Article
Mechanics
Gabriel Regnault, Alexander A. Doinikov, Cyril Mauger, Philippe Blanc-Benon, Claude Inserra
Summary: We experimentally investigate the attraction between two closely spaced, oscillating microbubbles. Above a certain value of the applied acoustic field, the bubbles jump to a new equilibrium location, separated by a thin fluid layer much smaller than the bubble radii. The sign reversal of the radiation interaction force between the bubbles, caused by multiple rescattering effects of the emitted waves, leads to this new equilibrium. Theoretical investigation reveals the presence of a new stable equilibrium at short distances, resulting in a quasi-contacting bubble pair.
Article
Physics, Fluids & Plasmas
Alexander A. Doinikov, Jonas Fankhauser, Juerg Dual
Summary: An analytical theory is developed to study acoustic streaming induced by an axisymmetric acoustic wave field around a solid spherical particle in a compressible viscoelastic fluid. The study shows that increasing polymer viscosity decreases streaming velocity magnitude, while increasing the elasticity of the polymer solution leads to an increase in streaming velocity magnitude as long as the relaxation time remains relatively small. Changes in polymer viscosity and relaxation time can alter the pattern of streamlines.
Article
Mechanics
JingTing Liu, ShanHao Cong, YongXing Song, DaZhuan Wu, SongYing Chen
Summary: This study developed a three-dimensional imaging system to examine the relationship between the flow patterns and acoustic characteristics of asymmetric bubbles formed in five nozzles. The results showed that the morphology of the bubbles became complex with increasing aspect ratio of the nozzle exit, and the asymmetry of the bubbles had a significant impact on the sound pressure.
Article
Multidisciplinary Sciences
Agnieszka Herman, Jan Marcin Weslawski
Summary: Surface waters of the oceans carry a variety of materials, and their transport and distribution depend on properties and dynamical processes. Research efforts have been invested in observations and modeling of ocean material transport, especially in the context of marine plastic pollution. This study analyzed typical and anomalous transport pathways of surface-floating particles in the northern North Atlantic and the Arctic Ocean using numerical simulations. The study highlighted the important role of wave-induced currents and the influence of seasonal variability and anomalous atmospheric circulation on material transport.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Analytical
Yuta Matsumoto, Yuki Mizushima, Toshiyuki Sanada
Summary: In this study, we demonstrate a method for removing gas from small holes using acoustic waves. We investigated the mechanism of liquid filling and gas removal in liquids by changing hole size, wettability, and liquid surface tension. Our experimental results show that combining two different frequencies of acoustic waves can completely remove gas in a short period of time. The formation of droplets or films and the approaching and coalescing of gas columns are the dominant mechanisms during the removal process.
Article
Environmental Studies
Begum Akcora, Ozge Kandemir Kocaaslan
Summary: This study examines price bubbles in the European natural gas markets and finds that countries in the same geographical region and using the same pricing methodology may have different numbers of price bubbles. The Dutch TTF market has the fewest price bubbles, followed by the British NBP, while the Austrian VTP market has the highest number of price bubbles. The study also shows that more established gas markets have fewer price bubbles.
Review
Mechanics
Luc Deike
Summary: Breaking waves have a significant impact on the climate system by influencing the transfer of energy, momentum, and mass between the ocean and atmosphere. This article explores the importance of drops and bubbles generated by breaking waves and discusses recent progress in understanding the processes involved. It also proposes a pathway towards mechanistic parameterizations that account for the effects of sea state.
ANNUAL REVIEW OF FLUID MECHANICS
(2022)
Article
Multidisciplinary Sciences
Annabel Westell, Taiki Sakai, Robert Valtierra, Sofie M. Van Parijs, Danielle Cholewiak, Annamaria DeAngelis
Summary: Sperm whales are an ideal species for studying with passive acoustic technology, and using acoustic line transect data can improve abundance estimation and provide population-level insights into their foraging ecology.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Marine
Yaobin Li, Xin Xin, Tianfu Xu, Huixing Zhu, Haibin Wang, Qiang Chen, Bo Yang
Summary: Gas hydrate reservoir productivity is significantly influenced by lithological characteristics and seepage parameters. Different reservoir lithologies result in varying gas production rates and spatial evolution characteristics of temperature and pressure fields. To ensure long-term and efficient production, both lithological parameters and the combined effect of seepage parameters should be considered.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Geosciences, Multidisciplinary
Zhi-Feng Wan, Wei Zhang, Chong Ma, Jin-Qiang Liang, Ang Li, Da-Jiang Meng, Wei Huang, Cheng-Zhi Yang, Jin-Feng Zhang, Yue-Feng Sun
Summary: The mechanism of submarine slope failure associated with overpressure caused by hydrocarbon migration and accumulation was studied through high-resolution seismic data and gas hydrate drilling data. It was found that the overpressure may lead to complete decomposition of gas hydrates buried beneath sediments, causing a new cycle of failure. Additionally, seepage-derived deformation may trigger submarine slope failure and gas hydrate dissociation.
