KRILLBASE is a data rescue and compilation project which aims to improve the availability of information on two of the Southern Ocean's most important zooplankton taxa: Antarctic krill (Euphausia superba) and salps (Family Salpidae). In 2016, the project released a database of information from 15,194 scientific net hauls, collected between 1926 and 2016 by scientists from ten countries. These data, on the density of Antarctic krill and salps, provide a resource for analysing the distribution and abundance of these taxa throughout the Southern Ocean, to support ecological and biogeochemical research as well as fisheries management and conservation. The data are available as a downloadable csv files and via a seachable web interface. Each row of the main data table represents either a net haul or a composite of several net hauls. The columns describe searchable and filterable sampling and environmental information as well as the krill and salp density. The krill data are presented as both the observed density (NUMBER_OF_KRILL_UNDER_1M2, no.m-2) and the density standardised to a single, relatively efficient sampling method (STANDARDISED_KRILL_UNDER_1M2, no.m-2). The salp data are presented as observed density for all species combined, where an individual can be either a solitary oozoid or a member of an aggregate chain (NUMBER_OF_SALPS_UNDER_1M2, no.m-2). 12,758 of the net hauls in the database include krill data, 9,726 include salp data. 7,295 of the net hauls include both krill and salp data. For hauls where data for either salps or krill were not available the relevant field is blank. The RECORD_TYPE column distinguishes between four types of record and we emphasise that every analysis of the data should first screen on this field to avoid using the same data twice. Most records are labelled "haul", and these result from a single net sampling the water column at a specific station. Others, labelled "stratified pooled haul", are the combined result of several (typically three) stratified hauls (labelled "stratified haul") sampling different parts of the water column. A small number of records, labelled "survey mean" represent the arithmetic mean densities from multiple stations as this was the only recoverable information from the relevant surveys, which were mainly conducted in the 1980s. The dataset is fully described in the following publication which should be cited in published analyses of these data: Atkinson A, Hill SL, Pakhomov E, Siegel V, Anadon R, Chiba S, Daly KL, Downie R, Fielding S, Fretwell P, Gerrish L, Hosie GW, Jessopp MJ, Kawaguchi S, Krafft BA, Loeb V, Nishikawa J, Peat HJ, Reiss CS, Ross RM, Langdon B Quetin, Schmidt K, Steinberg DK, Subramaniam RC, Tarling GA, Ward P (2017) KRILLBASE: a circumpolar database of Antarctic krill and salp numerical densities, 1926-2016. Earth Syst. Sci. Data, 9: 193-210 (doi:10.5194/essd-9-193-2017)

This dataset documents the trends and variability in the latitude and strength of the belt of lower-atmosphere westerly winds over the Southern Ocean, referred to as the 'westerly jet'. Time series of annual mean and seasonal diagnostics are available for the period 1979-present, specifically time series of seasonal and annual mean jet latitude and strength. The diagnostics are derived from the European Centre for Medium Range Weather Forecasts (ECMWF) ERA-Interim reanalysis (for more information see www.ecmwf.int and Dee et al. (2011)), which is an observationally-constrained reconstruction of atmospheric conditions. The broad characterisation of the westerly winds into these simple diagnostics has been found to be useful for understanding long-term climate change due to contrasting drivers of change and impacts on other aspects of the climate system. This is an index of winds around the full circumference of all longitudes at Southern Hemisphere middle latitudes. The exact latitude depends on the position of the jet at any given time, but on average the jet (the core of the westerlies) is located at approximately 52 deg S.

Faecal pellets and eggs of Antarctic silverfish have been collected over the seasons using a sediment trap deployed on 1998 in Terra Nova Bay, Ross Sea, Antarctica in the frame of the National Italian Antarctic Research project (PNRA). Antarctic silverfish (ASF) accounts for over 90% of the local fish communities in the Southern Ocean costal area. Samples have been investigated in order to quantify the contribution of fish faecal pellets and eggs to the export of carbon. Funding: CLIMA project (Climatic Long-term Interactions for the Mass Balance in Antarctica) of the Italian National Program for Research in Antarctica.

