ALBERT

Description: 〈jats:p〉Modern pollen–vegetation–climate relationships underpin palaeovegetation and palaeoclimate reconstructions from fossil pollen records. East Siberia is an ideal area for investigating the relationships between modern pollen assemblages and near natural vegetation under cold continental climate conditions. Reliable pollen-based quantitative vegetation and climate reconstructions are still scarce due to the limited number of modern pollen datasets. Furthermore, differences in pollen representation of samples from lake sediments and soils are not well understood. Here, we present a new pollen dataset of 48 moss/soil and 24 lake surface-sediment samples collected in Chukotka and central Yakutia in East Siberia. The pollen–vegetation–climate relationships were investigated by ordination analyses. Generally, tundra and taiga vegetation types can be well distinguished in the surface pollen assemblages. Moss/soil and lake samples contain generally similar pollen assemblages as revealed by a Procrustes comparison with some exceptions. Overall, modern pollen assemblages reflect the temperature and precipitation gradients in the study areas as revealed by constrained ordination analysis. We estimate the relative pollen productivity (RPP) of major taxa and the relevant source area of pollen (RSAP) for moss/soil samples from Chukotka and central Yakutia using Extended 〈jats:italic〉R〈/jats:italic〉-Value (ERV) analysis. The RSAP of the tundra-forest transition area in Chukotka and taiga area in central Yakutia are ca. 1300 and 360 m, respectively. For Chukotka, RPPs relative to both Poaceae and Ericaceae were estimated while RPPs for central Yakutia were relative only to Ericaceae. Relative to Ericaceae (reference taxon, RPP = 1), 〈jats:italic〉Larix〈/jats:italic〉, 〈jats:italic〉Betula〈/jats:italic〉, 〈jats:italic〉Picea〈/jats:italic〉, and 〈jats:italic〉Pinus〈/jats:italic〉 are overrepresented while 〈jats:italic〉Alnus〈/jats:italic〉, Cyperaceae, Poaceae, and 〈jats:italic〉Salix〈/jats:italic〉 are underrepresented in the pollen spectra. Our estimates are in general agreement with previously published values and provide the basis for reliable quantitative reconstructions of East Siberian vegetation.〈/jats:p〉

Description: This is a compilation of all short-wave and long-wave radiation datasets from Budapest that were and are published in the frame of BSRN. New data will be added regularly. The data are subject to the data release guidelines of BSRN (https://bsrn.awi.de/data/conditions-of-data-release/).

Description: We investigated the spatio-temporal trajectories of mountain agro-ecosystems by studying five lakes located between 880 and 2440 m a.s.l. in the north-western Alps. More specifically, we were interested in past interactions between agropastoral activities, plant community composition and erosion dynamics. To investigate this question, we relied on a multi-proxy dataset of lake sediment analyses. The selected proxies come mainly from plant and mammal sedimentary DNA analyses, but also from pollen and spore analyses of coprophilous fungi (Sporormiella sp.). The originality of this dataset is the creation of an index of (agro-)pastoral activity intensity valid for each lake catchment. This index showed a pattern of development of (agro-)pastoral activities according to altitude in this Alpine region. This index was then used to analyse the impact of (agro)pastoral activities on erosion dynamics and plant cover.

Description: Raw data acquired by GPS1 position sensors on board research aircraft Polar 5 during the campaign P6_231_HALO_P6_2022 were processed to receive a validated master track which can be used as reference of further expedition data. Novatel FlexPak6 GPS receiver was used as navigation sensors during the campaign. Data were downloaded from DAVIS SHIP data base (https://dship.awi.de) with a resolution of 1 sec. Processed data are provided as a master track with 1 sec resolution and a generalized track with a reduced set of the most significant positions of the master track. A detailed report on processing is also available for each flight.

Description: During the HALO-(AC)³ aircraft campaign in 2022, onboard of Polar 6 aircraft, refractory black carbon (BC) mass and number concentration was measured by a single particle soot photometer (SP2) in the mass equivalent diameter range of 70-675 nm. The instrument was installed behind the counter-flow virtual impactor (CVI) inlet, and therefore measured the BC properties of cloud residuals when the aircraft flew through clouds and the counter flow was switched on. During out-of cloud measurements, the counter flow of the CVI was switched off and the instrument measured the total aerosol's BC properties. In the data files, the column CVI_flag indicates if total aerosol was sampled (value of 0), cloud residuals were sampled (value of 1). A CVI_flag value of 2 indicates that the inlet counter flow was currently switched on or off and therefore the measurement is not valid. The provided time resolution is 3 seconds.

