Results 41 to 50 of about 285 (167)
On the Freeze‐In Distance of Solar Wind Fluid Entropy Variability in the Corona
Journal of Geophysical Research: Space Physics, Volume 131, Issue 3, March 2026.Abstract The strong correlation between solar wind entropy and the frozen‐in ion charge state ratio O7+/O6+ ${\mathrm{O}}^{7+}/{\mathrm{O}}^{6+}$ indicates that entropy variability on timescales of hours or longer is preserved from its solar source. This prompts the question: where in the solar atmosphere does this entropy variability come from, and at
Aidan J. Nakhleh +3 more
wiley +1 more source
Journal of Geophysical Research: Space Physics, Volume 131, Issue 2, February 2026.Abstract Solar superflares of S‐class (>X10 in soft X‐rays) pose extreme space weather hazards, yet their prediction remains a fundamental challenge owing to their rapid and transient natures and the limitations of conventional event‐based forecasts. We introduce for the first time, a probabilistic spatiotemporal framework designed to identify extended
V. M. Velasco Herrera +12 more
wiley +1 more source
Space Weather Impact of Three Solar Flares Observed by the POEMAS Telescope at 45 and 90 GHz
Journal of Geophysical Research: Space Physics, Volume 130, Issue 11, November 2025.Abstract Solar flares are often associated with coronal mass ejections (CMEs) that, when directed toward Earth, can disrupt the magnetosphere and impact space weather. In this study, we investigate three long‐duration solar flares observed in 2012 by the POlarization Emission of Millimeter Activity at the Sun (POEMAS) telescopes at 45 and 90 GHz.
Adriana Valio +4 more
wiley +1 more source
The Astrophysical Journal LettersWe present high-resolution multiline spectropolarimetric observations of a quiet-Sun network element obtained with the S unrise iii Chromospheric Infrared SpectroPolarimeter.
Ryan J. Campbell +37 more
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Solar Radio Wide‐Band Spectroscopy and Imaging Facilities of the Chinese Meridian Project Phase II
Space Weather, Volume 23, Issue 11, November 2025.Abstract Solar eruptions, including flares and coronal mass ejections, are the most energetic phenomena in the solar system. These explosive events accelerate high‐energy particles and generate electromagnetic radiation from radio to gamma‐ray wavelengths, producing heliospheric disturbances and acting as primary drivers of space weather hazards.
Yihua Yan +19 more
wiley +1 more source
Quiet Sun magnetic fields: an observational view
Living Reviews in Solar Physics, 2019 The quiet Sun is the region of the solar surface outside of sunspots, pores, and plages. In continuum intensity it appears dominated by granular convection.
Luis Bellot Rubio, David Orozco Suárez
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Journal of Geophysical Research: Machine Learning and Computation, Volume 2, Issue 3, September 2025.Abstract Recently, many machine learning‐based models have been developed to predict geomagnetic activity several days in advance directly from space‐borne solar imaging. To better understand and improve these models, we compare dimensionality reduction techniques to extract abstract features from solar images for space weather‐related downstream tasks.
Maria Tahtouh +5 more
wiley +1 more source
Turbulence and Its Potential Impact on Solar Chromospheric and Coronal Heating
The Astrophysical JournalLow-frequency turbulence in the solar chromosphere remains poorly understood. We address (1) the sources of low-frequency turbulence that potentially heat the chromosphere, and (2) how turbulence is transported and dissipated throughout the chromosphere ...
G. P. Zank +10 more
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Deriving the Coronal Separatrix‐Web With the WSA Model
Journal of Geophysical Research: Space Physics, Volume 130, Issue 8, August 2025.Abstract We demonstrate a new capability of the Wang‐Sheeley‐Arge (WSA) model to routinely derive the coronal separatrix web (S‐web) as a standard data product. We describe our methodology for deriving the squashing factor (Q $Q$) and we use Carrington rotation (CR) 2109 to illustrate the validation of our output with that derived from the POT3D model.
Samantha Wallace +5 more
wiley +1 more source
An In-depth Analysis of Quiet-Sun IRIS Brightenings
The Astrophysical JournalSmall-scale brightenings are ubiquitous, dynamic, and energetic phenomena found in the chromosphere. An advanced filter-detection algorithm applied to high-resolution observations from the Interface Region Imaging Spectrograph enables the detection of ...
Llŷr Dafydd Humphries +2 more
doaj +1 more source