ALBERT

Description: We present sea ice temperature and salinity data from first-year ice (FYI) and second-year ice (SYI) relevant to the temporal development of sea ice permeability and brine drainage efficiency from the early growth phase in October 2019 to the onset of spring warming in May 2020. Our dataset was collected in the central Arctic Ocean during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) Expedition in 2019 to 2020. MOSAiC was an international transpolar drift expedition in which the German icebreaker RV Polarstern anchored into an ice floe to gain new insights into Arctic climate over a full annual cycle. In October 2019, RV Polarstern moored to an ice floe in the Siberian sector of the Arctic at 85 degrees north and 137 degrees east to begin the drift towards the North Pole and the Fram Strait via the Transpolar Drift Stream. The data presented here were collected during the first three legs of the expedition, so all the coring activities took place on the same floe. The end dates of legs 1, 2, and 3 were 13 December, 24 February, and 4 June, respectively. The dataset contributed to a baseline study entitled, Deciphering the properties of different Arctic ice types during the growth phase of the MOSAiC floes: Implications for future studies. The study highlights downward directed gas pathways in FYI and SYI by inferring sea ice permeability and potential brine release from several time series of temperature and salinity measurements. The physical properties presented in this paper lay the foundation for subsequent analyses on actual gas contents measured in the ice cores, as well as air-ice and ice-ocean gas fluxes. Sea ice cores were collected with a Kovacs Mark II 9 cm diameter corer. To measure ice temperatures, about 4.5 cm deep holes were drilled into the core (intervals varied by site and leg) . The temperatures were measured by a digital thermometer within minutes after the cores were retrieved. The ice cores were placed into pre-labelled plastic sleeves sealed at the bottom end. The ice cores were transported to RV Polarstern and stored in a -20 degrees Celsius freezer. Each of the cores was sub-sampled, melted at room temperature, and processed for salinity within one or two days. The practical salinity was estimated by measuring the electrical conductivity and temperature of the melted samples using a WTW Cond 3151 salinometer equipped with a Tetra-Con 325 four-electrode conductivity cell. The practical salinity represents the the salinity estimated from the electrical conductivity of the solution. The dataset also contains derived variables, including sea ice density, brine volume fraction, and the Rayleigh number.

Description: Here we present dissolved nutrient data collected during Expedition 19S to the Arctic Ocean during September 2018 on board the R/V Sikuliaq, a research vessel operated by the University of Alaska. Data were generated within the framework of the NERC-BMBF Changing Arctic Ocean programme; project Primary productivity driven by escalating Arctic nutrient fluxes? (PEANUTS) in collaboration with the US Office of Naval Research Stratified Ocean Dynamics of the Arctic programme (SODA). A report is included, which provides further details about the data, funding agencies and research for which these data has been used.

Description: Time-series data of physical & biological oceanography, ocean current velocities, nutrient biogeochemistry, molecular biology and carbon/particle export were obtained from mooring HG-EGC-7 in the Fram Strait from June 2021 to July 2022 as part of the Helmholtz infrastructure program Frontiers in Arctic Marine Monitoring (FRAM) and the long-term monitoring program at AWI HAUSGARTEN. The mooring was deployed during RV POLARSTERN expedition PS126 and recovered during PS131. The attached archive contains raw data files of three Seabird SBE37 MicroCATs (nominal depths: 38m, 232m, 484m; sampling interval 1h), three AADI RCM11 current meters (nominal depths: 45m, 239m, 487m; sampling interval 1h), one AADI Seaguard current meter (nominal depth: 993m, sampling interval 1h), one Wetlabs ECO PAR sensor (nominal depth: 38m; sampling interval 1h), one Wetlabs ECO Triplet fluorometer (nominal depth: 38m; sampling interval 2h), two Satlantics SUNA nitrate sensors (nominal depths: 38m, 232m; sampling interval 4h), two Sunburst SAMI-pCO2 sensors (nominal depths: 38m, 232m; sampling interval 1h) and two Sunburst SAMI-pH sensors (nominal depths: 38m, 232m; sampling interval 3h). The mooring also included two McLane RAS water samplers (nominal depths: 38m, 232m; data archived elsewhere), one sediment trap (nominal depth: 480m; data archived elsewhere), and four PE samplers (nominal depths: 51m, 239m, 482m, 893m; data archived elsewhere). Auxiliary information such as sensor calibration sheets, mooring diagrams, and schedule files are also provided, if applicable. The pH sensor at 38 m, the ECO Triplet at 38 m and the SUNA at 232m had issues and did not record any valid data.

