Viser treff 141-160 av 947

    • Assessing ocean ensemble drift predictions by comparison with observed oil slicks 

      Martins de Aguiar, Victor Cesar; Röhrs, Johannes; Johansson, Malin; Eltoft, Torbjørn (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-05-16)
      Geophysical models are cornerstone pieces in marine forecasting of floating objects and pollution, such as marine surface oil slicks. Trajectory forecasts of oil spills inherit the uncertainties from the underlying geophysical forcing. In this work we compare the forecast capabilities of an ocean ensemble prediction system (EPS) to those from a higher resolution deterministic model on ...
    • Improving satellite-based monitoring of the polar regions: Identification of research and capacity gaps 

      Gabarró, Carolina; Hughes, Nick; Wilkinson, Jeremy; Bertino, Laurent; Bracher, Astrid; Diehl, Thomas; Dierking, Wolfgang Fritz Otto; Gonzalez-Gambau, Veronica; Lavergne, Thomas; Madurell, Theresa; Malnes, Eirik; Wagner, Penelope Mae (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-17)
      We present a comprehensive review of the current status of remotely sensed and in situ sea ice, ocean, and land parameters acquired over the Arctic and Antarctic and identify current data gaps through comparison with the portfolio of products provided by Copernicus services. While we include several land parameters, the focus of our review is on the marine sector. The analysis is facilitated by the ...
    • A dataset of direct observations of sea ice drift and waves in ice 

      Rabault, Jean; Müller, Malte; Voermans, Joey; Brazhnikov, Dmitry; Turnbull, Ian; Marchenko, Aleksey; Biuw, Martin; Nose, Takehiko; Waseda, Takuji; Johansson, Malin; Breivik, Øyvind; Sutherland, Graig; Hole, Lars Robert; Johnson, Mark; Jensen, Atle; Gundersen, Olav; Kristoffersen, Yngve; Babanin, Alexander; Tedesco, Paulina Souza; Christensen, Kai Håkon; Kristiansen, Martin; Hope, Gaute; Kodaira, Tsubasa; Martins de Aguiar, Victor Cesar; Taelman, Catherine Cecilia A; Quigley, Cornelius Patrick; Filchuk, Kirill; Mahoney, Andrew R. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-05-03)
      Variability in sea ice conditions, combined with strong couplings to the atmosphere and the ocean, lead to a broad range of complex sea ice dynamics. More in-situ measurements are needed to better identify the phenomena and mechanisms that govern sea ice growth, drift, and breakup. To this end, we have gathered a dataset of in-situ observations of sea ice drift and waves in ice. A total of 15 ...
    • Gender inequality and self-publication are common among academic editors 

      Liu, Fengyuan; Holme, Petter; Chiesa, Matteo; AlShebli, Bedoor; Rahwan, Talal (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-01-16)
      Scientific editors shape the content of academic journals and set standards for their fields. Yet, the degree to which the gender makeup of editors reflects that of scientists, and the rate at which editors publish in their own journals, are not entirely understood. Here, we use algorithmic tools to infer the gender of 81,000 editors serving more than 1,000 journals and 15 disciplines over five ...
    • Probing power laws in multifrequency AFM 

      Santos Hernandez, Sergio; Gadelrab, Karim; Olukan, Tuza Adeyemi; Font, Josep; Barcons, Victor; Chiesa, Matteo (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-17)
      Quantification of conservative forces in multifrequency atomic force microscopy requires solving the general equations of the theory expressed in terms of the virials of interaction. Power law expressions are commonly utilized when dealing with electrostatic, ferroelectric, magnetic, or long range (van der Waals) forces. Here, we discuss long range forces modeled in terms of power laws (n), where ...
    • α-Synuclein fibril and synaptic vesicle interactions lead to vesicle destruction and increased lipid-associated fibril uptake into iPSC-derived neurons 

      Stephens, Amberley D.; Villegas, Ana Fernandez; Chung, Chyi Wei; Vanderpoorten, Oliver; Pinotsi, Dorothea; Mela, Ioanna; Ward, Edward; McCoy, Thomas M.; Cubitt, Robert; Routh, Alexander F.; Kaminski, Clemens F.; Kaminski Schierle, Gabriele S. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-05-15)
      Monomeric alpha-synuclein (aSyn) is a well characterised protein that importantly binds to lipids. aSyn monomers assemble into amyloid fibrils which are localised to lipids and organelles in insoluble structures found in Parkinson’s disease patient’s brains. Previous work to address pathological aSyn-lipid interactions has focused on using synthetic lipid membranes, which lack the complexity of ...
    • Knowledge Gaps and Impact of Future Satellite Missions to Facilitate Monitoring of Changes in the Arctic Ocean 

