, 115. Subsamples were sliced in 1-cm steps down to 5 cm depth. Detailed methods are described in Säring et al. (submitted) except for stable isotopes: Flash combustion in a Flash 2000 (Thermo) elemental analyser to a Delta V advantage (Thermo) isotope ratio masspectrometer. δ values are reported relative to atmospheric N2 (δ15N) and Vienna PeeDee Belemnite (δ13C). Reference materials for stable isotope analysis: IAEA-N1, IAEA-N2, IAEA-N3, NBS 22, IAEA-CH-3 and IAEA-CH-6; calibration material: Acetanilide (Merck). The analytical precision for both stable isotope ratios was 〈±0.2‰. Cores with the label -e (Environment) were only used to collect the above data. Environmental and fauna data were collected from cores with the label -i (Incubation). This data table is part of a larger study analysing the role of environmental parameters for meio- and macrofaunal community composition (see Related to below).

Description: Swath sonar bathymetry data used for that dataset was recorded during RV SONNE during cruise SO276 using Kongsberg EM 122 multibeam echosounder. The cruise took place between 22.06.2020 - 26.07.2020 in the Atlanic Ocean. Data were recorded throughout the whole time spend outside EEZs. The approximate average depth of the entire dataset is around 4000m. To enhance MBES data accuracy, sound velocity profile casts were conducted in the vicinity of the working area prior to the survey using CTD rosette. During transits, sound velocity profile from the WOA13 were aplied via Sound Speed Manager Software. After processing, these data were directly imported into the MBES Acquisition software Kongsberg SIS Seafloor Information System. Data were manually edited for false measurements using Qimera. Raster were calculated and stored in GeoTIFF format with a 100m resolution (negative values), WGS85 as vertical datum and UTM as a projection, both for EM122 & EM710. Data products include ungridded soundings and bathymetric grids (100 m resolution) of the entire cruise for each EM122 & EM710. The data processing and provision was accomplished within work package 2 of the EU Horizon 2020 project iAtlantic- Integrated Assessment of Atlantic Marine Ecosystem in Space and Time and the IceAge project.

Description: Raw multibeam bathymetry data were recorded on RV SONNE during SO276 using Kongsberg EM710 multibeam echosounder. The cruise took place between 22.06.2020 - 26.07.2020 in the Atlantic Ocean. Data were recorded throughout the whole time spend outside EEZs in areas shallower than 1500m with an approximate average depth of around 400m. To enhance MBES data accuracy, CTD casts were made in the working area prior to each MBES survey using CTD rosette to raytrace beams with the obtained sound velocity profiles (SVP). During transits, SVPs from the WOA13 were applied via Sound Speed Manager Software to the data directly during acquisition with SIS Seafloor Information System. Data are unprocessed and can therefore contain incorrect depth measurements (artifacts) without further processing. 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. Ancillary sound velocity profiles (SVP) files from the cruise are archived at the BSH, thus SVP files are added to this dataset. Data acquisition and provision were 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/) IceAge project.

Description: The dataset is about temporal variability of dissolved methane along the freshwater-sea continuum in northern Germany. Sensors were installed at fixed stations at in total three sites at different water depths. This dataset is from the station in Cuxhaven (53.8771 N, 8.7048 E) taken at about 2-7m depth (depending on the tide). The data was obtained between 11 April and 28 August 2021 in high frequency measurements (1 min) with a methane sensor from Kongsberg (4H Jena model CONTROS HydroC CH4). Methane concentrations were calculated according to manufacturer's instructions, based on temperature and salinity values from COSYNA Container Cuxhaven. For the quality control of the data a local range of 0.1 – 1000 nmol/L was set, a technical range for the pump power 2 – 8 Watt, a spike and gradient value of 1. Due to heavy biofouling the external pump of the sensor failed, resulting in data gaps. For a more detailed description see the article cited in References.

Description: To determine the effect of the rate of temperature increase (acute vs. gradual) and magnitude as well as the timing of nutrient addition on a natural marine phytoplankton community, a bottle incubation experiment has been conducted at the Institute for Chemistry and Biology of the Marine Environment (ICBM) in Wilhelmshaven, Germany. The community was collected at the Helgoland Roads long-term time series site in the German part of the North Sea (https://deims.org/1e96ef9b-0915-4661-849f-b3a72f5aa9b1) on the 6ᵗʰ of March 2022. The surface water containing the phytoplankton community was collected from the RV HEINCKE with a pipe covered with a 200 µm net attached to a diaphragm pump. In the first experimental run, the community was exposed to either gradual or acute temperature increase (from 6 to either 12 or 18°C) with 25 different N:P supply ratios added as a batch at the beginning of the bottle incubation. Simultaneously, the same community was gradually acclimated to their experimental temperatures under ambient nutrients and was used in a second experimental run in which it received the same 25 different N:P supply ratios after temperature acclimation. The light conditions were set to 175 µmol s-1 m-2 and a day-night cycle of 12h:12h which corresponds to the natural conditions at that time of the year. With this, it was possible to test the effect of a gradual vs. acute temperature increase and the timing of nutrient addition i.e., before or after the temperature change. This experimental set-up summed up to 400 units (8 temperature treatments x 5 nitrogen levels x 5 phosphorus levels x 2 replicates). Each experimental run was ended after 12 days. Fluorescence (395/680 Exc./Em.) was measured every second day using a SYNERGY H1 microplate reader (BioTek®) to determine phototrophic growth over time. At the end of each experiment, one replicate was filtered onto pre-combusted acid-washed glass microfiber filters (WHATMAN® GF/C) for intracellular carbon (POC), nitrogen (PON), and phosphorus (POP) content. The POP filters were pre-combusted and then analysed by molybdate reaction after digestion with a potassium peroxydisulfate solution (Wetzel and Likens 2003). The POC and PON filters were dried at 60°C before they were measured in an elemental analyser (Flash EA 1112, Thermo Scientific, Walthman, MA, USA).

Description: Baffin Bay is a semi-enclosed basin connecting the Arctic Ocean and the western North Atlantic, thus making out a significant pathway for heat exchange. Here we reconstruct the alternating advection of relatively warmer and saline Atlantic waters versus the incursion of colder Arctic water masses entering Baffin Bay through the multiple gateways in the Canadian Arctic Archipelago and the Nares Strait during the Holocene. We carried out benthic foraminiferal assemblage analyses, X-ray fluorescence scanning, and radiocarbon dating of a 738 cm long marine sediment core retrieved from eastern Baffin Bay near Upernavik, Greenland (Core AMD14-204C; 987m water depth). Results reveal that eastern Baffin Bay was subjected to several oceanographic changes during the last 9.2 kyrCE1. Waning deglacial conditions with enhanced meltwater influxes and an extensive sea-ice cover prevailed in eastern Baffin Bay from 9.2 to 7.9 ka. A transition towards bottom water amelioration is recorded at 7.9 ka by increased advection of Atlantic water masses, encompassing the Holocene Thermal Maximum. A cold period with growing sea-ice cover at 6.7 ka interrupts the overall warm subsurface water conditions, promoted by a weaker northward flow of Atlantic waters. The onset of the neoglaciation at ca. 2.9 ka is marked by an abrupt transition towards a benthic fauna dominated by agglutinated species, likely in part explained by a reduction of the influx of Atlantic Water, allowing an increased influx of the cold, corrosive Baffin Bay Deep Water originating from the Arctic Ocean to enter Baffin Bay through the Nares Strait. These cold subsurface water conditions persisted throughout the Late Holocene, only interrupted by short-lived warmings superimposed on this cooling trend.

Description: This dataset provides abundance data for meiofauna taxa determined from sediment samples collected in the Weddell Sea (mostly South-Eastern). A minimum of three samples (cores) were collected at each station with a MUC10 multicorer or taken from a giant box corer during PS96. Sediment cores were sliced into depth layers (stations 017, 026, 061, 072: 0–2cm, 2–5cm, 5– bottom; stations 001, 037, 048: 0–1cm, 1–2cm, 2–3cm, 3–4cm, 4–5cm, 5– bottom) and preserved in 4%-borax-buffered formaldehyde solution prior to sieving (upper sieve size 500 µm, lower sieve size 32 µm) and counting (detailed methods in Säring et al. submitted). Abundance is presented per depth layer from the top 5 cm (note different slice volume) as ind./10 cm². Meiofauna communities included individuals from 22 higher taxa. The meiofauna abundance data are part of a larger ecological study on meio- and macrofauna communities and their relation to environmental conditions and remineralisation at the sediment-water interface (see “Related to” below). For the larger study, sediment cores from which meiofauna abundance data are deposited here were also used for microcosm incubations: Untreated incubations (Benthic ecosystem Function Experiments BEFEx), and incubations with and without microalgae addition (Algae Feeding Experiment AFEx). Cores from BEFEx and AFEx without algae are labeled with NT (not treated), cores from AFEx with algae are labeled as T (treated).

Description: A systematic investigation of the extant coccolithophore community around Azores Archipelago was performed during the cruise M150 of FS Meteor between August, 27, and October, 2, 2018, in the scope of the project BIODIAZ - Controls in benthic and pelagic BIODIversity of the AZores. For the description of the spacial and vertical distribution of the extant coccolithophore community sampling was done at 50 stations along 9 transects including 3 islands, a seamount and islets from 5 to 8 water depths between surface and 150 m. A total of 306 samples were obtained, filtered onboard onto polycarbonate membranes and sections of these filters mounted in the laboratory on microscope slides for analysis by cross-polarized light microscopy. At least 400 coccospheres were counted through a randomly selected sequence of fields of view and the absolute abundances (Coccospheres/L) were estimated.

Description: Multibeam bathymetry raw data was recorded in the North Atlantic during cruise SO276 MerMet 17-6 that took place between 2020-06-22 and 2020-07-26. The data was collected using the ship's own Kongsberg EM 122. Sound velocity profiles (SVP) were applied on the data for calibration. Please see environmental data (zip file) and the cruise report for details.

Description: This file contains data on number of mesopelagic fish collected during the CSIC-SUMMER survey carried out in October 2020 in five zones around the Iberian Peninsula: Balears and Alboran in the western Mediterranean, and Cadiz, Lisboa and Galicia. The scientific midwater trawl Mesopelagos fitted with a Multisampler placed at the end of the net was used to collect specimens at seven layers of the water column. The depth of the net was controlled by a SCANMAR system. In the five zones, hauls were carried out day and night to study vertical migration patterns of mesopelagic fish. A total of 24 deployments were made (between 0 and 700 m), of which 14 discriminated water layers. Additionally, to more accurately sample the epipelagic layers 7 night hauls were restricted to the first 210 m of the water column. Fish were identified and counted on board, or frozen for later processes in the laboratory. These data were obtained within the European Union Project 'Sustainable Management of Mesopelagic Resources' (SUMMER, Grant Agreement 817806) as funded by the Horizon 2020 Research and Innovation Programme.

Description: This raster dataset, in Cloud Optimized GeoTIFF format (COG), provides information on land surface changes at the pan-arctic scale. Multispectral Landsat-5 TM, Landsat-7 ETM+, and Landsat-8 OLI imagery (cloud-cover less than 80%, months July and August) was used for detecting disturbance trends (associated with abrupt permafrost degradation) between 2003 and 2022. For each satellite image we calculated the Tasseled Cap multi-spectral index to translate the spectral reflectance signal to the semantic information Brightness, Greenness, and Wetness. In order to characterize change information, we calculated the linear trend of the Brightness, Greenness and Wetness over two decades on the individual pixel level. The final map product therefore contains information on the direction and magnitude of change for all three Tasseled Cap parameters in 30m spatial resolution across the pan-arctic permafrost domain. Features detected include coastal erosion, lake drainage, infrastructure expansion, and fires. The general processing methodology was developed by Fraser et al. 2014 and adapted and expanded by Nitze et al. 2016 and Nitze et al. 2018. Here we upscaled the processing to the circum-arctic permafrost region and the recent 20-year period from 2003 through 2022. The service covers the permafrost region up to 81° North: Alaska (USA), Canada, Greenland, Iceland, Norway, Sweden, Finland, Russia, Mongolia, and China. For Russia and China, regions not containing permafrost were excluded. The data has been processed in Google EarthEngine within the research projects ERC PETA-CARB, ESA CCI+ Permafrost, NSF Permafrost Discovery Gateway, and EU Arctic PASSION. The dataset is a contribution to the 'Panarctic requirements-driven Permafrost Service' of the Arctic PASSION project (see references). Changes in the Tasseled Cap indices Brightness, Greenness, and Wetness are displayed in the image bands red, green, and blue, respectively. Here, coastal erosion (a trend of a land surface transitioning to a water surface) is depicted in dark blue colors, while coastal accretion (a trend of a water surface transitioning to a land surface) is depicted in bright orange colors. Drained lakes appear in bright yellow or orange colors, depending on the soil conditions and vegetation regrowth. Fire scars are a further common feature, which can appear in different colors, depending on the time of the fire and pre-fire land cover. The data can be explored via the Arctic Landscape EXplorer (ALEX, see references) and is available as a public web map service (WMS, see references), both hosted by Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research.

Description: The Holocene delta deposit (1st terrace) exposure SOB14-A-21 (72.53671°N, 127.98945°E) was sampled on 17 August 2014 North of Sobo-Sise Island in the Lena Delta during the framework of the joint Russian-German Expedition LENA 2014. The surface (top) of the exposure was characterized by mosses and sedges. The exposure itself was predominately sandy with few organic remnants. The top organic layer is thin (1.5 cm) and the active layer depth could not be determined exactly. However, the top 170 cm of the exposure were unfrozen although the thaw front might not only be from the top down but also horizontally due to the nature of the exposure. The exposure was first cleaned with a spade and then sampled with a knife and a hole saw from top to bottom. The entire exposure had a depth of 605 cm whereof the bottom 35 cm consisted of ice. Every 25 cm a sample was collected resulting in 22 samples (20 sediment samples and 2 ice samples). The samples were kept cool during the transport and later analyzed in the laboratory for bulk density, total organic carbon, and total nitrogen with a Vario EL III Elemental Analyzer. Prior to analysis, samples were freeze-dried, homogenized, and ground before measuring the samples with the elemental analyzer. The ice samples were not analyzed.

