Description: For the interpretation of proxy reconstructions it is necessary to understand the recent signals of different sea-ice proxies from various regions. We present 260 new sediment surface samples collected in the (sub-) Arctic Oceans that were analysed for specific sea-ice (IP~25~) and open-water phytoplankton biomarkers (brassicasterol, dinosterol, HBI III). This new biomarker dataset was combined with 615 previously published biomarker surface samples into a pan-Arctic database. This comprehensive dataset is compared to satellite-based sea-ice concentrations and other environmental parameters to contribute to a better understanding of biomarker distributions as a basis for sea-ice reconstructions on a (sub-) Arctic scale.

Description: The Northeast Greenland continental shelf became one of the tipping elements in our climate system. Ongoing mass loss of the Greenland Ice Sheet, intensive sea-ice loss, the influence of warm, recirculating Atlantic Water towards the inner shelf, intensive bottom-melting at the underside of local marine-terminating outlet glaciers, glacier retreat and ice-sheet disintegration plays a fundamental role in terms of ongoing anthropogenic warming. Marine sediment Core PS100/270 was recovered aboard the RV Polarstern cruise PS100 in 2016 directly in front of 79NG on the inner NEG continental shelf (79°29.83'N, 18°8.40'W) in a water depth of 424 m. Chronology of the 9.51 m long Core PS100/270 is based on 13 AMS 14C ages, measured on benthic foraminifera. Sediment samples of Core PS100/270 were investigated to analyse microfossil assemblages, biomarker and bulk parameter proxy data. Additionally, the lithology, x-ray radiographs and geophysical properties (wet bulk density and magnetic susceptibility) were considered to perform a direct comparison with other records nearby e.g. PS2623. Four distinct lithofacies units were identified within this sedimentary record and are based on the, x-ray, lithology and biomarker data: stiff, overconsolidated diamiction; an indistinct/irregular laminated silty clay; a laminated silty clay and silty clay. Gravity Core PS100/270 was selected and studied in detail to reconstruct past sea-ice formation and ice-sheet dynamics, terrigenous input, primary productivity and the influence of warm, recirculating Atlantic Water on the shelf during the late Weichselian deglacial to late Holocene. The new high-resolution records presented here from the Northeast Greenland continental shelf provide helpful information about the pace of small- and large-scale climate variations, form the basis to improve future climate predictions and might serve as suitable analogue to ongoing anthropogenic warming by covering warmer periods in the past e.g. early Holocene Thermal Maximum.

Description: The dataset contains measurements of organic biomarkers and sterols, dinoflagellate cyst census counts, and benthic and planktonic stable oxygen isotope data from core GS16-204-22CC-B on the Eirik Drift (58°02.83′N, 47°02.36′W; 3160 m water depth) for Marine Isotope Stage 6, 5e and 5d. Total Organic Carbon (TOC), the Highly Branched Isoprenoids (HBIs) IP25, HBI II, HBI III (Z), and HBI III (E), and the sterols brassicasterol, dinosterol, campesterol and sitosterol were measured in the organic geochemistry lab at the Alfred Wegener Institute, Bremerhaven, Germany. Biomarker values are presented as biomarker/g dry sediment and biomarker/g TOC. Dinoflagellate cysts were counted along non overlapping traverses at x40 magnification using a transmitted light microscope and classified to species level as much as possible. The dataset consists of raw counts, relative abundances and dinocyst concentrations (cysts/g dry sediment). Stable oxygen isotopes (δ18O) were measured on the planktic foraminifera Neogloboquadrina pachyderma (sinistral) and benthic foraminifera Cibicidoides wuellestorfi. Values are reported relative to Vienna Pee Dee Belemnite. The measurements were carried out at FARLAB, University of Bergen, Norway. The age model for core GS16-204-22CC-B was obtained by correlation of benthic and planktic δ18O measured in this core with previously published isotope records in Irvali et al. (2012; 2016) and a 14C age from Griem et al. (2019).