Results 61 to 70 of about 10,692 (216)

Estimating the Poynting Flux of Alfvénic Waves in Polar Coronal Holes across Solar Cycle 24

The Astrophysical Journal
Alfvénic waves are known to be prevalent throughout the corona and solar wind. Determining the Poynting flux supplied by the waves is required for constraining their role in plasma heating and acceleration, as well as providing a constraint for Alfvén ...
R. J. Morton, M. J. Weberg, N. Balodhi, J. A. McLaughlin   +3 more
doaj   +1 more source

Solar origins of solar wind properties during the cycle 23 solar minimum and rising phase of cycle 24

Journal of Advanced Research, 2013
The solar wind was originally envisioned using a simple dipolar corona/polar coronal hole sources picture, but modern observations and models, together with the recent unusual solar cycle minimum, have demonstrated the limitations of this picture.
Janet G. Luhmann, Gordon Petrie, Pete Riley   +2 more
doaj   +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

Unipolarity of the Solar Magnetic Field in Equatorial Coronal Holes

The Astrophysical Journal
A study of the unbalanced magnetic polarity distribution of 70 coronal holes was performed. Data from the Helioseismic and Magnetic Imager were used to examine the photospheric line-of-sight magnetic field ( B _LOS ) beneath these coronal holes.
Khagendra Katuwal, R. T. James McAteer
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

Discrete changes in solar coronal hole boundaries

The Astrophysical Journal, 1990
Sequences of Skylab X-ray images near central meridian passages of a large solar coronal hole are used here to examine hole boundary changes with a time resolution of 90 min. It is found that X-ray bright points play a key role in both the expansion and contraction of the coronal hole.
S. W. Kahler, D. Moses
openaire   +1 more source

Polarization vision and the physiological basis for trichromatic vision in Philaenus spumarius: Understanding host‐seeking behaviour in insect vectors for Xylella fastidiosa control

Annals of Applied Biology, Volume 188, Issue 2, Page 503-519, March 2026.
We investigated the role of vision in host‐seeking behaviour by Philaenus spumarius, the main European vector of Xylella fastidiosa, through an integrated anatomical, optical, physiological, and behavioural study. Our data highlight that the spittlebug uses visual cues, including polarized light, which may aid in detecting the polarized reflections ...
Domen Lazar, Elizabeth Clark, Andrej Meglič, Daniele Cornara, Gregor Belušič   +4 more
wiley   +1 more source

Global Effect of New Active Regions on Coronal Holes and Their Wind Streams

The Astrophysical Journal
Solar wind prediction algorithms and simulations of coronal events often employ photospheric field maps that are assembled over a 27 day solar rotation. This has stimulated efforts to update and better synchronize the maps by applying flux transport and ...
Y.-M. Wang, K. J. Knizhnik, I. Ugarte-Urra, M. J. Weberg   +3 more
doaj   +1 more source

Solar coronal-hole plasma densities and temperatures [PDF]

Astronomy & Astrophysics, 2006
Polar plumes extending from the Sun into the solar corona have long been seen during eclipses, and can now be studied without this restriction with telescopes and spectrometers on board of spacecraft. Despite the large amount of observational data available on this prominent phenomenon, it is not clear whether plumes contribute substantially to the ...
openaire   +2 more sources

Effects of the May 2024 Solar Storm on the Earth's Radiation Belts Observed by CALET on the International Space Station

Geophysical Research Letters, Volume 53, Issue 3, 16 February 2026.
Abstract In May 2024, extraordinary solar activity triggered a powerful solar storm, impacting Earth and producing the extreme geomagnetic storm of 10‐11 May, the most intense since 2003. This had significant effects on the magnetosphere, leading to the creation of a new long‐lasting component of relativistic electrons and to flux changes in the South ...
A. Ficklin, A. Bruno, L. Blum, N. Cannady, T. G. Guzik, R. Kataoka, K. Munakata, Y. Akaike, S. Torii   +8 more
wiley   +1 more source