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This dataset contains CCN concentrations at five supersaturation levels, averaged to 1 min time resolution, measured during the year-long Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition from October 2019 to September 2020. The measurements were performed in the Swiss container on the D-deck of Research Vessel Polarstern, using the model CCN-100 from Droplet Measurement Technologies (DMT, Boulder, USA). Detailed description of the measurement principle can be found in e.g. Roberts & Nenes (2005). The instrument was located behind an automated valve, which switched hourly between a total and an interstitial air inlet, with upper cutoff sizes of 40 and 1 µm respectively (Heutte et al., Submitted; Beck et al., 2022; Dada et al., 2022). The measurements were performed in 1-h cycles, with a 0.5 L/min sample flow and a 2 L/min make up flow, where the supersaturations 0.15, 0.2, 0.3, 0.5 and 1.0 % were measured. The supersaturation of 0.15 % is measured for 20 min, as it takes longer to equilibrate, and the remaining supersaturations were measured for 10 min each. The instrument was calibrated in July 2019 before the campaign, and in March and April 2020 during the campaign. Based on the inter-variability of the calculated supersaturation levels during these calibrations, we can expect values ranging from 0.15-0.20, 0.20-0.25, 0.29-0.33, 0.43-0.5, 0.78-1.0 % for the nominal supersaturations of 0.15, 0.2, 0.3, 0.5 and 1.0 %, respectively. The counting error for the CCNC is associated with the error in the optical counting of particles and is about 10 %. Data were removed during the cooling cycle (i.e., the time when the measurement cycle starts again and the temperature is cooled to set the lowest supersaturation), which corresponds roughly to the first 10 min of each hour (so 50 % of the 0.15 % supersaturation period). Additionally, the first minute of the transition between supersaturations was removed before averaging the data to 1 min time resolution. During some time periods, a difference pattern of mean and standard deviation of the measurements between even and odd hours was observed, most probably caused by a persistent pressure drop in the inlet lines, resulting in a proportional reduction of the concentration measurements. For correction, the 1-h arithmetic mean of interstitial inlet measurements and the mean of the two adjacent hours of total inlet measurements were subtracted, and the resulting difference was added as a constant to the data points of the interstitial inlet measurements. The dataset contains a pollution mask for local pollution (predominantly exhaust from the Research Vessel Polarstern) with 0 indicating clean, and 1 indicating polluted periods (Beck et al., 2022; Beck et al., 2022).

These datasets contain the total particle number concentrations and normalized size distributions (dN/dlogDp) of excited, fluorescent, and hyper-fluorescent particles of sizes 0.5 to 20 μm (optical diameter). The normalized size distribution datasets are split into 20 size bins: 0.5 - 0.6 μm, 0.6 - 0.72 μm, 0.72 - 0.87 μm, 0.87 - 1.05 μm, 1.05 - 1.26 μm, 1.26 - 1.51 μm, 1.51 - 1.82 μm, 1.82 - 2.19 μm, 2.19 - 2.63 μm, 2.63 - 3.16 μm, 3.16 - 3.8 μm, 3.8 - 4.57 μm, 4.57 - 5.5 μm, 5.5 - 6.61 μm, 6.61 - 7.95 μm, 7.95 - 9.56 μm, 9.56 - 11.50 μm, 11.5 - 13.83 μm, 13.83- 16.63 μm and 16.63 - 20 μm. The data were measured by a WIBS-NEO (Wideband Integrated Bioaerosol Sensor, model New Electronics option) by droplet measurement techniques ltd. The data were processed using the IGOR WIBS toolkit V1.36 (DMT) and python version 3.9.7. These datasets have been averaged to 1 hour time resolution. The datasets were cleaned from local pollution sources by applying a pollution flag developed by Beck et al. (2022a,b), which is based on the rate of change in particle number concentration with 1 min time resolution. Data points with more than 10 polluted minutes within an hour were removed from the WIBS datasets. Time periods with zero filter measurements and time periods with unstable flow that affected number concentrations have been removed from the dataset. The WIBS measures the size, asymmetry and fluorescence of particles with an optical diameter of 0.5 – 20 µm. Detected particles are excited by two UV flashlamps at wavelengths of 280 and 370 nm and their emitted fluorescence is measured by two photomultipliers with bandwidths of 310 - 400 nm, and 420 - 650 nm. The WIBS counts excited particles at a maximum frequency of 125 Hz, which corresponds to a maximum concentration of 2.5*104 particles/L with a sample flow of 0.3 L/min. Excited particles were classified as fluorescent if their fluorescent intensity exceeded the background intensity by three standard deviations (3σ) and as hyper-fluorescent if the fluorescent intensity exceeded the background intensity by 9σ. Excited particles with a lower fluorescent intensity were considered to be non-fluorescent. The background fluorescence was determined by measuring the fluorescent signal in the measurement chamber in absence of particles. Background measurements were performed every 26 h. The combination of two excitation wavelengths and two detector wavebands allows the classification of fluorescent particles into seven types: A, B, C, AB, AC, BC, and ABC (Perring et al. (2015); Savage et al. (2017)). For further information about the instrumental setup, refer to Heutte et al. (Submitted).

