ALBERT

Description: A standard CTD system from Sea-Bird Electronics Inc SBE911+ with duplicate temperature and conductivity sensors was used to measure temperature, conductivity and pressure at 86 stations during an expedition to the Kara and Laptev Seas and the adjacent Arctic Ocean in August-September 2021 aboard the research vessel “Akademik Tryoshnikov”. We followed the manufacturer's recommendation to calculate salinity with Seabird processing software. The salinity is given as Practical Salinity (PSU). Data were averaged in depth bins of 1 m. The processed, but not bin-averaged, cnv-files from each station are also part of this publication (zip file). The accuracy of the conductivity sensors was verified by measurements on water samples with a salinometer. The data set published here includes only the data from the first conductivity (SN 3290) and temperature (SN 4127) sensors. Only at station 26 the data of the second sensor pair (SN 2618/Cond, SN 5115/Temp) were used. The CTD was connected to an SBE32 carousel water sampler with 24 12-liter bottles. Additionally, a Wetlabs ECO-AFL Fluorometer was connected to the SBE911+ system. The data are provided by the Arctic Century Expedition, a joint initiative led by the Swiss Polar Institute (SPI), the Antarctic and Arctic Research Institute (AARI) and GEOMAR Helmholtz Centre for Ocean Research Kiel (GEOMAR) and funded by the Swiss Polar Foundation, AARI, Minobrnauki (CATS RFMEFI61619X0108) and BMBF (CATS 03F0831).

Description: A standard CTD system from Sea-Bird Electronics Inc SBE911+ with duplicate temperature and conductivity sensors was used to measure temperature, conductivity and pressure at 81 stations during an expedition to the Kara and Laptev Seas and the adjacent Arctic Ocean in August-September 2021 aboard the research vessel Akademik Tryoshnikov. We followed the recommendation of the manufacturer to calculate salinity with Seabird processing software. The salinity is given as Practical Salinity (PSU). The accuracy of the conductivity sensors was verified by measurements on water samples with a salinometer. The data set published here includes only the data from the first conductivity (SN 3290) and temperature (SN 4127) sensors. Only at station 26 the data of the second sensor pair (SN 2618/Cond, SN 5115/Temp) were used. The CTD was connected to a SBE32 Carousel Water Sampler with 24 12-liter bottles. Additionally, a Benthos Altimeter and a Wetlabs ECO-AFL Fluorometer were connected to the SBE911+ system. At 69 stations, 846 seawater samples were collected for analysis of dissolved inorganic nutrients (nitrate, nitrite, phosphate, ammonium, silicate), oxygen, total alkalinity, and pH. Dissolved inorganic nutrients were analyzed using a segmented flow analyzer from Seal Analytical. Ammonium was measured manually (colorimetric method) using a spectrophotometer (Shimadzu UV-1800). Dissolved oxygen was determined by the standard Winkler titration method using a Metrohm 916 TiTouch automatic titrator and a handheld titrator (BRAND). pH and total alkalinity were measured by potentiometric titration using an automatic titrator (Metrohm 916 TiTouch). The data are provided by the Arctic Century Expedition, a joint initiative led by the Swiss Polar Institute (SPI), the Antarctic and Arctic Research Institute (AARI) and GEOMAR Helmholtz Centre for Ocean Research Kiel (GEOMAR) and funded by the Swiss Polar Foundation, AARI, Minobrnauki (CATS RFMEFI61619X0108) and BMBF (CATS 03F0831).

Description: We here report measured densities from a combination of records from the EastGRIP ice-core site. The data come from a trench and two ice cores: the shallow EGRIP-S6 core and the deep main core of the project. Based on these data, we parametrize the density as a function of depth, allowing us to provide a standard transfer function between true depth and ice-equivalent depth which is consistent with the EGRIP density measurements. EGRIP density data are only available to 117 m depth, at which depth the density is about 900 kg/m^3 and the difference between true depth and ice-equivalent depth is about 22 m. The density and overburden profiles have been extended below this depth and all the way to 1200 m in order to provide a convenient, continuous and (mostly) smooth transfer function between true depth and ice-equivalent depth. See PDF file provided under 'Documentation' for full description of data and parametrization.

Description: Underway-CTD (UCTD) data were collected during an August-September 2021 expedition to the Arctic Ocean aboard the RV Akademik Tryoshnikov. The underway CTD manufactured by Ocean Science is a self-contained free-falling probe measuring temperature, conductivity, depth while the ship is transiting. The UCTD was operated mostly in yoyo-mode during selected transects on the shelf of the Kara and Laptev Seas and between the shelf and the basin across the continental slope of the Eurasian Basin while the ship was transiting with 4 - 10 knots. The UCTD probe records the start time of the measurements and stores 16 samples each second internally. The exact location of each profile was subsequently found based on the time stamp from the cruise track. The unpumped conductivity sensor has a slower response time than the temperature sensor, which makes the computation of salinity from conductivity and temperature potentially spiky, especially in the pycnocline or in frontal regions. We followed the recommendation of the manufacturer to calculate salinity with Seabird processing software. The salinity is given as Practical Salinity (PSU). The raw data profiles are provided as well and can be reprocessed if desired. In shallower waters (〈300 m), the water column was profiled all the way to the seafloor, while in deeper waters, only the upper 300-600 m were sampled. The UCTD was calibrated against a Seabird 9+ CTD during the cruise. The upper 5 m of the data were discarded due to the influence of the ship. The icebreaker Akademik Tyoshnikov has a deep draft. Mixing of the water column caused by the ship can reach depths of up to about 10 m, depending on the weather conditions and the ship's speed. The data are provided by the Arctic Century Expedition, a joint initiative led by the Swiss Polar Institute (SPI), the Antarctic and Arctic Research Institute (AARI) and GEOMAR Helmholtz Centre for Ocean Research Kiel (GEOMAR) and funded by the Swiss Polar Foundation, AARI, Minobrnauki (CATS RFMEFI61619X0108) and BMBF (CATS 03F0831)

