ALBERT

Description: This is a compilation of all short-wave and long-wave radiation datasets from Reunion Island that were and are published in the frame of BSRN. New data will be added regularly. The data are subject to the data release guidelines of BSRN (https://bsrn.awi.de/data/conditions-of-data-release/).

Description: Core MVSEIS08-TG-2 was acquired during the Euromargin-MVSEIS08 cruise on the Moroccan margin, south of the Gulf of Cadiz. This site was targeted to discuss the possibility of the saline upper branch of the Mediterranean Outflow Water (MOW) diverging southwards along the Moroccan margin, in addition to the well-established northern MOW current. The southern TG-2 is a 2.12 m gravity core. Contourite records cover the time interval from the last deglaciation starting at HS1 (18.6 ka) to the Holocene. New datasets of current velocity (sortable silt) and water mass origin (O and C isotopes of benthic foraminifera) define the intensity of the MOW as contourite deposits, together with element ratios (XRF-scan) and physical properties of the sediment. O and C isotopes of planktonic foraminifera, foraminiferal species and sea surface temperature (simmax.28 transfer function) were used to determine millennial climate changes during the last deglaciation.

Description: Core GC-01A was collected during the Contouriber-I cruise in the northern Gulf of Cadiz, bathed by the well-established northern Mediterranean Outflow Water (MOW) current along the Iberian margin; this site was a contrasting reference site to discuss the possibility of the saline upper branch of the MOW diverging southwards along the Moroccan margin (core MVSEIS08-TG-2). GC-01A-TC (0.87 m) and GC-01A-PC (5.21 m) consist of trigger and gravity cores from the same site, with both sections connected by a time gap at 8-9 ka. The contourite records cover the time interval from the Last Glacial Maximum (22 ka) through the last deglaciation to the Holocene (GC-01A). New datasets of current velocity (sortable silt) and water mass origin (O and C isotopes of benthic foraminifera) define the intensity of the MOW as contourite deposits, together with element ratios (XRF-scan) and physical properties of the sediment. O and C isotopes of planktonic foraminifera, foraminiferal species and sea surface temperature (simmax.28 transfer function) were used to determine millennial climate changes during the last deglaciation.

Description: This dataset shows benthic and planktic foraminiferal data, planktic foraminiferal fragmentation and coarse fraction values. The sampled sediment record PS93/016, consisting of the Giant box core (GKG) PS93/016-4 (81.217°N, 7.341°W, 1549.8 m water depth) and the Kastenlot core (KAL) PS93/016-6 (81.217°N, 7.341°W, 1548.3 m water depth), was obtained during the expedition PS93.1 (2015) (Stein, 2016) of RV Polarstern at the NE Greenland continental margin in the northwestern Fram Strait. The presented data covers the last ca. 195 ka. In representative splits of the 100-250 µm size fraction, planktic and benthic foraminifers were determined and counted. Fragmentation of planktic foraminifers was calculated by counting fragments which were no more determinable to species level. Thereby, the equation from Pfuhl and Shackleton (2004) was used which includes a fragment-divisor of 3. Aim of the study was to reconstruct glacial advance and retreat, changes in sea-ice and export of freshwater in the western Fram Strait and, to a certain extent, in the Arctic Ocean.

Description: This dataset shows measured stable isotopes of N. pachyderma & C. neoteretis (without vital effect correction). The sampled sediment record PS93/016, consisting of the Giant box core (GKG) PS93/016-4 (81.217°N, 7.341°W, 1549.8 m water depth) and the Kastenlot core (KAL) PS93/016-6 (81.217°N, 7.341°W, 1548.3 m water depth), was obtained during the expedition PS93.1 (2015) (Stein, 2016) of RV Polarstern at the NE Greenland continental margin in the northwestern Fram Strait. The presented data covers the last ca. 195 ka. For stable oxygen and carbon isotope analyses, ca. 30 specimens of the planktic foraminifer Neogloboquadrina pachyderma or the benthic foraminifer species Cassidulina neoteretis from the 100–250 μm fraction were used. Results are expressed in the δ notation referring to the PDB (Pee Dee Belemnite) standard while using NBS 19. Aim of the study was to reconstruct glacial advance and retreat, changes in sea-ice and export of freshwater in the western Fram Strait and, to a certain extent, in the Arctic Ocean.