This dataset presents the relative diatom abundances of 55 species/groups from the 132-120 ka interval in marine sediment core NBP9802-04 (-64.20 degN, -170.08 degE). This age interval corresponds to the peak of Marine Isotope Stage 5e (130- 116 ka). Microscope slides were prepared using a method adapted from Scherer (1994) and 300+ diatom valves were counted for each depth sample to produce the relative percentage abundance of each diatom species/group. This project was funded by the UK Natural Environment Research Council Grant NE/L002531/1

This dataset presents the relative diatom abundances of 56 species/groups from the 132-120 ka interval in marine sediment core PC509 (-68.31 degN, -86.03 degE). This age interval corresponds to the peak of Marine Isotope Stage 5e (130- 116 ka). Microscope slides were prepared using a method adapted from Scherer (1994) and 300+ diatom valves were counted for each depth sample to produce the relative percentage abundance of each diatom species/group. This project was funded by the UK Natural Environment Research Council Grant NE/L002531/1

This dataset presents the relative diatom abundances of 55 species/groups from the 132-120 ka interval in marine sediment core TPC287 (-60.31 degN, -36.65 degE). This age interval corresponds to the peak of Marine Isotope Stage 5e (130- 116 ka). Microscope slides were prepared using a method adapted from Scherer (1994) and 300+ diatom valves were counted for each depth sample to produce the relative percentage abundance of each diatom species/group. This project was funded by the UK Natural Environment Research Council Grant NE/L002531/1

This dataset presents the relative diatom abundances of 55 species/groups from the 132-120 ka interval in marine sediment core TPC288 (-59.14 degN, -37.96 degE). This age interval corresponds to the peak of Marine Isotope Stage 5e (130- 116 ka). Microscope slides were prepared using a method adapted from Scherer (1994) and 300+ diatom valves were counted for each depth sample to produce the relative percentage abundance of each diatom species/group. This project was funded by the UK Natural Environment Research Council Grant NE/L002531/1

This dataset presents the relative diatom abundances of 55 species/groups from the 132-120 ka interval in marine sediment core TPC290 (-55.55 degN, -45.02 degE). This age interval corresponds to the peak of Marine Isotope Stage 5e (130- 116 ka). Microscope slides were prepared using a method adapted from Scherer (1994) and 300+ diatom valves were counted for each depth sample to produce the relative percentage abundance of each diatom species/group. This project was funded by the UK Natural Environment Research Council Grant NE/L002531/1

This dataset presents the relative diatom abundances of 56 species/groups from the 132-120 ka interval in marine sediment core U1361A (-64.41 oN, 143.89 oE). This age interval corresponds to the peak of Marine Isotope Stage 5e (130- 116 ka). Microscope slides were prepared using a method adapted from Scherer (1994) and 300+ diatom valves were counted for each depth sample to produce the relative percentage abundance of each diatom species/group. This project was funded by the UK Natural Environment Research Council Grant NE/L002531/1

This dataset presents a harmonised collection of sediment carbon measurements from over 2,000 cores collected across the Southern Ocean and Southern Hemisphere (wider polar front), south of 49degrees. The dataset was compiled to enable quantitative assessments of sedimentary carbon stocks and identify regional hotspots and cold spots of blue carbon, as well as pinpointing trends and gaps in data collection. Drawing on published literature, data repositories, cruise archives, and correspondence with researchers, the compilation addresses longstanding fragmentation and inconsistency in sediment carbon reporting. The database includes measurements of total organic and inorganic carbon (TOC, TIC/CaCO3), and where possible some contextual biological information such as porosity, grain density and grain size. Additionally, where possible, data is georeferenced and cited (inclusive of access links) and further complimentary metadata is provided. The dataset may provide a key resource for future conservation planning, carbon accounting, and potentially climate modelling in polar marine ecosystems. This project was funded by the World Wildlife Fund (WWF) grant number GB096001.