Results 41 to 50 of about 989 (165)

A Novel Magnetosphere–Ionosphere Coupling Model for the Onset of Substrom Expansion Phase

Frontiers in Astronomy and Space Sciences, 2021
A novel magnetosphere–ionosphere (M-I) coupling model is proposed to simulate the brightening of the onset auroral arc of a magnetospheric substorm event.
P. S. Wang, L. H. Lyu
doaj   +1 more source

Substorm trigger conditions [PDF]

Journal of Geophysical Research: Space Physics, 1999
Critical conditions for the onset of fast interchange dynamics in the stressed geotail during the growth phase of the substorm are derived. We compare the ideal MHD interchange stability condition [Hurricane, 1997] with that for kinetically modified interchange‐ballooning motions.
W. Horton, H. V. Wong, J. W. Van Dam
openaire   +1 more source

Evolution of Open Magnetic Flux During Substorms: The Effects of Dipole Tilt Angle

Geophysical Research Letters, Volume 53, Issue 6, 28 March 2026.
Abstract There is a long‐standing debate on the causes of the semiannual variation of geomagnetic activity. One of the prevailing hypotheses is that the Earth's dipole tilt angle Ψ ${\Psi }$ modulates the dayside reconnection rate, causing the so‐called equinoctial effect. Here we perform the first large‐scale statistical study to test this hypothesis.
A. Nair, L. Holappa, H. Vanhamäki, S. E. Milan   +3 more
wiley   +1 more source

Hiss Wave Evolution During Substorms Based on Van Allen Probes Observations

Geophysical Research Letters, Volume 53, Issue 5, 16 March 2026.
Abstract Hiss waves frequently occur in the plasmasphere or plumes, playing a key role in energetic electron loss in the Earth's inner magnetosphere. While previous studies have linked hiss wave enhancements in the outer plasmasphere (just inside the plasmapause) to electron injections during substorms, their evolution across various substorm phases ...
Xiao‐Chen Shen, Wen Li, Qianli Ma, Nigel P. Meredith, Xiangning Chu, Murong Qin, Luisa Capannolo, Sheng Huang   +7 more
wiley   +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

Comparative Analysis of the Primary Drivers of Plasma Sheet Electron Precipitation

Geophysical Research Letters, Volume 53, Issue 5, 16 March 2026.
Abstract Plasma sheet electron precipitation into Earth's atmosphere plays a key role in magnetosphere–ionosphere coupling at auroral latitudes. Such precipitation can be driven by four primary mechanisms that scatter equatorial electrons into the loss cone: resonant interactions with whistler‐mode waves, electron cyclotron harmonics (ECH), broadband ...
Xiao‐Jia Zhang, Anton Artemyev
wiley   +1 more source

Abrupt Disappearance of Plasmaspheric Hiss Inside the Magnetic Dip

Geophysical Research Letters, Volume 53, Issue 5, 16 March 2026.
Abstract Plasmaspheric hiss plays an important role in radiation belt electron dynamics, and its excitation and propagation have long attracted attention. During a substorm, Van Allen Probe B observed the disappearance of plasmaspheric hiss at the magnetic dip, which was driven by the injection of energetic protons.
Yan Zhuang, Chao Yue, Shan Wang, Haimeng Li, Sibo Xu, Xu‐Zhi Zhou, Qiu‐Gang Zong   +6 more
wiley   +1 more source

Enhancing Low‐Latitude Ionospheric Irregularity Prediction With Generalized Linear Models

Space Weather, Volume 24, Issue 3, March 2026.
Abstract The ionosphere poses challenges for accurate forecasting due to its complexity and variability. Irregularities in the lower ionosphere are influenced by local time, season, geographic location, solar activity and space weather, complicating precise predictions.
Alysson Brhian, Marco A. Ridenti, Francisco Azpilicueta, Mauricio Gende, Marisa Roberto   +4 more
wiley   +1 more source

Model Validation of M‐I Coupling in SWMF

Journal of Geophysical Research: Space Physics, Volume 131, Issue 3, March 2026.
Abstract The accurate modeling of field‐aligned currents (FAC) and electron precipitation is critical for understanding magnetosphere‐ionosphere coupling and improving space weather predictions. This study evaluates the performance of the SWMF in replicating observed FAC magnitudes and distributions, as well as electron precipitation during storms and ...
Tre'Shunda James, Alex Glocer
wiley   +1 more source

The Evolution of a Polar Cap Patch Into a Blob in the Nightside Ionosphere: Direct Observations of Multiple Blob Formation Mechanisms Acting Simultaneously on the Same Plasma

Journal of Geophysical Research: Space Physics, Volume 131, Issue 3, March 2026.
Abstract A polar cap patch was observed to exit the polar cap to become a blob as it entered the auroral oval on the nightside of the Earth under moderately quiet geomagnetic conditions (Kp = 3−). Auroral particle precipitation led to an increase in the electron density of the blob.
S. J. Maguire, A. G. Wood, D. R. Themens, E. M. Henley, S. E. Milan, Y. Soobiah, K. Oksavik, W. J. Miloch, J. C. Coxon, M. G. Johnsen   +9 more
wiley   +1 more source