ALBERT

Description: Since 2001, current velocities have been measured continuously as part of a multilateral collaboration, the Prediction and Research Moored Array in the Tropical Atlantic (PIRATA), that regularly services a moored observatory located at 0°N, 23°W. Here, we present 20 years of full-depth current velocity observations at 0°N, 23°W. With the presented current velocity data product, we aim to provide an important and accessible reference data set against which models and reanalysis output could be validated. The velocity time series will also be helpful for studies focusing on long-term climate variability to search for connections with changes in the equatorial circulation over the last 20 years. Earlier versions of this data product have already been used in a variety of studies and provided a significant contribution to an overall improved understanding of equatorial ocean dynamics. The moored observatory at 0°N, 23°W is an ongoing example of a successful multinational collaboration extending over more than two decades.

Description: Plant protection products in the environment are partly responsible for the progressive loss of biodiversity. The mostly insufficient ecological status of surface waters is often explained by habitat degradation and excessive nutrient input. But what role do plant protection products play in this context? The Kleingewässermonitoring (KgM) project provides a worldwide unique quantitative assessment of the impact of pesticides from diffuse agricultural sources on small and medium-sized streams. The dataset comprises 124 monitoring stream sections all over Germany covering a wide pollution gradient where consistent measurements were carried out in 2018 and 2019 during the major pesticide application period from April to July. These measurements include event-driven sampling to record surface rainfall-induced short-term peak concentrations in addition to regular grab sampling of pesticides and a wide range of other pollutants resulting in more than 1,000 water samples. All further relevant anthropogenic and environmental parameters reigning ecological stream quality were recorded comprehensively (morphological and stream bed structure, temperature, flow velocity, dissolved oxygen, pH, catchment land use, stream profile). The dataset also contains effect monitoring data featuring sampled invertebrate communities and bioassay analyses of water samples. The data enables an assessment of pesticide exposure and related effects as well as the analysis of complex causal relationships in streams.

Description: The breakup of drops and bubbles in turbulent fluids is a key mechanism in many environmental and engineering processes. Even in the well-studied dilute case, quantitative descriptions of drop fragmentation remain elusive and empirical models continue to proliferate. We here investigate drop breakup by leveraging a novel computer code, which enables the generation of ensembles of experiments with thousands of independent, fully-resolved simulations. We show that in homogeneous isotropic turbulence breakup is a memoryless process whose rate depends only on the Weber number. A simple model based on the computed breakup rates can accurately predict experimental measurements and demonstrates that dilute emulsions evolve through a continuous fragmentation process with exponentially increasing time scales. Our results suggest a non-vanishing breakup rate below the critical Kolmogorov-Hinze diameter, challenging the current paradigm of inertial drop fragmentation.

Description: Raw data acquired by position sensors on board RV SONNE during expedition SO292 were processed to receive a validated master track which can be used as reference of further expedition data. During SO292 the motion reference unit Kongsberg SeaTex AS MRU-5 combined with Kongsberg SeaTex AS Seapath 320 and two GPS receivers SAAB MGL-4 were used as navigation sensors. Data were downloaded from DAVIS SHIP data base (https://dship.bsh.de) with a resolution of 1 sec. Processing and evaluation of the data is outlined in the data processing report. Processed data are provided as a master track with 1 sec resolution derived from the position sensors' data selected by priority and a generalized track with a reduced set of the most significant positions of the master track.

Description: We present data on distribution of inorganic nitrogen compounds including nitrate (NO2-) and nitrite (NO3-) in the northern Benguela and the Angola-Benguela Front regions between 10°S and 23°S. The fieldwork took place during the cruise No. M120 (Oct. 17th – Nov. 18th, 2015) onboard the R/V METEOR, which encompassed close-coastal and open ocean regions off Angola and Namibia. All nutrient samples were retrieved with the ship's CTD rosette (SBE 9+). Immediately after sampling, a volume of about 40 ml of each sample was filtered through a disposable syringe filter (CA, 0.45 µm) and filled in a pre-rinsed 50 ml PE bottle. The bottles were securely closed and kept frozen at -20°C until further analysis. The concentrations of nutrients were determined photometrically with a Skalar San++ Autoanalyzer following the procedures detailed in Grasshoff et al. (1999). For the quality control, a reference standard was also measured at regular intervals.

