Results 51 to 60 of about 20,493 (125)

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

Excitation of toroidal Alfvén eigenmodes with counter-current NBI in the TCV tokamak

Nuclear Fusion, 2023
In Tokamak á Configuration Variable (TCV), unstable modes excited by resonant interaction between the shear Alfvèn waves in continuum gaps and energetic particles have been observed in scenarios with neutral beam injection (NBI).
M. Vallar, M. Dreval, M. Garcia-Munoz, S. Sharapov, J. Poley, A. N. Karpushov, P. Lauber, S. Mazzi, L. Porte, the TCV Team   +9 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

Isotope impact on Alfvén eigenmodes and fast ion transport in DIII-D

Nuclear Fusion
Measurements of beam driven Alfvén Eigenmode (AE) activity in matched deuterium (D) and hydrogen (H) DIII-D plasmas show a dramatic difference in unstable mode activity and fast ion transport for a given injected beam power.
M.A. Van Zeeland, E. Bass, X.D. Du, W.W. Heidbrink, C. Chrystal, C. Crocker, G. DeGrandchamp, S. Haskey, D. Liu, J. Gonzalez-Martin, K.E. Thome, G. Yu, Y. Zhu   +12 more
doaj   +1 more source

Monte-Carlo model for nonlinear interactions of Alfvén eigenmodes with energetic ions

, 2012
A Monte-Carlo model for interactions between a single Alfvén eigenmode and energetic ions in a tokamak is presented. A phenomenological decorrelation of the wave-particle phase is introduced to mimic decorrelation by collisions or by other waves ...
Tholerus, Simon,, Hellsten, Torbjörn,
core   +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

Shear Alfvén waves within magnetic islands

Nuclear Fusion
We calculate Alfvén eigenmodes within a magnetic island (MiAE) which have been conjectured over a decade ago. Starting from a cylindrical plasma equilibrium, we calculate the complete metric of the island interior assuming an iota profile with a constant
Axel Könies, Jinjia Cao, Ralf Kleiber
doaj   +1 more source

Prediction of the Wave Normal Angle of Proton‐Band EMIC Waves Near Geosynchronous Orbit

Journal of Geophysical Research: Space Physics, Volume 130, Issue 12, December 2025.
Abstract We investigate how the wave normal angle (WNA) and polarization of proton‐band electromagnetic ion cyclotron (EMIC) waves change as they travel from their source to Earth. This paper marks a significant milestone as the first full‐wave simulation of proton‐band EMIC waves reflecting from the ionosphere.
Eun‐Hwa Kim, Khan‐Hyuk Kim, Jay R. Johnson, Peter A. Damiano, Syun'ichi Shiraiwa, Yu Lin, Wesley Martin   +6 more
wiley   +1 more source

Axisymmetric global Alfvén eigenmodes in the TCV tokamak

Nuclear Fusion
Global Alfvén eigenmodes (GAEs) with toroidal mode number n = 0 (i.e. axisymmetric) have been observed in the toroidicity-induced, ellipticity-induced, and above non-circularity-induced frequency ranges in the TCV tokamak.
M. Dreval, S.E. Sharapov, H.J.C. Oliver, M. Fitzgerald, A.N. Karpushov, A. Jansen van Vuuren, J. Poley, M. Podesta, F. Porcelli, the TCV Team, the EUROfusion Tokamak Exploitation Team   +10 more
doaj   +1 more source

Theory and Modeling of Large Scale Plasmapause Surface Waves

Journal of Geophysical Research: Space Physics, Volume 130, Issue 9, September 2025.
Abstract The plasmapause in Earth's magnetosphere represents the boundary between the plasma which co‐rotates with the Earth (plasmasphere), and the more tenuous plasmatrough outside. The density change across the plasmapause can be large, changing by approximately 1–2 orders of magnitude depending on the prevailing conditions. This would suggest it to
T. Elsden, D. J. Southwood, O. Allanson, M. O. Archer, M. D. Hartinger, A. N. Wright   +5 more
wiley   +1 more source