ALBERT

Description: Drillhole-determined sea-ice thickness was compared with values derived remotely using a portable small-offset loop-loop steady state electromagnetic (EM) induction device during expeditions to Fram Strait and the Siberian Arctic, under typical winter and summer conditions. Simple empirical transformation equations are derived to convert measured apparent conductivity into ice thickness. Despite the extreme seasonal differences in sea-ice properties as revealed by ice core analysis, the transformation equations vary little for winter and summer. Thus, the EM induction technique operated on the ice surface in the horizontal dipole mode yields accurate results within 5 to 10% of the drillhole determined thickness over level ice in both seasons. The robustness of the induction method with respect to seasonal extremes is attributed to the low salinity of brine or meltwater filling the extensive pore space in summer. Thus, the average bulk ice conductivity for summer multiyear sea ice derived according to Archie's law amounts to 23 mS/m compared to 3 mS/m for winter conditions. These mean conductivities cause only minor differences in the EM response, as is shown by means of 1-D modeling. However, under summer conditions the range of ice conductivities is wider. Along with the widespread occurrence of surface melt ponds and freshwater lenses underneath the ice, this causes greater scatter in the apparent conductivity/ice thickness relation. This can result in higher deviations between EM-derived and drillhole determined thicknesses in summer than in winter.

Description: Late-summer thickness distributions of large ice floes in the Transpolar Drift between Svalbard and the North Pole in 1991, 1996, 1998, and 2001 are compared. They have been derived from drilling and electromagnetic (EM) sounding. Results show a strong interannual variability, with significantly reduced thickness in 1998 and 2001. The mean thickness decreased by 22.5% from 3.11 m in 1991 to 2.41 m in 2001, and the modal thickness by 22% from 2.50 m in 1991 to 1.95 m in 2001. Since modal thickness represents the thickness of level ice, the observed thinning reflects changes in thermodynamic conditions. Together with additional data from the Laptev Sea obtained in 1993, 1995, and 1996, results are in surprising agreement with recently published thickness anomalies retrieved from satellite radar altimetry for Arctic regions south of 81.5°N. This points to a strong sensitivity of radar altimetry data to level ice thickness.

Description: As part of the large-scale, interdisciplinary deep-sea study "BIGSET", the relationship between the monsoon-induced regional and temporal variability of POC deposition and the small-sized benthic community was investigated at several sites 2316-4420 m deep in the Arabian Sea during four cruises between 1995 and 1998. Vertical and horizontal distribution patterns of chloroplastic pigments (a measure of phytodetritus deposition), readily soluble protein and activity, and biomass parameters of the small-sized benthic community (Electron Transport System Activity (ETSA); bacterial ectoenzymatic activity (FDA turnover) and DNA concentrations) were measured concurrently with the vertical fluxes of POC and chloroplastic pigments. Sediment chlorophyll a (chl. a) profiles were used to calculate chl. a flux rates and to estimate POC flux across the sediment water interface using two different transport reaction models. These estimates were compared with corresponding flux rates determined in sediment traps. Regional variability of primary productivity and POC deposition at the deep-sea floor creates a trophic gradient in the Arabian Basin from the NW to the SE, which is primarily related to the activity of monsoon winds and processes associated with the topography of the Arabian Basin and the vicinity of land masses. Inventories of sediment chloroplastic pigments closely corresponded to this trophic gradient. For ETSA, FDA and DNA, however, no clear coupling was found, although stations WAST (western Arabian Sea) and NAST (northern Arabian Sea) were characterised by high concentrations and activities. These parameters exhibited high spatial and temporal variability, making it impossible to recognise clear mechanisms controlling temporal and spatial community patterns of the small-sized benthic biota. Nevertheless, the entire Arabian Basin was recognised as being affected by monsoonal activity. Comparison of two different transport reaction models indicates that labile chl. a buried in deeper sediment layers may escape rapid degradation in Arabian deep-sea sediments.

Description: The distribution, biomass, and diversity of living (Rose Bengal stained) deep-sea benthic foraminifera (〉30 µm) were investigated with multicorer samples from seven stations in the Arabian Sea during the intermonsoonal periods in March and in September/October, 1995. Water depths of the stations ranged between 1916 and 4425 m. The distribution of benthic foraminifera was compared with dissolved oxygen, % organic carbon, % calcium carbonate, ammonium, % silica, chloroplastic pigment equivalents, sand content, pore water content of the sediment, and organic carbon flux to explain the foraminiferal patterns and depositional environments. A total of six species-communities comprising 178 living species were identified by principal component analysis. The seasonal comparison shows that at the western stations foraminiferal abundance and biomass were higher during the Spring Intermonsoon than during the Fall Intermonsoon. The regional comparison indicates a distinct gradient in abundance, biomass, and diversity from west to east, and for biomass from north to south. Highest values are recorded in the western part of the Arabian Sea, where the influence of coastal and offshore upwelling are responsible for high carbon fluxes. Estimated total biomass of living benthic foraminifera integrated for the upper 5 cm of the sediment ranged between 11 mg Corg m**-2 at the southern station and 420 mg Corg m**-2 at the western station. Foraminifera in the size range from 30 to 125 ?m, the so-called microforaminifera, contributed between 20 and 65% to the abundance, but only 3% to 28% to the biomass of the fauna. Highest values were found in the central and southern Arabian Sea, indicating their importance in oligotrophic deep-sea areas. The overall abundance of benthic foraminifera is positively correlated with oxygen content and pore volume, and partly with carbon content and chloroplastic pigment equivalents of the sediment. The distributional patterns of the communities seem to be controlled by sand fraction, dissolved oxygen, calcium carbonate and organic carbon content of the sediment, but the critical variables are of different significance for each community.

Description: Assemblages of living deep-sea benthic foraminifera, their densities, vertical distribution pattern, and diversity, were investigated in the intermonsoon period after the northeast monsoon in the Arabian Sea in spring 1997. Foraminiferal numbers show a distinct gradient from north to south, with a maximum of 623 foraminifera in 50 cm**3 at the northern site. High percentages of small foraminifera were found in the western and northern part of the Arabian Sea. Most stations show a typical vertical distribution with a maximum in the first centimeter and decreasing numbers with increasing sediment depths. But at the central station, high densities can be found even in deeper sediment layers. Diversity is very high at the northern and western sites, but reduced at the central and southern stations. Data and faunal assemblages were compared with studies carried out in 1995. A principal component analysis of intermonsoon assemblages shows that the living benthic foraminifera can be characterized by five principal component communities. Dominant communities influencing each site differ strongly between the two years. In spring 1997, stations in the north, west and central Arabian Sea were dominated by opportunistic species, indicating the influence of fresh sedimentation pulses or enhanced organic carbon fluxes after the northeast monsoon.