Description: Time-series data of physical & biological oceanography, nutrient biogeochemistry, molecular biology and carbon/particle export were obtained from mooring F4-S-5 in the Fram Strait from June 2021 to July 2022 as part of the Helmholtz infrastructure program Frontiers in Arctic Marine Monitoring (FRAM) and the long-term monitoring program at AWI HAUSGARTEN. The mooring was deployed during RV POLARSTERN expedition PS126 and recovered during PS131. The attached archive contains raw data files of four Seabird SBE37 MicroCATs (nominal depths: 17m, 22m, 46m, 241m; sampling interval 1h), one SBE56 temperature logger (nominal depth: 36m, sampling interval 60s), one Wetlabs ECO PAR sensor (nominal depth: 22m; sampling interval 1h), one Wetlabs ECO Triplet fluorometer (nominal depth: 22m; sampling interval 2h), two Satlantics SUNA nitrate sensors (nominal depths: 22m, 241m; sampling interval 4h), two Sunburst SAMI-pCO2 sensors (nominal depths: 22m, 241m; sampling interval 1h) and two Sunburst SAMI-pH sensors (nominal depths: 22m, 241m; sampling interval 3h). The mooring also included two McLane RAS water samplers (nominal depths: 22m, 241m; data archived elsewhere), two sediment traps (nominal depths: 194m, 603m; data archived elsewhere), and four PE samplers (nominal depths: 64m, 248m, 503m, 1112m; data archived elsewhere). Auxiliary information such as sensor calibration sheets, mooring diagrams, and schedule files are also provided, if applicable. The pH sensor at 22 m and both SUNAs had issues and did not record any data.

Description: Samples for the analysis of dissolved nutrients were collected during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) from the water column, sea ice cores and from special events/locations (e.g., leads, melt ponds, brine, incubation experiments). Samples for dissolved inorganic nutrients (NO3 +NO2 , NO2 , PO4 , Si(OH)4, NH4 ) were analysed onboard during PS122 legs 1 to 3, with duplicate samples collected from CTD casts for later analysis of total dissolved nitrogen (TDN) and total dissolved phosphorus (TDP). From leg 4, all samples collected were stored frozen at -20°C for later analysis. Analyses of stored samples were carried out at the AWI Nutrient Facility between January and March 2021. Nutrient analyses onboard and on land were carried out using a Seal Analytical AA3 continuous flow autoanalyser, controlled by the AACE software version 7.09. Best practice procedures for the measurement of nutrients were adopted following GO-SHIP recommendations (Hydes et al., 2010; Becker et al., 2019). Descriptions of sample collection and handling can be found in the various cruise reports (Haas & Rabe, 2023; Kanzow & Damm, 2023; Rex & Metfies, 2023; Rex & Nicolaus, 2023; Rex & Shupe, 2023). Here we provide data from the water column, obtained from the analysis of discrete samples collected from CTD-Rosette casts from Polarstern (https://sensor.awi.de/?site=search&q=vessel:polarstern:ctd_sbe9plus_321) and Ocean City (https://sensor.awi.de/?site=search&q=vessel:polarstern:ctd_sbe9plus_935). Data from sea ice cores and special events are presented elsewhere. Data from sea ice cores and special events are presented elsewhere. For reference, here we included data from CTD-BTL files associated with nutrient samples. These data are presented by Tippenhauer et al. (2023) Polarstern CTD and Tippenhauer et al. (2023) Ocean City CTD.