GEOSCIENCE FRONTIERS
(2022)
Article
Mechanics
Fatemeh Eslami, Hossein Hamzehpour, Sanaz Derikvandi, S. Amir Bahrani
Summary: The interaction acoustic radiation force between two small solid spheres immersed in a viscoelastic fluid is studied using perturbation theory. A mathematical model is derived from the governing equations using the upper-convected Maxwell model and first- and second-order perturbation theories. Finite element method simulations are conducted to validate the mathematical model. The study reveals the acoustic interaction force between two spheres in a viscoelastic fluid, showing that it is affected by the fluid's viscosity and relaxaction time.
Article
Environmental Sciences
Alexey V. Ermoshkin, Ivan A. Kapustin, Dmitry A. Kosteev, Alexander A. Ponomarenko, Dmitrii D. Razumov, Mikhail B. Salin
Summary: This paper focuses on an acoustical method for measuring mesoscale sea and ocean currents. A two-week marine experiment was conducted to test the applicability of the proposed method, which utilized an acoustic system operating at a lower frequency range of 1-3 kHz. The study demonstrated the potential of using stationary mounted underwater echosounding systems to accurately measure currents in the upper layers of the ocean.
Article
Environmental Studies
Chi Wei Su, Meng Qin, Hsu-Ling Chang, Alexandra-Madalina Taran
Summary: Ensuring the natural gas market's sound and ordered progress is crucial to Europe's sustainable development. This study investigates the presence of multiple bubbles in the European natural gas market using the Generalized Supremum Augmented Dickey-Fuller (GSADF) approach and explores the influencing factors that contribute to these boom and bust episodes. The empirical results suggest that European natural gas bubbles are mostly accompanied by abnormal fluctuations, influenced by factors such as geopolitics, climate, international oil market, and European economic situation.
Article
Engineering, Civil
Erin M. Fischell, Caileigh Fitzgerald, Kevin Manganini, Rui Chen, Henrik Schmidt
Summary: This article describes the 2021 collaborative Sea Ice Dynamics Experiment (SIDEx'21) conducted in the Beaufort Sea, including the deployment of sensing equipment, data collection, and array calibration. The authors also provide information on accessing and utilizing the data set to encourage interdisciplinary analysis.
IEEE JOURNAL OF OCEANIC ENGINEERING
(2023)
Article
Chemistry, Physical
Chad A. Hunter, Michael M. Penev, Evan P. Reznicek, Joshua Eichman, Neha Rustagi, Samuel F. Baldwin
Summary: As variable renewable energy penetration increases, clean power systems will need long-duration energy storage or low-carbon generation to meet the demand. Current research shows that hydrogen systems with geologic storage and natural gas with carbon capture are the least-cost low-carbon technologies, with compressed air and pumped thermal storage potentially being the least-cost options in the current capital cost scenario under uncertainty. A new storage system using heavy-duty vehicle fuel cells could significantly reduce the levelized cost of energy and help enable very high renewable energy grids.
Article
Chemistry, Analytical
Jochen Mohrmann, Jens Greinert
Summary: This article presents an algorithm that improves the quality and accuracy of seafloor mapping by aligning consecutive pings and calculating a globally consistent solution. The algorithm was tested on AUV and ship-based datasets, allowing for quantitative comparisons.
Article
Ecology
Katja Kuhwald, Jens Schneider von Deimling, Philipp Schubert, Natascha Oppelt
Summary: The study focused on mapping seagrass habitats in the Western Baltic Sea using Sentinel-2 data and different correction methods. The results showed that mapping seagrass in turbid waters is feasible, with a spatial resolution of 10-20 meters allowing for detailed delineation of seagrass habitat spatial patterns.