Description: Sediments from the western and southern part of the Arabian Sea were collected periodically in the spring intermonsoon between March and May 1997 and additionally at the end of the Northeast Monsoon in February 1998. Assemblages of Rose Bengal stained, living deep-sea benthic foraminifera, their densities, vertical distribution pattern, and diversity were analysed after the Northeast Monsoon and short-time changes were recorded. In the western Arabian Sea, foraminiferal numbers increased steadily between March and the beginning of May, especially in the smaller size classes (30-63 µm, 63-125 µm). At the same time, the deepening of the foraminiferal living horizon, variable diversity and rapid variations between dominant foraminiferal communities were observed. We interpret these observations as the time-dependent response of benthic foraminifera to enhanced organic carbon fluxes during and after the Northeast Monsoon. In the southern Arabian Sea, constant low foraminiferal abundances during time, no distinctive change in the vertical distribution, reduced diversity, and more stable foraminiferal communities were noticed, which indicates no or little influence of the Northeast Monsoon to benthic foraminifera in this region.

Description: Benthic fluxes and pore-water compositions of silicic acid, nitrate and phosphate were investigated for surface sediments of the abyssal Arabian Sea during four cruises (1995-1998). Five sites located in the northern (NAST), western (WAST), central (CAST), eastern (EAST), and southern (SAST) Arabian Sea were revisited during intermonsoonal periods after the NE- and SW-Monsoon. At these sites, benthic fluxes of remineralized nutrients from the sediment to the bottom water of 36-106, 102-350 and 4-16 mmol/m**2/yr were measured for nitrate, silicic acid and phosphate, respectively. The benthic fluxes and pore-water compositions showed a distinct regional pattern. Highest fluxes were observed in the western and northern region of the Arabian Sea, whereas decreasing fluxes were derived towards the southeast. At WAST, the general temporal pattern of primary production, related to the NE- and SW-Monsoon, is reflected by benthic fluxes. In contrast, at sites NAST, SAST, CAST, and EAST a temporal pattern of fluxes in response to the monsoon is not obvious. Our results reveal a clear coupling between the general regional pattern of production in surface waters and the response of the benthic environment, as indicated by the flux of remineralized nutrients, though a spatially differing degree of decoupling during transport and remineralization of particulate organic matter and biogenic opal was observed. This has to be taken into account regarding budget calculations and paleoceanographic topics.

Description: Eight different sites from 2300 to 4420 m water depth in the Arabian Sea were sampled for a biochemical quantification of phospholipid concentrations in the sediments. This method serves as a measure of microbial biomass in marine sediments comprising all small-sized organisms, including bacteria, fungi, protozoa and metazoa. Phospholipid concentrations can be converted to carbon units as an estimate of total microbial biomass in the sediments. The average phospholipid concentrations in the surface sediments (0–1 cm) of the 4 abyssal sites ranged from 7 nmol cm?3 at the southern site (SAST, 10°N 65°E, 4425 m) to 29 nmol/cm**3 at the western site (WAST, 16°N 60°E, 4045 m). The high values detected at the abyssal station WAST exceeded those in the literature for other abyssal sites and were comparable to values from the upper continental slope of the NE-Atlantic and the Arctic. At the four continental slope sites in the Arabian Sea, average phospholipid concentrations ranged from 9 to 53 nmol/cm**3 with the maximum values at stations A (2314 m) and D (3142 m) close to the Omani coast. Records of particulate organic carbon flux to the deep sea are available for four of the investigated locations, allowing a test of the hypothesis that the standing stock of benthic microorganisms in the deep sea is controlled by substrate availability, i.e. particle sedimentation. Total microbial biomass in the surface sediments of the Arabian Sea was positively correlated with sedimentation rates, consistent with previous studies of other oceans. The use of the measurement of phospholipid concentrations as a proxy for input of particulate organic matter is discussed.

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: Atmospheric and oceanographic interactions between the Atlantic and Indian Oceans influence upwelling in the southern Benguela upwelling system. In order to obtain a better knowledge of paleoceanographic and paleoenvironmental changes in the southern Benguela region during the Holocene, 12 marine surface sediment samples and one gravity core GeoB8331-4 from the Namaqualand mudbelt off the west coast of South Africa have been studied for organic-walled dinoflagellate cysts in high temporal resolution. The results are compared with pollen and geochemical records from the same samples. Our study emphasizes significantly distinct histories in upwelling intensity as well as the influence of fluvial input during the Holocene. Three main phases were identified for the Holocene. High percentages of cysts produced by autotrophic taxa like Operculodinium centrocarpum and Spiniferites spp. indicate warmer and stratified conditions during the early Holocene (9900-8400 cal. yr BP), suggesting reduced upwelling likely due to a northward shift of the southern westerlies. In contrast, the middle Holocene (8400-3100 cal. yr BP) is characterized by a strong increase in heterotrophic taxa in particular Lejeunecysta paratenella and Echinidinium spp. at the expense of autotrophic taxa. This indicates cool and nutrient-rich waters with active upwelling probably caused by a southward shift of the southern westerlies. During the late Holocene (3100 cal. yr BP to modern), Brigantedinium spp. and other abundant taxa interpreted to indicate fluvial nutrient input such as cyst of Protoperidinium americanum and Lejeunecysta oliva imply strong river discharge with high nutrient supply between 3100 and 640 cal. yr BP.

Description: Downcore measurements of SiO2 and 231Pa/230Th on sediment cores from the New Zaland Margin and the East Pacific Rise. The sediment cores were collected during expedtions PS75 (2010) and SO213 (2011). Our downcore records cover the last ~35 ka. SiO2 measurements were conducted to analyze a potential impact on opal on our 231Pa/230Th ratios, that in turn were used to reconstruct past changes in South Pacific Overtruning Circulation. Opal measurements followed the method of Müller and Schneider 1993. The concentrations of sedimentary 231Pa, 238U, 230Th, and 232Th were jointly measured by isotope dilution in a co-operation between AWI and Heidelberg University with contributions from the GEOMAR Kiel and using mass spectrometers at the AWI (Element 2), Heidelberg (Element 2, Neptune, iCap) and Kiel (Neptune).

Description: Airborne and dissolved water PCB congener specific concentrations from southern Lake Michigan 2010. The data were used to estimated instantaneous air-water PCB fluxes.

Description: Southwest Africa is an important region for paleo-climatic studies, being influenced by both tropical and temperate climate systems and thus reflecting the interplay of variable controls. The aim of this study was to unravel the interaction of sea-surface temperature (SST) changes in the southernmost Benguela upwelling system with precipitation changes in South Africa's winter rainfall zone (WRZ) during the late Holocene. Therefore, a marine sediment core from the southernmost Benguela upwelling system was investigated to reconstruct climate changes in this region for the past ~2000 years. Grain size and geochemical analyses were conducted to reconstruct changes in fluvial sediment discharge and weathering intensity, while SST changes were estimated using alkenone paleo-thermometry. Results show that the southernmost Benguela behaves distinctly in comparison with the rest of the Benguela system reflecting amplified SST changes. Decreasing SSTs accompanied increasing river discharge during times of increased precipitation in the WRZ, reflecting northerly shifted westerly winds during austral winter. We infer a control of past SST changes by processes not analogous to modern processes driving seasonal SST changes by changes through upwelling intensity. The findings suggest that late-Holocene SST changes in the southernmost Benguela upwelling system and the precipitation in the WRZ were both driven by latitudinal shifts of the austral westerly wind belt and associated changes in advection of cold sub-Antarctic waters and/or changes in Agulhas leakage of warm Indian Ocean waters.

