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This data set includes hydrographic and pore water and core incubation silicic acid concentration and isotope measurements, sediment Si-HCl and Si-Alk contents and isotope measurements, and pore water nutrient, major, and trace element concentrations measured in the fjords Ameralik Fjord and Nuup Kangerlua (Godhäbsfjord) in southwest Greenland. Data was collected during a research expedition, R/V Tulu 2019, in September 2019, as part of ERC funded (678371) project ICY-LAB (Isotope CYcling in the LABrador Sea) and Royal Society funded (RGF\EA\181036) project Biogeochemical Cycling in Greenlandic Fjords. Temperature and salinity data derived from CTD rosette casts were recorded at station AM10 in Ameralik Fjord and station GF-inlet in Nuup Kangerlua. Fjord water sampling was carried out at 2 stations (AM10 and AM12) in Ameralik Fjord and station GF-inlet in Nuup Kangerlua using Towfish and Niskin bottles for near surface and sub surface samples, respectively. For bottle samples, temperature and salinity were measured using an EXO3 Multiparameter Water Quality Sonde. Fjord sediments were collected by a large bore sediment corer (Aquatic Research Instruments) at station AM10a in Ameralik Fjord and station GF-inlet in Nuup Kangerlua. Pore waters were extracted from the sediment cores using Rhizon samplers and core incubation experiments were carried out following the methodology of Hammond et al. (2004, doi:10.4319/lom.2004.2.146). Sediment reactive silica was leached using a sequential extraction method from Michalopoulos and Aller (2004, doi:10.1016/j.gca.2003.07.018) and Pickering et al. (2020, doi:10.1029/2020GL087877).

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).

A global compilation of in situ data is vital to evaluate the quality of ocean-colour satellite data records. Here, we describe data compiled for the validation of ocean-colour products from the ESA Ocean Colour Climate Change Initiative (OC-CCI). The data were acquired from several sources (including, inter alia, MOBY, BOUSSOLE, AERONET-OC, SeaBASS, NOMAD, MERMAID, AMT, ICES, HOT, GeP&CO) and span the period from 1997 to 2021. Observations of the following variables were compiled: spectral remote-sensing reflectance, concentration of chlorophyll-a, spectral inherent optical properties, spectral diffuse attenuation coefficient and total suspended matter. The data were obtained from multi-project archives acquired via open internet services, or from individual projects, acquired directly from data providers. Methodologies were implemented for homogenisation, quality control and merging of all data. No changes were made to the original data, other than averaging of observations that were close in time and space, elimination of some points after quality control and conversion to a standard format. The result is a merged table available in text format. Metadata of each in situ measurement (original source, cruise or experiment, principal investigator) were propagated throughout the work and made available in the final table. By making the metadata available, provenance is better documented, and it is also possible to analyse each set of data separately. This paper also describes the changes that were made to the compilation in relation to the previous version.

Coccolithophores are globally important marine calcifying phytoplankton that utilize a haplo-diplontic life cycle. The haplo-diplontic life cycle allows coccolithophores to divide in both life cycle phases and potentially expands coccolithophore niche volume. Research has, however, to date largely overlooked the life cycle of coccolithophores and has instead focused on the diploid life cycle phase of coccolithophores. Through the synthesis and analysis of global scanning electron microscopy (SEM) coccolithophore abundance data (n=2534), we find that calcified haploid coccolithophores generally constitute a minor component of the total coccolithophore abundance (≈ 2 %–15 % depending on season). However, using case studies in the Atlantic Ocean and Mediterranean Sea, we show that, depending on environmental conditions, calcifying haploid coccolithophores can be significant contributors to the coccolithophore standing stock (up to ≈30 %). Furthermore, using hypervolumes to quantify the niche of coccolithophores, we illustrate that the haploid and diploid life cycle phases inhabit contrasting niches and that on average this allows coccolithophores to expand their niche by ≈18.8 %, with a range of 3 %–76 % for individual species. Our results highlight that future coccolithophore research should consider both life cycle stages, as omission of the haploid life cycle phase in current research limits our understanding of coccolithophore ecology. Our results furthermore suggest a different response to nutrient limitation and stratification, which may be of relevance for further climate scenarios. Our compilation highlights the spatial and temporal sparsity of SEM measurements and the need for new molecular techniques to identify uncalcified haploid coccolithophores. Our work also emphasizes the need for further work on the carbonate chemistry niche of the coccolithophore life cycle.