Description: The high surface productivity triggered by nutrient-rich Benguela upwelled waters results in significant enrichment of organic carbon in the sub-surface waters due to enhanced mineralization in the water column and benthic fluxes. Hence, microbial O2-consuming processes are promoted, driving oxygen depletion that favors trace gases i.e. methane (CH4) and nitrous oxide (N2O) production at relatively shallow depths. During upwelling, gas-rich subsurface waters are also transported towards the surface waters, enhancing trace gas sea-air fluxes. We investigate the variability of these fluxes on seasonal and shorter timescales to understand the intensity of the Benguela upwelling system in gas emissions. The data might serve as a base for projections under a changing climate. The fieldwork took place during the cruise M157 (August 4th – September 16th, 2019) onboard the R/V METEOR, which encompassed close-coastal and open ocean regions between Mindelo (Cape Verde) and Walvis Bay. The main transect lines around 18, 23 and 25°S represents the Angola-Benguela frontal zone, Walvis Bay and Lüderitz upwelling cells respectively, which are suggested to represent some regional hotspots of trace gas emissions to the atmosphere, in particular in the vicinity of the upwelling cells. The partial pressures of CH4, N2O, and CO2 as well as oxygen saturation in surface water were determined using IOW's self-built Mobile Equilibrator Sensor System (MESS). The system was described in details elsewhere (Sabbaghzadeh et al., 2021) but in brief, it consists of a custom-built equilibrator (combined shower-head/bubble type) with a water flow rate of about 5 l min-1 and an airflow rate of ~ 4 l min-1, which is linked to two off-axis integrated cavity output laser spectrometers (oa-ICOS, Los Gatos Instruments) for the detection of CH4 / CO2 and N2O / CO. Seawater was supplied by a pump installed at a water depth of about 6 m in the moon pool on board of RV METEOR. oa-ICOS sensors combine a highly specific infrared band laser with a set of reflective mirrors and achieve an effective absorption path length of several kilometers. This enables the detection of the trace gases with high accuracy. Three standard gases, provided by the central calibration lab of the European Integrated Carbon Observation System Research Infrastructure (ICOS RI) were used to calibrate the sensors almost daily throughout the entire expedition. To estimate sea-air gas fluxes, the atmospheric concentration of trace gases was also measured at several positions during the cruise using a tube with the inlet positioned to minimize ship contamination. All other ancillary parameters out of the MESS system were synchronized with D-ship data with a simultaneous data reduction to one-minute intervals.

Description: This publication comprises the following meteorological parameters: air temperature, relative humidity, soil temperature (at 2 cm, 5 cm, and 20 cm depths), soil water content (at 2 cm, 5 cm, and 20 cm depths), soil water potential (at 5 cm and 20 cm depths), precipitation, snow height, solar radiation, wind speed and wind direction. All parameters were collected by five automatic weather stations ranging from 983 m a.s.l. to 2705 m a.s.l. within the IT25 LT(S)ER site Matschertal – Val Mazia in Northern Italy. The automatic weather stations were installed and are operated by Eurac Research. The dataset covers the period from 2017 to 2022 and was collected for monitoring purposes within the LT(S)ER project. The data includes both raw time series and processed time series (cleaned data), including information on data treatments.

Description: The high surface productivity triggered by nutrient-rich Benguela upwelled waters results in significant enrichment of organic carbon in the sub-surface waters due to enhanced mineralization in the water column and benthic fluxes. Hence, microbial O2-consuming processes are promoted, driving oxygen depletion that favors trace gases i.e. methane (CH4) and nitrous oxide (N2O) production at relatively shallow depths. During upwelling, gas-rich subsurface waters are also transported towards the surface waters, enhancing trace gas sea-air fluxes. We investigate the variability of these fluxes on seasonal and shorter timescales to understand the intensity of the Benguela upwelling system in gas emissions. The data might serve as a base for projections under a changing climate. The fieldwork took place during the cruise M157 (August 4th – September 16th, 2019) onboard the R/V METEOR, which encompassed close-coastal and open ocean regions between Mindelo (Cape Verde) and Walvis Bay. The main transect lines around 18, 23 and 25°S represents the Angola-Benguela frontal zone, Walvis Bay and Lüderitz upwelling cells respectively, which are suggested to represent some regional hotspots of trace gas emissions to the atmosphere, in particular in the vicinity of the upwelling cells. To explore further, nearly 300 discrete water samples were collected from the Niskin bottles at different stations for determination of the concentrations of CH4, N2O, and total inorganic carbon (CT). Analysis for CH4 and N2O was performed using an in-house designed purge and trap system with a dynamic headspace. In brief, a subsample of the water is purged with an inert ultrapure carrier gas of Helium, and the gases are focused on a cryo-trap operated at about -120°C. The volatile compounds are desorbed by rapid heating and analyzed by a gas chromatograph (Agilent 7890 B), equipped with a Flame Ionization Detector for CH4 and an Electron Capture Detector for N2O measurements, respectively. Samples for CT were taken to investigate the carbonate system. CT was measured using an automated Infra-Red Inorganic Carbon Analyzer (AIRICA) system (Marianda e.K., 24145 Kiel) from discrete 250 ml samples. In brief, a subsample is drawn into a volume-calibrated syringe and injected into a purge vessel, where the discrete sample is acidified. All species of the inorganic carbon system are converted to CO2, which is purged from the water using a carrier gas that streams through the acidified probe. Then the gas flows through a Peltier cooler and a NAFION dryer to be dried. The concentration of CO2 is then measured by an infrared detector (LICOR 7000), which integrates the peak of the purged sample. The integrated signal is directly proportional to the carbon released, allowing the CT concentration to be calculated with high precision. Certified reference material (CRM) of known CT-concentration is used for standardization and to account for drift of the sensor response.