Description: This data set consists of in-situ measurements carried out aboard the Polar 6 research aircraft during HALO-AC3 campaign in March/April 2022. This comprises the aerosol properties of arctic ambient aerosol particle (outside cloud) and cloud particle residual (inside cloud) and the cloud water content / water vapor. The measurements were carried out north-west and west of Svalbard using the CVI inlet together with the PSAP, CPC, UHSAS aerosol instruments and the WVSS-II hygrometer of the Leibniz Institute for Tropospheric Research (TROPOS) in Leipzig, Germany.

Description: The Pliocene Epoch (~2.6–5.3 million years ago, Ma) was characterized by a warmer than present climate with smaller Northern Hemisphere ice sheets, and therefore offers an example of a climate system in long-term equilibrium with current or predicted near-future carbon dioxide concentrations. The end of the Pliocene (~2.6 Ma) is marked by further ice-sheet expansion and intensification of glacial (cold) stages, referred to as the "intensification of Northern Hemisphere Glaciation" (iNHG). Here we present the data used to assess the spatial and temporal variability of ocean temperatures and ice-volume indicators through the late Pliocene and early Pleistocene (from 3.3 to 2.4 Ma) to determine the character of this climate transition. The data come from the Atlantic, Pacific, Indian and Southern Ocean, as well as some marginal seas. Here we present the synthesized alkenone sea-surface temperature, Mg/Ca sea-surface temperature, planktonic foraminifera d18O and benthic foraminifera d18O data which were used in our synthesis. Although the original data sets are largely published, here we present the alkenone SST records calculated using the BAYSPLINE calibration where these were not part of the original publication; the Mg/Ca-SST records where we revised the absolute SSTs; any data sets where we revised the age model.

Description: This chapter outlines the principles and pitfalls of oxygen isotope stratigraphy, and presents a compilation of δ18O data representing 3.8 Ga of Earth history. The record is based on more than 64,000 analyses of Phanerozoic fossils and microfossils (carbonate and phosphate), including data for benthic foraminifera (N = 39,675), planktonic foraminifera (N = 10,800), belemnites (N = 4352), bivalves (N = 605), brachiopods (N = 4784), and conodonts and fish teeth (N = 3898), as well as 10,080 analyses of Precambrian rocks.

Description: This dataset consists of archaeological assessments of human land use across parts of the Middle East (Mesopotamia and Arabia) ca. 6000 BP (4000 BCE). The assessments have been made on the basis of published archaeological site locations, zooarchaeological and paleobotanical data, paleoenvironmental reconstructions, radiocarbon dates, and environmental data. Data dating to the time window 4250-3750 BCE have been included in the analysis. References and decision rules informing the assessments are detailed in Morrison et al forthcoming. Information on land use patterns are recorded using a classification system published in Morrison et al forthcoming. The assessments are recorded in a geospatial polygon shapefile consisting of a grid of 8x8 kilometer squares in the Eckert IV projection system. Included text files contain tables with domains (descriptions of the coded values in the attribute table of the shapefile). The data have been produced as part of LandCover6K, a collaborative working group of archaeologists, historians, geographers, paleoecologists and modelers aiming to improve the basis for incorporating past land cover change into earth system models. LandCover6k seeks to do this by producing global reconstructions of past vegetation and human land use through time that are grounded in paleoenvironmental and archaeological data. The present dataset is a regional contribution to this global effort.

Description: Data from Enhanced late Miocene chemical weathering and altered precipitation patterns in the watersheds of the Bay of Bengal recorded by detrital clay radiogenic isotopes in Paleoceanography and Paleoclimatology. Marine sediment samples from the late Miocene (approximately 9 to 5 million years ago) were taken from International Ocean Discovery Program (IODP) Site U1443 located on the top of the Ninety East ridge in the southern Bay of Bengal. Samples were taken along the composite sediment section or splice and the age model based on shipboard calcareous nannofossil biostratigraphy and magnetostratigraphy was refined using the stable carbon isotopes of benthic foraminifera. The detrital silicates of the clay size fraction were isolated and measured for their radiogenic Sr, Nd, and Pb isotope composition by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) to investigate the provenance of clays produced by weathering in the surrounding watersheds.