      Lucas, Sylvain; Johannessen, Johnny Andre; Cancet, Mathilde; Pettersson, Lasse H; Esau, Igor; Rheinlænder, Jonathan Winfield; Ardhuin, Fabrice; Chapron, Bertrand; Korosov, Anton; Collard, Fabrice; Herlédan, Sylvain; Olason, Einar; Ferrari, Ramiro; Fouchet, Ergane; Donlon, Craig (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-05-30)
      Polar-orbiting satellite observations are of fundamental importance to explore the main scientific challenges in the Arctic Ocean, as they provide information on bio-geo-physical variables with a denser spatial and temporal coverage than in-situ instruments in such a harsh and inaccessible environment. However, they are limited by the lack of coverage near the North Pole (Polar gap), the polar night, ...
    • Viewing life without labels under optical microscopes 

      Ghosh, Biswajoy; Agarwal, Krishna (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-05-25)
      Optical microscopes today have pushed the limits of speed, quality, and observable space in biological specimens revolutionizing how we view life today. Further, specific labeling of samples for imaging has provided insight into how life functions. This enabled label-based microscopy to percolate and integrate into mainstream life science research. However, the use of labelfree microscopy has been ...
    • A probabilistic framework for source localization in anisotropic composite using transfer learning based multi-fidelity physics informed neural network (mfPINN) 

      Kalimullah, Nur M.-M.; Shelke, Amit; Habib, Anowarul (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-04-17)
      The practical application of data-driven frameworks like deep neural network in acoustic emission (AE) source localization is impeded due to the collection of significant clean data from the field. The utility of the such framework is governed by data collected from the site and/or laboratory experiment. The noise, experimental cost and time consuming in the collection of data further worsen the ...
    • Stochastic modeling of blob-like plasma filaments in the scrape-off layer: Theoretical foundation 

      Losada, Juan Manuel; Theodorsen, Audun; Garcia, Odd Erik (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-04-25)
      A stochastic model for a superposition of uncorrelated pulses with a random distribution of amplitudes, sizes, and velocities is presented. The pulses are assumed to move radially with fixed shape and amplitudes decaying exponentially in time due to linear damping. The pulse velocities are taken to be time-independent but randomly distributed. The implications of a distribution of pulse amplitudes, ...
    • Laser-Generated Scholte Waves in Floating Microparticles 

      Ranjan, Abhishek; Ahmad, Azeem; Ahluwalia, Balpreet Singh; Melandsø, Frank (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-04)
      This study aims to demonstrate the generation and detection of Scholte waves inside polystyrene microparticles. This was proven using both experimental analysis and COMSOL simulation. Microspheres of different sizes were excited optically with a pulsed laser (532 nm), and the acoustic signals were detected using a transducer (40 MHz). On analyzing the laser-generated ultrasound signals, the results ...
    • Different mechanisms of Arctic first-year sea-ice ridge consolidation observed during the MOSAiC expedition 

      Salganik, Evgenii; Lange, Benjamin; Itkin, Polona; Divine, Dmitry; Katlein, Christian; Nicolaus, Marcel; Hoppmann, Mario; Neckel, Niklas; Ricker, Robert; Høyland, Knut Vilhelm; Granskog, Mats (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-22)
      Sea-ice ridges constitute a large fraction of the ice volume in the Arctic Ocean, yet we know little about the evolution of these ice masses. Here we examine the thermal and morphological evolution of an Arctic firstyear sea-ice ridge, from its formation to advanced melt. Initially the mean keel depth was 5.6 m and mean sail height was 0.7 m. The initial rubble macroporosity (fraction of seawater ...
    • Non-trace full-F gyro-fluid interchange impurity advection 

      Reiter, E.; Wiesenberger, M.; Held, Markus; Zarate-Segura, G.W.; Kendl, A. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-01)
      A full-F isothermal gyro-fluid model and code (which is based on the full distribution function F compared to only small fluctuations) is extended to handle self-consistent coupling of multiple quasi-neutral ion species via the polarisation equation in the long wavelength approximation. The numerical model is used to determine two-dimensional interchange driven ‘blob’ transport in a plasma with ...
    • Sea ice classification of TerraSAR-X ScanSAR images for the MOSAiC expedition incorporating per-class incidence angle dependency of image texture 

