Article
Astronomy & Astrophysics
P. A. Delamere, C. S. Ng, P. A. Damiano, B. R. Neupane, J. R. Johnson, B. Burkholder, X. Ma, K. Nykyri
Summary: This study explores the challenge of nonadiabatic plasma heating in giant planet magnetospheres, focusing on turbulent heating models and analytical expressions from turbulence theory. By comparing ion heating using hybrid simulations and analytical estimates, the research aims to validate turbulence theory and enhance understanding of ion heating nature. Results from three-dimensional Kelvin-Helmholtz simulations are discussed, with promising heating rate densities produced during the nonlinear growth phase. This study also addresses radial plasma transport in rapidly rotating magnetospheres, with a specific focus on Saturn.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Letter
Geosciences, Multidisciplinary
J. Montgomery, R. W. Ebert, F. Allegrini, F. Bagenal, S. J. Bolton, G. A. DiBraccio, S. A. Fuselier, R. J. Wilson, Adam Masters
Summary: In this study, observations of particle and magnetic field in Jupiter's magnetosphere were used to study the Kelvin-Helmholtz instability (KHI) condition. Magnetopause crossings that show evidence of being KH unstable were identified. The results indicate the presence of KH waves at Jupiter's dawn flank, with primary drivers such as high velocity shears and changes in plasma pressure. This study provides important insights into the prevalence of KHI at Juno's dawn magnetopause.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Astronomy & Astrophysics
Debanjan Sengupta, Orkan M. Umurhan
Summary: In this study, the settled particle layers in planet-forming disks are examined through simulations. The results suggest that the turbulence in the disks is mainly driven by the Kelvin-Helmholtz instability, the symmetric instability, and a weak secondary transition process. The dominant instability varies with the Stokes number of the particles.
ASTROPHYSICAL JOURNAL
(2023)
Article
Mechanics
Thi Thai Le, Thorsten Koch
Summary: This research aims to analyze the interface stability of the tangential-velocity discontinuity between two compressible gases using Darcy's model and including the porosity effect, providing a basis for considering underground gas storage, particularly for storing hydrogen. The relation between Mach number M, viscosity mu, and porosity epsilon on the stability of the interface is shown to affect gases' withdrawal and injection processes, helping determine the velocity at which gas can be extracted and injected effectively for storage. Solid walls along the flow direction significantly impact the critical values of these parameters regarding the stability of the interface, with bounded flows providing a more realistic approach to the problem, especially in two-dimensional gas flows in storages and pipes.
Article
Astronomy & Astrophysics
F. D. Wilder, A. King, D. Gove, S. Eriksson, N. Ahmadi, T. L. Workman, R. E. Ergun, J. L. Burch, R. B. Torbert, B. L. Giles, R. J. Strangeway
Summary: The Kelvin-Helmholtz instability on the flanks of the magnetosphere transfers energy and momentum from the solar wind, with in-plane magnetic reconnection observed in some KHI events. The event ratio decreases for events further down the magnetospheric flanks, while it increases with an increasing northward component of the interplanetary magnetic field.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Geosciences, Multidisciplinary
Wenjun Dong, David C. Fritts, Alan Z. Liu, Thomas S. Lund, Han-Li Liu
Summary: Fritts et al. conducted a 3-dimensional direct numerical simulation to study the interaction of Kelvin-Helmholtz instability billows and resulting tube and knot dynamics at a stratified shear layer. Through high-resolution compressible simulation, they discovered that these dynamics can emit gravity waves (GWs). The study confirms that shear can induce strong Kelvin-Helmholtz instability with large horizontal scales and billow depths, resulting in the emission of high-frequency, small horizontal wavelength, and large vertical group velocity GWs. The density-weighted amplitudes of GWs reveal fishbone structures in vertical cross sections above and below the instability source. This research suggests that Kelvin-Helmholtz instability and associated tube and knot dynamics may be an important additional source of high-frequency, small-scale GWs at higher altitudes.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Mechanics
Thi Thai Le, Thorsten Koch
Summary: This study focuses on the stability of flows in porous media in the presence of different gases, showing that the critical Mach number for stabilizing a flow with viscosity and porosity effects is related to the dimensionality of the flow and the angle between velocity and wavenumber vectors.