Description: Plant protection products in the environment are partly responsible for the progressive loss of biodiversity. The mostly insufficient ecological status of surface waters is often explained by habitat degradation and excessive nutrient input. But what role do plant protection products play in this context? The Kleingewässermonitoring (KgM) project provides a worldwide unique quantitative assessment of the impact of pesticides from diffuse agricultural sources on small and medium-sized streams. The dataset comprises 124 monitoring stream sections all over Germany covering a wide pollution gradient where consistent measurements were carried out in 2018 and 2019 during the major pesticide application period from April to July. These measurements include event-driven sampling to record surface rainfall-induced short-term peak concentrations in addition to regular grab sampling of pesticides and a wide range of other pollutants resulting in more than 1,000 water samples. All further relevant anthropogenic and environmental parameters reigning ecological stream quality were recorded comprehensively (morphological and stream bed structure, temperature, flow velocity, dissolved oxygen, pH, catchment land use, stream profile). The dataset also contains effect monitoring data featuring sampled invertebrate communities and bioassay analyses of water samples. The data enables an assessment of pesticide exposure and related effects as well as the analysis of complex causal relationships in streams.

Description: 499 emerging chemicals (ECs) were investigated in 56 effluent samples from 52 European wastewater treatment plants (WWTPs). The samples were collected between August 2017 and April 2019, using on-site large volume solid phase extraction (LVSPE) (Schulze et al., 2017). Chemical target screening by liquid chromatography high-resolution mass spectrometry (LC-HRMS) resulted in 366 detected compounds. Different capacities and conventional treatment technologies, as well as two advanced treatment technologies are included. One sample was taken at a WWTP with activated carbon (AC) treatment. Three WWTPs applying ozonation were sampled before and after this treatment step, providing two samples each. One of these WWTPs had already been sampled before the upgrade, resulting in a total of 56 (52+4) samples. More information can be found in Finckh et al. (2022). The two main objectives were (1) to extend our knowledge on chemicals occurring in treated wastewater, and (2) to identify and prioritize compounds of concern based on three different risk assessment approaches for the identification of consensus mixture risk drivers of concern.

Description: The Landscape Fire Scars Database for Chile makes publicly available for the first time a historical high-resolution (~30 m) burned area and fire severity product for the country. The georeferenced database is a multi-institutional effort containing information on more than 8,000 fires events between July 1984 and June 2018. Using Google Earth Engine (GEE), we reconstructed the fire scar area, perimeter, and severity for each fire. We also provide the Landsat mosaic image of pre- and post-fire events, including the NDVI and NBR indexes. In the related paper, we release the GEE code to reproduce our database or enable the international community to reconstruct another individual burned areas and fire severity data, with minimum input requirements. In the summary file is the list of reconstructed fire events. The identification number (ID) relates the initial information of the wildfires with fire scar and severity data.

Description: The inter-reef Halimeda bioherms of the northern Great Barrier Reef (GBR) have accumulated up to 25 m of positive relief throughout the Holocene. Covering 〉 6000 km2, the Halimeda bioherms represent a significant contribution to the development of the northeast Australian continental shelf geomorphology, neritic carbonate factory, and sedimentary archive of post-glacial environmental changes. Previously, the chronological record of initiation and development of the Halimeda bioherm carbonate factory was poorly constrained and based on very few age data points. A comprehensive new age dataset is presented, comprising sixty-three AMS radiocarbon measurements of Halimeda and foraminifera grains, mollusc shells and bulk soil from twelve inter-reef sediment cores, and ten previously published Halimeda ages that are newly calibrated. Radiocarbon measurements were undertaken at the ANSTO Centre for Accelerator Science in 2018, 2019 and 2020 from cores collected by the Bureau of Mineral Resources in 1983. Halimeda growth had established by 11,143 +237/-277 cal. yr BP, just ~450 years after the marine transgression commenced and approximately 1000 years earlier than previous inferred estimates. The outer-shelf carbonate factory was initially dominated by benthic foraminifera, then Halimeda was productive for at least 2100 years prior to the turn-on of Holocene coral reefs in the study area. Inter-reef Halimeda bioherm sediments including foraminiferal communities, might record a 〉10,000-year near-continuous geochemical record of northeast Australian Holocene oceanographic and climatic changes, potentially filling spatial and temporal gaps not covered by coral and other marine sediment proxies.

Description: This data set comprises radiogenic neodymium (Nd) isotope signatures of past deep water masses and detrital matter in the Early Cretaceous (Barremian-Albian) South Atlantic Ocean and Southern Ocean, recorded at Deep Sea Drilling Project (DSDP) Sites 249, 327, 361, and 511 and Ocean Drilling Project (ODP) Site 693. Deep water Nd isotope compositions were leached from authigenic ferromanganese coatings of bulk sediment particles. Detrital Nd isotope signatures were obtained from residues of the sediment leaching procedures after dissolution via alkaline fusion. Age estimates for individual samples were calculated based on biostratigraphic and carbon isotope stratigraphic age constraints and calibrated to the time GTS2012 time scale of Gradstein et al. (2012).