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: In paleoenvironmental studies, the mineralogical composition of sediments is an important indicator. In combination with other indicators, they contribute to the understanding of changes in sediment sourcing as well as in weathering and depositional processes. Fourier transform infrared spectroscopy (FTIRS) spectra contain information on mineralogical composition because each mineral has a unique absorption pattern in the mid-IR range. Although easily obtained, FTIR spectra are often too complex to infer mineral concentrations directly. In this study, we use a calibration set of ca. 200 sediment samples conventionally measured using X-ray diffraction (XRD) in order to develop multivariate, partial least squares (PLS) regression models relating mineral contents to sediment spectra. Good correlations were obtained for the most common minerals (e.g. quartz, K-feldspar, illite, plagioclase, smectite, calcite). Correlation coefficients ranged from 0.85 to 0.92, coefficients for the validation varied from 0.64 to 0.80, the number of latent variables (PLS regression components) in the models ranged between 3 and 7 and the range of variation of the RMSEcv gradient was from 15.28 to 5.7.

Description: Thermokarst lakes cover nearly one fourth of ice-rich permafrost lowlands in the Arctic. Sediments from an athalassic subsaline thermokarst lake on Herschel Island (69°36'N; 139°04'W, Canadian Arctic) were used to understand regional changes in climate and in sediment transport, hydrology, nutrient availability and permafrost disturbance. The sediment record spans the last ~11,700 years and the basal date is in good agreement with the Holocene onset of thermokarst initiation in the region. Electrical conductivity in pore water continuously decreases, thus indicating desalinization and continuous increase of lake size and water level. The inc/coh ratio of XRF scans provides a high-resolution organic-carbon proxy which correlates with TOC measurements. XRF-derived Mn/Fe ratios indicate aerobic versus anaerobic conditions which moderate the preservation potential of organic matter in lake sediments. The coexistence of marine, brackish and freshwater ostracods and foraminifera is explained by (1) oligohaline to mesohaline water chemistry of the past lake and (2) redeposition of Pleistocene specimens found within upthrusted marine sediments around the lake. Episodes of catchment disturbance are identified when calcareous fossils and allochthonous material were transported into the lake by thermokarst processes such as active-layer detachments, slumping and erosion of ice-rich shores. The pollen record does not show major variations and the pollen-based climate record does not match well with other summer air temperature reconstructions from this region. Local vegetation patterns in small catchments are strongly linked to morphology and sub-surface permafrost conditions rather than to climate. Multidisciplinary studies can identify the onset and life cycle of thermokarst lakes as they play a crucial role in Arctic freshwater ecosystems and in the global carbon cycle of the past, present and future.

Description: This study investigates Holocene sediments from Eilandvlei, a coastal lake located within the Wilderness embayment at the southern Cape coast of South Africa. The evolution of the present estuarine/coastal lake system is reconstructed based on seismic data as well as a multi-proxy approach on a 30.5 m sediment core spanning the last ~8.9 kyr. Geochemical (Ca, TOC/S, Br/TOC) and micropalaeontological data (diatoms, foraminifera) reflect changes in the degree of marine influence at the core site. The embayment likely developed via distinct phases of connectivity to the Indian Ocean caused by sea level changes and dune progradation. Marine conditions prevailed at the core site from ~8900 to 4700 cal BP. The rapid sea level rise during the early Holocene caused the inundation of a palaeovalley that most likely had formed at lower sea levels during the Pleistocene. Towards the mid-Holocene the sea level exceeded its present height around ~7500 cal BP creating a marine embayment. At ~4700 cal BP, the embayment became distinctly more disconnected from the ocean turning into a lagoon system that persisted until ~1200 cal BP. Subsequently, the marine influence further decreased and the present estuarine/coastal lake system was established. Grain size and geochemical data (Fe, Si/Al, chemical index of alteration (CIA)) further reflect changes in the deposition of terrigenous sediments at the core site. While the sedimentation of fine-grained (〈16 µm), iron-rich and highly weathered material is linked to periods of increased river discharge and rainfall, high amounts of deposited quartz (31-250 µm, high Si/Al) point to relatively dry and/or windy conditions during which increased aeolian transport of dune sands occurred. The proxies indicate reduced river discharge and hence possibly drier climatic conditions than today from ~8900 to 7900 cal BP and ~6400 to 3000 cal BP. In contrast, the periods between ~7900-6400 cal BP and ~3000 cal BP-present were likely characterized by high river discharge and thus, generally more rainfall. The reconstructed palaeoclimatic variations are discussed within the context of e.g., shifts in the position of the Antarctic sea ice extent and the mid-latitude westerly wind belt as well as changes in the El Niño-Southern Oscillation (ENSO).

Description: Pollen records from Siberia are mostly absent in global or Northern Hemisphere synthesis works. Here we present a taxonomically harmonized and temporally standardized pollen dataset that was synthesized using 173 palynological records from Siberia and adjacent areas (northeast Asia, 50°180°E and 42°75°N). Pollen data were taxonomically harmonized, that is the original 437 taxa were transformed to 106 combined pollen taxa. Age-depth models for all records were revised by applying a constant Bayesian age-depth modelling routine. The pollen dataset is available as count data and percentage data in a table format (taxa vs. samples) with age information for each sample. The dataset has relatively few sites covering the last glacial period between 40 and 11.5 cal ka BP (calibrated thousand years before present 1950 CE) particularly from the central and western part of the study area. In the Holocene period, the dataset has many sites from most of the area except the central part of Siberia. Of the 173 pollen records, 81% of pollen counts were downloaded from open databases (GPD, EPD, Pangaea) and 10% were contributions of the original data gatherers, while a few were digitized from publications. Most of the pollen records originate from peatlands (48%) and lake sediments (33%). Most of the records (83%) have ≥3 dates allowing the establishment of reliable chronologies. The dataset can be used for various purposes including pollen data mapping (example maps for Larix at selected time-slices are shown) as well as quantitative climate and vegetation reconstructions.

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.

Description: We integrate benthic foraminiferal δ18O data, X-ray fluorescence (XRF) scanner-derived elemental data, light reflectance spectroscopy and spectral gamma ray records from IODP Site U1483 (13°5.24'S, 121°48.25'E; 1733 m water depth) in the Timor Sea off NW Australia to monitor secular variations in terrigenous river discharge, productivity and bottom water oxygenation and to investigate the primary drivers of the Australian Monsoon's evolution between 1.6 and 0.4 Ma.