REMOTE SENSING IN ECOLOGY AND CONSERVATION
(2022)
Article
Computer Science, Software Engineering
Valentin Buck, Flemming Staebler, Jochen Mohrmann, Everardo Gonzalez, Jens Greinert
Summary: In this study, a web-based framework is introduced for contextual analysis of multiple data sources in time and space, enabling simultaneous visualization of multidimensional data and facilitating comprehensive study of the Earth System and its different environments.
COMPUTERS & GRAPHICS-UK
(2022)
Article
Geochemistry & Geophysics
Q. Tang, J. Geersen, A. Duering, D. Unverricht, J. Schneider von Deimling, K. -F. Lenz, W. Li, S. Krastel
Summary: Submarine mega-slides in the Sahara Slide Complex pose a major threat to offshore infrastructure and can trigger devastating tsunamis. New hydroacoustic data reveals the complex morphology of the slides, and through sediment dating, the history of slope failures in the headwall area has been reconstructed, showing a long-lasting series of events over thousands of years.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Environmental Sciences
Sabine Haalboom, Timm Schoening, Peter Urban, Iason-Zois Gazis, Henko de Stigter, Benjamin Gillard, Matthias Baeye, Martina Hollstein, Kaveh Purkiani, Gert-Jan Reichart, Laurenz Thomsen, Matthias Haeckel, Annemiek Vink, Jens Greinert
Summary: The dispersion and deposition of sediment plumes during deep-sea mining activities in the Clarion-Clipperton Zone (CCZ) were studied using optical and acoustic sensors. The experiment showed that seafloor imagery and sensors recording optical and acoustic backscatter are effective tools for monitoring sediment dispersion. The researchers recommended the use of AUVs for underwater imaging and particle size sensors to better understand the impact of suspended particle aggregation on backscatter signals.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Environmental Sciences
Svenja Karstens, Joshua Kiesel, Lennart Petersen, Kilian Etter, Jens Schneider von Deimling, Athanasios T. Vafeidis, Felix Gross
Summary: Coastal wetlands rely on vertical accretion and the input of beach wrack to cope with sea level rise. This study investigates how human footpaths in a Baltic coastal wetland affect the transport and accumulation of beach wrack. The findings provide insights into the fate of beach wrack in an anthropogenically influenced coastal wetland and serve as a starting point for further research on its behavior compared to sandy beaches.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Green & Sustainable Science & Technology
D. P. Connelly, J. M. Bull, A. Flohr, A. Schaap, D. Koopmans, J. C. Blackford, P. R. White, R. H. James, C. Pearce, A. Lichtschlag, E. P. Achterberg, D. de Beer, B. Roche, J. Li, K. Saw, G. Alendal, H. Avlesen, R. Brown, S. M. Borisov, C. Bottner, P. W. Cazenave, B. Chen, A. W. Dale, M. Dean, M. Dewar, M. Esposito, J. Gros, R. Hanz, M. Haeckel, B. Hosking, V. Huvenne, J. Karstens, T. Le Bas, T. G. Leighton, P. Linke, S. Loucaides, J. M. Matter, S. Monk, M. C. Mowlem, A. Oleynik, A. M. Omar, K. Peel, G. Provenzano, U. Saleem, M. Schmidt, B. Schramm, S. Sommer, J. Strong, I. Falcon Suarez, B. Ungerboeck, S. Widdicombe, H. Wright, E. Yakushev
Summary: This study conducted a controlled release of CO2 in sediments at 120 m water depth to simulate a leak and test novel detection and quantification methods. The results showed that even at a very low release rate, CO2 can be detected in sediments and in the water column, and the fluxes of dissolved and gaseous CO2 can be quantified.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2022)
Article
Robotics
Marc Seidel, Torsten Frey, Jens Greinert
Summary: The BASTA project aims to improve underwater UXO detection approaches and data acquisition techniques. It successfully integrated three magnetometers to an AUV and achieved reliable detection of munitions.
JOURNAL OF FIELD ROBOTICS
(2023)
Article
Limnology
Peter Urban, Mario E. Veloso-Alarcon, Jens Greinert
Summary: Water column imaging multibeam echo sounder systems (MBESs) have the potential to estimate gas bubble volume flow in large gas seepage areas. However, the lack of published processing methods has hindered their widespread use. This study presents a novel method called echo grid integration, which allows for assessing the backscattering cross section of targets within water layers and quantifying bubble stream gas flow rates using existing acoustic inversion methods. Numerical simulations validate the method's accuracy and uncertainty, showing promising results for gas flow quantification.