Description: This data set presents the results of an automated cluster analysis using Gaussian mixture models of the entire Atlantic seafloor environment. The analysis was based on eight global datasets and their derivatives: Bathymetry, slope, terrain ruggedness index, topographic position index, sediment thickness, POC flux, salinity, dissolved oxygen, temperature, current velocity, and phytoplankton abundance in surface waters along with seasonal variabilities (see Source data set). We obtained nine seabed areas (SBAs) that portray the Atlantic seafloor that are shown as polygons in the data set. The attribute table holds short descriptions of each SBA as well as about the colours used in the accompanying paper publication. Data sets like this can be used for further analysis like e.g. for landscape ecology metrics to identify regions of interest. The compressed file further contains a style file that can be used to directly load the correct style in the QGIS software package.

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: We determined dissolved stable silicon isotopes along with silicic acid concentrations in geochemically well-characterized seawater samples recovered during the expeditions TRANSDRIFT-XX (TI12, March and April 2012), TRANSDRIFT-XXI (VB13, August and September 2013) and TRANSDRIFT-XXII (VB14, September and October 2014) to the Laptev Sea. During the winter TRANSDRIFT-XX expedition, samples were collected using 2-l-Niskin bottles mounted on a frame at several helicopter stations to the sea ice, while during the summer expeditions TRANSDRIFT-XXI and TRANSDRIFT-XXII the samples were recovered with a carousel water sampler equipped with 12 Niskin bottles (2.5 L) under ice-free conditions onboard the Russian research vessel RV Viktor Buynitskiy on the entire Laptev Sea shelf and above the shelf slope. The dataset includes dissolved stable silicon isotope and silicic acid concentration data, which provide important information on the distribution and biogeochemical cycling of silicon and other nutrients in the Laptev Sea.

Description: 79 potential endocrine disrupting chemicals (EDCs) were investigated in 56 effluent samples from 52 European wastewater treatment plants (WWTPs). The samples were collected between August 2017 and April 2019, using on-site large volume solid phase extraction (LVSPE) (Schulze et al., 2017). Chemical target analysis by liquid chromatography high-resolution and tandem mass spectrometry (LC-HRMS and LC-MS/MS, respectively) resulted in 56 detected compounds. Different capacities and conventional treatment technologies, as well as two advanced treatment technologies are included. One sample was taken at a WWTP with activated carbon treatment. Three WWTPs applying ozonation were sampled before and after this treatment step, providing two samples each. One of these WWTPs had already been sampled before the upgrade, resulting in a total of 56 (52+4) samples. More information can be found in Finckh et al. (2022). The two main objectives of this study were (i) to compare three different receptor-based estrogenicity assays (ERα-GeneBLAzer, p-YES, ERα-CALUX®), and (ii) to investigate a combined approach of chemical target analysis and receptor-based testing for estrogenicity, glucocorticogenic activity, androgenicity and progestagenic activity (ERα-, GR-, AR- and PR-GeneBLAzer assays, respectively) in treated wastewater.

Description: This dataset comprises radon concentrations emanated from four polymetallic nodules of different sizes from the CCZ. The nodules were collected in the framework of the European collaborative JPI Oceans MiningImpact project onboard R/V SONNE cruises SO239 in 2015 and SO268 in 2019. Radon emanation was measured by enclosing the nodules in a glass chamber (volume = 2.02 L) while continuously circulating the gas in the system through a Rad7 device (Durrige Inc.), which is designed to measure specifically radon. As comparison, a 4.6 Bq Ra-226 standard was analyzed. The concentrations were evaluated with the Capture® software.

Description: The data file contains measured environmental concentrations of organic micropollutants in European streams and additional hydrological parameters (stream order, urban discharge fraction) of the investigated sites. A total of 445 surface water samples were collected during various sampling campaigns between 2016 and 2019. Chemical target screening of 610 compounds by liquid chromatography high-resolution mass spectrometry (LC-HRMS) resulted in 504 detected compounds. The measured environmental concentrations of the detected compounds ranged from 1 ng/L to 74 µg/L (3-cyclohexyl-1,1-dimethylurea). Detection frequencies ranged from one site (0.2 %) to 339 sites (76 %). More information can be found in Finckh and Carmona et al. (2024) DOI: 10.1016/j.envint.2023.108371. The main objective of this study was to quantify and characterise chemical footprints in European streams.

Description: Nd, oxygen isotopes and Mg/Ca ratio measured on foraminifera from sediments issue of core ODP 762. Nd and Sr measurements measured on the detrital fraction of sediment issue of core ODP 762. The data covered the last 500 Kyrs of climatic and oceanographic history of the east tropical Indian Ocean. The oxygen isotopes and Mg/Ca aims to reconstruct the paleotemperature and paleosalinity of the site over the glacial/interglacial oscillation of the last 500 Kyrs. The Nd isotopes measured on carbonate reconstruct the circulation pattern at intermediate depth (1360 mbsl) over the same time period. the isotopic measurements done on the detrital components of the sediments aim to identify the origin of the regional continental inputs.