Description: Foraminiferal shells of the species M. allisonensis from the PETM section of ODP Site 865, Central Pacific, were cast with 3 grains of UWC-3 calcite standard (Kozdon et al., 2009) in the center of a 25 mm round epoxy mount, ground to the level of best exposure, polished, cleaned, and Au-coated. Prior to geochemical analysis, shells were examined by Scanning Electron Microscopy (SEM) to identify subdomains suitable for in-situ d13C and Mg/Ca ratio measurements and to avoid diagenetically altered zones within each shell. In-situ d13C measurements were performed with ~7 µm beam spot size in the WiscSIMS Laboratory at UW-Madison by a CAMECA ims-1280 large radius multicollector ion microprobe) using the protocols described in a previous study (Kozdon et al., 2018). The in-situ d13C microanalyses primarily targeted subdomains located at the base of pustular outgrowths (muricae) along the chamber walls of each shell. Previous studies have shown that these subdomains are less susceptible to post-depositional alteration than the rest of the shell (Kozdon et al., 2011; Kozdon et al., 2013). Between one and five SIMS d13C microanalyses were performed for each shell. Reproducibility of the individual spot analysis of UWC-3 standard (d13C = -0.91‰ V-PDB, Kozdon et al., 2011) bracketing samples is on average 0.7‰ (± 2 SD).

Description: Tree canopies are considered to effectively buffer climate extremes and to mitigate climate change effects. Droughts, which are predicted to become more frequent in the course of climate change, might alter the microclimatic cooling potential of trees. However, our understanding of how microclimate at the tree canopy level is modulated by environmental and tree characteristics and their interactions is still limited. Here, we investigated canopy temperature regulation for five mature co-occurring tree species for two contrasting hydrological situations during the severe drought in 2018.

Description: Size, weight, body-mass density and swim bladder measurements of Cyclothone species were analysed during the IDEADOS (Mediterranean Sea, July 2010), Bathypelagic (North Atlantic, May-June 2018) and SUMMER (Mediterranean Sea and North Atlantic, September-October 2020), and cruises. Specimens used to analyse size and weight were collected with a Multiple Opening/Closing Net and Environmental Sensing System (MOCNESS-1 m²), fitted with nets of 0.2 mm mesh size. Hauls were carried out between the surface and 700-800 m, in IDEADOS and SUMMER cruises, and up to 1800 m in Bathypelagic survey. Measures of body mass-density were obtained during the SUMMER cruise from specimens collected using the "Mesopelagos" midwater trawl. Finally, measures of swim bladder length, height, width, angle, volume, equivalent spherical radius, and aspect ratio were measured from specimens collected during the Bathypelagic cruise.

Description: This file contains data on mesopelagic fish stomach content reported as the number of prey categories in each fish stomach and their carbon masses. These data come from samples collected around the Iberian Peninsula (sampled during the CSIC-SUMMER cruise in October 2020). 120 samples come from the western Mediterranean and 173 from the Atlantic. Overall 42 different prey taxa could be identified from the stomachs. Five zones around the Iberian Peninsula were studied: south of the Balearic Islands, Alboran Sea, Gulf of Cadiz, off Lisboa and off Galicia. The table contains 5785 prey data records from 293 stomachs of 29 species of mesopelagic fish. Each data record (row) corresponds to one prey item, therefore for each fish stomach there are as many records as number of prey in the stomach. The complete dataset presents predators (mesopelagic fish) identified to species level, and prey taxa identified to genus level when possible (42 prey taxa). The studied mesopelagic fish correspond to orders Stomiiformes and Myctophiphormes and were selected because they were the most common and abundant in the cruise. The most diverse group was Myctophidae, with 14 species. The Stomiiformes were represented by four families, of which 5 species were Gonostomatidae, 2 Phosichthyidae, 4 Sternoptychidae and 4 Stomiidae.

Description: We tested the antagonistic effects of three strains of the dinoflagellate HAB species Alexandrium catenella on three target species (the chlorophyte Tetraselmis sp., the cryptomonad Rhodomonas salina, and the diatom Thalassiosira weissflogii) at various biomass ratios between species, at ambient (16 ◦C and 400 μatm CO2) and OWA (20 ◦C and 2000 μatm CO2) conditions. In these experiments the Alexandrium strains had been raised under OWA conditions for ~100 generations. All three non-HAB species increased their growth rate under OWA relative to ambient conditions. This dataset is included in the OA-ICC data compilation maintained in the framework of the IAEA Ocean Acidification International Coordination Centre (see https://oa-icc.ipsl.fr). Original data were downloaded from the Zenodo (see Source). In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2024) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation by seacarb is 2024-05-13.

Description: Salinity and Oxygen were not calibrated beyond the manufacturer's calibration coefficients. Compared to climatological values (WOA18) salinity appears to be 0.05 PSU too low. Both CTD sensors and the two TSG sensors do however agree. Oxygen values are in the range of the climatological values, possibly 5 umol/kg too low. Some deep profiles show consistently low oxygen values that is not represented in the climatology. Use this data with caution.

Description: These datasets provide data for the lowest part of a new composite profile GOS18 from Lake Gościąż in central Poland. The composite profile was established using sediment cores recovered in 2015 and 2018 with an UWITEC Piston Corer at 19.6-21.5 m water depth (Bonk et al., in press). Our data covers the time interval from the onset of lacustrine sedimentation in the late Allerød to the early Preboreal. Since Lake Gościąż comprises a continuous, seasonally resolved (varved) and exceptionally well-preserved archive of the Younger Dryas (YD) climate variation, it is highly suitable for detailed investigations of lake system responses during periods of rapid climate cooling (YD onset) and warming (YD termination), respectively. Our varve chronology is the lowest part of a new floating varve chronology established for Lake Gościąż (central Poland) that has been anchored to the absolute time scale through radiocarbon dating and age modelling (Bonk et al., in press). The here presented varve chronology reaches from the onset of lacustrine sedimentation in the late Allerød until the early Preboreal. Uncertainties for the absolute ages are derived from radiocarbon age modelling and varve counting. The internal varve counting uncertainty for the observed time interval is generally low (+14/-22) due to the mostly excellent varve preservation. Microfacies analyses, including varve counting and measurements of varve and sublayer thickness, have been performed on overlapping large-scale thin sections under an Axioplan 2 and Axiolab pol imaging microscope at magnifications of 50-400x. Thin sections have been prepared from 10 cm long freeze-dried and resin impregnated sediment slices (Brauer & Casanova 2001; doi:10.1023/A:1008136029735). The dataset incorporates the composite depth, age [BP] and age uncertainties [BP] for the varve bottom, the total varve thickness, selected sublayer thicknesses, detrital sublayer occurrence, the different varve types and the varve quality index (VQI).

Description: Dinitrogen (N2) and carbon (C) fixation rates were measured on 9 cruises (see Table C17) using shipboard incubation experiments, complemented with nutrient and oxygen manipulations. During cruises M77/3, M77/4 and M80/2, N2 fixation was measured using the bubble addition method following Montoya et al (1996). During M80/2 a novel method based on 360 15N2 gas pre-dissolution, which was developed by Mohr et al. (2010), was tested in parallel to the classic method. An underestimation of N2 fixation rates by the classic method has been observed (Großkopf et al., 2012) and therefore the novel 'pre-dissolution method' was applied during the following cruises (M83/1, M90, M91, M93, M97, M104, M107). Single cell N2 fixation rates to differentiate the contribution of different clades of N2 fixers were measured using a NanoSIMS (Martinez-Perez et al., 2016).

Description: Potential rates for microaerobic respiration and aerobic organic matter degradation as a source of ammonia (NH4+) in the Peruvian OMZ was assessed using an 18O2 labelling approach suitable for microaerobic respiration (Holtappels et al., 2014). Further, the effects of O2 depletion associated with marine snow particles on microbial respiration was explored by combining 18O2 labelling experiments with in-situ particle size analysis and modelling of aggregate-size dependent respiration (Kalvelage et al., 2015). Anammox, denitrification, and nitrification, as well as N2O production rates were measured on several cruises (Kalvelage et al., 2011; Löscher et al., 2012; Callbeck et al., 2017; Bourbonnais et al., 2017; Frey et al., 2020) using isotope fractionation studies, 15N tracer additions, and inhibitor studies.

Description: This dataset provides abundance data for macrofaunal taxa determined from sediment samples collected in the Weddell Sea (mostly South-Eastern). A minimum of three samples (cores) were collected at each station with a MUC10 multicorer or a giant box corer during PS96. Sediment cores were sliced into depth layers (stations 017, 026, 061, 072: 0–2cm, 2–5cm, 5– bottom; stations 001, 037, 048: 0–1cm, 1–2cm, 2–3cm, 3–4cm, 4–5cm, 5– bottom) and preserved in 4%-borax-buffered formaldehyde solution prior to sieving (sieve size 500 µm, 1000 µm) and counting (detailed methods in Säring et al. submitted). Abundance is presented per depth layer (note different slice volume) as ind./m². Data from different size fractions are available upon request. Macrofauna communities included individuals from 18 higher taxa. The macrofauna abundance data are part of a larger ecological study on meio- and macrofauna communities and their relation to environmental conditions and remineralisation at the sediment-water interface (see Related to below). For the larger study, sediment cores from which macrofauna abundance data are deposited here were also used for microcosm incubations: Untreated incubations (Benthic ecosystem Function Experiments BEFEx), and incubations with and without microalgae addition (Algae Feeding Experiment AFEx). Cores from BEFEx and AFEx without algae are labeled with NT (not treated), cores from AFEx with algae are labeled as T (treated).

Description: Around the Antarctic Peninsula (North-Western Weddell Sea, Bransfield Strait, Drake Passage) water samples for measurements of chlorophyll-a were collected with Niskin bottles mounted on a CTD rosette. At each station samples were taken at two depths, the chlorophyll-a maximum (Cmax, defined as the water depth with maximum fluorescence detected during in-situ profiles) and close to the seafloor (bottom). Water samples were poured over a 100-µm sieve to remove larger particles and filtered over glass fibre filters GF/C at approximately 250 mbar. Colouring of filters determined the amount of sea water used (3–5l). Filters were stored at −80°C. Chloroplastic pigments were extracted with 10ml acetone (90%), determined using a fluorimeter and expressed in µg/l. For details see Hauquier et al. (2015) and Veit-Köhler et al. (2018).

Description: Around the Antarctic Peninsula (North-Western Weddell Sea, Bransfield Strait, Drake Passage) sediment samples were collected with a MUC6 multicorer. Cores were subsampled for environmental parameters with cut-off 10-ml syringes. Subsamples for determination of grain size, total organic carbon (TOC) and total nitrogen (TN) were stored at −20°C. Samples for pigment analyses were stored at −80°C. Subsamples were sliced in 1-cm slices (0–1 cm, 1–2 cm, 2–3 cm, 3–4 cm, 4–5 cm). Sediment grain sizes were determined with a Malvern Mastersizer 2000 and expressed as relative percentages of the different size fractions. Total organic carbon (TOC) and total nitrogen (TN) were determined from freeze-dried samples by elemental analysis. Prior to combustion samples used for TOC analyses were acidified with 2% HCl in order to remove inorganic carbon. Pigments were extracted with 10 ml acetone (90%) from lyophilised sediment, separated by HPLC (High Performance Liquid Chromatography) and determined with a fluorescence detector: Chlorophyll-a, phaeophytin and phorbide are expressed in µg/g. For details see Hauquier et al. (2015) and Veit-Köhler et al. (2018).

Description: KML files showing the distribution of lagoons wider than 500 m along the Arctic coast from the Taimyr Peninsula in Russia to the Tuktoyaktuk Peninsula in Canada. There are two files: one specific to thermokarst lagoons and the other showing all lagoons. Interconnected lagoons are marked as one system. The criteria for the identification of thermokarst lagoons is described in Angelopoulos et al. (2021).

Description: Benthic foraminifera assemblage data for marine sediment core DA17-NG-ST03-039G retrieved in the Westwind Trough on the Northeast Greenland Shelf. The marine gravity core was collected during the NorthGreen2017 cruise on board the research vessel RV Dana. The data covers the period 13.3 to 3.9 cal ka BP. The benthic foraminifera assemblage data was carried out in order to reconstruct the oceanographic development on the Northeast Greenland shelf.

Description: Along the ice rich pan-Arctic permafrost coasts thermokarst lagoons are a common landscape feature. These lagoons form when thermokarst lakes are inundated permanently or intermittently by the sea. This is the first estimation of the area of pan-Arctic thermokarst lagoons based on the mapping of 79 lagoons in 5 representative arctic regions: Mackenzie Delta (CA), Theshekpuk Lake coast (USA), Baldwin Peninsula (USA), Tiksi coast (RU), Lena Delta (RU). The extent of each of the lagoons was determined using the Global Surface Water dataset which is based on Landsat-5, -7, and -8 satellite images from 1984 to 2018 at 30m resolution (Pekel et al., 2016). Water bodies were defined by a water occurrence threshold of 〉75% over this time period. The raster dataset was vectorized and smaller geometric errors, which occurred during vectorization, were solved with the Fix Geometry function in QGIS3.6. The lagoon polygons were selected manually and these water bodies were split from the ocean by using the function “split by line”. The calculation of the polygon area is based on the re-projection in EPSG:32608, EPSG:26905, EPSG:32604, EPSG:32652 for Mackenzie Delta, Teshekpuk Lake coast, Baldwin Peninsula, Tiksi and Lena Delta coast respectively. The lagoon selection is based on the published dataset https://doi.org/10.1594/PANGAEA.934158. The dataset consists of a polygon shape file for the 79 extracted thermokarst lagoons, a point shape file with coordinates for all lagoons and a data sheet.

Description: Underway temperature and salinity data was collected along the cruise track with two autonomous measurement systems, called self-cleaning monitoring boxes (SMBs). Usually, the SMBs are changed after 12 hours. However, on this cruise only SMB_B was working properly. While temperature is taken at the water inlet in about 3 m depth, salinity is estimated within the SMB from conductivity and interior temperature. No calibration was performed, neither for temperature nor for salinity. For details to all processing steps see Data Processing Report.