We used a multibeam echosounder (Reson7125) front-mounted onto the ROV Isis (Dive D333, DY081 expedition) to map the terrain of a vertical feature marking the edge of a deep-sea glacial trough (Labrador Sea, [63°51.9'N, 53°16.9'W, depth: 650 to 800 m]). After correction of the ROV navigation (i.e. merging of USBL and DVL), bathymetry [m] and backscatter [nominal unit] were extracted at a resolution of 0.3 m and different terrain descriptors were computed: Slope, Bathymetric Position Index (BPI), Terrain Ruggedness Index, Roughness, Mean and Gaussian curvatures and orientations (Northness and Eastness), at scales of 0.9, 3 and 9 m. Using a Principal Component Analysis (PCA), the terrain descriptors enabled to retrieve 4 terrain clusters and their associated confusion index, to investigate the spatial heterogeneity of the terrain. This approach also underlined the presence of geomorphic features in the wall terrain. The extraction of the backscatter intensity for the first time considering vertical terrains, opens space for further acquisition and processing development. Using photographs collected by the ROV Isis (Dive D334, DY081 expedition), epibenthic fauna was annotated. Each image was linked to a terrain cluster in the 3D space and pooled into 20-m² bins of images. A Bray-Curtis dissimilarity matrix was constructed from morphospecies abundances. This enabled to test for differences of assemblage composition among clusters. Few species appeared more abundant in particular clusters such as L. pertusa in high-roughness cluster. However, nMDS suggested differences in assemblage composition but these dissimilarities were not strongly delineated. Whereas the design of this study may have limited distinctive differences among assemblages, this shows the potential of this cost-effective method of top-down habitat mapping to be applied in undersampled benthic habitat in order to provide a priori knwoledge for defining appropriate sampling design.

Gordon & Betty Moore FoundationGordon and Betty Moore Foundation [5596]; Canada Research Chairs FoundationCanada Research Chairs; European Union's Horizon 2020 research and innovation programme under Marie Sklodowska-Curie grant [747946]; Fundacao para a Ciencia e Tecnologia I.P. Portugal (FCT); Direcao-Geral de Politica do Mar (DGPM) [2/2017/001-MiningImpact 2]; FCTPortuguese Foundation for Science and TechnologyEuropean Commission [CEECIND005262017, UID/MAR/00350/2013, IF/01194/2013, IF/00029/2014/CP1230/CT0002, Mining2/0005/2017]; RF State Assignment [0149-2019-0009]; Horizon 2020 Agricultural Interoperability and Analysis System (ATLAS) projects [678760]; JM Kaplan Fund; National Science FoundationNational Science Foundation (NSF) [OCE 1634172]; JPI Oceans project Mining Impact -Environmental Impacts and Risks of Deep-Sea Mining Aug 2018-Feb 2022 (NWO-ALW) [856.18.001] info:eu-repo/semantics/publishedVersion

