Results 71 to 80 of about 3,043 (224)

Comparison of Solar Imaging Feature Extraction Methods in the Context of Space Weather Prediction With Deep Learning‐Based Models

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, Guillerme Bernoux, Antoine Brunet, Denis Standarovski, Gautier Nguyen, Angélica Sicard   +5 more
wiley   +1 more source

On the minimum temperature of the quiet solar chromosphere [PDF]

Astronomy & Astrophysics, 2011
10 pages, 12 figures, accepted for A& ...
Leenaarts, J., Carlsson, M., Hansteen, V., Gudiksen, B.V.   +3 more
openaire   +3 more sources

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, Aleida K. Higginson, David G. Simpson, Nicholeen M. Viall, Peter Wyper, C. Nick Arge   +5 more
wiley   +1 more source

On the Connection between Rieger-type and Magneto-Rossby Waves Driving the Frequency of the Large Solar Eruptions during Solar Cycles 19–25

The Astrophysical Journal, 2023
Global solar activity variation mainly occurs over about an 11 yr cycle. However, both longer and shorter periodicities than the solar cycle are also present in many different solar activity indices.
Marianna B. Korsós, Mausumi Dikpati, Robertus Erdélyi, Jiajia Liu, Francesca Zuccarello   +4 more
doaj   +1 more source

Solar Wind Heavy Ions and Alpha Particles Within Earth's Magnetosphere and Their Variability With Upstream Conditions

Journal of Geophysical Research: Space Physics, Volume 130, Issue 8, August 2025.
Abstract Working toward the goal of understanding solar wind (SW) entry to the Earth's magnetosphere, this study examines solar‐origin ion composition in the magnetotail. During its trajectory, Wind spent a significant amount of time in the Earth's magnetotail, where its SupraThermal Ion Composition Spectrometer (STICS) measured the mass and mass per ...
S. Colón‐Rodríguez, M. W. Liemohn, J. M. Raines, S. T. Lepri   +3 more
wiley   +1 more source

Heating of the quiet solar chromosphere [PDF]

Solar Physics, 1994
We have analyzed a large number of Caii H line profiles at the sites of the bright points in the interior of the network using a 35-min-long time sequence of spectra obtained at the Vacuum Tower Telescope (VTT) of the Sacramento Peak Observatory on a quiet regon of the solar disc and studied the dynamical processes associated with these structures. Our
Kariyappa, R., Sivaraman, K.R., Anadaram, M.N.   +2 more
openaire   +2 more sources

Propagation and damping of MHD waves in the solar atmosphere

, 2015
Quasi-periodic disturbances have been observed in the outer solar atmosphere for many years. Although first interpreted as upflows (Schrijver et al.
Kiddie, Greg
core  

The New Composite Solar Flare Index from Solar Cycle 17 to Cycle 24 (1937 – 2020)

, 2022
The chromosphere is a highly dynamic outer plasma layer of the Sun. Its physical processes accounting for the variability are poorly understood. We reconstructed the solar chromospheric flare index (SFI) to study the solar chromospheric variability from ...
Acosta Jara, Jose Nemesio
core   +1 more source

High-resolution observations of the solar photosphere, chromosphere, and transition region [PDF]

, 2020
NASA’s Interface Region Imaging Spectrograph (IRIS) provides high-resolution observations of the solar atmosphere through ultraviolet spectroscopy and imaging.
de Pontieu, B., Scharmer, G. B., Scharmer, G., Scharmer, Göran B.,, Sainz Dalda, A., Rouppe van der Voort, L. H. M., Kleint, L., M. M. Woods, B. De Pontieu, A. Sainz Dalda, Gošić, M., Henriques, V., S. Jafarzadeh, Skogsrud, H., Dalda, A. Sainz, G. Chintzoglou, J. Martínez-Sykora, Jafarzadeh, S., A. Popovas, L. H. M. Rouppe van der Voort, M. Szydlarski, G. B. Scharmer, M. Gošić, Szydlarski, M., Graham, D., Hansteen, V. H., Scullion, Eamon, de La Cruz Rodríguez, J., C. Quintero Noda, Carlsson, M., R. Timmons, van der Voort, L. H. M. Rouppe, Kohutova, P., Pereira, T., Hansteen, V., S. Bose, L. Kleint, G. J. M. Vissers, Noda, C. Quintero, Woods, M. M., J. de la Cruz Rodríguez, Zacharias, P., Vissers, G. J. M., Chintzoglou, G., D. Nóbrega-Siverio, V. H. Hansteen, Vissers, G., Schmit, D., Pereira, T. M. D., de la Cruz Rodríguez, Jaime,, M. Carlsson, V. M. J. Henriques, Rouppe van Der Voort, L., Scullion, E., T. Leifsen, Drews, A., D. R. Graham, Nóbrega-Siverio, D., A. Drews, P. Kohutova, A. Ortiz, Martínez-Sykora, J., E. Scullion, Quintero Noda, C., H. Skogsrud, J. Joshi, P. Zacharias, Leifsen, T., D. Schmit, Henriques, V. M. J., Froment, C., Bose, S., Joshi, J., Ortiz, A., Vissers, Gregal J. M.,, T. M. D. Pereira, Timmons, R., C. Froment, Popovas, A., Woods, M., Graham, D. R.   +80 more
core   +1 more source

Slow Solar Wind: Origin in an Independent Small‐Scale Solar Dynamo

Geophysical Research Letters, Volume 52, Issue 13, 16 July 2025.
Abstract Separation of the solar wind (SW) into three flow types (coronal mass ejections (CMEs), high speed streams (HSSs), and slow solar wind (SSW)) reveals an inverse relationship between the percentage of time Earth spends in SSW during a year and its annually averaged magnetic field strength (B).
E. W. Cliver, I. G. Richardson, S. F. Martin   +2 more
wiley   +1 more source