Description: This dataset contains hydroacoustic measurements collected by an autonomous ice-tethered bio-physical observatory during its drift across the Central Arctic Ocean from the end of MOSAiC in September 2020 to the next spring in May 2021. The measurements were performed by an Acoustic Zooplankton and Fish Profiler (AZFP, ASL) with factory calibrations. Data are provided as volume backscatter (Sv, in dB re 1 m⁻¹). We provide data for the frequencies 67, 125, 200 and 455 kHz. These files contain the quality-controlled raw data. The data were cleaned, processed and analysed in the paper Sea-ice decline makes zooplankton stay deeper for longer by Flores, Veyssiere et al. (submitted to Nature Cliimate Change), which contains a detailed description of the instrument and the measurement settings. The format can be readily ingested in the hydroacoustic data processing application EchoView.

Description: Raw multibeam bathymetry data were recorded on RV SONNE during SO276 using Kongsberg EM710 multibeam echosounder. The cruise took place between 2020-06-22 - 2020-07-26 in the Atlantic Ocean. Data were recorded throughout the whole time spend outside EEZs in areas shallower than 1500m with an approximate average depth of around 400m. To enhance MBES data accuracy, CTD casts were made in the working area prior to each MBES survey using CTD rosette to raytrace beams with the obtained sound velocity profiles (SVP). During transits, SVPs from the WOA13 were applied via Sound Speed Manager Software to the data directly during acquisition with SIS Seafloor Information System. Data are unprocessed and can therefore contain incorrect depth measurements (artifacts) without further processing. 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. Ancillary sound velocity profiles (SVP) files from the cruise are archived at the BSH, thus SVP files are added to this dataset. Data acquisition and provision were 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/) IceAge project.

Description: The dataset is about temporal variability of dissolved methane along the freshwater-sea continuum in northern Germany. Sensors were installed at fixed stations at in total three sites at different water depths. This dataset is from the station in Heligoland (54.1833 N, 7.8667 E) at about 9-12m depth (depending on the tide). The data was obtained between 27 April and 28 October in high frequency measurements (1 min) with a methane sensor from Kongsberg (4H Jena model CONTROS HydroC CH4,). Methane concentrations were calculated according to manufacturer's instructions, based on temperature and salinity values from UW-node Heligoland (Fischer, Philipp; Happel, Lea; Brand, Markus; Eickelmann, Laura; Lienkämper, Miriam; Bussmann, Ingeborg; Anselm, Norbert; Brix, Holger (2022): Hydrographical time series data of Helgoland, Southern North Sea, 2021. PANGAEA, https://doi.org/10.1594/PANGAEA.950173). A gap in the salinity data was replaced with the median value of the observed time span (31.66). For the quality control of the data a local range of 0.1 – 1000 nmol/L was set, a technical range for the pump power 2 – 8. Watt, a spike and gradient value of 1. For a more detailed description see the article cited in References.

Description: The dataset is about temporal variability of dissolved methane along the freshwater-sea continuum in northern Germany. Sensors were installed at fixed stations at in total three sites at different water depths. This dataset is from the station in Geesthacht (53.4112 N, 10.4032 E) at about 2 meter depth. The data was obtained between 14 April and 29 September 2021) in high frequency measurements (1 min) with a methane sensor from Kongsberg (4H Jena model CONTROS HydroC CH4,). Methane concentrations were calculated according to manufacturer's instructions. Data on temperature were provided by from Vattenfall, Kernkraftwerk Krümel, a salinity of 0.01 was assumed. Special thanks to the colleagues from Vattenfall for the logistic and technical support. For the quality control of the data a local range of 0.1 – 5000 nmol/L was set, a technical range for the pump power 2 – 8. Watt, a spike and gradient value of 1. For a more detailed description see the article cited in References.

Description: This data set comprises raw CTD data collected during the RV ALKOR cruise AL540 conducted in July 2020 (July 21st to July 31st 2020) in the Western Baltic Sea by the University of Hamburg. The cruise was part of the 5-year MARSYS teaching cruise program of the University of Hamburg GFP20-1_047. The cruises are designed to train students in sampling methods targeting the different compartments of a marine ecosystem.

Description: Foraminiferal shells of the species M. velascoensis from sediments spanning ~650 ka across the PETM section of ODP Site 865, Central Pacific, were cast with 3 grains of UWC-3 calcite standard (Kozdon et al., 2009) in the center of a 25 mm round epoxy mount, ground to the level of best exposure, polished, cleaned, and Au-coated. Prior to geochemical analysis, shells were examined by Scanning Electron Microscopy (SEM) to identify subdomains suitable for in-situ d13C and Mg/Ca ratio measurements and to avoid diagenetically altered zones within each shell. In-situ d13C measurements were performed with ~7 µm beam spot size in the WiscSIMS Laboratory at UW-Madison by a CAMECA ims-1280 large radius multicollector ion microprobe) using the protocols described in a previous study (Kozdon et al., 2018). The in-situ d13C microanalyses primarily targeted subdomains located at the base of pustular outgrowths (muricae) along the chamber walls of each shell. Previous studies have shown that these subdomains are less susceptible to post-depositional alteration than the rest of the shell (Kozdon et al., 2011; Kozdon et al., 2013). Between one and five SIMS d13C microanalyses were performed for each shell. Reproducibility of the individual spot analysis of UWC-3 standard (d13C = -0.91‰ V-PDB, Kozdon et al., 2011) bracketing samples is on average 0.7‰ (± 2 SD).

Description: This dataset contains the values of standard length, wet weight, and body mass-density of Cyclothone spp. measured during the SUMMER cruise (from 30th September to 18th October 2020). Samples were obtained with the "Mesopelagos" midwater trawl during day and night hauls carried out from the surface to 700-800 m depth. The Mesopelagos net consists of graded-mesh netting starting with 30 mm and ending with 4 mm. The specimens collected were immediately identified and measured (standard length, SL). Body-mass densities (ρ) of Cyclothone braueri, C. pseudopallida, C. pygmaea and C. pallida were determined on board via a density-bottle method (Greenlaw, 1977; Mikami et al., 2000).

Description: Arctic warming increases the degradation of permafrost soils but little is known about floodplain soils and other permafrost soils in the permafrost region. This dataset present soil properties from twelve analyzed cores located in the northeastern Siberian Lena River Delta within the continuous permafrost zone in northern Yakutia, Russia that were sampled in 2018. The cores represent intact yedoma, yedoma thaw slumps, and floodplain profiles. The soil coring and sampling was carried out in August 2018 for a total of 30 soil cores, 35 soil profiles, and 341 sediment samples. First, vegetation and other characteristics of the plots were described. Then, the active layer soils were excavated, described, and sampled with a fixed volume cylinder (250 cm³). Then the permafrost layers were sampled with a modified, snow, ice, and permafrost (SIPRE) auger to a depth of 1 m (core diameter of 7.62 cm) and visually described in their characteristics. Each core was divided into subsamples with 5-10 cm length according to its facies horizons, transported frozen to Alfred Wegener Institute in Potsdam, and stored at -20 °C until analysis. A subset of these sediment samples (n=105 from 12 cores) were later analyzed in the laboratory for physical and chemical properties; this data is presented here. The analysis from these samples includes: water content, dry bulk density, gravimetric ice content, pH, conductivity, total organic carbon content, total inorganic carbon content, total carbon content, total nitrogen content, carbon density, TOC storage, and TN storage. Selected samples were further analyzed for radiocarbon and grain size analysis.

Description: This dataset provides abundance data for macrofaunal taxa determined from sediment samples collected around the Antarctic Peninsula. A minimum of three samples (cores) were taken at each station with a MUC10 multicorer or giant box corer during PS81. The whole sediment cores (top to bottom) were preserved in a in 4%-borax-buffered formaldehyde solution prior to sieving (sieve size 500 µm) and counting (detailed methods in Säring et al. submitted). Only at station 241, cores were sliced into depth layers (0–2 cm, 2–5 cm, 5– bottom) and size fractions distinguished (sieve size 500 µm, 1000 µm). Abundances are presented per whole core as ind./m². Data from different layers and size fractions (station 241) are available upon request. Macrofauna communities included individuals from 13 higher taxa. The macrofauna abundance data are part of a larger ecological study on meio- and macrofauna communities and their relation to environmental conditions and remineralisation at the sediment-water interface (see Related to below). For the larger study, sediment cores from which macrofauna abundance data are deposited here were also used for microcosm incubations: Untreated incubations (Benthic ecosystem Function Experiments BEFEx), and incubations with and without microalgae addition (Algae Feeding Experiment AFEx). Cores from BEFEx and AFEx without algae are labeled with NT (not treated), cores from AFEx with algae are labeled as T (treated).

Description: This dataset contains biotic and abiotic data from water-column samples taken with Niskin bottles mounted on the CTD rosette from 14 sites in the Weddell Sea (mostly South-Eastern). Data are provided for water-column pigments (chlorophyll a and phaeopigment content through fluorometry), total carbon (TC) and nitrogen (TN) and stable isotope values of carbon and nitrogen (δ13C, δ15N) from the chlorophyll maximum (Cmax, defined as the water depth with maximum fluorescence detected during in-situ profiles) and close to the sea bottom. Water was filtered onto glass fiber filters (GF/C for pigments, combusted GF/F for C and N analyses) and stored at -80°C prior to analysis. Detailed methods are described in Säring et al. (submitted) except for stable isotopes: Flash combustion in a Flash 2000 (Thermo) elemental analyser to a Delta V advantage (Thermo) isotope ratio masspectrometer. δ values are reported relative to atmospheric N₂ (δ15N) and Vienna PeeDee Belemnite (δ13C). Reference materials for stable isotope analysis: IAEA-N1, IAEA-N2, IAEA-N3, NBS 22, IAEA-CH-3 and IAEA-CH-6; calibration material: Acetanilide (Merck). The analytical precision for both stable isotope ratios was 〈±0.2‰. Samples were not acidified to avoid loss of material. We assumed low inorganic carbon content in the water column for our analyses. This data table is part of a larger study analysing the role of environmental parameters for meio- and macrofaunal community composition (see Related to below).

Description: Underway temperature and salinity data was collected along the cruise track with two autonomous measurement systems, called self-cleaning monitoring boxes (SMBs). Usually, the SMBs are changed after 12 hours. However, on this cruise only SMB_B was working properly. While temperature is taken at the water inlet in about 3 m depth, salinity is estimated within the SMB from conductivity and interior temperature. No calibration was performed, neither for temperature nor for salinity. For details to all processing steps see Data Processing Report.

Description: This dataset contains measured dissolved trace element concentrations (Fe, Mn, Co, Ni, Cu, Zn, Cd and Pb) of station depth profiles sampled in Fram Strait (North Greenland Sea) during GEOTRACES expedition GN05 (PS100) between 21 July and 1 September 2016. Samples were collected strictly following GEOTRACES guidelines (Cutter et al., 2017; https://www.geotraces.org) and analysed exactly as per Rapp et al., 2017 ( Anal. Chim. Acta; doi:10.1016/j.aca.2017.05.008). Concentrations were intercalibrated with GEOTRACES reference materials SAFe S and GSC (Bruland Research Lab), with exception of dissolved Cd data. Information on the analytical procedure including reference materials and limits of detection can be found in related published manuscripts, the PhD thesis of Stephan Krisch (Christian-Albrechts-Universität zu Kiel) or can be obtained from the authors upon request. Table caption: Measured concentrations of dissolved trace elements in Fram Strait sampled during GEOTRACES expedition GN05 (PS100) between 21 July-1 September 2006. Uncertainty is calculated as one standard deviation (1σ, STD) to replicate measurements via ICP-MS. ND = no data. Use of quality flags (QF) according to GEOTRACES policy (https://www.geotraces.org/geotraces-quality-flag-policy/). Plesae note, dissolved Cd data is not quality controlled. Somes samples were pooled (indicated in column "Bottle") from different bottles at one depth; the concentrations reflects the mean and the corresponding uncertainty is calculated as the standard deviation to replicate measurements. Trace metal concentrations at station 24 may show larger variations between different bottles at one specific depth. Because station 24 is located at Dijmphna Sund entrance sill, we associate these discrepancies to the water column's strong lateral and vertical turbulence (see ucCTD physical oceanography data) (e.g. Mortensen et al. 2011, 2013, Carroll et al. 2017) that goes in hand with localized TM aggregation-dissolution and sediment resuspension processes, thus affecting TM fractionation (e.g. Homoky et al. 2012).

