Results 61 to 70 of about 1,964 (170)

Could a Low‐Frequency Perturbation in the Earth's Magnetotail Be Generated by the Lunar Wake?

Geophysical Research Letters, Volume 51, Issue 22, 28 November 2024.
Abstract Both ground based magnetometers and ionospheric radars at Earth have frequently detected Ultra Low Frequency (ULF) fluctuations at discrete frequencies extending below one mHz‐range. Many dayside solar wind drivers have been convincingly demonstrated as driver mechanisms.
K. Nykyri, S. Di Matteo, M. O. Archer, X. Ma, M. D. Hartinger, M. Sarantos, E. Zesta, W. R. Paterson   +7 more
wiley   +1 more source

Exact Nonlinear Decomposition of Ideal-MHD Waves Using Eigenenergies

The Astrophysical Journal
In this paper, we introduce a new method for exact decomposition of propagating, nonlinear magnetohydrodynamic (MHD) disturbances into their component eigenenergies associated with the familiar slow, Alfvén, and fast wave eigenmodes, and the entropy and ...
Axel Raboonik, Lucas A. Tarr, David I. Pontin   +2 more
doaj   +1 more source

Buoyancy Modes in a Low Entropy Bubble

Journal of Geophysical Research: Space Physics, Volume 129, Issue 11, November 2024.
Abstract In the nightside region of Earth's magnetosphere, braking oscillations or buoyancy modes have been associated with the occurrence of low entropy bubbles. These bubbles form in the plasma sheet, particularly during geomagnetically disturbed times, and because of interchange, move rapidly earthward and may eventually come to rest in the inner ...
F. R. Toffoletto, R. A. Wolf, J. Derr
wiley   +1 more source

Modeling of frequency-sweeping Alfvén modes in the TJ-II stellarator

Nuclear Fusion
Alfvénic activity has been observed in the TJ-II stellarator which resembles the frequency sweeping demonstrated by Alfvén cascade modes in tokamaks. A numerical validation study was conducted using a reduced magnetohydrodynamic (MHD) model to show that ...
A.G. Ghiozzi, M.J. Mantsinen, P. Pastells, D.A. Spong, A.V. Melnikov, L.G. Eliseev, S.E. Sharapov   +6 more
doaj   +1 more source

Kinetic Theory of Drift‐Mirror Mode

Geophysical Research Letters, Volume 51, Issue 18, 28 September 2024.
Abstract We present a nonlocal gyrokinetic theory for the drift‐mirror mode in high‐β $\beta $ anisotropic plasmas. Here, β $\beta $ represents the ratio of plasma pressure to magnetic pressure. The equilibrium distribution is established self‐consistently via guiding‐center Hamiltonian theory.
Yao Yao, Haotian Chen, Zilong Li, Jiquan Li   +3 more
wiley   +1 more source

A proton-cyclotron wave storm generated by unstable proton distribution functions in the solar wind [PDF]

, 2016
We use audification of 0.092 s cadence magnetometer data from the Wind spacecraft to identify waves with amplitudes >0.1 nT near the ion gyrofrequency (~0.1 Hz) with duration longer than 1 hr during 2008.
Alexander, RL, Gilbert, JA, III, WLB, Jian, LK, Moya, PS, O'Modhrain, S, Roberts, DA, Stevens, M, Vinas, A, Wicks, RT, Zurbuchen, TH   +10 more
core   +1 more source

Parametric Study of the Harmonic Structure of Lower Hybrid Waves Driven by Energetic Ions

Journal of Geophysical Research: Space Physics, Volume 129, Issue 9, September 2024.
Abstract The harmonic structure of lower hybrid waves (LHWs) driven by energetic ions can be generated through non‐linear wave‐wave coupling. We investigate the parameter dependence of the excitation and time evolution of this structure, using one‐dimensional electromagnetic particle‐in‐cell (PIC) simulations.
Tsubasa Kotani, Mieko Toida, Toseo Moritaka, Satoshi Taguchi   +3 more
wiley   +1 more source

Relationship Between Low‐Latitude Pi2 Pulsations and Cavity Mode Oscillations

Journal of Geophysical Research: Space Physics, Volume 129, Issue 9, September 2024.
Abstract On the ground, Pi2 magnetic pulsations are detected at low latitudes (L<2) $(L< 2)$ at all magnetic local times (MLTs), unlike in the inner magnetosphere. To gain insight into the mechanism for the global appearance, we study the MLT dependence of the properties of low‐latitude ground Pi2 pulsations detected at four longitudinally separated ...
Kazue Takahashi, Robert Lysak, Khilav Majmudar   +2 more
wiley   +1 more source

Radiative damping of toroidal Alfvén eigenmode in low-shear plasmas

Fundamental Plasma Physics
Instabilities of Alfvén eigenmodes (AEs) are of significant concern because they can enhance the cross-field transport of fusion-born alpha particles beyond the neoclassical level in magnetic fusion plasmas. The threshold value of alpha-particle pressure
B.N. Breizman, S.E. Sharapov
doaj   +1 more source

Density and Magnetic Field Asymmetric Kelvin‐Helmholtz Instability

Journal of Geophysical Research: Space Physics, Volume 129, Issue 3, March 2024.
Abstract The Kelvin‐Helmholtz (KH) instability can transport mass, momentum, magnetic flux, and energy between the magnetosheath and magnetosphere, which plays an important role in the solar‐wind‐magnetosphere coupling process for different planets. Meanwhile, strong density and magnetic field asymmetry are often present between the magnetosheath (MSH)
Xuanye Ma, Peter Delamere, Katariina Nykyri, Antonius Otto, Stefan Eriksson, Lihui Chai, Brandon Burkholder, Andrew Dimmock, Yu‐Lun Liou, Shiva Kavosi   +9 more
wiley   +1 more source