Description: The goal of this project was to provide the first estimates of blue carbon stocks and carbon accumulation rates in the high and low marsh zones of salt marshes from the Pacific Coast of Canada, within the Clayoquot Sound UNESCO Biosphere Reserve and Pacific Rim National Park Reserve on the Pacific Coast of Canada. To achieve this goal, 34 sediment cores were collected from seven salt marshes during summer (June-September) 2016. At each core site, marsh zone (high vs low) was determined using vegetation types surrounding the core site. Sediment cores were then collected using a simple percussion coring technique in which a length of two-inch (57 mm) diameter, PVC vacuum tubing fitted with a plastic core catcher (AMS Inc.) was hammered into the ground until the depth of refusal. At the GBK location, a steel sledge corer (AMS Inc.) was used to extract four cores before mechanical problems required switching to the simpler percussion method. For all sites, we recorded the deepest sediment depth at which peat was found (referred to as the "Peat Base"), as well as the sediment type at the base of each core. On all 34 cores, we measured core compaction, dry bulk density, % loss-on-ignition, and % organic carbon (using an elemental analyzer, on select number of samples). From these parameters we estimated % organic carbon (using a regression equation between % organic carbon and %LOI), soil carbon density, and carbon stocks measured to (a) the depth of the basal peat layer, (b) a depth of 20 cm, and (c) to the depth of the 30-year horizon (estimated in the 8 cores where 210Pb analysis was completed). Radioisotope (210Pb and 226Ra) measurements were conducted on 8 cores (4 from high marsh zone and 4 from low marsh zone) from marshes CBE, CRF, GBK, and TMF, to create age models for estimating carbon accumulation rates. This research was funded by a grant from the Commission for Environmental Cooperation to KEK, a Natural Sciences and Engineering Research Council [Discovery Grant RGPIN342251] to KEK; and Natural Sciences and Engineering Research Council Canada Research Chair Award to KEK. It received substantial in-kind field and laboratory support from Parks Canada (MGP).

Description: This data collection comprises environmental data and taxonomic parameters of the investigated biocrusts of sampling sites in coastal and inland sand dunes in northern Germany. Sampling took place in spring 2020 and winter 2021. Biocrusts and uppermost sediment samples were collected along dune successional gradients and sequenced by LGC Genomics Ltd. Corresponding sequence data of biocrust organisms are archived at the European Nucleotide Archive.

Description: We investigated the effects of soil management on plant diversity, vegetation cover, soil parameters, bacterial and fungal diversity, and soil functions (soil respiration and decomposition of two different substrates) using a balanced experimental design covering nine vineyards in Rhine-Hesse, Germany. In all vineyards, we applied four soil management types: complete cover, herbal seed mixture cover, alternating tillage, and complete tillage. Plots were installed in 2015. Data acquisition was done in 2016 and 2017, except for soil respiration, which was only measured in 2016. Plant diversity and vegetation cover were assessed in the field. Soil parameters (C and N, pH, P, K, Mg, Cu) were measured using standard methods. Soil bacterial and fungal diversity was assessed using DNA extraction and Illumina sequencing. The Shannon Diversity Index based on bacterial and fungal OTUs was used as a metric for diversity. Basal soil respiration rate was measured by oxygen consumption using a customized respirometer in the lab. Litter decomposition was measured in the field over a period of 90 days by using the Tea Bag Index method, which applies standardized tea types as organic material.

Description: We present high-resolution measurements of CO mixing ratios from ice cores drilled at five different sites on the Greenland ice sheet. An optical-feedback cavity-enhanced absorption spectrometer (OF-CEAS) was coupled with continuous melter systems and operated during four analytical campaigns conducted between 2013 and 2019 at the Desert Research Institute (DRI, USA) and the Institut des Géoscience de l'Environnement (IGE, France). The CFA-based CO measurements exhibit excellent external precision (ranging from 3.3 to 6.6 ppbv, 1 sigma) and achieve consistently low blanks (ranging from 4.1 +/- 1.2 to 12.6 +/- 4.4 ppbv), enabling paleoatmospheric interpretations. Consistent baseline CO records from four Greenlandic sites (PLACE, D4, NGRIP, and NEEM) are combined to produce a multisite average ice core reconstruction of past atmospheric CO for the Northern Hemisphere high latitudes, covering the period from 1700 to 1957 CE. Such a reconstruction should be taken as an upper bound of past atmospheric CO abundance.

Description: This data set displays a refined age scale for the U1361A marine sediment core (64.41°S, 143.89°E, 3,454 m water depth), recovered from the continental rise offshore of the Wilkes Subglacial Basin, during the Integrated Ocean Drilling Program (IODP) Expedition (Escutia et al. 2011). This age scale is a refined version of the age scale published in Wilson et al. 2018. Here we use the AICC2012 ice core chronology as a reference curve in order to compare the late Pleistocene sediment core data from U1361A to the TALDICE ice core record. Specifically, we refine the existing U1361A age model through the alignment of barium/aluminium (Ba/Al) ratios from XRF-scanning7 with the EDC δD record on the AICC2012 age scale. We apply a conservative tuning strategy to align the two records, using tie points (derived by visual matching) only at the mid-points of the major glacial terminations I-V. Over the interval of interest for the present study (i.e. ~100-350 ka), the new age model for core U1361 differs by only 0 to 6 ka compared to the previous age model in which the sedimentation rate was assumed to be constant. The Nd and IBRD (ice rafted debris) and 143 Nd/144 Nd records for the U1361A published in Wilson et al. (2018) are drawn on the refined age scale.

Description: The datasets compile Ba/Ca (µmol/mol), Mg/Ca (mmol/mol), δ18O (VPDB, ‰), and δ13C (VPDB, ‰) measured in individual and bulk shells of spinose planktic foraminifera Trilobatus sacculifer and non-spinose planktic foraminifera Neogloboquadrina dutertrei and Pulleniatina obliquiloculata collected from two cores on the Ontong Java Plateau (OJP) and two cores from the Eastern Equatorial Pacific (EEP). Trace elements in individual shells are measured with a laser ablation inductively coupled plasma mass spectrometer (ICP-MS) and trace elements in bulk shells are measured with a solution ICP-MS. Stable isotope analysis is conducted on paired individual shells (paired based on Mg/Ca content) with an isotope ratio mass spectrometer. ID denotes which individual shells are paired for the analysis.

Description: Empirical study of the isotopic features of river runoff were carried out at three hydrological posts in 3 different river basins: the Zakza river in the southwest of the Moscow region, the Dubna river in the north of the Moscow region and the Sosna river in the Voronezh region. Samples of river water, groundwater and precipitation were collected at weekly intervals from September 2019 to October 2021. The analysis was performed by a Picarro L2130-i isotope analyzer. The accuracy was 0.04‰ for δ18О and 0.1‰ for δ2Н. The values are calibrated in the VSMOW-VSLAP scale.