Description: A new version (2022) is available: https://doi.org/10.1594/PANGAEA.946915 Marine particulate organic carbon-13 stable isotope ratios (δ13CPOC) provide additional constraints and insights on the cycling of carbon from dissolved pools to the marine ecosystem including anthropogenic contributions. For such purposes, robust spatio-temporal coverage of δ13CPOC observations is essential. We collected all such available known data sets, merged and uniformed them to provide – to the best of our knowledge – the largest available marine δ13CPOC data set. The data set consists of 4732 data points covering all major ocean basins from the 1960s to 2010s. We provide the data in twenty-one different files for best direct application on specific research purposes: a csv file including the 4732 δ13CPOC measurements, their anomalies relative to their mean −23.96 ‰ as well as all available meta-information a NetCDF file including an interpolation onto the 1°x1°-resolution grid based on the World Ocean Atlas (WOA18) data product of all δ13CPOC measurements with full spatio-temporal metadata, averaging all observations from each year together, each year accounting for a time increment on the time axis twelve NetCDF files - one for each month of the year - including an interpolation onto the 1°x1°-resolution grid based on the World Ocean Atlas (WOA18) data product of all δ13CPOC measurements with full spatio-temporal metadata, averaging only observations from the respective month, each year accounting for a time increment on the time axis a NetCDF file including an interpolation onto a 1.8°x3.6°-resolution grid of a δ13CPOC simulating model of all δ13CPOC measurements with full spatial metadata six NetCDF files – one for each decade between the 1960s and 2010s – including an interpolation onto the 1.8°x3.6°-resolution grid of a δ13CPOC simulating model of all δ13CPOC measurements with full spatial metadata and available sample year information

Description: DE: Transkripte der Interviews, die für die von Stephan Lessenich geleitete Studie "Alter(n) als Zukunft" durchgeführt wurden. Der Datensatz enthält 87 in zwei Wellen erhobene problemzentrierte Interviews mit älteren und alten Menschen. Die Interviews wurden von 2013 bis 2019 in und um zwei deutsche Städte (jeweils in Ost- und Westdeutschland) durchgeführt. Das Sampling kombinierte den Ansatz der Grounded Theory mit Aspekten des selektiven Samplings. Für die erste Befragungswelle wurden 57 Personen im Alter von mindestens 60 Jahren ausgewählt, die bereits im Ruhestand waren. Von diesen 57 Personen wurden 20 bereits im Rahmen der Vorgängerprojekte "Zonen des Übergangs" und "Vom wohlverdienten Ruhestand zum Alterskraftunternehmer" interviewt. Dabei wurde anhand der Merkmale Bildungsgrad, Geschlecht, Familienstand, sozioökonomischem Status, Erfahrung kritischer Lebensereignisse sowie eventuellen Sorgeverpflichtungen gegenüber Angehörigen kontrastiert. Die Interviews der ersten Welle fokussieren das Verständnis des Begriffs "Ruhestand", die Zeit- und Alltagsgestaltung der Befragten sowie die Endlichkeit des Lebens. In der zweiten Welle lag der Fokus der Stichprobenbildung auf Ruheständler:innen im Alter von über 70 Jahren. Dabei ergaben sich 7 Interviews mit Personen, die bereits in der ersten Welle interviewt wurden. Der inhaltliche Schwerpunkt der Interviews lag auf der biographischen Bedeutung der Lebensphasen Ruhestand und Alter mit Themen wie Endlichkeit, Sterben und Tod. Neben der Thematik des Zeithandelns im Alter bietet der Datensatz u.a. Nachnutzungspotenziale in den Bereichen Biographieforschung, Geschlechterforschung und Methodologie. EN: Transcripts of the interviews conducted for the study "Alter(n) als Zukunft" (="Age(ing) as future") led by Stephan Lessenich. The dataset contains 87 problem-centered interviews with elderly and old people collected in two waves. The interviews were conducted between the years 2013 and 2019 in and around two German cities (each in East and West Germany). The sampling combined the grounded theory approach with aspects of selective sampling. For the first wave, 57 persons of at least 60 years were selected who were already retired. Out of these 57 persons, 20 had been already interviewed during the two previous projects "Zonen des Übergangs" (="Zones of transition") and "Vom wohlverdienten Ruhestand zum Alterskraftunternehmer" ("From well-deserved retirement to retirement entrepreneur"). The sample was contrasted according to the properties educational level, gender, marital status, socio-economic status, experience of critical life events and possible care obligations for relatives. The interviews conducted in the first wave focussed perceptions of the concept "retirement", the organisation of time and everyday life and the finiteness of life. In the second wave, the sampling criteria focused on retirees aged 70 years or older. In this group, 7 interviews were conducted with persons who already participated in the first wave. Content-wise, the main focus was now the biographical meaning of the life phase of retirement and old age, including topics such as finiteness, dying and death. Potentials for scientific re-use of the dataset include the meaning of time in the old age, and also relate to (among others) biographical research, gender research, and methodology.

Description: Multibeam bathymetry raw data was recorded in the North Atlantic during cruise SO276 MerMet 17-6 that took place between 2020-06-22 and 2020-07-26. The data was collected using the ship's own Kongsberg EM 122. Sound velocity profiles (SVP) were applied on the data for calibration. Please see environmental data (zip file) and the cruise report for details. The bathymetric data acquisition was carried out within the IceAge project which aims to investigate the North Atlantic ecosystem. Working areas have been selected to offer a variability of environments (e.g., variability of water depth, and geological setting (shelf, mid-ocean ridge, deep basin)). The bathymetric data were used to plan ROV dives and sampling stations as well as background for habitat mapping studies.

Description: Swath sonar bathymetry data used for that dataset was recorded during RV SONNE during cruise SO276 using Kongsberg EM710 multibeam echosounder. The cruise took place between 22.06.2020 - 26.07.2020 in the Atlanic Ocean. Data were recorded throughout the whole time spend outside EEZs. The approximate average depth of the entire dataset is around 4000m. To enhance MBES data accuracy, sound velocity profile casts were conducted in the vicinity of the working area prior to the survey using CTD rosette. During transits, sound velocity profile from the WOA13 were aplied via Sound Speed Manager Software. After processing, these data were directly imported into the MBES Acquisition software Kongsberg SIS Seafloor Information System. Data were manually edited for false measurements using Qimera. Raster were calculated and stored in GeoTIFF format with a 100m resolution (negative values), WGS85 as vertical datum and UTM as a projection, both for EM122 & EM710. Data products include ungridded soundings and bathymetric grids (100 m resolution) of the entire cruise for each EM122 & EM710. The data processing and provision was accomplished within work package 2 of the EU Horizon 2020 project iAtlantic- Integrated Assessment of Atlantic Marine Ecosystem in Space and Time and the IceAge project.

Description: Data presented here were collected between May 2021 to September 2023 within the research unit DynaCom (Spatial community ecology in highly dynamic landscapes: From island biogeography to metaecosystems, https://uol.de/dynacom/ ) of the Universities of Oldenburg, Göttingen, and Münster, the iDiv Leipzig and the Nationalpark Niedersächsisches Wattenmeer. Experimental islands and saltmarsh enclosed plots were created in the back barrier tidal flat and in the saltmarsh zone of the island of Spiekeroog. Temperature in the mudflat sediment surface layer (in approximately 0.05m depth) was measured with DEFI-T miniature temperature recorders (JFE Advantech Co., Ltd., Tokyo; DEFI-T). The manufacturer pre-calibrated the temperature recorders and were installed in the surface layer of the back barrier tidal flat and at the salt marsh edge of Spiekeroog. Recorded data were internally logged until readout with the DEFI Series software (V1.02). The position was derived from a portable DGPS-system. Date and Time is given in UTC. Data handling was performed according to Zielinski et al. (2018): Post-processing of collected data was done using MATLAB (R2018a). Quality control was performed by (a) erasing data covering maintenance activities, (b) removing outliers, defined as data exhibiting changes of more than two standard deviations within one time step, and (c) visually checks.

Description: Ocean Alkalinity Enhancement (OAE) could augment long-term carbon storage and mitigate ocean acidification by increasing the bicarbonate ion concentration in ocean water. However, the side effects and/or potential co-benefits of OAE on natural planktonic communities remain poorly understood. To address this knowledge gap, 9 mesocosms were deployed in the oligotrophic waters of Gran Canaria, from September 14th to October 16th, 2021. A CO2-equilibrated Total Alkalinity (TA) gradient was employed in increments of 300 µmol·L-1, ranging from ~2400 to ~4800 µmol·L-1. The carbonate chemistry conditions in terms of TA and Dissolved Inorganic Carbon (DIC), which were then used to calculate pCO2 and pH, and the nitrate+nitrite, phosphate and silicate concentrations were measured every two days over the course of the 33-day experiment alongside the following biotic parameters. Net Community Production (NCP), Gross Production (GP), Community Respiration (CR) rates, as well as the metabolic balance (GP:CR), were monitored every two days through oxygen production and consumption using the winkler method. Fractionated 14C uptake and chlorophyll a were also determined every four days although, initially, the total PO14C and DO14C production were also measured every 4 days, in between, up to day 13. Finally, flow cytometry was also carried out every two days and synecococcus, picoeukaryote and nanophytoplankton abundances were obtained. No damaging effect of CO2-equilibrated OAE in the range applied here, on phytoplankton primary production, community metabolism and composition could be inferred from our results. In fact, a potential co-benefit to OAE was observed in the form of the positive curvilinear response to the DIC gradient up to the ∆TA1800 treatment. Further experimental research at this scale is key to gain a better understanding of the short and long-term effects of OAE on planktonic communities.

Description: Foraminiferal shells of the species M. allisonensis from the PETM section of ODP Site 865, Central Pacific, were embedded in epoxy and polished to midsection. Suitable, well-preserved domains for in-situ analysis were identified by scanning electron microscopy. In-situ measurements of the Mg/Ca ratios were performed using a CAMECA SX-51 electron microprobe housed in the Cameron and Wilcox Microbeam Laboratory at the UW-Madison Department of Geoscience. Depending on the number of suitable targets for analysis, between one and seven Mg/Ca measurements were performed for each shell. Fully quantitative microanalyses (mineral standards, background subtracted, and matrix corrected) were performed using Probe for EPMA software (Probe Software, Inc.). The natural carbonate standards Delight Dolomite and Callender Calcite were used for Mg and Ca, respectively. Mg-K alpha X-rays were measured on two spectrometers and aggregated. Carbon was calculated within the matrix correction, being allocated as one atom of carbon to 3 atoms of oxygen, and oxygen by stoichiometry to the cations measured, thus analytical totals of 98 – 100.5 wt. % are a measure of accuracy. Analyses featuring analytical totals below 98 wt. % or above 100.5 wt. % were excluded from the data set

Description: Vertical profiles of water temperature, pressure and salinity were measured by the Drift Towing Ocean Profiler (DTOP) buoy 2019V4, a.k.a. 2019E, an autonomous platform, installed on drifting sea ice in the Arctic Ocean during MOSAiC (Leg 1) 2019/20. The resulting time series describes the vertical profile of the ocean below the sea ice as a function of place and time between 09 October 2019 and 17 August 2020 in sample intervals of 12 hours. In addition, the DTOP measured air temperature, relative humidity and barometric pressure and GPS position at hourly intervals. This instrument was deployed as part of the projects National Key R&D Program of China and The Marine S&T Fund of Shandong Province for Qingdao National Laboratory for Marine Science and Technology.

Description: We present a continuous and well-resolved record of climatic variability for the past 100,000 yrs from a marine sediment core taken in Delagoa Bight, off southeastern Africa. In addition to providing a sea surface temperature reconstruction for the past ca. 100,000 yrs, this record also allows a high-resolution continental climatic reconstruction. Climate sensitive organic proxies, like the distribution and isotopic composition of plant-wax lipids as well as elemental indicators for fluvial input and weathering type provide information on climatic changes in the adjacent catchment areas (Incomati, Matola, and Lusutfu rivers). At the transition between glacials and interglacials, shifts in vegetation correlate with changes in sea surface temperature in the Agulhas current. The local hydrology, however, does not follow these orbital-paced shifts. Instead, precipitation patterns follow millennial scale variations with different forcing mechanisms in glacial versus interglacial climatic states. During glacials, southward displacement of the Intertropical Convergence Zone facilitates a transmission of northern hemispheric signals (e.g. Heinrich events) to the southern hemispheric subtropics. Furthermore, the southern hemispheric westerlies become a more direct source of precipitation as they shift northward over the study site, especially during Antarctic cold phases. During interglacials, the observed short-term hydrological variability is also a function of Antarctic climate variability, however, it is driven by the indirect influence of the southern hemispheric westerlies and the associated South African high-pressure cell blocking the South Indian Ocean Convergence Zone related precipitation. As a consequence of the interplay of these effects, small scale climatic zones exist. We propose a conceptual model describing latitudinal shifts of these zones along the southeastern African coast as tropical and temperate climate systems shift over glacial and interglacial cycles. The proposed model explains some of the apparent contradictions between several paleoclimate records in the region.

Description: The data comprise sample locations and results of grain size measurements and optically stimulated luminescence dating of sediments from the Orog Nuur Basin (southern Mongolia). Samples were taken in order to gain a comprehensive sedimentological and geochronological overview over late Quaternary sediment cascades and respective archives. Grain size measurements were conducted in Aachen using a Beckmann Coulter Laser Particle Sizer. OSL data were obtained in the Luminescence lab of Cologne University. Samples were classified into 7 sediment archives according to the field description and grain size analysis (fluvial, beach ridge, lacustrine, littoral sand, dune sand, basin silty sands, and mountain silt). The grain size statistics is presented in the .xlsx-table according to this classification. The combination of sedimentological, geomorphologic and geochronological observations led to a late Quaternary landscape reconstruction, including alluvial fan evolution, lake level history and aeolian dynamics in this arid region of the northern Gobi Desert.

Description: We performed laboratory friction experiments on simulated fault gouges, measuring both the velocity- and slip-dependence of friction in velocity-step tests. Here, we evaluate the relative importance of slip- and velocity-dependent friction in laboratory velocity-stepping experiments, and assess the impact of friction slip dependence on natural faults.As an analogue fault gouge, we used a mixture of silt-sized quartz and commercially obtained clay-rich sediment (Grüne Tonerde, Argiletz Laboratories) mixed with deionized water. All tests were conducted at an (effective) normal stress of 2 MPa, with total shear displacements of up to ~16 mm.

Description: We present a multi-proxy dataset of two sediment cores (0.61 and 0.41 m long) from interconnected infilled depositional basins in the Kobbefjord area, southwestern Greenland. We performed analyses of magnetic susceptibility, grain size distribution, X-ray fluorescence (XRF) element composition , total content of carbon, nitrogen and sulfur, biogenic silica (at 0.5-cm resolution), and diatom stratigraphy (at 1 to 5-cm resolution). The sequences provide evidence of sedimentation in former shallow Arctic lakes or ponds in sparsely glacierized catchments.

Description: Surface ablation/accumulation was measured at 55 locations at the 79°N Glacier (Nioghalvfjerdsbraeen Glacier) in northeast Greenland in 2017 and 2018 (see links in "Further details"). Ablation/Accumulation are measured changes in height above ground level of bamboo poles installed in early July 2017 and changes were measured in late July 2017 or/and in July 2018.

Description: Temperature and heating-induced temperature differences were measured along a chain of thermistors. SIMBA 2020T76(a.k.a. PRIC_10_04, IRIDIUM number 300234068528490) is an autonomous instrument that was installed on drifting sea ice in the Arctic Ocean during the 3rd leg of the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) in April 2020. The buoy was deployed at the site about 2 km from the ship with initial thicknesses of snow and ice of 0.14 and 150 m, respectively, on 4 April 2020. The thermistor chain was 5 m long and included 241 sensors with a regular spacing of 2 cm. The depths for the sensors are 72 to -406 cm, referring to the initial interface between snow and ice. The last sensor was used to measure the air temperature at 1 m above the initial snow surface. The resulting time series describes the evolution of temperature and temperature differences after two heating cycles of 30 and 120 s as a function of depth and time between 4 April 2020 and 20 July 2020 in sample intervals of 6 hours for temperature and 24 hours for temperature differences. In addition to temperature, geographic position, barometric pressure, tilt and compass were measured.