Description: Raw data acquired by position sensors on board RV SONNE during expedition SO292 were processed to receive a validated master track which can be used as reference of further expedition data. During SO292 the motion reference unit Kongsberg SeaTex AS MRU-5 combined with Kongsberg SeaTex AS Seapath 320 and two GPS receivers SAAB MGL-4 were used as navigation sensors. Data were downloaded from DAVIS SHIP data base (https://dship.bsh.de) with a resolution of 1 sec. Processing and evaluation of the data is outlined in the data processing report. Processed data are provided as a master track with 1 sec resolution derived from the position sensors' data selected by priority and a generalized track with a reduced set of the most significant positions of the master track.

Description: This data is part of the BMBF project CUSCO (Coastal Upwelling Systems in a Changing Ocean). Here we report carbon and nitrogen uptake rates by phytoplankton collected during a 35-day experiment where we enclosed natural plankton communities in in-situ mesocosms off Peru. The experiment investigated the interactive effects of light and upwelling on the Humboldt upwelling ecosystem by mimicking a gradient of upwelling intensities (0%, 15%, 30%, 45% and 60%) under summer-time high light and winter-time low light. Integrated seawater samples from a depth between 0 and 10m were collected using a 5L Integrating Water sampler (IWS; Hydro-Bios, Kiel). Samples were spiked with 13C labelled sodium bicarbonate and 15N labelled potassium nitrate. Samples were incubated for 24 hours at light intensities that resemble the light conditions in the mesocosms. After incubation a subsample (150-1000 ml) was filtered onto a 0.7 µm pre-combusted glass-fiber filters (GFF, Whatmann). The filters were acidified, then dried in the oven at 60 °C and later measured using an elemental analyzer (Flash IRMS, ThermoFisher) connected to a mass spectrometer (Delta V Advantage Isotope Ratio MS, ThermoFisher) with the ConFlo IV (ThermoFisher). Carbon and nitrogen uptake rates were calculated based on Slawyk et al. (1977, DOI:10.4319/lo.1977.22.5.0925) and Shiozaki et al. (2009, DOI:10.3354/meps07837) respectively.

Description: DE: Dieser Datensatz besteht aus den Transkripten von vier Fokusgruppeninterviews der Migrantenwahlstudie. Ziel des Projektes war es, für die Bundestagswahl 2017 die erste deutsche Wahlstudie unter deutschen Staatsbürger/innen mit Migrationshintergrund durchzuführen, d.h. unter solchen Personen, die entweder selbst nach Deutschland immigriert sind oder die mindestens einen Elternteil mit eigener Migrationserfahrung haben. Die Migrantenwahlstudie umfasst eine qualitative und eine quantitative Phase. Ziel der ersten qualitativen Phase (Oktober 2016 bis Juli 2017) war der explorative Zugang zur Themen- und Kandidatenorientierung von Migrant/innen, um die Ergebnisse für eine Publikation sowie die Fragebogenentwicklung der quantitativen Phase zu nutzen: Welche Themenfelder werden als wichtig erachtet? Welche Vorstellung von Links-Rechts gibt es? Welche Kandidateneigenschaften sind besonders relevant? Wie stark ist die Bindung an das Herkunftsland? Als Methode haben wir dabei auf Gruppendiskussionen mit Russlanddeutschen zurückgegriffen, die in Duisburg und Köln durchgeführt wurden. Dabei haben wir mit etwa 5-6 Teilnehmer/innen jeweils knapp zwei Stunden lang diskutiert. Die Forschungsdaten der quantitativen Phase wurden beim Forschungsdatenzentrum GESIS archiviert. EN: This dataset is composed of the transcripts of four focus group interviews for the Immigrant German Election Study. The project aims to conduct the first Immigrant German Election Study for the federal election in 2017, targeting German citizens with an immigrant background, i.e. people who either migrated to Germany themselves (first generation) or have at least one parent who was born in another country (second generation). The Immigrant German Election Study encompasses a qualitative and a quantitative phase. The first qualitative stage of the project (October 2016 until July 2017) explored the issue and candidate orientations of migrants. The results were used for a publication as well as for the development of the questionnaire for the quantitative stage. The core questions are: Which political issues are classified as important to all Germans/all migrants from the same group? What political issues do Germans of immigrant origin perceive as "left" and "right"? What are the identity contents that Germans of migrant origin associate with being German? We used focus group interviews as the research method in the Duisburg/Cologne area that consisted of 5-6 participants each and lasted for about 90 minutes.The research data originating from the quantitative phase have been archived at GESIS Data Archive.