Description: To test polyhalite age dating of the mineral polyhalite [K2Ca2Mg(SO4)4·2H2O], samples of the evaporitic Permian Haselgebirge Formation were collected in the Eastern Alps. Samples were taken from two salt bodies. The salt body of Altaussee (UTM 33T 405316 5278325) has a vertical thickness of 〉800 m. Samples were collected in the Altaussee mine (ALT). The salt body of Bad Dürrnberg-Berchtesgaden (UTM 33T 351091 5278007) is at least 1000 m thick. The salt body comprises two separate mines, where samples were collected, Bad Dürrnberg (DÜ) and Berchtesgaden (BGD) salt mines. The samples were collected during several field trips, and investigated at the University of Salzburg during the years 2007-2015. Electron microprobe analyses were conducted to determine possible chemical variations of polyhalite.

Description: The data here described are presented in the submitted paper Response of the Wilkes Subglacial Basin Ice Sheet to Southern Ocean Warming During Late Pleistocene Interglacials by Crotti et al. This data set includes new high resolution measurements of d-excess, d18O and ssNa+ for the Antarctic TALDICE ice core (Latitude: -72.783330, Longitude: 159.066670, Elevation: 2315.0 m). The new data set covers the interglacials periods of MIS 5.5, MIS 7.5 and MIS 9.3 (1486 m depth - 1548 m depth). The data are drawn on the TALDICE deep1 chronology (Crotti et al. 2021). The d-excess (d = δD − 8 × δ18O) (permill) record covers the periods MIS 5.5 , MIS 7.5 and 9.3 MIS is at 5 cm resolution and spans the following age-depths intervals: • MIS 5.5. Between 1378.5 and 1421.65 m depth, 110-135 ka • MIS 7.5. Between 1521.85 and 1524.5 m depth, 243-248 ka • MIS 9.3. Between 1541.80 and 1547.90 m depth, 320-343 ka The d18O record (permill) covers the periods MIS 5.5 , MIS 7.5 and 9.3 MIS is at 5 cm resolution and spans the following age-depths intervals: • MIS 7.5. Between 1521.85 and 1524.5 m depth, 243-248 ka • MIS 9.3. Between 1541.80 and 1547.90 m depth, 320-343 ka The ssNa+ fluxes record covers the periods MIS 5.5 , MIS 7.5 and 9.3 MIS is at 8 cm resolution and pans the following age-depths intervals: • MIS 7.5. Between 1521.81 and 1524.54 m depth, 243-248 ka • MIS 9.3. Between 1541.73 and 1547.96 m depth, 320-343 ka The d18O and dD (non presented here) to calculate the d-excess were analysed in Italy (University of Venice) and France (LSCE) using the Cavity Ring Down Spectroscopy (CRDS) technique. Analyses were performed using a Picarro isotope water analyser (L2130-i version for both laboratories). The data were calibrated using a three-point linear calibration with three lab-standards that were themselves calibrated versus Standard Mean Ocean Water (SMOW). The average precision for the δ18O and δD measurements is 0.1 and 0.7 ‰, respectively. The concentrations of ssNa+ were measured on TALDICE ice samples at 8 cm resolution by classical ion chromatography on discrete samples collected using a melting device connected to an auto-sampler for the MIS 7.5 and MIS 9.3 whereas Continuous Flow Analysis (CFA) was applied for MIS 5.5 samples. The total deposition ssNa+ flux was calculated multiplying the measured ice concentration of ssNa+ by the reconstructed accumulation rate. The accumulation rates were derived from the accumulation rates were obtained from the TALDICE deep1 age scale (Crotti et al. 2021).

Description: Identification of advancing and retreating modes in fossil orogenic belts is not always straightforward. Such issue is addressed in the submitted paper via the case study of the northwestern Chinese Altai where the suprasubduction structures are well preserved. Combined with detailed mapping, structural/petrological observations, seven samples were collected from the key lithological units of Jiadengyu and Chonghuer region in the Xinjiang Uygur Autonomous Region for zircon and monazite U-Pb dating to provide critical geochronological constraints on the individual deformational episodes, including two zircon samples (19CA36 and 17CA105-7) and five monazite samples (17CA107, 17CA105-4, 19CA41, 19CA45-1, and 19CA45-3). Migmatite samples 19CA41 and 17CA107 are characterized by sub-horizontal S1 foliations associated with extensional shear bands. Sample 19CA45-1 collected from the migmatitic Habahe Group domain shows nearly complete transposition of S1 foliation by S2 fabric. Samples 19CA36 and 19CA105-7 were collected from syn-D2 granite intrusions. Leucogranite dyke (sample 17CA105-4) and pegmatite (sample 19CA45-3) were emplaced as tensional fractures that formed in response to D2 shortening. Zircon and monazite grains were separated after rock crushing using conventional heavy liquid and magnetic properties and then selected under a binocular microscope. These grains were mounted in epoxy resin, polished to approximately one-third of their thickness. U-Pb dating of zircon and monazite were analyzed by LA-ICP-MS at the Wuhan SampleSolution Analytical Technology Co., Ltd. U-Pb dating of zircon samples were conducted by a COMPexPro 102 ArF excimer laser and a MicroLas optical system coupled with an Agilent 7700e ICP-MS. Most analyses were performed with a beam diameter and frequency of 32 μm and 5 Hz. GJ-1 standard zircon was also determined for monitoring the accuracy of U-Pb dating. Zircon 91500 was used as an external standard for U-Pb dating calibration. U-Pb dating of monazite samples was performed using the same operating processes and instruments. In this work, the spot size and frequency of the laser were set to 16 μm and 2 Hz, respectively. Monazite standard 44069 was used as an external standard for U-Pb dating. Monazite standard Trebilcock was used as a secondary standard to assess the accuracy of analyses. Each analysis of zircon/monazite was performed using a background acquisition of approximately 25 s followed by 65 s of data acquisition.

Description: We present sea ice temperature and salinity data from first-year ice (FYI) and second-year ice (SYI) relevant to the temporal development of sea ice permeability and brine drainage efficiency from the early growth phase in October 2019 to the onset of spring warming in May 2020. Our dataset was collected in the central Arctic Ocean during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) Expedition in 2019 to 2020. MOSAiC was an international transpolar drift expedition in which the German icebreaker RV Polarstern anchored into an ice floe to gain new insights into Arctic climate over a full annual cycle. In October 2019, RV Polarstern moored to an ice floe in the Siberian sector of the Arctic at 85 degrees north and 137 degrees east to begin the drift towards the North Pole and the Fram Strait via the Transpolar Drift Stream. The data presented here were collected during the first three legs of the expedition, so all the coring activities took place on the same floe. The end dates of legs 1, 2, and 3 were 13 December, 24 February, and 4 June, respectively. The dataset contributed to a baseline study entitled, Deciphering the properties of different Arctic ice types during the growth phase of the MOSAiC floes: Implications for future studies. The study highlights downward directed gas pathways in FYI and SYI by inferring sea ice permeability and potential brine release from several time series of temperature and salinity measurements. The physical properties presented in this paper lay the foundation for subsequent analyses on actual gas contents measured in the ice cores, as well as air-ice and ice-ocean gas fluxes. Sea ice cores were collected with a Kovacs Mark II 9 cm diameter corer. To measure ice temperatures, about 4.5 cm deep holes were drilled into the core (intervals varied by site and leg) . The temperatures were measured by a digital thermometer within minutes after the cores were retrieved. The ice cores were placed into pre-labelled plastic sleeves sealed at the bottom end. The ice cores were transported to RV Polarstern and stored in a -20 degrees Celsius freezer. Each of the cores was sub-sampled, melted at room temperature, and processed for salinity within one or two days. The practical salinity was estimated by measuring the electrical conductivity and temperature of the melted samples using a WTW Cond 3151 salinometer equipped with a Tetra-Con 325 four-electrode conductivity cell. The practical salinity represents the the salinity estimated from the electrical conductivity of the solution. The dataset also contains derived variables, including sea ice density, brine volume fraction, and the Rayleigh number.