Description: Temperature and heating-induced temperature differences were measured along a chain of thermistors. SIMBA 2020T77 (a.k.a. PRIC_10_05, IRIDIUM number 300234068524740) is an autonomous instrument that was installed on drifting sea ice in the Arctic Ocean during the 3rd leg of the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) in April 2020. The buoy was deployed at the site about 2 km from the ship with initial thicknesses of snow and ice of 0.06 and 1.64 m, respectively, on 4 April 2020. The thermistor chain was 5 m long and included 241 sensors with a regular spacing of 2 cm. The depths for the sensors are 84 to -394 cm, referring to the initial interface between snow and ice. The last sensor was used to measure the air temperature at 1 m above the initial snow surface. The resulting time series describes the evolution of temperature and temperature differences after two heating cycles of 30 and 120 s as a function of depth and time between 4 April 2020 and 4 June 2020 in sample intervals of 6 hours for temperature and 24 hours for temperature differences. In addition to temperature, geographic position, barometric pressure, tilt and compass were measured.

Description: Temperature and heating-induced temperature differences were measured along a chain of thermistors. SIMBA 2020T75 (a.k.a. PRIC_10_03, IRIDIUM number 300234068325170) is an autonomous instrument that was installed on drifting sea ice in the Arctic Ocean during the 3rd leg of the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) in April 2020. The buoy was deployed at the old helicopter site of central observatorysite with initial thicknesses of snow and ice of 0.12 and 1.64 m, respectively, on 23 April 2020. The thermistor chain was 5 m long and included 241 sensors with a regular spacing of 2 cm. The depths for the sensors are 56 to -422cm, referring to the initial interface between snow and ice. The last sensor was used to measure the air temperature at 1 m above the initial snow surface. The resulting time series describes the evolution of temperature and temperature differences after two heating cycles of 30 and 120 s as a function of depth and time between 23 April 2020 and 6 August 2020 in sample intervals of 6 hours for temperature and 24 hours for temperature differences. In addition to temperature, geographic position, barometric pressure, tilt and compass were measured.

Description: Measurements of cell density, nutrient concentration and genotype composition in a long term experiment (91 days) with the marine phytoplankton species Chaetoceros affinis and Emiliania huxleyi, each consisting of nine genotypes. Cultivation of species was done separately in mono-cultures and together in mix-cultures at three different nutrient regimes (10N:1P, 20N:1P, and 30N:1P) with increasing nitrate concentration in a semi-continuous batch cycle system. Transfer of part of the cells into bottles with new nutrients every 7 days at fixed batch cycle length and after 7,4, and 10 days in a recurring fashion at variable batch cycle length. With the information about the genotype abundance we assessed how intraspecific diversity is maintained in response to species competition and nutrient fluctuations. Individual trait measurements for growth, nutrient uptake, and cell volume of the genotypes at seven nitrate levels in a 4-day experiment allowed us to connect traits to the genotype sorting of the long term experiment.

Description: We provide high-resolution surface temperature data for a better understanding of the spatial and temporal variability of sea ice surface characteristics in the Arctic winter. Surface temperature images were recorded during helicopter survey flights with the Infrared VarioCAM HD head 680 from InfraTec. The thermal infrared imaging was performed with a down-looking infrared camera installed in a helicopter. This data set includes 35 flights, which were performed, from a local up to a regional scale, during winter 2019/2020 as part of the MOSAiC expedition in the Arctic Ocean. The measurements were done along the transpolar drift from the northern Laptev Sea towards the Fram Strait between 02.10.2019 and 23.04.2020. The usual flight duration was 90 minutes with a flight altitude of about 300 m. The data set includes one file for every flight in all four different data types: (i) a series of images in NetCDF format, (ii) the displayed map in png format, as well as surface temperature maps in (iii) 1 m resolution and (iv) 5 m resolution, both in NetCDF format. The flights can be identified by the event-related Device Operation label or Flight ID. The metadata of the infrared Camera is registered in the AWI Sensor Web at the current Version under https://hdl.handle.net/10013/sensor.0542bbfb-172a-496f-9bce-b21c59cd02c9. Further information can be found in our Data Manual, linked under *Further details*.

Description: Stalagmites GL-S1, GL-S2, GL-S3 and GL-S4 were collected under scientific license issued by Western Australia's Department of Biodiversity, Conservation and Attractions from Golgotha Cave (34.1°S, 115.1°E) in southwest Western Australia, with collection dates of 2005, 2005, 2008 and 2012, respectively. Cave location is rounded to nearest tenth of a degree as exact locations not disclosed for cave conservation purposes. Speleothems were collected for paleoclimate and paleohydrology studies. Golgotha Cave is located in Eucalyptus forest with dense understorey in the Leeuwin-Naturaliste National Park. The hostrock is Quaternary aeolinite and the soil thickness is variable with measurements ranging from 0.3-3 m deep. The cave entrance is 70 m above sea level. Stalagmites GL-S1 and GL-S4 are located approximately 60 m from the entrance where the limestone thickness overhead is 30 m while GL-S2 and GL-S3 are located approximately 90 m from the entrance where the limestone thickness overhead is 40 m. Mean annual site temperature is 15.6 ±0.5°C and mean annual rainfall is 1101±157 mm (1911-2018 period; Australian Bureau of Meteorology AWRA-L dataset http://www.bom.gov.au/water/landscape. Inside the cave, temperature ranges from 14.5-14.8°C, windspeed is low (≤0.03 m s-1) and relative humidity ranges from 98-100% (Treble et al 2019). Each speleothem was sectioned along the growth axis and milled using a Taig micromill to produce homogenised powders representing increments of 0.1 to 0.2 mm, depending on the speleothem growth rate. Powders were weighed to 180–220 μg and analysed for O and C isotopic values (δ18O and δ13C) using a Finnigan MAT-251 isotope ratio mass spectrometer coupled to a Kiel I carbonate device, or a Thermo MAT-253 isotope ratio mass spectrometer coupled to a Kiel IV carbonate device (using 110–130 μg samples), at the Research School of Earth Sciences, ANU. Analyses were calibrated using NBS-19 standard (δ18Ov-PDB = -2.20 ‰ and δ13Cv-PDB = 1.95 ‰). A further linear correction for δ18O measurements was carried out using the NBS-18 standard (δ18Ov-PDB = -23.0 ‰). The original delta values for NBS-19 and NBS-18 are used to maintain consistency of results through time in the RSES Stable Isotope Facility. Analytical precision for the analyses reported here (NBS-19) are ±0.04 ‰ for δ18O and ±0.02 ‰ for δ13C (N=236) for the MAT-251; and ±0.05 ‰ for δ18O and ±0.01 ‰ (N=27) for the MAT-253 instrument (±1σ standard deviation). Speleothem chronologies were determined by combining information from the date of collection, bomb pulse chronology, laminae counting of annual Sr concentration and U-series disequilibrium (see Supplementary Table 8 in Treble et al., 2022). For GL-S1, the age-depth model for 17th percentile was used in Treble et al., (2022) and the 50th percentile used for other stalagmites.

Description: High-resolution multi-proxy records from two lakes on the southern Tibetan Plateau, Nam Co and Tangra Yumco, are used to infer long-term variations in the Asian monsoon system. We examine the moisture evolution during the Late Glacial Maximum and Holocene using the trace element and stable isotope composition of ostracod shells. The sediment records covering the past 24 cal. ka BP and 18 cal. ka BP, respectively, demonstrate the suitability of ostracod shell chemistry as paleoenvironmental proxy. We analysed (i) Mg/Ca, Ba/Ca and Sr/Ca ratios as salinity proxies, (ii) Fe/Ca, Mn/Ca and U/Ca ratios representing redox conditions and microbial activity, and (iii) rare earth elements (REEs) reflecting weathering and changes in provenance.

Description: A multi-proxy palaeoecological investigation including pollen and spore, loss-on-ignition, total organic carbon, stable carbon isotope and micro- and macrocharcoal was carried out on two peat cores collected from coastal area in eastern Sumatra. The study was conducted to understand the development and dynamics of the coastal peatlands, the Kampar Peninsula in Sumatra. Pollen and spore was extracted follwing Fagri and Iversen (1989) and identified using available literature (e.g. Anderson and Muller, 1975; Cheng et al., 2020; Hofmann et al., 2019; Jones and Pearce, 2015; Pollen and Spore Image Database of the University of Goettingen). Microcharcoal analysis was conducted following point count method (Clark, 1982) and counted counted on the same slides for pollen and spore analysis. Macrocharcoal analysis was conducted following protocols in Rhodes (1998) and Stevenson and Haberle (2005). Loss-on-ignition analysis was carried out following (Chambers et al., 2011). Organic carbon content and isotopes were determined in Euro EA3000 elemental analyzer and Thermo Finnigan Delta Plus mass spectrometer, respectively, at the Leibniz Centre for Tropical Marine Research (ZMT), Bremen.

Description: We estimated fine-root biomass (FRB) and production (FRP) and their depth distribution and plant functional type (PFT) composition in four forested boreal peatland site types that varied in soil nutrient and water-table level regimes, ground vegetation and tree stand characteristics. Two were pine-dominated nutrient-poor sites (dwarf-shrub pine bog, tall-sedge pine fen) and two spruce-dominated nutrient-rich sites (Vaccinium myrtillus spruce swamp, herb-rich hardwood-spruce swamp). Measurements were done in two sites per site type: one undrained site and one site that had been drained for forestry. In each of the eight sites, we established three measurement plots. FRB was estimated by separating and visually identifying roots from soil cores extending down to 50-cm depth. The cores were taken in late August, 2016. FRP was estimated using ingrowth cores covering the same depth, and the separated roots were identified using Fourier transform infrared spectroscopy (FTIR). The ingrowth cores were incubated for two years, starting in November 2015 and ending in November 2017. Tree-stand basal area and stem volume per species, and projection cover of ground vegetation per species were determined in summer 2018. We monitored the soil water-table level and soil temperatures in 5 and 30 cm depths with dataloggers. Soil pH, bulk density, and carbon, nitrogen, phosphorus, potassium, calcium, magnesium, iron, manganese, boron, zinc, and copper concentrations were measured from peat cores extending down to 50-cm depth and taken simultaneously with the FRB cores. FRB, FRP and peat properties are presented for 10-cm depth segments. FRB, FRP and peat properties are presented for 10-cm depth segments. Peat cores were taken with a box-shaped 65 mm x 37 mm peat corer, except in the wet TP site where a 60 mm x 60 mm corer was used.

Description: Diatom assemblages document surface hydrographic changes over the Bermuda Rise. Between 19.2 and 14.5 ka, subtropical diatom species and Chaetoceros resting spores dominate the flora, as in North Atlantic productive regions today. From 16.9 to 14.6 ka, brackish and fresh water diatoms are common and their contribution is generally coupled with total diatom abundance. This same interval also contains rare grains of ice-rafted debris. Coupling between those proxies suggests that successive discharge of icebergs might have stimulated productivity during Heinrich event 1 (H1). Iceberg migration to the subtropics likely created an isolated environment involving turbulent mixing, upwelled water, and nutrient-rich meltwater, supporting diatom productivity in an otherwise oligotrophic setting. In addition, the occurrence of mode water eddies likely brought silica-rich waters of Southern Ocean origin to the euphotic zone. The persistence of lower-salinity surface water beyond the last ice rafting suggests continued injection of fresh water by cold-core rings and advection around the subtropical gyre. These results indicate that opal productivity may have biased estimates of meridional overturning based on 231Pa/230Th ratios in Bermuda Rise sediments during H1.

Description: Predation is a key modifier of community dynamics, but information on its magnitude in community regulation in systematically understudied Arctic coastal habitats is sparse. To test the magnitude and direction of predation effects on the diversity and structure of Arctic benthic communities, we conducted caging experiments in which consumers were excluded from plots at two intertidal sedimentary sites in Svalbard (Longyearbyen and Thiisbukta) for 2.5 months. At the end of the experiment, we took a sediment core from each plot and quantified the total biomass and, separately for each taxon encountered, the number of individuals. At both sites, the exclusion of predators changed the species composition of the communities, but had negligible effects on biomass, total abundance, species richness, evenness and Shannon index. In addition, we found spatial variability and artifact effects at both sites on several response variables.

Description: In the framework of the Multidisciplinary Observatory for the Study of Arctic Climate (MOSAiC) expedition, the tethered balloon system BELUGA (Balloon-bornE moduLar Utility for profilinG the lower Atmosphere) was deployed from a research camp on an ice floe drifting in the Fram Strait in Summer 2020. The BELUGA system consists of a 90 m³ helium-filled balloon with modular instrumentation. Lonardi et al. (2022) gives an overview of the BELUGA observations during MOSAiC leg 4. Pilz et al. (2023) describe the BELUGA operations and data processing routines. The present data set covers the aerosol particle measurements with the Cubic Aerosol Measurement Platform (CAMP) (details in Pilz et al., 2022) on 18 flights with mean altitudes of 1 km between 29 June and 27 July 2020.

Description: Carbon and hydrogen isotope values with molecular distributions of normal-alkanes (n-alkanes), carbon and nitrogen isotope values of bulk leaf material, as well as xylem water hydrogen and oxygen isotope values are presented from five co-occurring tree species. Species were collected during the 2006-growing season from a climate transect along the East Coast of the United States where high-resolution temperature, precipitation, and humidity data were available. Efforts focused on Acer rubrum, Platanus occidentalis, Juniperus virginiana, Pinus taeda, and Pinus strobus. In addition, meteoric water samples were collected from rivers, streams, and other bodies of water along the transect. Leaf wax n-alkanes were extracted, isolated, identified, and quantified following Tipple and Pagani, 2013 (Geochimica et Cosmochimica Acta, 111, 64-77). The average chain length of n-alkanes, carbon preference index, among other indices were calculated. The carbon and hydrogen isotope values of leaf wax n-alkanes were conducted following Tipple et al., 2018 (Oecologia, 187, 1053-1075) and Tipple and Pagani, 2013, respectively. The carbon and nitrogen isotope values of bulk leaf materials were measured according to Tipple et al., 2018. Xylem waters were extracted from woody stems and both the hydrogen and oxygen isotope values of xylem and meteoric waters were measured following Tipple and Pagani, 2013. The purpose of this study was to compare leaf wax distributions and isotope values along a climate transect to better understand the environmental factors and species' effects responsible for the carbon and hydrogen isotopic compositions of terrestrial plant materials, as well as the factors that influence n-alkane chain length. This study focused on species that inhabit the same environments and co-occur along a climate transect. This design allowed for interspecies and intraspecies variation to be explored. Site selections for this study allowed for an assessment of the importance of precipitation and temperature, while limiting the effects of humidity and elevation.