We studied the distribution of coccoliths in surface sediments across the Drake Passage and calcification of Emiliania huxleyi morphotypes in surface sediment samples retrieved during PS97. Dataset 1 (morphometrical measurements and mass estimations) is reporting the morphometrical measurements of E. huxleyi coccoliths measured with the Coccobiom2 macro (Coccobiom2 macros: http://ina.tmsoc.org/nannos/coccobiom/Usernotes.html, last access: 3 September 2016) based on 570 Scanning Electron Microscope images (showing E. huxleyi coccoliths of morphotypes A, Aovercalcified, B/C and O), and calcite mass estimations based on two different formulas 1) after Beuvier et al. 2019 (doi:10.1038/s41467-019-08635-x) and 2) after Young and Ziveri 2000 (doi:10.1016/S0967-0645(00)00003-5). The morphometrical measurements (in µm) include coccolith distal shield length, distal shield width, Central Area length, Central Area width. The mass estimations (in pg) include the mass calculated after 1) and 2) and the respective shape factor used for 2). The coccoliths stem from surface sediments that were sampled with a Multicorer and are approximately of Mid to Late Holocene Age. Dataset 2 (morphotype counts) is reporting the relative number of E. huxleyi morphotypes per sample, based on an additional count with the SEM. Further details in the material and methods section in the corresponding paper.

A total of 35 samples from the late-middle Eocene to earliest Oligocene (643.73-520.88 mbsf) were analysed for their pollen and spore content. Slides were analysed using a Leica DM500 and Leica DM2000 transmitted light microscopes at 200x and 1000x magnification. Where possible, counts of 300 (excluding reworked grains) sporomorphs were made. Only samples containing 50 or more in situ sporomorphs were used for further analysis and evaluation. Sporomorph diversity was measured using both the Shannon–Wiener index and the observed number of taxa. A rarefaction method for sums of ≥50 and ≥100 grains was applied, so that the effect caused by differences in the sample size may be removed allowing the estimation of the number of sporomorph species at a constant sample size. Detrended Correspondence Analysis (DCA) was performed, with downweighting of rare species by removing pollen types whose representation is <5%. Estimates for terrestrial mean annual temperature (MAT), mean annual precipitation (MAP), warmest month mean temperature (WMMT) and coldest month mean temperature (CMMT) were obtained using the NLR approach in conjunction with the Probability Density Function (PDF) method.

Much of our understanding of Earth's past climate states comes from the measurement of oxygen and carbon isotope variations in deep-sea benthic foraminifera. Yet, major intervals in those records that lack the temporal resolution and/or age control required to identify climate forcing and feedback mechanisms. Here we document 66 million years of global climate by a new high-fidelity Cenozoic global reference benthic carbon and oxygen isotope dataset (CENOGRID). Using recurrence analysis, we find that on timescales of millions of years Earth's climate can be grouped into Hothouse, Warmhouse, Coolhouse and Icehouse states separated by transitions related to changing greenhouse gas levels and the growth of polar ice sheets. Each Cenozoic climate state is paced by orbital cycles, but the response to radiative forcing is state dependent.

Glider vehicles are now perhaps some of the most prolific providers of real-time and near-real-time operational oceanographic data. However, the data from these vehicles can and should be considered to have a long-term legacy value capable of playing a critical role in understanding and separating inter-annual, inter-decadal, and longterm global change. To achieve this, we have to go further than simply assuming the manufacturer’s calibrations, and field correct glider data in a more traditional way, for example, by careful comparison to water bottle calibrated lowered CTD datasets and/or “gold” standard recent climatologies. In this manuscript, we bring into the 21st century a historical technique that has been used manually by oceanographers for many years/decades for field correction/inter-calibration, thermal lag correction, and adjustment for biological fouling. The technique has now been made semi-automatic for machine processing of oceanographic glider data, although its future and indeed its origins have far wider scope. The subject of this manuscript is drawn from the original Description of Work (DoW) for a key task in the recently completed JERICO-NEXT (Joint European Research Infrastructure network for Coastal Observatories) EU-funded program, but goes on to consider future application and the suitability for integration with machine learning. Refereed 14.A Sea surface salinity Subsurface salinity TRL 8 Actual system completed and "mission qualified" through test and demonstration in an operational environment (ground or space) Manual (incl. handbook, guide, cookbook etc) Standard Operating Procedure 2019-12-03