Description: Geochemical data for three sedimentary records of the Frasnian–Famennian extinction and Upper Kellwasser Event, from the H-32 core (Iowa, USA), the Kowala Quarry (Poland), and Sinsin (Poland), together with time vs depth information for the revised age model of the H-32 core. Nitrogen-isotope and nitrogen content data are included for all three sites, together with biomarker information for Kowala and the H-32 core, carbon isotope data for Kowala and Sinsin, total organic carbon for the H-32 core and Sinsin, Rock Eval data from the H-32 core, phosphorus and aluminium content data, and P/Al and TOC/P ratios, from the H-32 core, and time-depth data from the H-32 core.

Description: Millennial scale events marked by the contribution of detrital sand are recorded in North Atlantic sediments during the Last Glacial Maximum (LGM), between Heinrich events (HE) 1 and 2, and left their imprint on Laurentian Fan (LF – 43◦N) sediments off eastern Canada. The LF counterpart of the wellknown detrital events consist of glacial red-brick sediments resulting from subglacial flows separated by olive-grey sediments appears at ∼21.4–19.9 and ∼19.5–18.65 cal kyr BP. High-resolution analyses of diatom assemblages and lithic grains coupled with planktonic oxygen isotopic records reveal that while the red sediment is almost barren of diatoms, foraminifera and lithics (〉150 μm), they are abundant in the olive-grey sediment. Diatom assemblages reveal three phases during these events: (1) initial relatively warm/temperate conditions followed by (2) very cold surface water and drifting ice, and (3) a final phase characterized by relatively warmer waters and the appearance of detrital carbonate. Although these events possibly reflect the variability specific to the slope water region, they are likely the response to Atlantic Meridional Overturning Circulation perturbations and ice-sheet instability. Through a chain of mechanisms, meltwater inputs into the North Atlantic led ultimately to an increased volume of tropical waters and part of the heat stored in the subsurface was flushed by a brief convective episode that was not sustained, accounting for the return of cold conditions after the events. The sequence of mechanisms deduced from the paleo data here and elsewhere is consistent with previous modeling results. These data suggest that the detrital events between Heinrich event 1 and 2 may be synchronous across the North Atlantic, and that the LGM was probably not a time of prolonged steady state in the climate system.

Description: Modern-day solar cycles due to the solar magnetic field oscillation are well recognized. Owing to the response of Earth's climate to solar activity fluctuation, solar cycles in the Phanerozoic eon have been recorded by laminites and fossil tree rings. However, the existence of magnetic cycles within the Sun younger than 3100 million-year-old is still unknown. The deposition of Precambrian banded iron formations (BIFs) reflects the primary productivity of the early ferruginous oceans and is coupled to climatic fluctuations. Here we apply synchrotron-radiation-based µ-XRF with 20 µm interval on a 60 mm long, 2470 million-year-old BIF from the Kuruman Formation, South Africa. The sample is from core GKF01 drilled at the location S 28° 56' 06.0” E 023° 15' 00.0”, as described in Schröder et al. (2006). µ-XRF measurements of the sample were performed at beamline BL15U1 of Shanghai synchrotron radiation facilities (SSRF) with a designed 3.5 GeV electron storage ring and 150-250 mA current. For these measurements, the beam size was controlled at 5 µm × 3 µm (horizontal × vertical). For the XRF measurement, the excitation energy was set at 14.0 KeV, and the dwelling time was set to 5 s. A line of 2972 points was scanned with an interval of 20 µm, perpendicular to the BIF sample's microbands. Relative elemental concentrations in counts per second (cps) were obtained by fitting the µ-XRF profiles using PyMca (raw). Segments with systematic measuring anomalies were removed (tail removed). Our spectral analyses of multiple elemental concentration series reveal prominent and consistent 80-year cyclicity, which is best explained as the Gleissberg solar cycle. The result is reported in the article 2470 million-year-old banded iron formation reveals a climatic oscillation consistent with the Gleissberg solar cycle published in Communications Earth & Environment.

Description: Alkenone concentration and radiocarbon age in 7 gobally-distributed surface sediment samples and their associated grain-size fractions. Total organic carbon (TOC) and fractional abundance of grain-size fractions from bulk sediments (Bulk%) are taken from Ausín et al. (2021). Analytical precision of Uk'37 is 0.003 units. Uk'37-SST propagated error is ±0.51℃. These parameters were measured to explore the influence of alkenone-mineral associations and hydrodynamic mineral sorting processes on alkenone proxy signals. Bulk sediment samples were fractionated into four grain-size fractions (sand (〉300-63 µm); coarse silt (63-10 µm); fine silt (10-2 µm); and clay (〈 2 µm) prior to lipid extraction and manual column chromatography to obtain a ketone fraction containing the alkenones. The concentration and distribution of C37 alkenones was analyzed using gas chromatography with flame ionization detection (GC-FID) at the Biogeoscience Group Laboratories, ETH Zürich in 2018. The ketone fractions used for determination of alkenone concentration and unsaturation were further purified for compound specific radiocarbon analysis following Ohkouchi et al. (2005). Samples, were measured as CO2 using an Elemental-Analyzer system interface coupled to a gas ion source (GIS)-equipped Minicarbon Dating System (MICADAS) at the Laboratory of Ion Beam Physics, ETH Zürich in 2018. References Ausín, B., Bruni, E., Haghipour, N., Welte, C., Bernasconi, S. M., & Eglinton, T. I. Controls on the abundance, provenance and age of organic carbon buried in continental margin sediments. Earth and Planetary Science Letters, 558, 116759, doi:10.1016/j.epsl.2021.116759, 2021. Ohkouchi, N., Xu, L., Reddy, C. M., Montluon, D., & linton, T. I. Radiocarbon dating of alkenones from marine sediments: I. Isolation Protocol Radiocarbon, 47, 401-412, doi:10.1017/S0033822200035189, 2005.