Description: In order to understand the hydrothermal input of barium (Ba) to the ocean interior and the changes of Ba in the hydrothermal plume, we measured dissolved (〈0.2 μm) and particulate (〉0.2 μm) Ba concentrations, as well as stable isotopes, in the non-buoyant hydrothermal plume at the Rainbow hydrothermal vent field on the Mid-Atlantic Ridge. Samples were taken during a GEOTRACES compliant cruise (M176/2) onboard the German R/V Meteor from September to October 2021. Particulate samples were first leached to measure labile components and then digested to measure refractory components. Our investigation covered the plume with a high spatial resolution, extending from a distance of 200 m to 60 km away from the Rainbow hydrothermal vent field.

Description: This data is part of the BMBF project CUSCO (Coastal Upwelling Systems in a Changing Ocean). Here we report particulate organic matter concentrations collected during a 35-day experiment where we enclosed natural plankton communities in in-situ mesocosms off Peru. The experiment investigated the interactive effects of light and upwelling on the Humboldt upwelling ecosystem by mimicking a gradient of upwelling intensities (0%, 15%, 30%, 45% and 60%) under summer-time high light and winter-time low light. Integrated seawater samples from a depth between 0 and 10m were collected using a 5L Integrating Water sampler (IWS; Hydro-Bios, Kiel). Samples (150-1000 ml) were filtered onto a 0.7 µm pre-combusted glass-fiber filters (GFF, Whatman). The filters were acidified and then dried in the oven at 60 °C for 24 hours and total particulate carbon (TPC), particulate organic carbon (POC) and nitrogen (PON) content were measured using a CN analyzer (Euro EA3000, HEKAtech GmbH, Wegberg, Germany). POP filters were autoclaved for 30 min in 100 mL Schott Duran glass bottles using an oxidizing decomposition solution (Merck, catalogue no. 112936) to convert organic phosphate to orthophosphate. Phosphate concentrations were determined spectrophotometrically following Hansen and Koroleff (1999; doi:10.1002/9783527613984.ch10).

Description: This data is part of the BMBF project CUSCO (Coastal Upwelling Systems in a Changing Ocean). Here we report pigment concentrations and the phytoplankton community composition based on CHEMTAX analysis during a 35-day experiment, where we enclosed natural plankton communities in in-situ mesocosms off Peru. The experiment investigated the interactive effects of light and upwelling on the Humboldt upwelling ecosystem by mimicking a gradient of upwelling intensities (0%, 15%, 30%, 45% and 60%) under summer-time high light and winter-time low light. Integrated seawater samples from a depth between 0 and 10m were collected using a 5L Integrating Water sampler (IWS; Hydro-Bios, Kiel). To obtain pigment concentrations 0.15 – 1L of water sampled from the water column were filtered onto glass-fiber filters (precombusted at 450°C for 6h, GFF, 0.7 µm nominal pore size, Whatman) using a low vacuum of 200 mbar. Afterwards the filters were stored in cryovials at -80°C until analysis of photosynthetic pigments using reverse-phase high-performance liquid chromatography (HPLC) following (Barlow et al., 1997; doi:10.3354/meps161303) as described by (Paul et al., 2015; doi:10.5194/bg-19-5911-2022). The phytoplankton community composition was calculated with CHEMTAX, which classifies phytoplankton taxa based upon taxon-specific pigment ratios (Mackey et al., 1996; doi:10.3354/meps144265). The values for the Peruvian upwelling system determined by (DiTullio et al., 2005; doi:10.4319/LO.2005.50.6.1887) as described by (Meyer et al., 2017; doi:10.3389/fmars.2017.00001) were used as pigment ratios. As phytoplankton microscopy revealed high abundances of the raphydophite Fibrocapsa japonica, the initial pigment matrix was complemented by ratios for F. japonica from (Laza-Martinez et al., 2007; doi:10.1093/plankt/fbm069) from the Atlantic.