We present an age model for the 651 m deep Skytrain Ice Rise ice core (79°44.5'S, 78°32.7'W). The top 2000 years have previously been dated using age markers interpolated through annual layer counting. Below this, we align the Skytrain core to the AICC2012 age model using tie points in the ice and air phase, and apply the Paleochrono program to obtain the best fit to the tie points and glaciological constraints. In the gas phase, ties are made using methane and, in critical sections, δ18Oair; in the ice phase ties are through 10Be across the Laschamps Event, and through ice chemistry related to long-range dust transport and deposition. This strategy provides a good outcome to about 108 ka (~605 m). Beyond that there are signs of flow disturbance, with a section of ice probably repeated. Nonetheless values of CH4 and δ18Oair confirm that part of the last interglacial (LIG), from about 117-126 ka (617-628 m), is present and in chronological order. Below this there are clear signs of stratigraphic disturbance, with rapid oscillation of values in both the ice and gas phase at the base of the LIG section. Based on methane values, the warmest part of the LIG and the coldest part of the penultimate glacial are missing from our record. Ice below 631 m appears to be of age >150 ka.

This dataset contains relative abundance (%) of diatom species, and includes the Eucampia antarctica terminal/intercalary valve ratio (Eucampia index), biogenic silica and Si/Al values from core TAN1302-44, which was collected from the WEGA channel on the continental slope, offshore Adélie Land, East Antarctica. Diatoms were analysed at 10 cm, resolution within interval 350-5 cm-depth, while biogenic silica was analysed every 20 cm, and Si/Al (X-ray Flourescence scanning, XRF) comprises a 3-point average, from every 0.2 cm, of entire core. The data also includes four radiocarbon dates, calculated from 0 cm, 25 cm, 35 cm and 45 cm- depths; Shannon-Wiener biodiversity index based on all species identified, and principal component analysis based on species identified at >1.8% relative abundance (in at least two samples). The main purpose of this dataset compilation was to understand the distribution of species, and species assemblages. The interpretation of the data sets suggests changes in Antarctic sea ice and ocean circulation occured near the ice sheet, over the last glacial cycle. These changes are especially evident in the last glacial, and during the last deglacial (warming).

Stable isotope ratios from tree rings are important proxies of past climate variations. We have access to a calendar-dated wood material from wood collected at glacier forefields and peat bog sites located in the Alps. They are of two species, larch (Larix decidua) and cembran pine (Pinus cembra). All the wood samples were collected at high altitudes in the Swiss and Tyrol Alps, they cover the whole Holocene period and belong to the Eastern Alpine Conifer Chronology Dataset (Nicolussi et al., 2009; doi:10.1177/0959683609336565). We analysed the δ13C, δ18O and δ2H isotope ratios of alpha cellulose obtained from blocks of 5 annual rings from 203 trees. Cellulose was extracted following the modified Jayme-Wise method (Boettger et al., 2007; doi:10.1021/ac0700023). The isotopes values were determined using conventional Isotope Ratio Mass Spectrometry (Isoprime 100) coupled to a pyrolysis unit (HEKAtech GmbH, Germany), which is similar to the previously used TC/EA (for technical details see (Leuenberger 2007). This approach was extended to measurements of non-exchangeable hydrogen of alpha-cellulose using the on-line equilibration method (Filot et al., 2006 (doi:10.1002/rcm.2743); Loader et al., 2015(doi:10.1021/ac502557x)). The results are reported in per mil (‰) relative to the Vienna Pee Dee Belemnite (VPDB) for carbon and to Vienna Standard Mean Ocean Water (VSMOW) for hydrogen and oxygen (Coplen 1994; doi:10.1351/pac199466020273). For all the δ13C values after 1000 CE we applied the factor described in Leuenberger (2007; doi:10.1016/S1936-7961(07)01014-7) to correct for the δ13C depletion of CO2 caused by the Industrial Revolution from about 1850 onwards (Leuenberger, 2007).

This data set contains the age model and air-sea CO2 exchange tracer ([CO32-]as) of deep water core NEAP 4K and Intermediate water core GGC90. Seawater [CO32-]as is calculated following the approach in Yu et al. (2019). The Seawater [CO32-]as reconstructions at GGC90 are obtained based on [CO32-] and [PO43-] from Lacerra et al. (2019) and Umling et al. (2019), but these data have not yet been used to infer air-sea CO2 exchange histories. Importantly, building upon previous work (Lund et al., 2015), 23 new radiocarbon dates substantially improve the GGC90 age model. We present new deep-water [CO32-] and [PO43-] reconstructions at NEAP 4K using benthic foraminiferal B/Ca and Cd/Ca, respectively. The age model for NEAP 4K is based on 4 new and 13 published radiocarbon dates (Hall et al., 2004) and new Neogloboquadrina pachyderma (sinistral) coiling ratios. Based on the novel approach to reconstruct upper Atlantic air-sea CO2 exchange signatures, we provide evidence for a net release of CO2 via the Atlantic sector of the Southern Ocean, which contributes to the millennial atmospheric CO2 rise during Heinrich Stadial 1.