Description: 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

Description: This data set is a higher-processing-level version of Gridded segments of sea-ice or snow surface elevation and freeboard from helicopter-borne laser scanner during the MOSAiC expedition, version 1 (Hutter et al., 2022; doi:10.1594/PANGAEA.950339), where the individual 30-second segments of the small scale grid flights have been combined into merged grids. The data were collected using a near-infrared, line-scanning Riegl VQ-580 airborne laser scanner (https://hdl.handle.net/10013/sensor.7ebb63c3-dc3b-4f0f-9ca5-f1c6e5462a31 & https://hdl.handle.net/10013/sensor.7a931b33-72ca-46d0-b623-156836ac9550) mounted in a helicopter along the MOSAiC drift from the north of the Laptev Sea, across the central Arctic Ocean, and towards the Fram Strait from September 2019 to October 2020. The merged data are stored in netCDF and geotiff format. The data are drift corrected using the position and heading data of RV Polarstern and elevation offset corrected using overlapping segments to overcome degraded GPS altitude data 〉85°N. For the flights with degraded GPS altitude quality, we provide only a freeboard estimate. The merged grids include all data variables of the gridded 30-s segments: surface elevation, freeboard (estimate), freeboard uncertainty, estimated sea surface height, surface reflectance, echo width, and number of points used in the interpolation. Also the calculated elevation offset correction term is provided for each flight as a csv file.

Description: The dataset comprises data on the lipid composition (carboxylic acids and alkanols) and stable isotope values (δ13C and δ15N) obtained from fresh stomach oils and sub-stomach oil deposits of snow petrels (Pagodroma nivea). The samples were collected in different un-glaciated regions of East Antarctica (Dronning Maud Land, Mac. Robertson Land, Prince Charles Mountains and Windmill Islands). The stomach oils and sub-fossil stomach oil deposits were analyzed to investigate the paleodiet of the birds and to relate information of paleodiet to past environmental conditions. The alkanoic acids and alkanols were analysed from total lipid extracts by capillary gas chromatography with GC-FID (Gas chromatograph with Flame ionization detector) and GC-MS (single quadrupole mass spectrometer coupled with gas chromatograph). Total lipid extracts were analysed for the δ13C isotopic composition. The un-soluble residues, retained after lipid extraction, was analysed for δ13C and δ15N isotopic composition. This work was funded by the Deutsche Forschungsgemeinschaft (DFG) in the framework of the priority program "Antarctic Research with comparative investigations in Arctic ice areas" (grants BE 4764/5-1 and BE 4764/6-1).

Description: To assess the thermal adaptation of microscopic stages of the kelp Laminaria digitata along latitudes, we conducted laboratory experiments on samples from six locations in the NE Atlantic (Spitsbergen (SPT), Tromsø (TRM), Bodø (BOD; all Norway), Helgoland (HLG; Germany), Roscoff (ROS) and Quiberon (QUI; both France)), spanning the species' entire distribution range. In experiment 1, we exposed gametophytes to (sub-) lethal high priming temperatures (20-25°C) for two weeks, followed by two weeks of recovery at 15°C, to observe gametophyte survival and sporophyte formation. In experiment 2, samples were subjected to (sub-) optimal low temperatures (0-15°C) for 21 days, to assess gametophyte survival, sporophyte formation and growth. During the experiments, samples were kept in 15 µmol photons/m²/s white light under a 16:8h light:dark cycle. Prior to the experiments, cultures were stored at 15°C in iron-free ½ Provasoli enriched seawater in 3-4 µmol photons/m²/s red light.

Description: The dataset compiles pigment content, absorptance data, photosynthetic parameters and primary production data as proxies for summertime photoacclimation of the temperate intertidal eelgrass Zostera marina after a 25-day exposure to a natural light intensity gradient (6, 36, 74, 133, 355, 503 and 860 µmol photons/m²/s) under laboratory conditions at the Pointe-au-Père research station, East Rimouski, Quebec, Canada. The data bundle contains: 1) photosynthetic and total absorptance data at the end of the experiment, which respectively represent the fraction of incident visible light absorbed by the photosynthetic tissues corrected and not corrected for non-photosynthetic absorption; 2) pigment content at the end of the experiment, which includes chlorophyll a and b and total carotenoids contents; 3) photosynthetic parameters obtained by Rapid Light Curves (RLC) on days 5 and 25, including photosynthetic apparatus efficiency (alpha), capacity (ETRmax) and saturation (Ek); 4) whole shoot primary production at the end of the experiment, which was calculated from oxygen fluxes under light and dark conditions, and normalized by leaf surface.

Description: The Knapps Narrows core was drilled at 38.72129N, -76.33162W on the Eastern Shore of Maryland. The cored target interval lies between 84-102 meters in the Nanjemoy Formation. Calcareous nannofossil biozonation was established in conjunction with paleomagnetic data, allowing us to date the interval to approximately 53.7 mya. Benthic foraminiferal and bulk carbon isotope data allowed for further refinement of the dating of this interval, allowing us to identify ETM2 and H2 on the basis of carbon isotope stratigraphy. For analyses of benthic foraminifera 4-6 Anomalinoides acutus specimens were picked from the 180-250 μm size fraction at each interval. Dinoflagellate cyst assemblages were counted in order to allow for paleo-environmental analysis. Benthic foraminiferal δ18O and TEX86 temperature proxies were compiled over the interval of interest. Semi-quantitative clay mineral assemblages were used to test for changes in the weathering response over hyperthermal intervals. There is excellent agreement between the δ18O and TEX86 temperature proxies, although the highest temperatures do not correspond to either hyperthermal event. There is a noticeable increase in illite content during the ETM2 interval, and an absence of kaolinite. Dinoflagellate assemblages suggest changes in marine paleo-environmental conditions were driven by long-term trends rather than immediate responses to the hyperthermal events.

Description: Measurements of cell size, cell density, nutrient concentration and genotype composition in a long-term experiment (182 days) with the marine phytoplankton species Chaetoceros affinis and Emiliania huxleyi, each consisting of nine genotypes. The species were cultivated together at three different nutrient regimes (10 N, 20 N, 30 N) with increasing nitrate supply in a semi-continuous batch cycle system. The genotype composition of both species was assessed after 49, 91, and 182 days using microsatellites. In a short-term experiment cell size and density of nine Chaetoceros affinis genotypes separately were measured after 7 days growth at seven nitrate levels (2.5, 5, 7.5, 12.5, 20, 30, and 45 μmol L−1 N).

Description: In the sediment Core EN-032-18PC, collected below the influence of the Loop Current in the eastern Gulf of Mexico, we aimed to investigate mixed layer conditions, the intensity of the surface and subsurface waters flowing from the Caribbean to the gulf, and the extension of the Loop Current. We analyzed 136 samples that include: (S1) Bulk sediment and sand fraction (〉62 μm) weight (g), the absolute abundance (tests per sample) of 33 species of planktonic foraminifera. (S2) Relative abundance (%) of planktonic foraminifera and factor loadings of two factors (Q-mode factor analysis). (S3) Stable isotopes (δ18O-PDB and δ13C-PDB) (‰) of Globigerinoides ruber (white) and the loess-smoothing of the series with polynomial regression.