Description: Data presented here are trace-elements and boron isotope composition of planktic foraminifera G. ruber (250-355 μm) along with reconstructed surface ocean temperature, salinity, pH and pCO2 for the past 136 Ka from the south-eastern Arabian Sea. Foraminifera cleaning was carried out using the method adopted from Barker et al. 2003. Boron was purified using the micro-distillation method (Misra et al., 2014a). Trace-element analysis (e.g. Mg/Ca) was carried out using the High-Resolution Inductively Coupled Plasma Mass Spectrometer (HR-ICPMS) (Misra et al., 2014b). Boron isotope analysis was carried out using Thermo Neptune Plus multi-collector inductively coupled plasma mass spectrometer (MC–ICPMS), following the method described in Tarique et al. 2021, and Lloyd et al. 2018. Sea surface temperature (SST) was calculated using the foraminifera Mg/Ca utilizing the method adapted from Gray and Evans 2019. Sea surface salinity (SSS) was calculated using the Mg/Ca derived SST, foraminifera d18O and regional seawater d18O and salinity relationship.

Description: During the HALO-(AC)³ field campaign in spring 2022, the Basler BT-67 research aircraft Polar 6, based in Spitzbergen (78.24 N, 15.49 E), was equipped with an advanced in situ cloud payload by the DLR. This payload contained a combination of cloud instruments, including the Cloud Droplet Probe (CDP), the Cloud Imaging Probe (CIP), and the Precipitation Imaging Probe (PIP). The published data contain the particle size distributions measured by each particle measurement system. The respective instruments operate in different size ranges, and by combining their data, an additional data set is calculated that covers cloud particles in the size range from 2.8 µm to 6400 µm. Microphysical cloud properties such as cloud particle number concentration, liquid water content, ice water content, and effective diameter are derived from the given particle size distributions. The in situ cloud measurements focused on low and mid-level clouds in the Fram Strait, over the sea ice and the open ocean. The measurement campaign is embedded in the Transregional Collaborative Research Centre TR 172 (ArctiC Amplification: Climate Relevant Atmospheric and SurfaCe Processes, and Feedback Mechanisms (AC)³).

Description: This data set contains in-situ analysis of individual particles measured during HALO-(AC)³ in March/April 2022. Using the single particle aerosol mass spectrometer ALABAMA, particle size and chemical composition of single particles were analyzed onboard of the research aircraft Polar 6. The data provides time, location, particle size (if available), an integer value inlet_pos as indicator for the position of the ALABAMA inlet switch (2: CVI inlet, 4: standard aerosol inlet) as well as counts of different cluster types for each analyzed particle. The 38 clusters were determined by using a fuzzy-c-means algorithm, a method for grouping data points with similar signal pattern. The key chemical species of each cluster are given in the longname version of the cluster variables in the data files. A detailed description of the data processing will be done in an upcoming data paper.

Description: During the HALO-(AC)³ campaign performed in March/April 2022, broadband solar and thermal-infrared irradiances in the vicinity of Svalbard were measured by pairs of CMP22 (0.2-3.6 µm) and CGR4 (4.5-42 µm) radiometers (Kipp&Zonen), respectively, onboard Polar 5 and Polar 6. The data set contains time series of both upward and downward solar and thermal-infrared irradiances obtained during in total 26 research flights (13 with each aircraft). All irradiances were corrected for instrument inertia (Ehrlich and Wendisch, 2015), the solar downward irradiance additionally for the aircraft attitude (Bannehr and Schwiesow, 1993). Since the latter correction is only valid for cloud-free conditions dominated by direct illumination, both a corrected and an uncorrected version are given. A rough cloud flag is included in the data set to distinguish between situations dominated by direct and diffuse illumination. To avoid too large uncertainties, the attitude flag can be used to filter situations with aircraft attitude angles (roll, pitch) exceeding 5°. Additionally, obvious icing and large temperature gradients, which disturb the thermal equilibrium between sensor and instrument body, are flagged. The data set further contains the solar downward irradiance simulated for cloud-free conditions and the upward brightness temperature measured by the KT-19 infrared thermometer (HEITRONICS, 9.6-11.5 µm).

Description: Vegetated coastal ecosystems have been increasingly recognized for their capacity to sequester organic carbon in their soils and sediments under the term blue carbon. The vegetation of these habitats shows specific adaptations to severe abiotic soil conditions, particularly, waterlogging and salinity, and supports therefore ecosystem functioning and services. Wadden Sea salt marshes in Schleswig-Holstein (Germany) have been utilized for high density sheep grazing over centuries. At the beginning of the 1990s, in many parts of salt marshes livestock densities were reduced and the maintenance of the anthropogenic drainage system was ceased. In 2012, 17 years after the change of land utilization, the contents, densities, and accumulation rates of surface soil carbon were investigated at 50 sampling positions with different elevations along eight transects in Wadden Sea mainland salt marshes at Hamburger Hallig, Schleswig-Holstein, Germany, under different livestock grazing regimes (ungrazed, moderately grazed, intensively grazed). Surface soil was collected in 150 permanent plots (2 m * 2 m) at 50 sampling positions, covering a salt marsh area of 1050 ha. The carbon contents, pH, and bulk density were determined from dried soil. The elevations of the 150 permanent plots were measured and annual vertical accretion rates were calculated from 17 years sedimentation monitoring. This study was supported by the BASSIA project (Biodiversity, management, and ecosystem functions of salt marshes in the Wadden Sea National Park of Schleswig-Holstein), funded by the Bauer-Hollmann Foundation and Universität Hamburg.

