Modal mineralogy data of iceberg-rafted debris deposited at IODP Site U1538 in the Scotia Sea 1.2 million years ago based on QEMSCAN® analyses, which infer minerals from chemistry

40Ar/39Ar ages of 37 mica and 21 hornblende from the sand-sized fraction of an iceberg-rafted debris-rich layer deposited in the Scotia Sea at IODP Site U1538 ~1.2 million years ago during the early Pleistocene.

This dataset provides a 308 year record of methansulphonic acid (MSA) from coastal West Antarctica, representing sea ice conditions in the Amundsen-Ross Sea. Annual average MSA has been calculated from the 136 m Ferrigno ice core (F10), drilled on the Bryan Coast in Ellsworth Land, West Antarctica during the austral summer 2010/11. The sea ice extent is based on geometric mean regression of MSA flux with satellite sea ice extent from 146 degrees west. The record was measured using a Dionex ICS2500 anion system at 5 cm resolution, corresponding to approximately 14 samples a year. Funding was provided by the NERC grant NE/J020710/1.

The dataset (FSD-GFL-res2m-Preponding) contains sea-ice floe ice distribution (FSD) data derived from the Global Fiducials Library (GFL) imagery during the pre-ponding period at the three fiducial sites, using the algorithms described in Hwang et al. (2017). The GFL imagery is 1-m resolution declassified National Technical Means satellite imagery, also known as the Literal Image Derived Products (LIDPs) (Kwok, 2014). The FSD data derived from the GFL imagery cover the period of 2000 to 2014 at the three fiducial sites at Chukchi Sea (70 deg N and 170 deg W), East Siberian Sea (82 deg N and 150 deg E), and Fram Strait (84.9 deg N and 0.5 deg E). For the production of this dataset, the spatial resolution of the GFL imagery degraded to 2 meters ("res2m") for fast processing. The FSD data are produced for robust model calibration and validation for FSD parameterisations within sea-ice models, and also to improve our understanding of spatial and temporal variations of FSD across the Arctic Ocean. The FSD data have been generated by B. Hwang. This FSD dataset is produced as part of NERC MIZ NE/R000654/1 (Towards a marginal Arctic sea ice cover).

This data set comprises sea ice-related biomarkers for three time intervals, corresponding to the pre-MPT (1.53-1.36 Ma), the MPT (1.22-0.8 Ma), and the post-MPT (0.5-0.34 Ma) climate cycles from International Ocean Discovery Program (IODP) Site U1343 in the eastern Bering Sea (57deg33.4''N, 176deg49.0''W, 1950 m water depth). The biomarkers are the Arctic sea ice biomarker IP25, together with HBI III and brassicasterol, indicative of open water in the ice marginal zone and general phytoplankton production, respectively. Funding was provided by the NERC grant NE/L002434/1.

Data were collected as part of the DiatomARCTIC project during the Multidisciplinary Arctic Program - Last Ice sampling campaign (82.576 N 62.471 W), 7-23 May, 2018. The bottom 10 cm of ice samples were collected during this time from neighbouring first-year and multi-year sea ice floes, from which the following parameters were determined: chlorophyll a, exopolymeric substances, ice algal taxonomic composition, oxygen-based net community production and bulk-ice nitrate, nitrite and phosphate concentrations. All samples were melted without dilution and were processed by K Campbell. This work is a contribution to the Diatom ARCTIC project (NE/R012849/1; 03F0810A), part of the Changing Arctic Ocean program, jointly funded by the UKRI Natural Environment Research Council and the German Federal Ministry of Education (BMBF) and Fisheries and Oceans Canada (DFO) Science and the Marine Productivity Laboratory Program. The Multidisciplinary Arctic Program (MAP) - Last Ice is funded by Fisheries and Oceans Canada (DFO) Science in support of Tuvaijuittuq Marine Protected Area (MPA). Additional support was provided by Polar Continental Shelf Program (PCSP, Project 10718) and the Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Funds to CM and CHSR.