Description: The data comprise measurements of magnetic susceptibility and brightness (L*) for Site Me68-91 and Site Me68-89, water content data for Site Me68-89, and XRF elemental counting intensities for Site Me68-196. Furthermore, geochemical data were collected in the form of metal concentrations including rare earth elements (measured with ICP-QMS), carbonate contents, and neodymium isotope compositions (measured with MC-ICP-MS) in the authigenic sediment fraction extracted via weak sediment leaching and dissolution of picked foraminifera, and in the detrital sediment fraction. The data were interpreted in terms of sedimentology, rare earth element exchange between seawater and sediment, and past ocean circulation. Radiocarbon data (measured with MICADAS) from planktic foraminifera were measured for age model construction.

Description: Micropaleontological analyses from the western South Atlantic core AU_Geo02_GC20 (45° 55' S - 58°30' W, 2589 m water depth) revealed changes in the primary productivity and sea surface temperature (SST) during MIS 3 that point to significant changes in the Brazil Malvinas Confluence Zone dynamics. These changes led to a marked increase in the SST and the primary productivity between 44.0 - 36.1 ka BP, as indicated by the quantitative reconstruction of the subsurface temperature, and the high relative abundance of the planktonic foraminifera Globigerina bulloides and other planktonic-based index, such as the eutrophic index. The increase in the SST and the primary productivity could be related to frequent or more persistent southward penetration of subtropical waters over the north Patagonian margin due to a southward extension of the Brazil Current and a weakening of the Malvinas Current. The high primary productivity led to intensive use of phosphate during spring. Conversely, benthic assemblages do not reflect high surface productivity. The dominance of coccolithophorids over diatoms as primary producers, which allows inferring the shoaling of the nutricline and the thermocline, justifies the decoupling between planktonic and benthic communities as a consequence of reduced efficiency of the biological pump. The deposition of the calcareous muddy contourite facies during the period of enhanced primary productivity indicates a slowing down of the bottom circulation, probably due to a weakening of the Atlantic Meridional Overturning Circulation.

Description: The dataset includes speleothem carbon isotopes, oxygen isotopes, U-Th ages, and fluid inlcusion hydrogen isotopes used to reconstruct climate in southeastern Alaska during the past ~3,500 years. Speleothem WB-21-5-A was collected in Wishbone Cave (55.774 N, -133.191 E; 420 m.a.s.l.) and speleothem WA-21-6-A was collected in Walkabout Cave (55.776° N, 133.195° W; 350 m.a.s.l.) on May 21, 2022 and June 21, 2022, respectfully. The data collection was completed between September 2021-March 2022. U-Th ages were measured on a ThermoFisher Neptune Plus multi-collector inductively coupled plasma mass spectrometer, and stable/fluid inclusion isotopes were measured on a ThermoFisher Delta V isotope ratio mass spectrometer.

Description: We present results of Th/U dating, oxygen isotope, saturation magnetization (Ms), coercivity (Bc) data from a speleothem from northern Tasmania, Australia. The depths are relative to the base of the stalagmite. The oxygen isotopic compositions of the stalagmite were analyzed by two laboratories, Beijing Createch Testing Technology Co., Ltd. for the base section and Australian National University for the upper section. The oxygen isotopic values are reported with respect to the Vienna Pee Dee Belemnite (VPDB) standard and the Peedee Belemnite (PDB) standard, respectively. The d18O record spans 129.6 - 108.6 ka BP. The Ms and Bc are derived from hysteresis loop, which were only conducted for the interval of MIS5e.

Description: This expedition was conducted in the North Eastern Lau Basin, Southwest Pacific. The program aimed at improving our understanding of the igneous, hydrothermal, and tectonic processes that occur during island arc and back-arc formation. Cruise SO263 operated in June 2018. Raw data of physical oceanography was obtained during research cruise SO263 on RV SONNE. Data of vertical CTD casts was binned to 1 meter intervals and is reported with shortend header. Data of tow-yo CTD casts was binned to 1 second intervals and is reported with shortend header.

Description: The dataset compiles counts of larvae of the European flat oyster Ostrea edulis, settled on various substrates under three different experimental conditions. The data was collected within the AWI-RESTORE project (Alfred-Wegener-Institute, Germany), examining basic preconditions for successful restoration of the European flat oyster within the German Bight. The data is separated in three experimental setups: the columns for experiment 1 (hatchery/laboratory) include date stamp in ISO format, Latitude, Longitude, abiotic factors (Flow rate, temperature, salinity, pH, dissolved oxygen), substrate types, area and orientation as well as the count of settled larvae for each set-up. Data for experiment 2 (hatchery) include date stamp in ISO format, Latitude, Longitude, abiotic factors (Flow rate, temperature, salinity, pH), reef number, specifics of examined area and orientation as well as the count of settled larvae for each reef. Columns for experiment 3 (field) include date stamp in ISO format, Latitude, Longitude, abiotic factors (depth, temperature, salinity), chlorophyll concentration, substrate types, specifics and orientation as well as the count of settled larvae for each submerged substrate.

Description: Fifty-nine bulk soil samples were from a collection known as the “Mainz Sandbank”, comprising samples from across the Sahara-Sahel region collected on multiple field trips since 1970. Elemental and radiogenic isotope analyses were performed on the fine silt-clay fraction of the soil (〈 20 µm). Major and trace element composition were obtained using an Agilent 7900 quadrupole ICP-MS instrument with 2.5% HNO3 as eluent. International reference materials (basalts BHVO-2 and BCR-2) were analyzed during each measurement session, and the data agree within ±10% of the recommended reference concentrations (Jochum et al., 2016). Strontium, Nd, and Pb isotope compositions were measured by thermal ionization mass spectrometry (TIMS Triton, ThermoFisher). Accuracy and reproducibility were determined with replicate measurements of SRM 987 and La Jolla standards, respectively. The Pb isotope data were corrected offline for instrumental mass bias using a double (207Pb-204Pb) or triple (204Pb-206Pb-207Pb) spike technique. Accuracy and reproducibility were determined using multiple analyses of the NIST SRM-981 standard. In addition, four soil samples with distinct bedrock ages and soil types were selected from Mali and Morocco to test the effect of grain size and of selective HBr leaching (to remove anthropogenic Pb) on radiogenic isotope signatures. HBr leaching experiments were also performed on aerosols collected along the sahelian Harmattan road. Finally, and in addition to this new dataset, a summary of available radiogenic isotope signatures (Sr-Nd-Pb) from North African soils in the literature is provided for future studies. This dataset is a support of the article Characterization of Saharan and Sahelian dust sources based on geochemical and radiogenic isotope signatures published by Guinoiseau et al., 2022 (doi:10.1016/j.quascirev.2022.107729).