Description: This archive contains the primary raw data and intermediate results to an extended morphometric investigations about the evolution of menardiform globorotalids (planktonic foraminifera) from ODP Hole 806C (Ontong-Java Platform) from 37 stratigraphic levels during the past 8 million years (Knappertsbusch, 2021, submitted). This study is complementary to earlier such investigations about Globorotalia menardii, G. limbata and G. multicamerata from DSDP Holes 502 and 503 and from ODP Hole 925B. The goal of these investigations is to document the tempo & mode and paleobiogeographic patterns of morphological shell evolution and speciation with special emphasis on the Neogene Globorotalia menardii – limbata – multicamerata plexus. The present archive from Hole 806C consists of another large set of digital images and structured morphometric measurements, together with the software codes to extract the data. If unpacked, the entire data set expands to 12.3 GB (119'271 files). Morphometric parameters were extracted from shell outlines in keel view and include measurements of spiral height and axial length, the area of the silhouette, radii of osculating circles in the lower and upper keel region, spiral and umbilical convexities, and convexity ratios from more than 11'300 specimens. The final results and statistical treatment, that are illustrated in the above mentioned study form a subset of the presented data archive and are provided in an extra – reduced - set of electronic supplements alongside with the publication. A mirror of the present archive is stored on the internal media server of the Natural History Museum Basel, Switzerland. Samples, measured slides, and residues from this study are also deposited in the micropaleontological reference collections at the same institution.

Description: Strontium, neodymium and lead isotopic signatures were measured on the carbonate-free lithogenic fraction of a suite of terrestrial and marine sediments from the North American Southwest. We present radiogenic isotope data from 1) surface sediments from nine different playa lakes in the Mojave Desert, 2) Late Quaternary silt mantles which drape the bedrock of Anacapa and San Clemente Islands offshore California and 3) fluvially-derived and hemipelagic sedimentary horizons in Late Quaternary age marine sediments from Ocean Drilling Project sites 893 and 1015 in the California Borderland Basins. We also present a compilation of measurements of bedrock Sr, Nd and Pb isotopic composition across the North American Southwest from the published literature. These datasets allow us to identify the isotopic signature of aeolian material exported from the North American Southwest and explore the contribution of dust to the California Borderland Basins.

Description: Tap waters were collected from major metropolitan areas of the western United States. Tap waters were sampled between 2012-2015 from seven metropolitan areas: Los Angeles-Long Beach-Santa Ana (CA), Phoenix-Mesa-Glendale (AZ), Salt Lake City (UT), San Diego-Carlsbad-San Marcos (CA), San Francisco-Oakland-Fremont (CA), San Jose-Sunnyvale-Santa Clara (CA), and Riverside-San Bernardino-Ontario (CA). These areas represent some of the most populous in the US and employ a diversity of water management practices. Here hydrogen (d2H) and oxygen (d18O) isotope values along with strontium isotope ratios (87Sr/86Sr) and element abundances were measured. d2H and d18O of 2039 tap waters were measured following Tipple et al., 2017 (Water Research, 119, 212-224). 87Sr/86Sr and elemental compositions of 820 and 806 waters were analyzed following Tipple et al., 2018 (Scientific Reports, 8, 2224), respectively. The purpose of these data was to assess spatial, temporal, and climatic dynamics in isotope and elemental geochemistry of tap waters. We found that the isotope and elemental geochemistry of tap waters corresponded to the water sources (e.g., transported water, local surface water, groundwater, etc.) and management practices (e.g., storage in open reservoirs, mixing, etc.) for discrete areas within the larger metropolitan areas.

Description: Spatial snow and ice thickness measurements from ice stations PS81/503, PS81/506 and PS81/517 from Research Vessel Polarstern in the Antarctic Weddell Sea in austral winter 2013 (cruise leg ANT-XXIX/6, AWECS campaign). Terrestrial laser scanning (TLS) was used to determine the snow surface height above sea level for an approximately 50x50m patch. The reference to sea level was obtained using registration targets drilled through the ice with a measured distance between the target and the water level in the drill holes. Magnaprobe measures snow depth (Sturm et al., 2018) and the GEM-2 instrument measures the combined snow and ice thickness (Hunkeler et al., 2016). Magnaprobe and GEM-2 was performed inside the laser scan field after all scans had been acquired. Additionally floe-scale walks were performed using Magnaprobe and GEM-2 to capture variability on a larger scale than the laser scan field. Further information can be found in Wever et al. (2021).

Description: This data set consists of isotopic and molecular information obtained from samples of particulate and dissolved organic matter collected throughout the ice-free season in the Lena River Delta, supplemented with samples from Central Siberian Rivers Kochechum and Nizhnyaya Tunguska. Particulate samples were obtained by filtering water through pre-combusted glass-fibre filters, dissolved organic matter was studied in the filtrate. Molar concentration ratios of organic carbon to nitrogen in particulate samples are additionally reported as well as stable carbon isotopic composition (δ13C in ‰ VPDB) and radiocarbon content (∆14C in ‰) of particulate and dissolved organic carbon. Concentrations of long-chain n-alkanes (n-C17 to n-C33) in suspended particulate matter samples collected on glass-fibre filters in the Lena Delta. The data set also contains stable hydrogen isotopic composition (δD) of odd-chain n-alkanes n-C23 to n-C31 expressed in permille relative to VSMOW. Contents of long-chain n-alkanes (n-C17 to n-C33) in soil samples as well as particles settled from a large-volume water sample collected in the Lena Delta. The data set also contains stable hydrogen isotopic composition (δD) of odd-chain n-alkanes n-C23 to n-C31 expressed in permille relative to VSMOW.

Description: These five cores were obtained from a terrestrial permafrost area in northeastern Siberia (U1: March 2019; B3, B2, B1, U3: July 2019) during the Chersky 2019 field campaign. This campaign was part of both the CACOON and the PeCHEc project and was based at the Northeast Science Station in Chersky, Sakha, Russia (RU-LAND-2019/CHERSKIY; 02.07.2019 - 19.07.2019). They were taken from the area of the Pleistocene Park experiment (Zimov, 2005; doi:10.1126/science.1113442) and cover areas of a drained thermokarst lake basin (B) as well as the adjacent Yedoma uplands (U). The cores were drilled in areas of different large herbivore impact intensities (3= intensive; 2= extensive; 1= no animal presence). The data are used in a study exermining the impact of large herbivore presence on permafrost stability, vegetation composition and ground carbon storage. The active layer was sampled excavating profiles with a spade using fixed volume cylinders on the profile wall (250 ccm). The frozen ground was sampled using a SIPRE permafrost auger with a Stihl motor. All samples taken from these cores were analyzed between January 2020 and March 2021 at the facilities of AWI. The samples were analyzed for water/ice content, water isotopes, pH, conductivity, DOC, TC, TN, TOC, δ13C, mass specific magnetic susceptibility, grain size composition and radiocarbon age. Water/ice content was derived from weight differences before and after freeze-drying the samples. Water isotope ratios (δ18O, δ2H, d excess), pH, conductivity and DOC were measured using pore water extracted from the sediment samples using Rhizone samplers. Water isotopes were measured at AWI Potsdam Stable Isotope Laboratory using a Finnigan MAT Delta-S mass spectrometer. DOC was measured at AWI Potsdam Hydrochemistry Laboratory using a Shimadzu TOC-V CPH Total Organic Carbon Analyzer. TC and TN were measured at AWI Potsdam CARLA Laboratory using a vario EL III Element Analyzer. TOC was measured at the same laboratory using a varioMAX C Element Analyzer. δ13C was measured at AWI Potsdam Stable Isotope Laboratory using a Delta V Advantage Isotope Ratio MS supplement equipped with a Flash 2000 Organic Elemental Analyzer. Mass specific magnetic susceptibility was measured using a Bartington MS-2 Magnetic Susceptibility System. Grain size composition was determined using a Malvern Mastersizer 3000 equipped with a Malvern Hydro LV wet-sample dispersion unit. Statistics were calculated for this using Gradistat 8.0. Radiocarbon dating was carried out using the Mini Carbon Dating System (MICADAS) at AWI Bremerhaven.

Description: Lacustrine-peat sediments from the small forest-steppe natural archive Oskino-09, spanning about 7000 years were studied by pollen method. Radiocarbon dating was obtained for four samples; the age of the deposits was determined using the Bhron age model. In the southwest of Western Siberia, meadow-steppe landscapes occupied the largest areas in the middle of the Holocene 7.5-4.7 cal ka BP because of reduced effective moisture due to warming. A subsequent gradual decrease in temperatures and a decrease in evaporation led to an improvement in moisture and provided birch resettlement 4.7-2.0 cal ka BP, with short interruptions ca 3.3 and 2.5 cal ka BP. The expansion of pine forests and the advancement of taiga to the south were revealed ca 2.0 cal ka BP. Signs of the human impact were not so significant in antiquity and the Middle Ages and do not confirm the assumption of the forest-steppe belt formation due to anthropogenic deforestation on the southern border of the taiga.

Description: The datasets include information on physical, climatological and lake water δ2H and δ18O from lakes located ca. between 38ºS-46ºS along Chile, South America. All samples were taken during austral spring/summer 2017 to 2019.

Description: In July 2017, we collected apparent resistivity data (ohm-m) in a sub-aquatic permafrost environment on the southern coastline of the Bykovsky Peninsula in northeast Siberia. The project goal was to determine the depth to the top of frozen sediment for multiple submerged landscapes. The submerged landscapes included ice-rich Yedoma permafrost, permafrost that had undergone prior thermokarst (Alases), and a former lagoon (i.e. offshore at the lagoon's coastline positions in earlier years). The data was collected with an IRIS Syscal Pro Deep Marine resistivity system that was equipped with a GPS and an echo-sounder to record water depths. The geoelectric cable had an electrode separation of 10 m and the electrodes were arranged in a reciprocal Wenner Schlumberger array. The offset between the first electrode and the boat was approximately 10 m.

Description: Here we present a merged and calibrated dataset of temperature, practical salinity and dissolved organic matter (DOM) fluorescence obtained from several Ice Tethered Profilers (ITPs) deployed across the central Arctic (2011-2016). The data offer a unique spatial coverage of the distribution of DOM in the surface 800 m below Arctic sea ice. A total of 5044 profiles are gathered. The ITP data are level 3 data products pressure-bin-averaged at 1-db vertical resolution with depth down to either 200 or approximately 750 m. Data (max 800m depth) from CTD casts made during two oceanographic cruises are also included. These were used as part of the calibration and validation of the ITP calibration routines. The cruises were PS94 (ARK-XXIX/3) with POLARSTERN in 2015 and NAACOS with DANA in 2012. The presented DOM fluorescence data are smoothed, corrected for instrument drift and calibrated to provide intercomparable data across the sensors. Fluorescence is reported in Raman Units (nm-1), and comparable to laboratory measurements conducted according to current community recommendations.

Description: We provide a dataset of 42 newly collected surface sediment samples from the East Siberian Sea by analysis of Arctic sea ice (IP25) and open water phytoplankton biomarkers (Brassicasterol, Dinosterol, HBI-III and HBI-IV). Terrigenous sterols (campesterol and β-sitosterol) data in this region are also included in the dataset. All biomarkers are based on TOC calculations.

Description: Total (snow+ice) thickness measurements obtained during the international Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) campaign using the helicopters on board the research vessels Polarstern and Akademik Fedorov. The data was gathered during 14 flights between October 2019 and July 2020 in the Transpolar Drift on spatial scales up to 80 km distance from the position of the ships. Version 1.0. For details for the processing, please see Henricks & Rohde (2020), Haas et al. (2009) and von Albedyll et al. (2021).

Description: Amino acids were isolated from the muscle tissue of Potamocorbula amurensis, an invasive clam species, collected from two locations in the northern portion of the San Francisco Bay. Clam specimens were collected biannually in 1997, 2002, and from 2009-2017 at both locations. The carbon and nitrogen isotope values of individual amino acids were measured. Clam specimens were collected at USGS Sites 4.1 (Suisun Bay) and 8.1 (Carquinez Strait) in the San Francisco Bay and processed as described in Stewart et al. (2013; doi:10.3354/meps10503). Amino acids were hydrolyzed from P. amurensis, derivatized, and isolated following Vokhshoori et al. (2013; doi:10.3354/meps10746). Carbon and nitrogen isotope values of individual amino acids were measured following Vokhshoori et al., 2013 and Vokhshoori and McCarthy, 2013 (doi:10.1371/journal.pone.0098087), respectively. The purpose of this study was to assess long-term changes in the biogeochemistry of the San Francisco Bay estuary following the arrival of invasive P. amurensis. Sites were selected both due to species occurrence as well as significantly different salinity ranges. This design allowed for intraspecies and site-specific variations to be explored. Nitrogen isotopes of amino acids were used to isolate variations in nutrient baseline over the twenty-year period. Carbon isotopes of amino acid were utilized to understand long-term changes in dietary sources and/or changes in the baseline carbon isotope value of the estuary's food-web.

Description: Vertical profiles of water temperature, pressure and salinity were measured by the Drift Towing Ocean Profiler (DTOP) buoy 2019V5, a.k.a. 2019D, an autonomous platform, installed on drifting sea ice in the Arctic Ocean during MOSAiC (Leg 1) 2019/20. The resulting time series describes the vertical profile of the ocean below the sea ice as a function of place and time between 11 October 2019 and 25 October 2019 in sample intervals of 12 hours. In addition, the DTOP measured air temperature, relative humidity and barometric pressure and GPS position at hourly intervals. This instrument was deployed as part of the projects National Key R&D Program of China and The Marine S&T Fund of Shandong Province for Qingdao National Laboratory for Marine Science and Technology.