Description: The high surface productivity triggered by nutrient-rich Benguela upwelled waters results in significant enrichment of organic carbon in the sub-surface waters due to enhanced mineralization in the water column and benthic fluxes. Hence, microbial O2-consuming processes are promoted, driving oxygen depletion that favors trace gases i.e. methane (CH4) and nitrous oxide (N2O) production at relatively shallow depths. During upwelling, gas-rich subsurface waters are also transported towards the surface waters, enhancing trace gas sea-air fluxes. We investigate the variability of these fluxes on seasonal and shorter timescales to understand the intensity of the Benguela upwelling system in gas emissions. The data might serve as a base for projections under a changing climate. The fieldwork took place during the cruise M157 (August 4th – September 16th, 2019) onboard the R/V METEOR, which encompassed close-coastal and open ocean regions between Mindelo (Cape Verde) and Walvis Bay. The main transect lines around 18, 23 and 25°S represents the Angola-Benguela frontal zone, Walvis Bay and Lüderitz upwelling cells respectively, which are suggested to represent some regional hotspots of trace gas emissions to the atmosphere, in particular in the vicinity of the upwelling cells. The partial pressures of CH4, N2O, and CO2 as well as oxygen saturation in surface water were determined using IOW's self-built Mobile Equilibrator Sensor System (MESS). The system was described in details elsewhere (Sabbaghzadeh et al., 2021) but in brief, it consists of a custom-built equilibrator (combined shower-head/bubble type) with a water flow rate of about 5 l min-1 and an airflow rate of ~ 4 l min-1, which is linked to two off-axis integrated cavity output laser spectrometers (oa-ICOS, Los Gatos Instruments) for the detection of CH4 / CO2 and N2O / CO. Seawater was supplied by a pump installed at a water depth of about 6 m in the moon pool on board of RV METEOR. oa-ICOS sensors combine a highly specific infrared band laser with a set of reflective mirrors and achieve an effective absorption path length of several kilometers. This enables the detection of the trace gases with high accuracy. Three standard gases, provided by the central calibration lab of the European Integrated Carbon Observation System Research Infrastructure (ICOS RI) were used to calibrate the sensors almost daily throughout the entire expedition. To estimate sea-air gas fluxes, the atmospheric concentration of trace gases was also measured at several positions during the cruise using a tube with the inlet positioned to minimize ship contamination. All other ancillary parameters out of the MESS system were synchronized with D-ship data with a simultaneous data reduction to one-minute intervals.

Description: The stable silicon isotopic composition of siliceous sponge skeletal elements, spicules, is a potential archive of past dissolved silicon (silicic acid, or DSi) concentrations in bottom waters. Several field-based studies have shown that there is a non-linear relationship between the concentration of ambient DSi and both the isotopic composition (denoted by d30Si) of spicules and apparent isotopic fractionation by sponges during growth. There is considerable scatter in the calibration, with some studies highlighting variation within an individual sponge, and between individuals in both monospecific and more diverse populations. When reconstructing past DSi, it is only possible to differentiate spicules by their morphology, which in many cases will not be taxonomically diagnostic. However, there has yet to be a systematic study of core top and downcore d30Si measurements from different spicule types. Here we address that gap using spicules extracted from two shallow sediment cores from the Schultz Massif Seamount between the Norwegian and Greenland Seas collected on R/V G.O.Sars expedition GS2016109A. Sediments were sliced at 1cm intervals, washed and dried, and spicules hand-picked out and sorted by morphological type. The spicules were dissolved and analysed for silicon isotopic composition using a multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS).