Data from: Pelagic Ecosystem Characteristics Across the Atlantic Water Boundary Current From Rijpfjorden, Svalbard, to the Arctic Ocean During Summer (2010–2014) The dataset contains six sub-datasets: CTD, Biogeochemistry, Carbonate, Phytoplankton abundance, Phytoplankton biomass, Zooplankton abundance. The datasets are published in Hop et al. 2019 “Pelagic Ecosystem Characteristics across the Atlantic Water Boundary Current from Rijpfjorden, Svalbard, to the Arctic Ocean During Summer (2010-2014)”.

Data set on colored dissolved organic matter (CDOM) absorption and dissolved organic carbon (DOC) in the Fram Strait (~78°50’ N), collected during the annual Norwegian Polar Institute's research and monitoring cruises to the Fram Strait Arctic Outflow Observatory. CDOM data has been collected annually since 2009 in August September, and DOC during a number of years.

We performed measurements of carbon dioxide fugacity (fCO2) in the surface water under 8 Arctic sea ice from January to June 2015 during the Norwegian young sea ICE (N-ICE2015) expedition. Over 9 this period, the ship drifted with four different ice floes and covered the deep Nansen Basin, the slopes 10 north of Svalbard, and the Yermak Plateau. This unique winter-to-spring data set includes the first 11 winter-time under-ice water fCO2 observations in this region. The observed under-ice fCO2 ranged between 12 315 matm in winter and 153 matm in spring, hence was undersaturated relative to the atmospheric fCO2. 13 Although the sea ice partly prevented direct CO2 exchange between ocean and atmosphere, frequently 14 occurring leads and breakup of the ice sheet promoted sea-air CO2 fluxes. The CO2 sink varied between 0.3 15 and 86 mmol C m22 d21, depending strongly on the open-water fractions (OW) and storm events. The 16 maximum sea-air CO2 fluxes occurred during storm events in February and June. In winter, the main drivers 17 of the change in under-ice water fCO2 were dissolution of CaCO3 (ikaite) and vertical mixing. In June, in 18 addition to these processes, primary production and sea-air CO2 fluxes were important. The cumulative loss 19 due to CaCO3 dissolution of 0.7 mol C m22 in the upper 10 m played a major role in sustaining the 20 undersaturation of fCO2 during the entire study. The relative effects of the total fCO2 change due to CaCO3 21 dissolution was 38%, primary production 26%, vertical mixing 16%, sea-air CO2 fluxes 16%, and temperature 22 and salinity insignificant.

This dataset contains results from seawater column samples collected in Rijpfjorden (80°N, 22°30’E) and northern coast of Svalbard during three years in July 2012-2014 using R/V Lance. Measured variables include seawater total alkalinity (AT), total dissolved inorganic carbon (DIC), salinity, and temperature.

Dataset for paper "Niches of marine mammals in the European Arctic" in Ecological Indicators. Data include carbon and nitrogen stable isotope compositions for blue whales, fin whales, humpback whales, minke whales, white whales, walruses, bearded seals, ringed seals and polar bears, and dietary fatty acids compositions for blue whales, fin whales, humpback whales, minke whales, white whales, walruses and polar bears.

This dataset contains results from seawater column samples collected in Kongsfjorden (between 78°50' and 79°04'N and 11°20' and 12°30'E) and West-Spitsbergen shelf (Svalbard) during three years in July 2012-2014 using R/V Lance. Measured variables include seawater total alkalinity (AT), total dissolved inorganic carbon (DIC), salinity, and temperature.