Description: The sedimentary C/N and δ13C in six Yangtze floodplain (China) lake sediment cores since 1800s CE. The sediment cores were dated using lead-210. C/N ratios and δ13C were analysed at the National Environmental Isotope Facility at the British Geological Survey, after preliminary treatment (HCl (5%) to remove calcites) in the School of Geography at the University of Nottingham, using Costech Elemental Analyser (EA) and on-line VG TripleTrap and Optima dual-inlet mass spectrometer. TOC and TN content were calibrated using the acetanilide standard. δ13C was calibrated to the Vienna Pee Dee Belemnite (VPDB) using laboratory standards which were calibrated against NBS-18, NBS-19 and NBS-22.

Description: Palaeo-environmental and -climatic data from core CEN-17.4 from the central Congo peatlands, Likouala Department (1°11'0.49"N, 17°38'23.7"E) and data from supporting cores. Bulk organic (TOC, TN, C/N) data and Rock Eval data to assess peat occurrence and degradation status for the central core CEN-17.4 and supporting cores. Radiocarbon dates on fine fractions for all cores. Plant-wax derived n-alkane stable carbon (δ^13^C) and stable hydrogen (δD) isotope data to assess vegetation changes and rainfall changes for the central core CEN-17.4. Selected pollen data for the central core CEN-17.4 to assess palaeo-ecological changes.

Description: Silicic volcanic rocks (primarily ignimbrite, tuff, and volcanic breccia) were collected in the Sana'a region, Yemen section of the Afro-Arabian large igneous province in 1999. Rock descriptions are available in Ukstins Peate et al. (2005; doi: 10.1007/s00445-005-0428-4). Zircon from four samples (three ignimbrites, one caldera collapse breccia) was separated and analyzed for trace element concentrations and uranium-lead isotope ratios at the Boise State University Isotope Geology Laboratory. Trace element concentrations and uranium-lead isotope ratios were obtained from laser ablation-inductively-coupled mass spectrometry (LA-ICP-MS) over three days in November 2019. Preliminary uranium-lead dates were calculated and are reported to two standard deviations. 32 zircon crystals were selected for chemical abrasion-thermal ionization mass spectrometry (CA-TIMS) analysis. Dissolved zircons were spiked with ET535 mixed uranium-lead tracer solution prior to uranium and lead separation using hydrochloric acid-based anion-exchange chromatography. Uranium-lead isotope ratios and dates obtained from TIMS analysis are reported to two standard deviations.

Description: Temperature and heating-induced temperature differences were measured along a chain of thermistors. SIMBA 2019T69 (a.k.a. FMI6-02) is an autonomous instrument that was installed on drifting sea ice in the Arctic Ocean during the 1st leg of MOSAiC in October 2019. The thermistor chain was 5 m long and included 241 sensors with a regular spacing of 2cm. The resulting time series describes the evolution of temperature and temperature differences after two heating cycles of 30 and 120 s as a function of place, depth and time between 11 October 2019 and 30 September 2020 in sample intervals of 6 hours for temperature and 24 hours for temperature differences. In addition to temperature, geographic position, barometric pressure, air temperature measured 1m over the ice level, tilt and compass were measured.

Description: Temperature and heating-induced temperature differences were measured along a chain of thermistors. SIMBA 2019T66 (a.k.a. PRIC_09_05) is an autonomous instrument that was installed on drifting sea ice in the Arctic Ocean during the 1st leg of MOSAiC in October 2019. The thermistor chain was 5 m long and included 241 sensors with a regular spacing of 2cm. The resulting time series describes the evolution of temperature and temperature differences after two heating cycles of 30 and 120 s as a function of place, depth and time between 29 October 2019 and 14 August 2020 in sample intervals of 6 hours for temperature and 24 hours for temperature differences. In addition to temperature, geographic position, barometric pressure, air temperature measured 1m over the ice level, tilt and compass were measured.

Description: The history of the coastal environment in the northern part of northeastern Brazil and the role of sea-level and climate change as well as the human impact during the past has been still little know. In order to shed more light on coastal ecosystem dynamics and its influencing factors, a 300 cm long sediment core has been taken using a Russian corer from Lago Formoso (3°15'14S / 45°23'10W; elevation of 10 meters above sea-level) located around 150 km distance from the present-day coast in Maranhão State. The fieldwork has been carried out during the dry season, with the sampling on the 10th of December 2018. The lake has an area of approximately 500 ha and is inserted into the coastal plains of Maranhão. During the rainy season (in May is the maximum) the lake is seasonally inundated with the highest water stand of up to 8 m, while during the dry season the shallow lake has a 1.3 m water depth. The core has been radiocarbon dated and analyzed by pollen, spores, charcoal, X-Ray Fluorescence (XRF), X-ray Powder Diffraction (XRPD), LOI, and sedimentary characteristics. The main aim of this work is to answer the specific research questions: 1) How were the dynamics of vegetation in the study area? 2) How sea-level and climate influenced the coastal environment since the mid-Holocene? 3) When occurred the Atlantic Ocean regression? 4) Since when and how strong did humans have influenced the environment in the region?

Description: Drifter position data from drifter deployments in July 2019 im the German Bight. The drifters were deployed from RV Alkor. The drifter position was send every 10 minutes via the Globalstar satellite transmission service. The drifters were 0.5 m in height with a subsurface drogue which is directly to the housing. The drag area ration of the deployed configuration is R=25.6.

Description: Aquatic and terrestrial plant materials were collected from the Sacramento-San Joaquin Delta region. Carbon and nitrogen isotope values of individual amino acids and bulk materials were measured. Fifty-six specimens were collected from three locations within the Delta, two flooded islands, Mildred and Liberty Islands, as well as an adjacent terrestrial riparian habitat (Big Break Regional Shoreline). Specimens included terrestrial trees, shrubs, forbs, and grasses as well as floating, submerged, and emergent aquatic plants. Bulk leaf tissues were processed and the carbon and nitrogen isotope values of bulk tissues were measured following Tipple and Ehleringer, 2018 (Oecologia, 187, 1053-1075). Amino acids were hydrolyzed, derivatized, and isolated following Vokhshoori et al., 2013 (Marine Ecology Progress Series, 504, 59-72). Carbon and nitrogen isotope values of individual amino acids were measured following Vokhshoori et al., 2013 and Vokhshoori and McCarthy, 2013 (PLoS ONE, 9, 6, e98087), respectively. The purpose of this research was to create a novel molecular isotope toolset to increase the understanding of biogeochemistry and food web structure of the Sacramento-San Joaquin Delta's tidal wetlands and estuarine marshes.

Description: Eight overlapping sediment cores, representing an approximately 6.6 m–long composite sequence, were collected on March 24, 2013 from Lake Malaya Chabyda in Central Yakutia (exact coring location 61°57.509' 129°24.500'). Sampling was conducted during a German–Russian Expedition (“Yakutia 2013”) as a cooperation between the North Eastern Federal State University in Yakutsk (NEFU) and the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI). To penetrate ca. 1 m of lake ice cover, 250-mm-diameter holes were drilled using a hand-held Jiffy ice auger. Water depth was measured using an Echo sounder (HONDEX PS-7 LCD) and a calibrated rope for verification. 100 cm-long parallel cores were collected at 2 m water depth using a Russian peat corer and supported by an UWITEC gravity coring system. Cores were stored in waterproof sealed, transparent PVC plastic tubes in cool and dark conditions. After the field season, the cores were transported to Potsdam, Germany and stored at 4°C in the cold rooms at AWI. The cores did not experience any visible drying or surface oxidation during storage. High–resolution X–ray fluorescence (XRF) analyses were carried out with 10 mm resolution on the entire sequence using an Avaatech XRF core scanner at AWI (Bremerhaven, Germany) with a Rh X-ray tube at 10 kV (without filter, 12 s, 1.5 mA) and 30 kV (Pd-thick filer, 15 s, 1.2 mA). The sediment surface was cleaned, leveled, and covered with a 4µm ultralene foil to avoid sediment desiccation prior to XRF scanning. Individual element counts per second (CPS) were transformed using a centered log transformation (CLR) and element ratios were transformed using an additive log ratio (ALR) to account for compositional data effects and reduce effects from variations in sample density, water content, and grain size. Statistical analysis was completed using the Python programming language (Python Software Foundation, https://www.python.org/). XRF analysis of the sequence indicated 24 detectable elements and a subset of these were selected for analysis based on low element χ2 values. These selected elements include the major rock forming elements of Silicon (Si) (Chi2 1.4), Calcium (Ca) (Chi2 6.3), Titanium (Ti) (Chi2 1.3), Rubidium (Rb) (Chi2 0.6), Strontium (Sr) (Chi2 0.7), Zircon (Zr) (Chi2 0.6) and the redox sensitive, productivity indicating elements of Manganese (Mn) (Chi2 1.3), Iron (Fe) (Chi2 2.5), and Bromine (Br) (Chi2 0.8). All subsequent analyses took place after the extracted subsamples had been freeze–dried until completely dry (approximately 48 hours). Grain size analysis was conducted on 18 samples that were chosen to span the entire sequence at relatively regular intervals. The samples were first treated for five weeks with H2O2 (0.88 M) in order to isolate clastic material. After treatment, seven samples were eliminated from the analysis because the remaining inorganic sediment fraction was too low for detection by the laser grain size analyzer. The remaining samples were homogenized using an elution shaker for 24 h and then analyzed using a Malvern Mastersizer 3000 laser. Standard statistical parameters (mean, median, mode, sorting, skewness, and kurtosis) were determined using GRADISTAT 9.1. Total carbon (TC), total organic carbon (TOC), and total nitrogen (TN) analyses were completed after the freeze–dried subsamples were ground in a Pulverisette 5 (Fritsch) planetary mill at 3000 rpm for 7 minutes. TC and TN were measured in a carbon–nitrogen–sulphur analyzer (Vario EL III, Elementar). Five mg of sample material were encapsulated in tin (Sn) capsules together with 10 mg of tungsten–(VI)–oxide. The tungsten–(VI)–oxide ensures complete oxidation of the sample during the measurement process. Duplicate capsules were prepared and measured for each subsample. Blanks and calibration standards were placed every 15 samples to ensure analytical accuracy (〈 ± 0.1 wt%). Between each sample spatula was cleaned with KIMTECK fuzz-free tissues and isopropyl. Analysis of TOC began by removing the inorganic carbon fraction by placing each subsample in a warm hydrochloric acid solution (1.3 molar) for at least three hours and then transferring the sample to a drying oven. The TC measured for each subsample in the previous analysis was used to determine the amount of sample required for the TOC analysis. The appropriate amount of sample was weighted in a ceramic crucible and analyzed using the Vario Max C, Elementar. The TOC/TN ratio was converted to the TOC/TNatomic ratio by multiplying the TOC/TN ratio by 1.167 (atomic weight of carbon and nitrogen). Total inorganic carbon (TIC) analysis was completed using a Vario SoilTOC cube elemental analyzer after combustion at 400ºC (TOC) and 900ºC (TIC) (Elementar Corp., Germany). Calculation of δ13C was completed twice for a subset of samples using two different methodologies. The analysis completed at the AWI Potsdam ISOLAB Facility removed carbonate by treating the samples with hydrogen chloride (12 M HCl) for three hours at 97 °C, then adding purified water and decanting and washed three times. Once the chloride content was below 500 parts per million (ppm), the samples were filtered over a glass microfiber (Whatman Grade GF/B, nominal particle retention of 1.0 µm). The residual sample was dried overnight in a drying cabinet at 50°C. The dry samples were manually ground for homogenization and weighted into tin capsules and analyzed using a ThermoFisher Scientific Delta–V–Advantage gas mass spectrometer equipped with a FLASH elemental analyzer EA 2000 and a CONFLO IV gas mixing system. In this system, the sample is combusted at 1020°C in O2 atmosphere so that the OC is quantitatively transferred to CO2, after which the isotope ratio is determined relative to a laboratory standard of known isotopic composition. Capsules for control and calibration were run in between. The isotope composition is given in permil (‰) relative to Vienna Pee Dee Belemnite (VPDB). The analysis of a small subset of samples which took place at Laboratoire des sciences du climat et de l'environnement Isotopic Laboratory for methodological comparison underwent a slightly different treatment, as follows. The sediment underwent a soft leaching process to remove carbonate using pre-combusted glass beakers, HCl 0.6N at room temperature, ultra-pure water and drying at 50 C. The samples were then crushed in a pre-combusted glass mortar for homogenization prior to carbon content and δ13 C analysis. The handling and chemical procedures are common precautions employed with low-carbon-content sediments. Analysis was performed online using a continuous flow EA-IRMS coupling, that is, a Fisons Instrument NA 1500 Element Analyzer coupled to a ThermoFinigan Delta+XP Isotope-Ratio Mass Spectrometer. Two in-house standards (oxalic acid, δ13C =−19.3% and GCL, _13C =−26.7 %) were inserted every five samples. Each in-house standard was regularly checked against international standards. The measurements were at least triplicated for representativeness. The external reproducibility of the analysis was better than 0.1 %, typically 0.06 %. Extreme values were checked twice. Those samples for which the carbonate was leeched at the room temperature, with lower HCl concentration (0.6N), and without a filtration step (samples analyzed at Laboratoire des sciences du climat et de l'environnement Isotopic Laboratory) had δ13C values 0.1‰ to 1.0‰ (average 0.5‰) higher than the samples treated at the higher temperature (97.7 ºC). However, the plotted δ13C curve is nearly identical for the subset of samples which were subjected to both treatments. There is some heterogeneity in the amount of offset between the two treatment methods. This might be related to an asymmetrical distribution of hot acid-soluble organic compounds throughout the sediment core. A correction of ca. +0.5‰ was applied to the results of the high temperature treatment. These values were then combined with the low temperature results to provide a complete dataset for the whole core. The standard deviation (1σ) is generally better than δ13C = ±0.15‰.