Description: Discrete seawater samples for total dissolved oxygen were collected from the Polarstern (vessel:polarstern:ctd_sbe9plus_321) and Ocean City (vessel:polarstern:ctd_sbe9plus_935) CTD/Rosette systems during the Multidisciplinary drifting observatory for the study of Arctic Climate (MOSAiC) expedition, 20 September 2019 – 14 October 2020. Dissolved oxygen was analyzed on board RV Polarstern during legs 3, 4, and 5 between 6 March 2020 and 17 September 2020. Seawater was drawn from Niskin bottles into Winkler flasks using silicon tubing, filling from the bottom and allowing seawater to overflow by at least two flask volumes (approximately 120 mL). The samples were directly pickled by the addition of 1 mL each of concentrated manganese chloride (3 M) and alkaline (NaOH 8 M) sodium iodide (4 M) solutions to form manganese oxyhydrodoxide precipitate. Samples were stored in the dark and underwater at room temperature until analysis. Dissolved oxygen was determined using an automatic Winkler titration setup with potentiometric detection (Titrino plus 848, Metrohm, Switzerland). Reagents were prepared according to Langdon (2010). Blanks were determined before each run by addition of reagents to MilliQ water. The titrations were performed directly in the flasks used for sampling after the manganese oxyhydroxide precipitate was dissolved by addition of sulphuric acid (5 M). Sodium thiosulphate (~0.2 N) solutions were prepared onboard for the titration and the concentration was determined before each run using an iodate standard (0.01 N, OSIL, United Kingdom). The analytical precision based on duplicate samples analysis was 0.4 ± 2.6 µmol/kg (n = 60).

Description: To investigate the effect of temperature on a North Sea spring bloom community, we performed an incubation experiment in the mesocosm facility of the Institute for Chemistry and Biology of the Marine Environment (ICBM) in Wilhelmshaven. The plankton community was sampled from the long-term ecological research station Helgoland Roads (https://deims.org/1e96ef9b-0915-4661-849f-b3a72f5aa9b1) on the 6ᵗʰ of March, 2022. Collection of the surface community was conducted from the RV Heincke with a pipe covered with a 200 µm net that was attached to a diaphragm pump. The month-long incubation was started on the 7ᵗʰ of March in twelve indoor mesocosms, the Planktotrons (Gall et al., 2017). We chose three temperatures along the ascending part of the thermal performance curve (TPC) of the in situ community: the minimum temperature for positive growth (6°C, also the field temperature), the middle between the minimum and the optimum temperature (12 °C), and the optimum temperature for growth (18 °C). Ramping up the temperatures was conducted by 1 °C per day until the treatment temperatures were reached, resulting in a ramp phase (first twelve days) and a constant temperature phase. This dataset comprises all data collected within the experiment. Temperature, oxygen, pH, salinity, and in vivo fluorescence were measured daily at 10 am. Samples for dissolved nutrients (nitrate, nitrite, phosphate, silicate), chlorophyll a, DNA, particulate nutrients (biogenic silica, particulate organic carbon/nitrogen/phosphorus), as well as flow cytometric counts of bacteria (stained) and the unstained community were sampled every third day at the same time. The mesocosm water was generally filtered over a 200 µm mesh before sampling to exclude mesozooplankton. However, due to the appearance of large Phaeocystis colonies, additional samples without pre-filtration were taken for particulate organic carbon, nitrogen, phosphorus, and chlorophyll a starting on incubation day 15. PAR, total nitrogen and phosphorus as well as total alkalinity were measured at the start, in the middle, and at the end of the incubation. Samples for Mesozooplankton enumeration were taken and plankton species identified at the end of the experiment. All analysis scripts can be found on github (https://github.com/AntoniaAhme/TopTrons22MesocosmIncubation). The sequence data are available at the European Nucleotide Archive (ENA).