Description: This dataset includes the results of the analysis of a set of surface sediment samples recovered from the Labrador Sea. Analysis includes measurement of the radiogenic Nd isotope signatures in the authigenic Fe-Mn oxyhydroxide fraction of the bulk sediment (leachates) and of the totally dissolved residual silicate (detrital) as well as analysis of uncleaned foraminifera.

Description: This data is part of the BMBF project CUSCO (Coastal Upwelling Systems in a Changing Ocean). Here we report carbon and nitrogen uptake rates by phytoplankton collected during a 35-day experiment where we enclosed natural plankton communities in in-situ mesocosms off Peru. The experiment investigated the interactive effects of light and upwelling on the Humboldt upwelling ecosystem by mimicking a gradient of upwelling intensities (0%, 15%, 30%, 45% and 60%) under summer-time high light and winter-time low light. Integrated seawater samples from a depth between 0 and 10m were collected using a 5L Integrating Water sampler (IWS; Hydro-Bios, Kiel). Samples were spiked with 13C labelled sodium bicarbonate and 15N labelled potassium nitrate. Samples were incubated for 24 hours at light intensities that resemble the light conditions in the mesocosms. After incubation a subsample (150-1000 ml) was filtered onto a 0.7 µm pre-combusted glass-fiber filters (GFF, Whatmann). The filters were acidified, then dried in the oven at 60 °C and later measured using an elemental analyzer (Flash IRMS, ThermoFisher) connected to a mass spectrometer (Delta V Advantage Isotope Ratio MS, ThermoFisher) with the ConFlo IV (ThermoFisher). Carbon and nitrogen uptake rates were calculated based on Slawyk et al. (1977, DOI:10.4319/lo.1977.22.5.0925) and Shiozaki et al. (2009, DOI:10.3354/meps07837) respectively.

Description: During the HALO-(AC)³ campaign in March/ April 2022, in-situ particle number concentration and size distribution of ambient aerosol particles and cloud residual particles were measured using a Grimm Sky OPC (model 1.129 Sky-OPC). This data set provides the particle size distribution divided in 31 size bins between 0.25 µm and 40 µm. Particle number concentrations are pressure-corrected to standard temperature and pressure (STP). The time resolution of the instrument is 6 seconds. Each data point is given at the end of the corresponding measurement interval.

Description: Liquid water content and total water content from the Nevzorov probe, collected during the HALO-AC³ campaign out of Longyearbyen, Svalbard in April 2022. The dataset contains measurements from the three collector sensors of the Nevzorov probe. These are the cylindrical LWC sensor, the 8 mm TWC cone and the 12 mm TWC cone (for a description of the probe see doi:10.1175/1520-0426(1998)015〈1495:TNAHWL〉2.0.CO;2, doi:10.5194/egusphere-2022-647 ). Furthermore, corrected LWC and TWC values are contained in the dataset. These values are best estimates of LWC and TWC. They are computed by solving a system of equations and they consider collection efficiencies, the different latent heats of water and ice and the sensitivity of the LWC sensor to ice particles. For a description of the computation see Lucke et al. (2023) (doi:10.4271/2023-01-1485). However, for this data, the 12 mm cone was not included in the computation, as its data were deemed to be too unreliable in conditions where droplet diameters are low. NaNs are represented as 9999.999 in the dataset. The dataset only contains research flight 8 - 13. For the previous flights a problem with the probe existed and no data was recorded.

Description: This dataset contains the processed and raw data collected with the Backscatter Cloud Probe with Polarization Detection during the HALO-AC³ campaign in March and April 2022 with the Polar 6 Aircraft out of Longyearbyen, Svalbard. The dataset contains two kinds of data. Data to which no inversion procedure has been applied and data to which the inversion procedure has been applied. The inversion procedure is applied to account for an uneven intensity of the laser beam across the sample area and resulting undersizing effects. The inversion procedure has been discussed in Lucke et al. (2023) (doi.org/10.4271/2023-01-1485) and Beswick et al. (2014) (doi.org/10.5194/amt-7-1443-2014). All quantities which carry the suffix inv are based on the inverted data, all other properties are not. It should be noted, that the necessity of the inversion procedure remains unclear (see the previously mentioned publications). The inversion procedure could only be applied when more than 2000 particles were present over a 5 second interval. When this was not the case, the inverted data are 9999.999. The inverted data are therefore also computed from a 5s rolling average. The measurements of the BCPD are likely severely influenced by inertial separation effects, due to the proximity of the BCPD sample area to the fuselage (approx. 3cm). When ice particles are present, shattering occurs on the fuselage and artificially increases the ice number concentration. The number of ice and liquid particles listed in this data set can be useful for assessing the presence of ice and liquid particles. To estimate the number of liquid and ice particles more than 100 particles are required over a 5s interval. When this is not the case, the data are 9999.999. The number of ice and liquid particles were computed as rolling averages over 5s intervals. The sample area in case no inversion procedure is applied is 0.273 square millimeters.

