Results 21 to 30 of about 196 (131)

Inertial Alfvén Waves With Magnetosphere‐Ionosphere Coupling and Feedback

Journal of Geophysical Research: Space Physics, Volume 131, Issue 7, July 2026.
Abstract We present a theory of the ionospheric feedback instability (IFI) in which the finite‐thickness h $h$ of the ionosphere is represented by a frequency‐ and scale‐dependent height‐integrated Pedersen conductance, YI≡∑inΩ,k⊥,h, ${Y}_{\mathrm{I}}\equiv {\mathrm{\sum }}_{\text{in}}\left({\Omega },{k}_{\perp },h\right),$ electromagnetically coupled ...
R. Rankin, Q.‐G. Zong, W. Wang
wiley   +1 more source

Broadband Alfvénic excitation correlated to turbulence level in the Wendelstein 7-X stellarator plasmas

Nuclear Fusion, 2023
During the first operational phase (OP1) of the Wendelstein 7-X (W7-X) stellarator, poloidal magnetic field fluctuations, $\dot{B}_{\theta}$ , were measured in several different plasma scenarios with a system of Mirnov coils.
S. Vaz Mendes, K. Rahbarnia, C. Slaby, H. Thomsen, J. Schilling, M. Borchardt, R. Kleiber, A. Könies, J.-P. Bähner, A. von Stechow, T. Sunn Pedersen, T. Klinger, the W7-X Team   +12 more
doaj   +1 more source

Nonlinear Evolution of Auroral Fine Structures Through the Feedback Instability in a Dipole Field Configuration

Journal of Geophysical Research: Space Physics, Volume 131, Issue 6, June 2026.
Abstract Nonlinear simulations of the feedback instability in the Alfvénic magnetosphere‐ionosphere (M‐I) coupling system have been carried out by means of the reduced magnetohydrodynamic (MHD) equations with spatially non‐uniform kinematic viscosity and resistivity, coupled with two‐fluid equations, in order to investigate auroral fine‐structure ...
T. Sakaki, T.‐H. Watanabe
wiley   +1 more source

Toroidal modeling of Alfvén eigenmodes excited by runaway electrons in DIII-D and ITER

Nuclear Fusion
The non-perturbative MHD-kinetic hybrid code MARS-K (Liu et al 2014 Phys. Plasmas 21 056105) is updated to include relativistic effects for kinetic fast particles, enabling the code to model excitation of Alfvén eigenmodes (AEs) by runaway electrons (REs)
Yueqiang Liu, Chang Liu, Andrey Lvovskiy
doaj   +1 more source

Effect of Field Line Torsion on the Polarization of ULF Waves

Journal of Geophysical Research: Space Physics, Volume 131, Issue 5, May 2026.
Abstract In this paper we suggest a simple modification of the dipole magnetic field which introduces field‐aligned currents and torsion to the field lines. The resulting field lines are not contained in the meridional planes and have resemblance to the geomagnetic field lines in the dawn and dusk flanks of the magnetosphere. We analyze polarization of
K. Kabin, A. W. Degeling, R. Rankin
wiley   +1 more source

Kelvin‐Helmholtz Stability Analysis as a Function of Dipole Tilt and Solar Wind Property

Journal of Geophysical Research: Space Physics, Volume 131, Issue 5, May 2026.
Abstract Kelvin‐Helmholtz instabilities (KHIs) play a critical role in facilitating mass and momentum transport across the magnetopause boundary. Recent studies have demonstrated that KHI occurrence exhibits both seasonal and diurnal variability, with enhanced activity when Earth's magnetic dipole is more closely aligned with the northward direction in
Alexander Navarro, Xuanye Ma, Jay Johnson, Simon Wing, Shiva Kavosi, Yu‐Lun Liou   +5 more
wiley   +1 more source

Nonlinear Gyrokinetic Simulation of the Magnetosphere‐Ionosphere Feedback Coupling

Geophysical Research Letters, Volume 53, Issue 8, 28 April 2026.
Abstract A nonlinear gyrokinetic simulation is applied to the magnetosphere‐ionosphere (M‐I) coupling system to investigate spontaneous growth of auroral structures and electron acceleration self‐consistently. Perturbations of electron density, potential and field‐aligned current in the auroral ionosphere develop through the feedback instability ...
T.‐H. Watanabe, K. Fujita, S. Maeyama
wiley   +1 more source

Counter-propagating toroidal Alfvén eigenmodes in tokamaks

Nuclear Fusion
Mechanisms of destabilization of toroidal Alfvén eigenmodes (TAEs) in tokamaks are analyzed with the aim to reveal those leading to modes propagating in the direction opposite to plasma current, i.e. counter-propagating modes (ctr-TAE). Plasmas with fast-
Ya.I. Kolesnichenko, E.D. Fredrickson, V.V. Lutsenko, A.V. Tykhyy   +3 more
doaj   +1 more source

Resonant Vibrational Excitation and Overtone Vibrational Emissions of Nitric Oxide (NO) in Sub‐Auroral Ion Drift (SAID) Region: A Source of STEVE Continuum Emission

Geophysical Research Letters, Volume 53, Issue 5, 16 March 2026.
Abstract At elevated electron temperature (Te≥3000°K ${T}_{e}\mathit{\ge }3000\mathit{{}^{\circ}}\mathrm{K}$) inside Sub‐Auroral Ion Drift, resonant vibrational excitation (RVE) increases the vibrationally excited (v≥8 $v\mathit{\ge }8$) nitric oxide (NO) population in the E‐region, which undergoes overtone vibrational emissions (Δv≥8 ${\Delta }v ...
Andrew W. Yau, Andrew D. Howarth, William K. Peterson   +2 more
wiley   +1 more source

Efficiency of Electromagnetic Energy Transfer From Solar Wind to Ionosphere Through Magnetospheric Ultra‐Low Frequency Waves

Geophysical Research Letters, Volume 53, Issue 1, 16 January 2026.
Abstract Ultra‐low frequency (ULF) waves are a ubiquitous carrier of energy in geospace. However, their efficiency in transferring solar wind energy into the upper atmosphere remains a fundamental and not well‐understood question. This is due to their global presence, which cannot be fully quantified by spatially limited observations, and the need for ...
Dong Lin, Michael Hartinger, William Lotko, Wenbin Wang, Xueling Shi, Kareem Sorathia, Bharat Kunduri, Viacheslav Merkin, Kevin Pham, Michael Wiltberger   +9 more
wiley   +1 more source