Results 71 to 80 of about 1,347 (224)

Relative Contributions of Solar Wind Dynamic Pressure and Interplanetary Electric Field on the Early Positive Part of Main Phase of Geomagnetic Storms

Space Weather, Volume 24, Issue 3, March 2026.
Abstract The important early declining part of the main phase (MP) of geomagnetic storms in SYM‐H (and Dst) from positive main phase onset (MPO) to 0‐level of SYM‐H was somehow missed in the treatment of the storms. We included the missed part (or revised the storms) by raising the 0‐level of SYM‐H to MPO‐level, and showed that the inclusion is ...
Jijin K. Raj, N. Balan, Qing‐He Zhang, Y. Otsuka, K. Shiokawa, Zan‐Yang Xing, V. Manu, B. Nilam, Yu‐Zhang Ma, Yong Wang   +9 more
wiley   +1 more source

Solar coronal observations and formation of the He II 304 A line

The Astrophysical Journal, 1993
Although a large body of recent work supports the formation of the He II 304 A resonance line by collisional excitation in the quiet sun, the formation mechanism is less clear in strong coronal active regions and flares. The 1989 May 5 flight of the Goddard Solar Extreme Ultraviolet Rocket Telescope and Spectrograph (SERTS-3) provided a data set that ...
S. D. Jordan, W. T. Thompson, R. J. Thomas, W. M. Neupert   +3 more
openaire   +1 more source

Calibrating Probabilistic Solar‐Wind Forecasts Driven by the Wang‐Sheeley‐Arge Model

Space Weather, Volume 24, Issue 3, March 2026.
Abstract By spatially perturbing coronal model output within a coupled coronal‐heliospheric model we can generate probabilistic predictions of solar‐wind speed. We apply these spatial perturbations to the Wang‐Sheeley‐Arge (WSA) model output to generate large sets of input conditions for the Heliospheric Upwind eXtrapolation with time dependence (HUXt)
N. O. Edward‐Inatimi, M. J. Owens, L. Barnard, H. Turner, M. Marsh, S. Gonzi, M. Lang   +6 more
wiley   +1 more source

When Magnetic Field Lines Stretch, Snap, and Expand: A New Look at Solar Flares with L-maps

The Astrophysical Journal
Understanding the three-dimensional evolution of coronal magnetic fields during solar flares remains challenging due to the lack of direct coronal field measurements.
Maria D. Kazachenko, Yuhong Fan, Andrey N. Afanasyev   +2 more
doaj   +1 more source

Evolution and decay of an active region: Magnetic shear, flare and CME activity [PDF]

Geofísica Internacional, 2000
An activity complex was observed on the solar disk between April, 1996 and February, 1997 that reached its highest level of activity during the birth of AR 7978.
P. Démoulin, S. Punkett, B. Thompson, L. van Driel-Gresztelyi, C. H. Mandrini, G. Aulanier   +5 more
doaj  

Quantifying the Impacts of the May 2024 Geomagnetic Storm on Transatlantic Aviation: Rerouting, Delays, and Economic Losses

Space Weather, Volume 24, Issue 3, March 2026.
Abstract The May 2024 geomagnetic storm, one of the most intense events of Solar Cycle 25 to date, caused widespread disruptions in aviation operations, particularly for polar and high‐latitude routes. This study quantifies the operational and economic impacts of the storm on 12 selected transatlantic flights between North America and Europe.
Jie Li, Xiaojian Hu, Dabin Xue, Zhizhao Liu, Qing‐He Zhang, Xueshang Feng   +5 more
wiley   +1 more source

The [Fe xiii] Infrared 10747 and 10798 Å Lines in Novae

The Astrophysical Journal
The forbidden lines of [Fe xiii ] at 10747 and 10798 Å are among the most prominent lines in the near-infrared spectrum of the solar corona. They have been used routinely, both outside and during eclipses, as sensitive probes of the electron density and ...
D. P. K. Banerjee, C. E. Woodward, A. Evans, T. R. Geballe, V. Joshi, S. Starrfield   +5 more
doaj   +1 more source

Localized Threats: How Ground Conductivity Shapes the Geoelectric Response

Space Weather, Volume 24, Issue 3, March 2026.
Abstract Geomagnetic storms can induce strong geoelectric fields in the ground. These fields drive geomagnetically induced currents in technological conductor systems, such as power grids. In this study, we analyze 4‐hr periods of two such major geomagnetic storms: the Halloween storm (29–31 October 2003) and the 7–8 September 2017 storm.
M. Kellinsalmi, E. Marshalko, L. Juusola, A. Viljanen   +3 more
wiley   +1 more source

Two Distinctly Different Characteristics of Flare-driven Coronal Rain Revealed from High-resolution Spectroscopic Imaging Observations with FISS/GST

The Astrophysical Journal
We report on a flare-driven coronal rain event observed along postflare loops during the decay phase of an X1.6-class solar flare. Although high-resolution studies of flare-driven coronal rain have been conducted, imaging spectroscopic studies are rare ...
Donguk Song, Eun-Kyung Lim, Jongchul Chae, Maria S. Madjarska, Masahito Kubo, Hannah Kwak, Juhyung Kang, Ryohtaroh T. Ishikawa, Kyoung-Sun Lee   +8 more
doaj   +1 more source

Extended Lead‐Time Geomagnetic Storm Forecasting With Solar Wind Ensembles and Machine Learning

Space Weather, Volume 24, Issue 3, March 2026.
Abstract Geomagnetic storms are large disruptions of the magnetosphere, which can impact satellites, communications systems, and power grids, causing significant technological and economic impacts. Current forecasting models utilize L1 satellite data, constraining lead time to a few hours, often insufficient for effective mitigation. We investigate how
M. Billcliff, A. W. Smith, M. Owens, W. L. Woo, L. Barnard, N. Edward‐Inatimi, I. J. Rae   +6 more
wiley   +1 more source