Description: Three sediment cores were retrieved from marshes at the southern North Sea coast, recovering the past 100 years. Core RD04 originates from a natural back-barrier marsh (island of Sylt); cores BT02 and BT03 from a reinstated, former managed marsh (Eiderstedt peninsula). Whereas the marsh in Sylt is a low-energy, back-barrier marsh, the marsh in Eiderstedt is exposed to storm waves from the open North Sea. The study provides a characterisation of the sedimentary processes that control vertical salt marsh growth in different energetic settings. Data include grain-size analysis and radionuclide activity of 137-Cs, 210-Pb and 226-Ra. Measurements of the radionuclides were used to determine sediment accretion rates. Grain-size data were used to determine and quantify multiple sedimentary processes by the application of end-member modelling.

Description: Aerosol particles are considered to be one of the main contributors in affecting the feedback mechanisms of the Arctic Amplification. However, to which extent is far away from quantification and this is partly related to a sparse knowledge of the spatial distribution of aerosols, in particular of the vertical distribution in the atmospheric boundary layer. The data set provides measurements of aerosol particle number concentration (for different size classes, above 3 nm, above 12 nm, and in the ranges of 300-500 nm, 500-700 nm and ~700-900 nm) as well as the meteorological parameters of air temperature, air pressure and humidity based on the unmanned research aircraft ALADINA (Application of Light-weight Aircraft for Detecting IN-situ Aerosol) that was used for a field application in Ny-Ålesund, Spitsbergen. Between 24 April and 25 May 2018, 49 measurement flights were performed that consist of vertical profiles (in sum 230) with a total maximum altitude of 850 m above mean sea level (AMSL) above land and horizontal legs (around 300) that were operated at different heights crossing the coast, as well as above open water in order to study a potential impact of different surface properties on the aerosol distribution. Information to studies/references: Preliminary results of the data contributed to the studies of Lampert et al. (2020), Petäjä et al. (2020) and Xavier et al. (2022) and will be presented in an overview study soon.

Description: Results from Underwater Vision Profiler 5hd measurements from campaign ARCTIC2018 (Transdrift-XXIV). Depth profiles for optical particle quantification (〉~0.1 mm) and particle image acquisition (〉~0.8 mm) were performed in August and September 2018 in the Laptev and East Sibirian Sea as well as the Nansen and Amundsen Basin onboard RV Akademik Tryoshnikov.

Description: The Suhia Kladenetz loess-paleosol sequence was sampled in 2018 on freshly cleaned vertical faces segmenting the larger quarry steps in two to three sub-sections. A continuous column of sediment was prepared and sampled at a 2 cm depth resolution. Slices of bulk sediment of about 10 x 6 x 2 cm in dimension (approx. 300g of material) were taken per sampling interval. The SK sequence is 26.72 m in total vertical thickness, which at a 2 cm continuous depth sampling resolution results in 1336 bulk sediment samples collected. Laboratory measurements of magnetic susceptibility, frequency dependence of magnetic susceptibility both absolute values and percentage, anhysteretic remanent magnetisation, isothermal remanent magnetisation, coercivity and coercive force are reported. Data of two correlative age models built from (1) the correlation of the frequency dependent magnetic susceptibility to the LR04 benthic foraminifera oxygen isotope record, and (2) the correlation of the ratio of a 2T isothermal remanent magnetisation and magnetic susceptibility to the EPICA Dome C (EDC) dust flux record. Estimates of sedimentation rates based on the correlative ages models are also reported.

Description: In a 13-months laboratory experiment conducted in 2014/2015, the interactive effects of gradually increasing temperature and pCO2 levels on survival, growth and respiration of two prominent colour morphotypes (white and orange) of the framework-forming cold-water coral Lophelia pertusa (also known as Desmophyllum pertusum), as well as bioerosion and dissolution of dead coral framework were assessed. In six-week intervals, three treatments (T1: acidification, T2: warming, T3: combined acidification and warming) were gradually increased in their respective manipulated parameters by 1°C and/or 200 µatm pCO2 after an initial two intervals under ambient (near in-situ) conditions. Each treatment consisted of 7 replicates that were manipulated over the course of the experiment and 3 control replicates that remained at ambient conditions throughout the entire duration of the experiment. Each replicate tank consisted of one live coral fragment of the white morphotype, one fragment of the orange morphotype and one dead framework fragment (naturally bioeroded framework material). Dead framework was examined with regard to attached bioeroders and calcifying organisms, the latter being removed prior to the experiment. All coral samples were collected from an inshore Norwegian cold-water coral habitat in the outer Trondheim-Fjord near Nord-Leksa (63°36.4'N, 09°22.7'E) between 150 to 230 m water depth using the manned submersible JAGO (GEOMAR, 2017; doi:10.17815/jlsrf-3-157) during RV POSEIDON (GEOMAR, 2015; doi:10.17815/jlsrf-1-62) cruise POS455 in June/July 2013. In situ conditions at the time of sampling near the corals were 7.7°C in temperature, 35.2 in salinity and ~6 mL/L oxygen concentration. Prior to the experiment, corals were kept in a closed recirculating system of 1,700 L in a climate-controlled laboratory facility at GEOMAR in Kiel at near in situ conditions of temperature and salinity (7.8 145 ± 0.2 °C and 35.8 ± 0.6) for half a year. Calcification/dissolution rates of live corals and bioerosion/dissolution rates of dead coral framework were determined using the buoyant weighing technique (Davies, 1989; doi:10.1007/BF00428135) with a high precision analytical balance (Sartorius CPA225D, readability = 0.1 mg) placed above every individual aquarium for each measurement. Respiration rates were determined via oxygen consumption measurements using an optode-based oxygen analyser (Oxy-10 mini, PreSens GmbH). Mortality was examined during every six-week interval by visual inspection of all live fragments. Dead polyp counts were calculated as percentage of total polyps counts of every individual fragment. Carbonate system parameters were calculated from the two measured parameters total alkalinity (TA) and dissolved inorganic carbon (DIC). TA and DIC samples were taken at the end of every 6-week interval and analyzed via potentiometric open-cell titration (862 Compact Titrosampler, Metrohm) in case of TA and by infrared detection of CO2 using an Automated Infra-Red Inorganic Carbon Analyzer (AIRICA with LI-COR 7000, Marianda) in case of DIC. TA and DIC were corrected against Certified Reference Material from A.G. Dickson (Scripps Institution of Oceanography) and density-corrected. The purpose of this study was to examine thresholds and optima of live corals under gradual increases of ocean acidification and warming and to quantify dissolution and bioerosion rates of dead coral framework to ultimately assess the balance between live coral calcification and degradation of dead coral framework under future ocean conditions.

Description: A total of 140 samples were collected from the il-Blata section outcropping on the Mediterranean Island of Malta (base of section at 35.9004˚N, 14.3309˚E, top of section at 35.9000˚N, 14.3314˚E). 16 of these samples were selected to determine the 87Sr/86Sr in the bulk sediment and used to generate numerical ages using the LOWESS FIT for Sr-Stratigraphy (McArthur et al., 2012). All 87Sr/86Sr measurements conducted at the University of Geneva using a Thermo Neptune PLUS Multi-Collector inductively coupled plasma mass spectrometer. Data and numerical age model presented in table S1. The εNd data from (Bialik et al., 2019) were recalibrated to fit the new age model and presented in table S2. The percentage carbonate matter was measured using a FOGl digital calcimeter at the University of Malta (table S3). Dry powders were used to generate a stable isotope (δ18O & δ13C) record (table S4), all measurements were conducted on a Gasbench II coupled to a Thermo Delta V Advantage isotope ratio mass spectrometer at the School of Earth and Environmental Sciences, Cardiff University. Dry bulk sediment powders were also used to obtain major element composition and calculate element ratios Sr/Ca, Ti/Al, K/Al, Zr/Al, Si/Ti. All element measurements were conducted at The School of Earth and Environmental Sciences, Cardiff University using a hand-held Olympus Delta Innov-X XRF gun. Element data presented in table S5. Mean values of the ratios Sr/Ca, Ti/Al, K/Al, Zr/Al and Si/Ti were obtained for three different parts in the section in order to determine regime changes (table S6).

Description: Hyperspectral radiometric quantities were observed at a 5-minute sampling interval in the Ugandan portion of Lake Victoria during a scientific field campaign aboard research vessel (RV) IBIS from 13 to 15 October 2021. The three-day fieldwork was coordinated starting from the Napoleon Bay, Jinja, Uganda. A radiometer setup with one TriOS RAMSES-ACC hyperspectral cosine irradiance meter to measure incoming solar irradiance and two TriOS RAMSES-ARC hyperspectral radiance meters to measure total upward sea surface leaving radiance (Lsfc) at 45° nadir and sky-leaving radiance (Lsky) at 45° zenith angle, was installed using a custom-made frame at the bow of RV IBIS. Data logging of raw and calibrated radiometric quantities was automated using TriOS MSDA XE version 8.9.2 software. Further processing was done using Mathworks Matlab 2016a and R software. Processed data was interpolated to 1 nm spectral resolution using PCHIP function in Matlab between 320 and 950 nm. Only the data with valid GPS coordinates and with spectra contributing less than 3% is included in this file, the rest of the data is available on request.

Description: Net catches of cephalopods were obtained during the cruises POS320/2 (March 2005), MSM49 (November/December 2015) and WH383 (March/April 2015) off Cabo Verde at a total of 18 stations at depths between 0 and 1000 m. Cephalopods were caught during POS320/2 with either a Isaacs-Kidd midwater trawl (IKMT) with a 6 m2 net opening, 4 mm mesh size equipped with a flowmeter, a Hydro-Bios Multinet Maxi with a 0.5 m2 net opening and 500 µm mesh size between the surface and 250 m water depth, or an 80 feet bottom trawl. Net sampling during MSM49 was conducted with two types of multiple opening/closing nets (MOCNESS) and an IKMT. The smaller MOCNESS had a net opening of 1 m2 opening (three nets with a mesh size of 2 mm and six nets with a mesh size of 335 μm) and the larger MOCNESS a net opening of 10 m2 opening (five nets, mesh size: 1.5 mm) and were deployed between the surface to 1000 m. The IKMT had a net opening of 7 m2 and ended in a cod end of 500 µm mesh size. It was deployed to a maximum depth of 500 m. During WH383 a pelagic trawl ('Aalnetz', Engel Netze, Bremerhaven, Germany) with a mouth opening of 16 x 30 m, length of 150 m including multiple opening-closing device, 260 meshes by 180 cm stretched mesh size at the front, a cod end 20 mm stretched mesh-opening and a 1.8 mm inlet sewn into last 1 m of cod end was used with a multisampler (Construction Services AS, Bergen, Norway) allowing depth-stratified sampling. During WH383 three strata (mean vertical extension of ca. 40 m) were trawled mostly during night and one time during daytime at depths between 30 and 700 m in horizontal tows for 30 minutes per stratum with a mean speed of three knots (2.8-3.3 kn). During this cruise, night trawls took place at 22:00 local time, and the day-time trawl at 12:00 local time. Onboard, cephalopods were identified morphologically to the lowest taxonomic level possible (species, genus or family), and whole specimens were preserved in formalin as voucher. In addition, tissue samples of some specimen were collected and preserved in ethanol for barcoding and the genetic reference database used for eDNA metabarcoding. Pelagic video transects with the Pelagic In-Situ Observation System (PELAGIOS, (Hoving et al., 2019a)) were conducted during the cruises MSM49 (Christiansen et al., 2016) (transects between 30 and 1000 m, total towing duration 〉 80h), MSM61 (Fiedler et al., 2020) (transects between 80 and 1200 m, total hours of observations 〉 32h), POS520 (Hoving et al., 2018, p. 520) (transects between 30 and 2500 m, total hours of observations 27h), POS532 (Hoving et al., 2019b) (transects between 30 and 990 m, total hours of observations 19h) and M119 (Brandt, 2016) (transects between 50 and 700 m, total hours of observations 〉 20h) between 2015 and 2019 (Figure 1). PELAGIOS is a battery powered, high-definition camera system that is towed horizontally via a single-wired conductive sea-cable at 0.5 m s -1. Around 0.45 m2 of the water column in front of the camera is illuminated with an LED array. The attached depth sensor and/or a sensor for conductivity, temperature and depth (CTD) with oxygen sensor allows for hydrographic measurements and depth monitoring during transects. Pelagic video transects were conducted between 11-33 minutes per depth, towing the camera horizontally at specified depths. A deep-sea telemetry system allows for transmission of a low-resolution preview of the recorded video. During the cruises POS520 and POS532 the manned submersible JAGO (GEOMAR, Helmholtz Centre for Ocean Research) was used for 30 deployments of about four hours each between the surface and 350 m water depth. During the dives, video was recorded by a high-resolution camera. The videos taken during the PELAGIOS and JAGO dives were annotated manually using the Video Annotation and Reference System (VARS) developed at the Monterey Bay Aquarium Research Institute, which allows annotation and congruent collection of video frames. We also provide raw data on environmental DNA samples taken during POS532 in February 2019 at five stations. The stations off the islands Santo Antão and Fogo were close to the coast (maximum sampled depth 2500 m), CVOO was a reference station in the open ocean (maximum sampled depth 3000 m) and the stations Cyclone and Anticyclone were located eddies that had formed in the wake of Fogo and had propagated southwards (maximum sampled depths 2200 and 600 m, respectively). Per sampled depth, three biological replicates of two liters of seawater each were collected from three different 10 liter Niskin bottles mounted on a CTD rosette. For filtration, 0.22 µm pore size Sterivex-GP filter (Merck Millipore) were directly connected to the Niskin bottle with sterile tubing. The weight of the water in the Niskin bottles was sufficient to filter two liters of seawater per filter. The filters were closed with sterile plastic caps and stored at -80°C until further processing in the laboratory.

Description: Vertical profiles of water temperature, pressure and salinity were measured by the Drift Towing Ocean Profiler (DTOP) buoy 2019V2, a.k.a. 2019B, an autonomous platform, installed on drifting sea ice in the Arctic Ocean during MOSAiC (Leg 1) 2019/20. The resulting time series describes the vertical profile of the ocean below the sea ice as a function of place and time between 07 October 2019 and 09 August 2020 in sample intervals of 12 hours. In addition, the DTOP measured air temperature, relative humidity and barometric pressure and GPS position at hourly intervals. This instrument was deployed as part of the projects National Key R&D Program of China and The Marine S&T Fund of Shandong Province for Qingdao National Laboratory for Marine Science and Technology.