      Guo, Wenkai; Itkin, Polona; Singha, Suman; Doulgeris, Anthony Paul; Johansson, Malin; Spreen, Gunnar (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-16)
      We provide sea ice classification maps of a subweekly time series of single (horizontal–horizontal, HH) polarization X-band TerraSAR-X scanning synthetic aperture radar (TSX SC) images from November 2019 to March 2020, covering the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition. This classified time series benefits from the wide spatial coverage ...
    • Solved and unsolved riddles about low-latitude daytime valley region plasma waves and 150-km echoes 

      Chau, J.L.; Longley, W.J.; Reyes, P.M.; Pedatella, N.M.; Otsuka, Y.; Stolle, C.; Liu, H.; England, S.L.; Vierinen, Juha; Milla, M.A.; Hysell, D.L.; Oppenheim, M.M.; Patra, A.; Lehmacher, G.; Kudeki, E. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-27)
      The Earth’s atmosphere near both the geographic and magnetic equators and at altitudes between 120 and 200 km is called the low-latitude valley region (LLVR) and is among the least understood regions of the ionosphere/thermosphere due to its complex interplay of neutral dynamics, electrodynamics, and photochemistry. Radar studies of the region have revealed puzzling daytime echoes scattered from ...
    • Observations of the urban boundary layer in a cold climate city 

      Varentsov, Mikhail; Konstantinov, Pavel; Repina, I.; Artamonov, Arseny; Pechkin, Alexander Sergeevich; Ezau (Esau), Igor; Baklanov, Aleksander (Journal article; Tidsskriftartikkel, 2022-11-30)
      Cold environment supports a large diversity of local climates. Among them, urban climates in northern cities stand out for their pronounced warm temperature anomaly known as the Urban Heat Island (UHI). UHI in northern cities has been already studies through satellite images and in-situ observations in the urban canopy layer (UCL). Yet, the vertical structure of the urban atmospheric boundary layer ...
    • Borealis: An Advanced Digital Hardware and Software Design for SuperDARN Radar Systems 

      McWilliams, K.A.; Detwiller, M.; Kotyk, K.; Krieger, K.; Rohel, R.; Billett, D.D.; Huyghebaert, Devin Ray; Ponomarenko, P. (Journal article; Tidsskriftartikkel, 2023-02-17)
      The Borealis radar system is a hardware and software upgrade to the conventional Super Dual Auroral Radar Network radar system, which has been used since the early 1990s. The conventional system has hardware and software that is aging, and many components are no longer supported. Limitations of the conventional system limit radar and data techniques for scientific discovery. Using software defined ...
    • Instant Volume Microscopy of Organoids with SOLIS 

      Ströhl, Florian (Journal article; Tidsskriftartikkel, 2023)
      Advancements in microscopy techniques have revolutionized our ability to explore the intricacies of biological systems, with engineered human heart tissue (EHT) being a particularly challenging target. In this article, we will have an in-depth look at the award-winning SOLIS technique (scanned oblique light-sheet instant-volume sectioning), a new twist on multifocus fluorescence microscopy. Through ...
    • Apparent universality of 1/f spectra as an artifact of finite-size effects 

      Korzeniowska, Magdalena A.; Theodorsen, Audun; Rypdal, Martin Wibe; Garcia, Odd Erik (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-29)
      Power spectral density scaling with frequency f as 1/ f <sup>β</sup> and β ≈ 1 is widely found in natural and socioeconomic systems. Consequently, it has been suggested that such self-similar spectra reflect the universal dynamics of complex phenomena. Here, we show that for a superposition of uncorrelated pulses with a power-law distribution of duration times the estimated scaling exponents β¯ ...
    • Metasurface supporting quasi-BIC for optical trapping and Raman-spectroscopy of biological nanoparticles 

      Hasan, Md Rabiul; Hellesø, Olav Gaute (Journal article; Tidsskriftartikkel, 2023-02-09)
      Optical trapping combined with Raman spectroscopy have opened new possibilities for analyzing biological nanoparticles. Conventional optical tweezers have proven successful for trapping of a single or a few particles. However, the method is slow and cannot be used for the smallest particles. Thus, it is not adapted to analyze a large number of nanoparticles, which is necessary to get statistically ...