Description: A key goal of the AL544 cruise in September 2020 in the Baltic Sea was to enhance our understanding of environmental and zooplankton (especially gelatinous) population fluctuations along an east-west transect. Vertically integrated mesozooplankton abundance and diversity was obtained from plankton net hauls followed by image analysis. Samples were collected using a Hydrobios standard WP2 net (200µm) vertical from bottom to surface. Samples were scanned using an Epson V750 Pro flatbed scanner at 2400dpi, scanned as one size fraction, split sometimes multiple times. Processed using ZooProcess. Image data are available on https://ecotaxa.obs-vlfr.fr/prj/5189 and were sorted into taxonomic categories (examples in AL544_mesozoo_examples.zip). Using the export file (.tsv) individual biomass was calculated based on object area and taxonomic identity according to Lehette and Hernandez-Leon (2009). Abundance and biomass are then aggregated to concentrations (per volume).

Description: Imagery transects with a camera attached to a frame design for taking pictures in a 50 x 50 cm area. Seabed images transects were carried out by scientific divers during the Heincke HE601 cruise focusing on developing and testing monitoring techniques at the Borkum Reef Ground and Sylt Outer Reef Marine Protected Areas. The camera used was a Canon EOS M6 camera, the pictures were taken perpendicularly to the seabed. The transects were done along a preset track across the reefs, number of pictures per transect varied based on diving time. The seabed images provide insights into the general composition of key species, higher systematic groups and ecological guilds. The images also contain valuable information on how benthic species are associated to each other. Transect files include individual images, whereas metadata of each image including diving depth, date/time, if the image was further analyzed, corresponding diver is found in a separate file. Geographical coordinates of individual images is unavailable.

Description: We here report measured densities from a combination of records from the EastGRIP ice-core site. The data come from a trench and two ice cores: the shallow EGRIP-S6 core and the deep main core of the project. Based on these data, we parametrize the density as a function of depth, allowing us to provide a standard transfer function between true depth and ice-equivalent depth which is consistent with the EGRIP density measurements. EGRIP density data are only available to 117 m depth, at which depth the density is about 900 kg/m^3 and the difference between true depth and ice-equivalent depth is about 22 m. The density and overburden profiles have been extended below this depth and all the way to 1200 m in order to provide a convenient, continuous and (mostly) smooth transfer function between true depth and ice-equivalent depth. See PDF file provided under 'Documentation' for full description of data and parametrization.

Description: We here report measured densities from a combination of records from the EastGRIP ice-core site. The data come from a trench and two ice cores: the shallow EGRIP-S6 core and the deep main core of the project. Based on these data, we parametrize the density as a function of depth, allowing us to provide a standard transfer function between true depth and ice-equivalent depth which is consistent with the EGRIP density measurements. EGRIP density data are only available to 117 m depth, at which depth the density is about 900 kg/m^3 and the difference between true depth and ice-equivalent depth is about 22 m. The density and overburden profiles have been extended below this depth and all the way to 1200 m in order to provide a convenient, continuous and (mostly) smooth transfer function between true depth and ice-equivalent depth. See PDF file provided under 'Documentation' for full description of data and parametrization.

Description: We here report measured densities from a combination of records from the EastGRIP ice-core site. The data come from a trench and two ice cores: the shallow EGRIP-S6 core and the deep main core of the project. Based on these data, we parametrize the density as a function of depth, allowing us to provide a standard transfer function between true depth and ice-equivalent depth which is consistent with the EGRIP density measurements. EGRIP density data are only available to 117 m depth, at which depth the density is about 900 kg/m^3 and the difference between true depth and ice-equivalent depth is about 22 m. The density and overburden profiles have been extended below this depth and all the way to 1200 m in order to provide a convenient, continuous and (mostly) smooth transfer function between true depth and ice-equivalent depth. See PDF file provided under 'Documentation' for full description of data and parametrization.

Description: We here report measured densities from a combination of records from the EastGRIP ice-core site. The data come from a trench and two ice cores: the shallow EGRIP-S6 core and the deep main core of the project. Based on these data, we parametrize the density as a function of depth, allowing us to provide a standard transfer function between true depth and ice-equivalent depth which is consistent with the EGRIP density measurements. EGRIP density data are only available to 117 m depth, at which depth the density is about 900 kg/m^3 and the difference between true depth and ice-equivalent depth is about 22 m. The density and overburden profiles have been extended below this depth and all the way to 1200 m in order to provide a convenient, continuous and (mostly) smooth transfer function between true depth and ice-equivalent depth. See PDF file provided under 'Documentation' for full description of data and parametrization.