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To reconstruct the climatic and paleoceanographic variability offshore Northeast Greenland during the last ~10 ka with multidecadal resolution, sediment core PS93/025 from the outermost North-East Greenland continental shelf (80.5°N) was studied by a variety of micropaleontological, sedimentological and isotopic methods. High foraminiferal fluxes, together with high proportions of ice-rafted debris and high Ca/Fe ratios, indicate a maximum in bioproductivity until ~8 ka related to a low sea-ice coverage. Sortable silt values, planktic foraminifer associations, and stable isotope data of planktic and benthic foraminifers suggest a strong westward advection of relatively warm Atlantic Water by the Return Atlantic Current during this time, with a noticeable bottom current activity. This advection may have been facilitated by a greater water depth at our site, resulting from postglacial isostatic depression. For the following mid-Holocene interval (ca. 8–5 ka), isotope data, lower foraminiferal fluxes and a shift in grain size maxima point to a lasting but successively decreasing Atlantic Water inflow, a weakening productivity, and a growing sea-ice coverage which is also revealed by the PIIIIP25 index. A final stage in the environmental development was reached at ~5 ka with the establishment of pre-industrial conditions. Low Ca/Fe ratios, low foraminiferal fluxes, low sortable silt values and the sea-ice indicating PIIIIP25 index point to a limited productivity and a weak Atlantic Water inflow by the Return Atlantic Current to our research area, as well as a higher and/or seasonally more extended sea-ice coverage during the Late Holocene. Two intervals with somewhat enhanced Atlantic Water advection around 2.0 and 1.0 ka are indicated by slightly increased foraminiferal fluxes and the reoccurrence of subpolar foraminifers. These intervals may correlate with the Roman Warm Period and the Medieval Climate Anomaly, as defined in the North Atlantic region. [ABSTRACT FROM AUTHOR]

Proximal evidence of the surface ocean response to size reduction of the Greenland Ice Sheet (GIS) during the Last Interglacial (MIS5e) and preceding glacial termination (T2) remains largely elusive. Using a new sediment record from the western Iceland Sea, the behavior of the northeastern GIS and its relation to the subpolar North Atlantic surface hydrography is examined. Extremely light oxygen isotopic (δ 18 O) values are found off central East Greenland during early MIS5e and point to enhanced meltwater release, potentially from the northeastern sector of the GIS. Data from downstream the cold East Greenland Current (EGC) and its eastward branches suggest a far-reaching effect of this meltwater not only in the Nordic Seas but also in the SE Labrador Sea. In particular, whereas an early MIS5e warming (at ∼128.5–126.5 ka) in the two regions coincided with the relative reduction of meltwater input into the EGC, the subsequent cooling noted at ∼126.5 ka followed a renewed major freshwater event off central East Greenland. Our data further indicate persistent freshwater influence from the East Greenland margin over the entire MIS5e interval and, in addition, also reveal a late MIS5e meltwater event. The latter event occurred just prior to the last glacial inception and emphasizes the importance of Greenland meltwater as forcing factor on Interglacial climates. [ABSTRACT FROM AUTHOR]

While the Holocene history of the eastern Fram Strait is well investigated, only little is known about the past climate and the oceanographic conditions of the western part near Greenland. To fill this knowledge gap, a high-resolution Holocene sediment record from the outermost NE Greenland shelf, obtained during expedition PS93.1 (2015) of RV Polarstern, was investigated using micropaleontological and geochemical methods. Used proxies allow a profound assessment of Atlantic Water advection, bioproductivity, sea-ice coverage, water mass properties (e.g., temperature, salinity, ventilation) and stratification, while also indicating possible cold events and their cyclicity.The 264 cm long sediment record (80.5°N, 8.5°W, 290 m water depth) was radiocarbon-dated and investigated at high resolution for sediment composition, foraminifer contents, grain size variations (sortable silt, grain size distribution), contents of ice-rafted debris, element ratios and the isotopic composition of planktic and benthic foraminifers. Planktic and benthic foraminifer flux rates show highest values between 10.6 and 8.0 cal. ky BP, marking the maximum in bioproductivity and indicating either ice-free conditions or a reduced sea-ice cover during this time interval. Correlating high planktic foraminifer fragmentation values are likely related to dissolution through organic carbon oxidation due to an increased accumulation of organic matter. The subpolar planktic foraminifer species T. quinqueloba appears continuously until ca. 5.6 cal. ky BP and can be linked to an increased advection of warmer Atlantic Water (AW). Low shares of rounded IRD and quartz grains before 5.0 cal. ky BP are characteristic for low amounts of sea-ice sediments and therefore display a lower degree of sea-ice coverage, possibly also due to the mentioned AW advection. Between 10.0 and 5.0 cal. ky BP, the IRD-corrected sortable silt curve tends towards coarse grains, reflecting stronger currents. Afterwards, a trend to finer grains implies weaker currents and thus a decreasing AW advection. Low foraminifer flux rates after 4.4 cal. ky BP and an increase in rounded IRD and quartz grains beginning at ca. 5.0 cal. ky BP imply a stronger sea-ice coverage. Grain size distribution curves are flat with a decreasing coarse-silt mode around 35 µm until 6.0 cal. ky BP, representing sea-ice and iceberg deposition. From 5.0 cal. ky BP onwards, distribution curves show an increasing medium-silt mode at 15 µm and only small amounts of coarser grains, which is typical for sea-ice deposition. Pronounced isotope peaks and high shares of T. quinqueloba around 2.0 and 1.0 cal. ky BP correlate with the Roman Warm Period and the Medieval Warm Period. In addition, 11 short-timed cold events like the 8.2 event, the Dark Ages Cold Period and the Little Ice Age can be identified by using the sortable silt curve and the isotope records. [ABSTRACT FROM AUTHOR]