LIMNOLOGY AND OCEANOGRAPHY-METHODS
(2023)
Article
Multidisciplinary Sciences
Benson Mbani, Jens Greinert
Summary: We provide analysis-ready optical underwater images from the CCZ of the Pacific Ocean, which were originally recorded using a towed camera sledge at a water depth of 4,250 meters. The images have been pre-processed to address visual quality degradation and inconsistent scale. Accompanying metadata, including geographic coordinates, seafloor depth, absolute scale, and habitat class, are also provided. These images are directly usable for seafloor substrate classification and megafauna detection by the marine scientific community.
Article
Ecology
Damian L. Arevalo-Martinez, Amir Haroon, Hermann W. Bange, Ercan Erkul, Marion Jegen, Nils Moosdorf, Jens Schneider von Deimling, Christian Berndt, Michael Ernst Boettcher, Jasper Hoffmann, Volker Liebetrau, Ulf Mallast, Gudrun Massmann, Aaron Micallef, Holly A. Michael, Hendrik Paasche, Wolfgang Rabbel, Isaac Santos, Jan Scholten, Katrin Schwalenberg, Beata Szymczycha, Ariel T. Thomas, Joonas J. Virtasalo, Hannelore Waska, Bradley A. Weymer
Summary: For thousands of years, humans have been attracted to coastlines for their resource potential and as geopolitical centers. The supply and demand of potable water are crucial for water security in coastal communities, but the interaction between freshwater and saltwater in coastal settings is complicated by natural and human-driven environmental changes. Understanding groundwater fluxes across the land-sea continuum is important for (bio)geochemical budgets and the potential use of offshore freshened groundwater as a resource. Assessing land-ocean connectivity through groundwater requires a multidisciplinary approach and is relevant for climate change, pollution, and sustainable development goals.
Article
Geology
Arne Lohrberg, Jens Schneider von Deimling, Henrik Grob, Kai-Frederik Lenz, Sebastian Krastel
Summary: This study updates the distribution of tunnel valleys in the southeastern North Sea using high-resolution seismic data and identifies an even deeper and older tunnel valley. The study also reveals the process of incision during high-pressure bank-full conditions and the changing sedimentation environment in tunnel valleys. The results highlight the importance of dense seismic profiles for understanding the formation of tunnel valleys and demonstrate the potential of high-resolution seismic data for studying tunnel valley characteristics in different geological settings.
E&G QUATERNARY SCIENCE JOURNAL
(2022)
Article
Geosciences, Multidisciplinary
Wei Chen, Joanna Staneva, Sebastian Grayek, Johannes Schulz-Stellenfleth, Jens Greinert
Summary: Temperature extremes have direct and indirect effects on the marine environment, ecosystems, hydrodynamics, and marine life. This study analyzed the role of heat wave events in the occurrence and persistence of thermal stratification in the North Sea. The results showed that the differences in stratification between the northern and southern North Sea are attributed to changes in water depth.
NATURAL HAZARDS AND EARTH SYSTEM SCIENCES
(2022)
Article
Meteorology & Atmospheric Sciences
Knut Ola Dolven, Benedicte Ferre, Anna Silyakova, Par Jansson, Peter Linke, Manuel Moser
Summary: Improved quantification techniques are needed to explain variations in atmospheric methane. This study focuses on the uncertainties in current estimates of methane release from the seabed in polar regions. The researchers present new information on short-term and seasonal variations in methane concentrations, as well as potential influencing factors. The results suggest that wind forcing, water column stratification, and seasonal variations may affect the potential for methane release into the atmosphere.
Article
Geosciences, Multidisciplinary
Matthias Baeye, Kaveh Purkiani, Henko de Stigter, Benjamin Gillard, Michael Fettweis, Jens Greinert
Summary: The purpose of this study was to measure the background suspended particulate matter concentration (SPMC) and its increase due to mechanical mobilization of the seabed in the DISCOL area. The study found that the SPMC in the disturbance area was easily up to 10 mg/L, about 200 times higher than the background concentration. The downstream sediment plume had a SPMC of about 1 mg/L. The transport of the plume was controlled by tides and vertical velocity component, and depending on the particle size, the plume could disperse for up to 100+ days until the background concentration is reached.