Article
Astronomy & Astrophysics
A. Ramada C. Sukarmadji, Patrick Antolin, James A. McLaughlin
Summary: The recent study presents observations of nanojets in multiple coronal structures and environments, showing that they are accompanied by small nanoflare-like intensity bursts, have velocities of 150-250 km/s, occur transversely to the field line of origin, and have kinetic and thermal energies within the nanoflare range.
ASTROPHYSICAL JOURNAL
(2022)
Article
Multidisciplinary Sciences
Narsing K. Jha, Victor Steinberg
Summary: Kelvin-Helmholtz instability describes the growth of perturbations at the interface of counterpropagating streams of Newtonian fluids. Elastically driven KH-like instability is observed in straight viscoelastic channel flow, displaying self-organized structures of velocity fluctuations. The instability mechanism arises from velocity difference and curvature at the interface perturbation.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Geosciences, Multidisciplinary
Xing Wang, Xiaojun Xu, Yudong Ye, Jing Wang, Ming Wang, Zilu Zhou, Qing Chang, Qi Xu, Jiaying Xu, Lei Luo, Peishan He, Shaoguan Cheng
Summary: Using measurements of Mars Atmosphere and Volatile EvolutioN, a wave train of vortices in different developing phases of the Kelvin-Helmholtz instability was observed above the Martian northern hemisphere. The vortices were associated with changes in magnetic topologies and caused significant ion loss.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Astronomy & Astrophysics
Sergio Diaz-Suarez, Roberto Soler
Summary: High-resolution and high-cadence observations have shown that Alfven waves are widespread in the solar atmosphere. The study demonstrates that torsional Alfven waves can induce the formation of filamentary plasma structures in the solar corona, and the experiments also reveal the impact of Kelvin-Helmholtz instability.
ASTROPHYSICAL JOURNAL LETTERS
(2021)
Article
Astronomy & Astrophysics
A. Settino, Yu V. Khotyaintsev, D. B. Graham, D. Perrone, F. Valentini
Summary: In this study, we introduce the mixing parameter to analyze in situ measurements of a Kelvin-Helmholtz event observed by the Magnetospheric Multiscale mission. By defining the parameter using distinct particle energies, we are able to identify different populations interacting at the Earth's magnetopause and the boundaries of Kelvin-Helmholtz vortices. The shapes observed in the parameter space correspond to different evolutionary phases of the Kelvin-Helmholtz instability.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Meteorology & Atmospheric Sciences
Yuichi Minamihara, Kaoru Sato, Masaki Tsutsumi
Summary: We conducted two 10-day observational campaigns in 2019 to study turbulence in the troposphere and lower stratosphere using a radar imaging technique and radiosonde observations. Seventy three Kelvin-Helmholtz (K-H) billows were detected, and two characteristic cases were examined in detail. The observations showed that gravity waves associated with cyclones and an enhanced upper-tropospheric jet are the mechanisms for K-H excitation. The characteristics of the observed K-H billows were consistent with the most unstable modes.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Geosciences, Multidisciplinary
Wenjun Dong, David C. Fritts, Alan Z. Liu, Thomas S. Lund, Han-Li Liu, Jonathan Snively
Summary: Gravity waves (GWs) and their associated multi-scale dynamics are important in atmospheric energy and momentum processes. We present CAM-Net, an initial machine learning model trained on high-resolution simulations. Two applications to Kelvin-Helmholtz instability and mountain wave generation are described, showing CAM-Net's ability to capture key dynamics and spectral characteristics compared to CGCAM. CAM-Net demonstrates the potential for efficient and accurate descriptions of primary and secondary GWs in global atmospheric models.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Mechanics
Kadry Zakaria, Yasser Gamiel
Summary: Negative energy waves play a significant role in hydrodynamic instabilities and can withdraw energy from the flow. This study investigates the effects of subsonic gas flow and vorticity on the existence of negative energy waves and the occurrence of wave blocking. The results are consistent with a previous experiment. The study aims to establish the existing condition for negative energy waves and blocking waves in the presence of subsonic gas flow and a moving liquid layer.