Description: This data is part of the BMBF project CUSCO (Coastal Upwelling Systems in a Changing Ocean). Here we report biogenic Silica concentrations in the watercolumn collected during a 35-day experiment, where we enclosed natural plankton communities in in-situ mesocosms off Peru. The experiment investigated the interactive effects of light and upwelling on the Humboldt upwelling ecosystem by mimicking a gradient of upwelling intensities (0%, 15%, 30%, 45% and 60%) under summer-time high light and winter-time low light. Integrated seawater samples from a depth between 0 and 10m were collected using a 5L Integrating Water sampler (IWS; Hydro-Bios, Kiel). Samples (0.15-1L) were filtered onto polycarbonate filters (0.65 µm pore size, Whatman). The filters were then dried in the oven at 60 °C for 24 hours and measured following a modified procedure by DeMaster (1981, doi:10.1016/0016-7037(81)90006-5). A standard water bath (Fisher Scientific Isotemp Water Bath, Thermo Fisher Scientific, Waltham, US) was used to digest BSi samples at 85°C. The BSi analysis was carried out with a 4.5-hour time course alkaline digestion (0.1N Na2CO3) to dissolve the BSi followed by a 48 hour HF acid digestion (2.0M) to release the remaining lithogenic silica (LSi). Spectrophotometric analysis of the solubilized silica was done using a Thermo Scientific Genesys 10 UV- VIS Spectrophotometer (Thermo Fisher Scientific, Waltham, US). Model I linear regression was performed to calculate the concentrations of BSi while accounting for the amount of LSi that leached out during the alkaline digestion. Due to restrictions caused by the COVID-19 pandemic BSi data is only available for day 1 until day 17 and for day 31 until day 35.

Description: This data is part of the BMBF project CUSCO (Coastal Upwelling Systems in a Changing Ocean). Here we report pigment concentrations and the phytoplankton community composition based on CHEMTAX analysis during a 35-day experiment, where we enclosed natural plankton communities in in-situ mesocosms off Peru. The experiment investigated the interactive effects of light and upwelling on the Humboldt upwelling ecosystem by mimicking a gradient of upwelling intensities (0%, 15%, 30%, 45% and 60%) under summer-time high light and winter-time low light. Integrated seawater samples from a depth between 0 and 10m were collected using a 5L Integrating Water sampler (IWS; Hydro-Bios, Kiel). To obtain pigment concentrations 0.15 – 1L of water sampled from the water column were filtered onto glass-fiber filters (precombusted at 450°C for 6h, GFF, 0.7 µm nominal pore size, Whatman) using a low vacuum of 200 mbar. Afterwards the filters were stored in cryovials at -80°C until analysis of photosynthetic pigments using reverse-phase high-performance liquid chromatography (HPLC) following (Barlow et al., 1997; doi:10.3354/meps161303) as described by (Paul et al., 2015; doi:10.5194/bg-19-5911-2022). The phytoplankton community composition was calculated with CHEMTAX, which classifies phytoplankton taxa based upon taxon-specific pigment ratios (Mackey et al., 1996; doi:10.3354/meps144265). The values for the Peruvian upwelling system determined by (DiTullio et al., 2005; doi:10.4319/LO.2005.50.6.1887) as described by (Meyer et al., 2017; doi:10.3389/fmars.2017.00001) were used as pigment ratios. As phytoplankton microscopy revealed high abundances of the raphydophite Fibrocapsa japonica, the initial pigment matrix was complemented by ratios for F. japonica from (Laza-Martinez et al., 2007; doi:10.1093/plankt/fbm069) from the Atlantic.