Datasets collected during TW-ICE cruise to Kongsfjorden in July 2017. The datasets contain measurements close to glacier fronts taken with a research vessel and helicopter, and have been published in Halbach et al. (2019; see the "Citation Custom" field). The datasets are compiled following files: **Nutrient data.csv** Nutrient measurements together with station metadata. Columns: station = station name; vessel = either the research vessel (Lance) or helicopter; lon = longitude as decimal degrees (WGS84); lat = latitude as decimal degrees (WGS84); date = date in ISO8601 format; area = zone used in the article; dist = distance from the closest glacier front in km; depth = bottom depth in m at the station; from = the water depth from which the sample was collected in m; sal = salinity from the closest CTD; temp = water temperature from the closest CTD; type = water type classification based on salinity and temperature (see the article); ctd.name = name of the closest CTD cast; chla = chlorophyll a in mg m-3; phaeo = phaeophytin in mg m-3; tsm = total suspended matter in g m-3; no2 = nitrite concentration in mmol m-3; no3 = nitrate concentration in mmol m-3; sioh4 = silicate concentration in mmol m-3; po4 = phosphate concentration in mmol m-3; nh4 = ammonium concentration in mmol m-3; urea = urea concentration in mmol m-3. **Phytoplankton data.csv** Phytoplankton taxonomy data together with station metadata. Columns: station = station name; lon = longitude as decimal degrees (WGS84); lat = latitude as decimal degrees (WGS84); date = date in ISO8601 format; area = zone used in the article; dist = distance from the closest glacier front in km; depth = bottom depth in m at the station; from = the water depth from which the sample was collected in m; sal = salinity from the closest CTD; temp = water temperature from the closest CTD; type = water type classification based on salinity and temperature (see the article); ctd.name = name of the closest CTD cast; group = coarse functional grouping; species = species or taxa; abundance = abundance of the species in cells dm-3. **CTD data.json** CTD data in a list format. See the [oce-class](https://www.rdocumentation.org/packages/oce/versions/1.0-1/topics/ctd-class) documentation for the `oce` R package for further details on formatting. The results are from a Sea-Bird SBE 9 (Lance) and Hydro-Bios Multi-Water-Sampler (helicopter). **Water type data.csv** Water type classification data together with station metadata. Columns: row_id = unique ID for a CTD cast; station = station name; vessel = either the research vessel (Lance) or helicopter; lon = longitude as decimal degrees (WGS84); lat = latitude as decimal degrees (WGS84); date = date in ISO8601 format; area = zone used in the article; depth = bottom depth in m at the station; ctd.name = name of the closest CTD cast; type = water type classification based on salinity and temperature (see the article); freq = frequency of 1 decibar bins containing the given water type; per = percentage of 1 decibar bins containing the given water type as compared to total number of bins for a CTD cast. **Mixed layer data.csv** Mixed layer data. Columns: station = station name; ctd.name = name of the closest CTD cast; pres = pressure of the maximum N2 bin in decibars; sal = salinity at the maximum N2 depth; temp = water temperature at the maximum N2 depth in Celsius; rho = potential water density at the maximum N2 depth; n2 = the maximum Brunt-Väisälä-frequency during CTD cast close to the surface; mld = estimated mixed layer depth based on maximum N2 in m. **Euphotic depth data.csv** Euphotic depth data. Columns: station = station name; depth = depth of the estimated euphotic depth in m; par = photosynthetically active radiation at the euphotic depth; spar = photosynthetically active radiation on the surface; per = percentage ratio between par and spar.

The phytoplankton and ice-algae dataset contains counts of algae performed in an Imaging Flow Cytobot (IFCB) and in an inverted microscope. The counts were performed after the cruise using fixed samples collected from the sea ice and the water column.

This is an umbrella (metadata-only) dataset that provides links to all individual datasets collected during the Norwegian young sea ICE expedition (N-ICE2015). The metadata is available in [DCAT (JSON-LD)](http://api.npolar.no/dataset/?q=&filter-sets=N-ICE2015&format=json&variant=ld) and as [DIF XML via OAI-PMH](http://api.npolar.no/dataset/oai?verb=ListRecords&metadataPrefix=dif&set=N-ICE2015). For humans: The NPDC dataset catalogue contains a searchable [list of N-ICE2015 datasets](https://data.npolar.no/dataset/?filter-sets=N-ICE2015).