Results 61 to 70 of about 14,687 (203)

Solar Soft X‐Ray Proxy Derived From Observed Auger Photoelectrons by MGS and a 1999–2006 Flare Catalog at Mars

Geophysical Research Letters, Volume 53, Issue 3, 16 February 2026.
Abstract This study uses a novel approach to infer the solar soft X‐ray (SXR) irradiance from Auger photoelectron fluxes. Solar SXR irradiance is highly variable, particularly during solar flares. Solar SXR photons at ∼< ${\sim} < $2.5 nm produce oxygen Auger photoelectrons by photoionizing atmospheric constituents. More specifically, we derive the fit
Shaosui Xu, Edward M. Thiemann, David L. Mitchell, Phillip C. Chamberlin   +3 more
wiley   +1 more source

A new view of quiet-Sun topology from Hinode/SOT [PDF]

, 2008
Context. With the recent launch of the Hinode satellite our view of the nature and evolution of quiet-Sun regions has been improved. In light of the new high resolution observations, we revisit the study of the quiet Sun's topological nature. Aims.
Haynes, A. L., Parnell, C. E., Regnier, S.   +2 more
core   +3 more sources

A New Method for Probabilistic Spatiotemporal Forecasts of Solar Soft X‐Ray “S‐Class” (>X10) Superflares

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, G. Velasco Herrera, W. Soon, A. Özgüç, N. Babynets, A. Tlatov, M. Švanda, S. Qiu, S. Baliunas, B. Kotan, G. González González, L. A. Bautista Flores, M. Pazos   +12 more
wiley   +1 more source

Influence of Ionization on the Polytropic Index of the Solar Atmosphere within Local Thermodynamic Equilibrium Approximation

The Astrophysical Journal
An initial theoretical attempt to explain the observed decrease of the polytropic/adiabatic index γ in the solar corona has been accomplished. The chemical reactions of the ionization–recombination processes in local thermodynamic equilibrium (LTE) of a ...
Albert M. Varonov, Todor M. Mishonov
doaj   +1 more source

MAVEN EUVM Data Products for Space Weather at Mars

Space Weather, Volume 24, Issue 2, February 2026.
Abstract Space weather monitoring is critical to protect not only our technological assets in space, but also mitigate disruptions to life and society that depends on these vulnerable assets. Significant attention and resources have been dedicated to space weather monitoring at Earth, but little attention to date has been paid to planetary space ...
P. C. Chamberlin, G. A. DiBraccio, R. J. Borelli, Y. M. Collado‐Vega, S. Curry, F. G. Eparvier, C. O. Lee, M. L. Mays, E. M. B. Thiemann, C. Wiegand   +9 more
wiley   +1 more source

Magnetic Topology and Loop Statistics in Observed Coronal Holes Using Potential Field Modeling

The Astrophysical Journal
Potential field source surface (PFSS) models are widely used to study the solar corona and form the basis for solar wind forecasting, yet they often fail to reproduce observed properties of coronal holes.
Stephan G. Heinemann, Jens Pomoell, Manuela Temmer   +2 more
doaj   +1 more source

Measurements of Photospheric and Chromospheric Magnetic Fields

, 2015
The Sun is replete with magnetic fields, with sunspots, pores and plage regions being their most prominent representatives on the solar surface. But even far away from these active regions, magnetic fields are ubiquitous.
Centeno, Rebecca, Gosain, Sanjay, Harvey, Jack, Lagg, Andreas, Lites, Bruce   +4 more
core   +1 more source

The quiet Sun average Doppler shift of coronal lines up to 2 MK [PDF]

, 2011
The average Doppler shift shown by spectral lines formed from the chromosphere to the corona reveals important information on the mass and energy balance of the solar atmosphere, providing an important observational constraint to any models of the solar ...
Achour, Athay, Athay, Ayres, Brekke, Brekke, Chae, Cheng, Culhane, Dammasch, Danilovic, De Pontieu, De Pontieu, Delaboudinière, Domínguez Cerdeña, Doschek, Edlén, Hansteen, Hansteen, Hansteen, Hara, Hassler, Judge, Korendyke, L. Teriaca, Laming, Lemaire, Mariska, Marsch, McIntosh, McIntosh, N. Dadashi, Pagano, Peter, Peter, Peter, Peter, Peter, Pneuman, S. K. Solanki, Samain, Spadaro, Teriaca, Teriaca, Teriaca, Tian, Trujillo Bueno, Tu, Wilhelm, Withbroe, Wood   +50 more
core   +1 more source

EXPLAINING INVERTED-TEMPERATURE LOOPS IN THE QUIET SOLAR CORONA WITH MAGNETOHYDRODYNAMIC WAVE-MODE CONVERSION [PDF]

The Astrophysical Journal, 2016
ABSTRACT Coronal loops trace out bipolar, arch-like magnetic fields above the Sun’s surface. Recent measurements that combine rotational tomography, extreme-ultraviolet imaging, and potential-field extrapolation have shown the existence of large loops with inverted-temperature profiles, i.e., loops for which the apex temperature is a ...
Avery J. Schiff, Steven R. Cranmer
openaire   +2 more sources

The Geomagnetic Storm on 10–12 May 2024 and Its Effect on the Swedish Power Grid

Space Weather, Volume 24, Issue 2, February 2026.
Abstract On 10–12 May 2024, at least five interplanetary coronal mass ejections (ICMEs) arrived at Earth and caused the strongest geomagnetic storm in over 20 years. During this geomagnetic storm, a disturbance occurred in a transformer in southern Sweden, causing a drop in power supply in the power line connecting Sweden and Poland.
A. V. L. Wallner, A. P. Dimmock, V. Lanabere, A. Johlander, S. Molenkamp Venholen, A. Viljanen, L. Juusola, L. Rosenqvist, J. Setréus, E. Yordanova, S. Buchert, U. Heiter, Yu. V. Khotyaintsev   +12 more
wiley   +1 more source