ALBERT

Description: The data presented herein originates from a mesocosm study conducted as part of the EU H2020 OceanNETs project, aimed at investigating the ecological ramifications of ocean alkalinity enhancement. Nine mesocosms were deployed in Taliarte Harbour, Gran Canaria, Spain, and systematically sampled using integrated water samplers over the period spanning from September 10th to October 25th, 2021. Alkalinity was employed in a gradient design, ranging from ambient (0 µeq kg-1 added alkalinity, OAE0) to elevated levels of 2400 µeq kg-1 additional alkalinity (OAE2400) in increments of 300 µeq kg-1. The dataset encompasses a spectrum of sediment trap particle flux data, water column biogeochemistry variables, including inorganic nutrients, carbonate chemistry parameters, and particulate matter, alongside chlorophyll a concentrations. The study and data set offer insights into impacts of alkalinity enhancement on marine ecosystems and their associated biogeochemistry.

Description: Upward transport and/or mixing of trace gas-enriched subsurface waters fosters the exchange of nitrous oxide (N2O) and methane (CH4) with the atmosphere in the Eastern-South Atlantic (ESA). To date, it is, however, unclear whether this source is maintained by local production or advection of trace-gas enriched water masses. So, the meridional and zonal variability of N2O and CH4 in the ESA were investigated to constrain the contributions of the major regional water masses to the overall budget of N2O and CH4. The fieldwork took place during the cruises M99 (July 31st - August 23rd, 2013) and M120 (October 17th - November 18th, 2015) onboard the R/V METEOR, which encompassed close-coastal and open ocean regions off Angola and Namibia. To investigate the regional concentration gradients of N2O and CH4 and corresponding sea-air fluxes, seven hydrographic sections (six zonal transects and one alongshore transect) were conducted between ~10°S and 26°S. Concentrations of dissolved N2O and CH4 in surface waters were continuously measured by using the Mobile Equilibrator Sensor System. To evaluate, the oceanic-atmospheric trace gas exchange, the atmospheric N2O and CH4 in ambient air were measured at several sporadic locations, with an inlet installed at 35 m height. The data were quality controlled by comparing with the data generated by NOAA in the nearest atmospheric sampling station (23.58° S, 15.03°E, Station NMB (Gobabeb, Namibia)). Also, to better understand the underlying patterns of the trace gas in the ESA, the vertical profiles were investigated by measuring discrete samples of N2O using the dynamic headspace method on M99. N2O and CH4 concentrations were also measured using a purge and trap system during M120 expedition.

Description: This dataset contains energy content measurements performed on zooplankton collected in the Arctic Ocean during the MOSAiC expedition (PS122) from November 2019 untill September 2020. Energy content measurements were done on Apherusa glacialis, Themisto abyssorum, Chaetognatha, Thysanoessa longicaudata and Calanus hyperboreus. These species are all known prey of polar cod (Boreogadus saida), and their energy content was measured to be included in a bioenergetic model of the growth rate of this predator and to gain insight in the differences between prey species. The meaurements were performed on freeze-dried specimens using a 6725 semi-micro oxygen calorimeter (Parr, USA) connected to a 6772 calorimetric thermometer (Parr, USA).

Description: The glider was deployed from R/V METEOR cruise M120 (17.10.-18.11. 2015) as part of a group of 4 gliders. The gliders mission was related to the PREFACE project "Enhancing prediction of tropical Atlantic climate and its impacts" (http://preface.b.uib.no) funded by the European Union within the 7th Framework programme. PREFACE is combining European and African expertise in observations, modelling, and marine ecosystems to improve our understanding and capabilities to predict Tropical Atlantic climate and its impacts. The specific objectives of the gliders mission were related to work package (WP) 3 and 4 of the project. In WP 3, the Glider data contributed to determining seasonal and interannual variability of the mixed layer heat and fresh water budgets by quantifying air-sea fluxes and diapycnal, isopycnal and advective heat and freshwater fluxes in the eastern boundary upwelling systems and the Gulf of Guinea. In WP 4, the Gilder data contributed to monitoring variability along the southern hemisphere coastal wave guide.

Description: The glider was deployed from R/V METEOR cruise M120 (17.10.-18.11. 2015) as part of a group of 4 gliders. The gliders mission was related to the PREFACE project "Enhancing prediction of tropical Atlantic climate and its impacts" (http://preface.b.uib.no) funded by the European Union within the 7th Framework programme. PREFACE is combining European and African expertise in observations, modelling, and marine ecosystems to improve our understanding and capabilities to predict Tropical Atlantic climate and its impacts. The specific objectives of the gliders mission were related to work package (WP) 3 and 4 of the project. In WP 3, the Glider data contributed to determining seasonal and interannual variability of the mixed layer heat and fresh water budgets by quantifying air-sea fluxes and diapycnal, isopycnal and advective heat and freshwater fluxes in the eastern boundary upwelling systems and the Gulf of Guinea. In WP 4, the Gilder data contributed to monitoring variability along the southern hemisphere coastal wave guide.

Description: The glider was deployed from R/V METEOR cruise M120 (17.10.-18.11. 2015) as part of a group of 4 gliders. The gliders mission was related to the PREFACE project "Enhancing prediction of tropical Atlantic climate and its impacts" (http://preface.b.uib.no) funded by the European Union within the 7th Framework programme. PREFACE is combining European and African expertise in observations, modelling, and marine ecosystems to improve our understanding and capabilities to predict Tropical Atlantic climate and its impacts. The specific objectives of the gliders mission were related to work package (WP) 3 and 4 of the project. In WP 3, the Glider data contributed to determining seasonal and interannual variability of the mixed layer heat and fresh water budgets by quantifying air-sea fluxes and diapycnal, isopycnal and advective heat and freshwater fluxes in the eastern boundary upwelling systems and the Gulf of Guinea. In WP 4, the Gilder data contributed to monitoring variability along the southern hemisphere coastal wave guide.

Description: Yellowstone Plateau Volcanic Field, USA: Ge concentrations measured by inductively coupled plasma mass spectrometry (ICP-MS), Si concentrations measured by inductively coupled plasma optical emission spectrometry (ICP-OES), Ge/Si ratio, Si isotope compositions (d30Si and standard deviation SD) measured by Multicollector ICP-MS, concentrations in Ca, Na, Mg, K measured by ICP-OES, and concentrations in SO4 and Cl measured by ion chromatography in thermal waters, major rivers draining the Yellowstone Plateau Volcanic Field, and creeks flowing into Yellowstone Lake.

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.