Description: Sediment core PS93/031-5 was obtained during RV POLARSTERN expedition PS93.1 in the northwestern Fram Strait on the Northeast Greenland continental margin from 2,135 m water depth. Sediment slices of approx. 5 mm thickness were taken from sediment core PS93/031-5 every 0.5 cm (~30 g dry sediment per sample). Sediments were freeze-dried, weighed, and washed with deionized water through a 63 µm mesh. The remaining coarse fraction was dried at 50°C. Radiocarbon datings were performed on 9 samples of sediment core PS93/031-5 at the AMS-14C facility of the Leibniz Laboratory for Age Determination and Isotope Research of Kiel University from August 2018 to April 2019 on ~2,000 specimens of N. pachyderma (morphotype 1-2) per sample (identification following the morphotype concept of Eynaud, 2011). According to the radiocarbon datings (no reservoir correction applied) the sediment core covers the Late Quaternary time interval from 4,023 to 18,135 years before present (1950 CE). No sediments are present from the interval 11,170-15,950 years before present (hiatus at 25 cm core depth). When a conversion to calibrated years is performed with the program Calib 8.2 (http://calib.org/calib/), using the IntCal20 data set and applying a reservoir correction of 550 years, the core covers the interval of 3,750-23,230 years before present, with the hiatus covering the interval 12,660-18,550 years.

Description: The 26,000-year long time-series analyzed in a marine sediment core from the northern Bay of Bengal includes Mg/Ca-based SST estimates, Ba/Ca-based mixed layer salinity estimates, and estimates of ice-volume corrected d18O of the mixed layer. The data are provide new insights into the control of Indian Summer Monsoon over the last 26,000 years, including a strong influence of zonal and meridional SST gradient changes within the tropical Indian Ocean on Indian Summer Monsoon variability.

Description: This dataset includes the results of the analysis of a marine sediment downcore record recovered from the Labrador Sea: core MD99-2227 (58° 12.38 N, 48° 22.22 W, 3460 m). Analysis includes measurement of the radiogenic Nd isotope signatures in the authigenic Fe-Mn oxyhydroxide fraction of the bulk sediment (leachates) and of the totally dissolved residual silicate (detrital) as well as analysis of uncleaned foraminifera. The downcore records were sampled with resolution of about 1 kyr and cover roughly the last 33 ka.

Description: This dataset includes the results of the analysis of a marine sediment downcore record recovered from the Labrador Sea: core HU08-029-004 (61°27.49 N, 58°02.11 W, 2674 m). Analysis includes measurement of the radiogenic Nd isotope signatures in the authigenic Fe-Mn oxyhydroxide fraction of the bulk sediment (leachates) and of the totally dissolved residual silicate (detrital) as well as analysis of uncleaned foraminifera. The downcore records were sampled with resolution of about 1 kyr and cover roughly the last 33 ka.

Description: This dataset includes the results of the analysis of a marine sediment downcore record recovered from the Labrador Sea: HU84-030-021 (58°22.06 N, 57°30.42 W, 2853 m). Analysis includes measurement of the radiogenic Nd isotope signatures in the authigenic Fe-Mn oxyhydroxide fraction of the bulk sediment (leachates) and of the totally dissolved residual silicate (detrital) as well as analysis of uncleaned foraminifera. The downcore records were sampled with resolution of about 1 kyr and cover roughly the last 33 ka.

Description: This dataset includes the results of the analysis of a marine sediment downcore record recovered from the Labrador Sea: core HU91-045-094 (50°12.26 N, 45°41.14 W, 3448 m). Analysis includes measurement of the radiogenic Nd isotope signatures in the authigenic Fe-Mn oxyhydroxide fraction of the bulk sediment (leachates) and of the totally dissolved residual silicate (detrital) as well as analysis of uncleaned foraminifera. The downcore records were sampled with resolution of about 1 kyr and cover roughly the last 33 ka.