Micropaleontological (coccolith, planktonic foraminifera) and geochemical (CaCO3, CaXRF, δ18O N. pachyderma, δ13C N. pachyderma) analyses from sediment core MD04-2718 retrieved from the Subantarctic zone (SAZ) of the Indian Southern Ocean covering the time interval from Marine Isotope Stage (MIS) 12 to MIS 10 (440,000– 360,000 years). Coccolith abundances and masses were performed using SYRACO software at Geoscience Paris-Saclay Laboratory (GEOPS). CaCO3 percentages were also measured at GEOPS. Foraminifera abundances and masses and stable oxygen and carbon isotopes were performed at Laboratoire des Sciences du Climat et de l'Environnement (LSCE). SST were calculated using two methods : the Modern Analogue Technique (Haddam et al., 2016) and the percentage of N. pachyderma s. (Govin et al., 2009). CaXRF measurements were performed at ETH, Zurich. These approaches allowed to decipher the variations in Carbonate Counter Pump and upwelling strength in the Indian Sector of the Southern Ocean between MIS 12 and MIS 10, including the Termination V and interglacial MIS 11.

There is a growing need for past weather and climate data to support science and decision-making. This paper describes the compilation and the construction of a global multivariable (air temperature, pressure, precipitation sum, number of precipitation days) monthly instrumental climate database that encompasses a substantial body of the known early instrumental time series. The dataset contains series compiled from existing databases that start before 1890 (though continuing to the present) as well as a large amount of newly rescued data. All series underwent a quality control procedure and subdaily series were processed to monthly mean values. An inventory was compiled, and the collection was deduplicated based on coordinates and mutual correlations. The data are provided in a common format accompanied by the inventory. The collection totals 12452 meteorological records in 118 countries. The data has been merged from 18250 original data files. The data can be used for climate reconstructions and analyses. It is the most comprehensive global monthly climate data set for the preindustrial period.

This archive contains raw data, intermediate and final results for the morphometric investigation of menardiform globorotallids (planktonic foraminifera) from ODP Hole 667A (Sierra Leone Rise in the eastern equatorial Atlantic Ocean; Lat: 4.569167°N, Lon: -21.911333°E ) from 33 stratigraphic levels during the past 8 million years. Complementary to previous investigations about the evolution in the Neogene Globorotalia menardii-G. limbata-G. multicamerata lineage from DSDP Holes 502 and 503, ODP Hole 925B and Hole 806C by Knappertsbusch, these data were collected to investigate the tempo and mode of evolution of the shell (=test) morphology and speciation. This dataset comprises digital images and morphometric measurements, as well as software (codes) needed to process the data according to the processing given in Friesenhagen (2022). Unpacked, the dataset has a size of 6.4 Gb (~66.500 files). The measured morphometric parameter of 6719 specimens incorporate, amongst others, the spiral height, axial length, the test area, the spiral and umbilical convexity, and the radii of the osculating circles of the upper and the lower keel region of the test in keel view. A subset of the data used in the study, their statistical treatment and illustrations of these are given alongside the publication as an electronic supplementary. The measured specimens, samples and their residuals are deposited in the micropalaeontological reference collection at the Natural History Museum Basel.

These sedimentological and geochemical analyses were carried out on three on-mound cold-water coral mound cores (MD13-3455G, MD13-3459G and MD13-3462G) recovered in the East Melilla Coral Province (Southeast Alboran Sea, Mediterranean Sea) during the EUROFLEETS cruise MD194 “Gateway” on board the RV Marion Dufresne II in June 2013. The time period of the studied core sections covers the last 15 ky and offers a high-resolution temporal record of the Bølling–Allerød interstadial. The core sites are situated approximately 1 km apart on the crest of Brittlestar Ridge I (35°26.087'N, 2°30.100'W). More precisely, the three datasets presented here correspond to: (1) particle size analysis results determined on the siliciclastic fraction using the Malvern Mastersizer 3000 at the Department of Geology at Ghent University. These analyses were carried out in order to quantify important changes in sediment flux and bottom current velocity. (2) Scanning X-ray fluorescence (XRF) was carried out using the Itrax high-resolution XRF core scanner at the Institute of Geological Sciences, University of Bern, to measure relative element concentration changes in the sediments of the cold-water coral mounds; whereas (3) RockEval6 pyrolysis was carried out at the Laboratory of Sediment Geochemistry at the University of Lausanne (Switzerland) to characterize the organic carbon content of the mound sediments