Description: We present sea ice temperature and salinity data from first-year ice (FYI) and second-year ice (SYI) relevant to the temporal development of sea ice permeability and brine drainage efficiency from the early growth phase in October 2019 to the onset of spring warming in May 2020. Our dataset was collected in the central Arctic Ocean during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) Expedition in 2019 to 2020. MOSAiC was an international transpolar drift expedition in which the German icebreaker RV Polarstern anchored into an ice floe to gain new insights into Arctic climate over a full annual cycle. In October 2019, RV Polarstern moored to an ice floe in the Siberian sector of the Arctic at 85 degrees north and 137 degrees east to begin the drift towards the North Pole and the Fram Strait via the Transpolar Drift Stream. The data presented here were collected during the first three legs of the expedition, so all the coring activities took place on the same floe. The end dates of legs 1, 2, and 3 were 13 December, 24 February, and 4 June, respectively. The dataset contributed to a baseline study entitled, Deciphering the properties of different Arctic ice types during the growth phase of the MOSAiC floes: Implications for future studies. The study highlights downward directed gas pathways in FYI and SYI by inferring sea ice permeability and potential brine release from several time series of temperature and salinity measurements. The physical properties presented in this paper lay the foundation for subsequent analyses on actual gas contents measured in the ice cores, as well as air-ice and ice-ocean gas fluxes. Sea ice cores were collected with a Kovacs Mark II 9 cm diameter corer. To measure ice temperatures, about 4.5 cm deep holes were drilled into the core (intervals varied by site and leg) . The temperatures were measured by a digital thermometer within minutes after the cores were retrieved. The ice cores were placed into pre-labelled plastic sleeves sealed at the bottom end. The ice cores were transported to RV Polarstern and stored in a -20 degrees Celsius freezer. Each of the cores was sub-sampled, melted at room temperature, and processed for salinity within one or two days. The practical salinity was estimated by measuring the electrical conductivity and temperature of the melted samples using a WTW Cond 3151 salinometer equipped with a Tetra-Con 325 four-electrode conductivity cell. The practical salinity represents the the salinity estimated from the electrical conductivity of the solution. The dataset also contains derived variables, including sea ice density, brine volume fraction, and the Rayleigh number.

Description: Time-series data of physical & biological oceanography, nutrient biogeochemistry and molecular biology were obtained from mooring HG-IV-S-4 in the Fram Strait in August 2019 - June 2021 as part of the Helmholtz infrastructure program Frontiers in Arctic Marine Monitoring (FRAM) and the long-term monitoring program at AWI HAUSGARTEN. The mooring was deployed during RV POLARSTERN expedition PS121, and recovered during PS126. The attached archive contains raw data files of three Seabird SBE37 microcats (nominal depths: 18m, 23m, 47m; sampling interval 1h), two Seabird SBE56 temperature loggers (nominal depths: 28m, 38m; sampling interval 30s), one Wetlabs ECO Triplet fluorometer (nominal depth: 23m; sampling interval 2h) and one Wetlabs ECO PAR sensor (nominal depth: 23m; sampling interval 2h). One ISUS nitrate sensor (nominal depth: 23m) was flooded and no data is available. The mooring also included a McLane RAS water sampler (nominal depth: 23m) and a McLane PPS phytoplankton sampler (nominal depth: 25m). Auxiliary information such as sensor calibration sheets, mooring diagrams and schedule files are also provided, if applicable.

Description: Time-series data of physical & biological oceanography, nutrient biogeochemistry and molecular biology were obtained from mooring F4-W-2 in the Fram Strait in August 2019 - June 2021 as part of the Helmholtz infrastructure program Frontiers in Arctic Marine Monitoring (FRAM) and the long-term monitoring program at AWI HAUSGARTEN. The mooring was deployed during RV POLARSTERN expedition PS121, and recovered during PS126. The attached archive contains raw data files of one Seabird SBE37 microcat (nominal depths: 249m; sampling interval 1h), one Satlantics SUNA nitrate sensor (nominal depth: 249m; sampling interval 6h), one Sunburst SAMI-pCO2 sensor (nominal depth: 249m; sampling interval 2h) and one Sunburst SAMI-pH sensor (nominal depth: 249m; sampling interval 3h). The mooring also included a McLane RAS water sampler (nominal depth: 249m). The profiling SBE19plus system that was operated on the NGK winch (nominal depth: 153m) was lost. Additionally, the available data could not be downloaded from the main controller due to a corrupt SD card. Auxiliary information such as sensor calibration sheets, mooring diagrams and schedule files are also provided, if applicable.