Article
Physics, Fluids & Plasmas
Xiangrong Fu, Misa M. Cowee, S. Peter Gary, Dan Winske
PHYSICS OF PLASMAS
(2016)
Article
Astronomy & Astrophysics
J. R. Woodroffe, S. K. Morley, V. K. Jordanova, M. G. Henderson, M. M. Cowee, J. G. Gjerloev
SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS
(2016)
Article
Astronomy & Astrophysics
C. T. Russell, H. Y. Wei, M. M. Cowee, F. M. Neubauer, M. K. Dougherty
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2016)
Article
Astronomy & Astrophysics
Xiangrong Fu, Misa M. Cowee, Vania K. Jordanova, S. Peter Gary, Geoffrey D. Reeves, Dan Winske
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2016)
Article
Physics, Fluids & Plasmas
D. B. Schaeffer, D. Winske, D. J. Larson, M. M. Cowee, C. G. Constantin, A. S. Bondarenko, S. E. Clark, C. Niemann
PHYSICS OF PLASMAS
(2017)
Article
Astronomy & Astrophysics
S. Peter Gary, Xiangrong Fu, Misa M. Cowee, Dan Winske, Kaijun Liu
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2017)
Article
Astronomy & Astrophysics
R. T. Desai, M. M. Cowee, H. Wei, X. Fu, S. P. Gary, M. Volwerk, A. J. Coates
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2017)
Article
Geosciences, Multidisciplinary
R. T. Desai, S. A. Taylor, L. H. Regoli, A. J. Coates, T. A. Nordheim, M. A. Cordiner, B. D. Teolis, M. F. Thomsen, R. E. Johnson, G. H. Jones, M. M. Cowee, J. H. Waite
GEOPHYSICAL RESEARCH LETTERS
(2018)
Article
Physics, Fluids & Plasmas
X. R. Fu, M. M. Cowee, K. Liu, S. Peter Gary, D. Winske
PHYSICS OF PLASMAS
(2014)
Article
Astronomy & Astrophysics
Weichao Tu, M. M. Cowee, K. Liu
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2014)
Article
Astronomy & Astrophysics
Xiangrong Fu, Misa M. Cowee, Reinhard H. Friedel, Herbert O. Funsten, S. Peter Gary, George B. Hospodarsky, Craig Kletzing, William Kurth, Brian A. Larsen, Kaijun Liu, Elizabeth A. MacDonald, Kyungguk Min, Geoffrey D. Reeves, Ruth M. Skoug, Dan Winske
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2014)
Article
Astronomy & Astrophysics
W. W. Eshetu, W. Tu, V. K. Jordanova, M. Cowee
Summary: The study reveals that the cumulative field line curvature (FLC) scattering leads to faster loss of higher energy, larger mass, smaller pitch angle ions at higher L shells under different geomagnetic conditions. Additionally, an empirical formula for the e-folding lifetime (tau) as a function of ion characteristics and Kp level has been formulated to account for the FLC scattering effects in ring current models.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Ari Le, Dan Winske, Adam Stanier, William Daughton, Misa Cowee, Blake Wetherton, Fan Guo
Summary: By revisiting the coupling between a rapidly expanding cloud of ionized debris and an ambient magnetized plasma using a hybrid simulation code, the study derived and verified scaling laws for the maximal size of the debris cloud and the fraction of debris that free-streams along the magnetic field based on total debris mass and explosion speed. The amount of debris escaping with minimal coupling to the background magnetic field was found to increase with the debris gyroradius, highlighting the dependence of collisionless coupling on single particle trajectories and the conservation of energy and momentum.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Physics, Fluids & Plasmas
Brett D. Keenan, Ari Le, Dan Winske, Adam Stanier, Blake Wetherton, Misa Cowee, Fan Guo
Summary: The study presents a large-scale hybrid particle simulation to investigate the impact of ionized debris from explosions on the background plasma. It is found that the instabilities differ notably from the 1D equivalent due to the presence of unique transverse structure. Additional 2D simulations explore how debris beam characteristics affect the coupling between debris and background, with implications for the generation of quasi-parallel shocks.
PHYSICS OF PLASMAS
(2022)
Article
Physics, Fluids & Plasmas
R. S. Dorst, D. B. Schaeffer, A. Le, J. J. Pilgram, C. G. Constantin, S. Vincena, S. K. P. Tripathi, D. Winske, D. Larson, M. Cowee, C. Niemann
Summary: The laminar coupling between a laser-produced plasma and a background magnetized plasma was investigated through experiments and simulations. The experiments utilized planar laser induced fluorescence diagnostic and magnetic flux probes to study the two-dimensional spatiotemporal evolution of the ion velocity distribution function. The simulations confirmed the observed coupling and the collisionless nature of the process.
PHYSICS OF PLASMAS
(2022)