Results 41 to 50 of about 1,433,455 (143)

First looks at solar active regions with ALMA

Frontiers in Astronomy and Space Sciences, 2022
During the first few years of observing the Sun with the Atacama Large Millimeter/submillimeter Array (ALMA), the scientific community has acquired a number of observational datasets targeting various structures in active regions, including sunspot umbra
Maria Loukitcheva, Maria Loukitcheva, Maria Loukitcheva, Kevin P. Reardon, Kevin P. Reardon   +4 more
doaj   +1 more source

Comparison of the Composition of ICMEs from Active Regions and Quiet-Sun Regions

The Astrophysical Journal, 2023
The composition of interplanetary coronal mass ejections (ICMEs), including the ionic charge states and elemental abundances of heavy elements, is tightly correlated with their source regions and eruption processes.
Jinrong Li, Hongqiang Song, Qi Lv, Hui Fu, Leping Li, Ruisheng Zheng, Yao Chen   +6 more
doaj   +1 more source

Evolution of Active Regions

Living Reviews in Solar Physics, 2015
The evolution of active regions (AR) from their emergence through their long decay process is of fundamental importance in solar physics. Since large-scale flux is generated by the deep-seated dynamo, the observed characteristics of flux emergence and ...
Lidia van Driel-Gesztelyi, Lucie May Green   +1 more
doaj   +1 more source

A Strong-flare Prediction Model Developed Using a Machine-learning Algorithm Based on the Video Data Sets of the Solar Magnetic Field of Active Regions

The Astrophysical Journal Supplement Series, 2023
It is well accepted that the physical properties obtained from the solar magnetic field observations of active regions (ARs) are related to solar eruptions.
Jingjing Wang, Bingxian Luo, Siqing Liu, Yue Zhang   +3 more
doaj   +1 more source

Polarization properties of the decameter spikes

Frontiers in Astronomy and Space Sciences
An analysis of the observational polarization properties of the decameter spikes is presented in the paper. It is shown that decameter spikes possess high degree of circular polarization with average value of about 60%.
Mykola Shevchuk, Valentin Melnik, Anatolii Brazhenko, Vladimir Dorovskyy, Anatolii Frantsuzenko, Stefaan Poedts, Stefaan Poedts, Jasmina Magdalenic, Jasmina Magdalenic   +8 more
doaj   +1 more source

Multi‐Wavelength Transformer‐Based 24‐Hour Solar Flare Forecasting at the Active‐Region Level

Space Weather
Solar flare forecasting remains challenging due to the complex spatiotemporal evolution of solar active regions (ARs) and the severe class imbalance associated with high‐impact events. In this work, we investigate a transformer‐based framework for active‐
Dunia Alatoom, Nikos Nikolaou
doaj   +1 more source

Cancellation analysis of current density in solar active region NOAA10019

Journal of Space Weather and Space Climate, 2015
Solar flares are often associated with changes in the fine magnetic structure of the emitting active region. Such topological modification results in variations of both the scaling properties of the fields’ fluctuations, and the fractal dimension of the ...
De Vita Gaetano, Vecchio Antonio, Sorriso-Valvo Luca, Briand Carine, Primavera Leonardo, Servidio Sergio, Lepreti Fabio, Carbone Vincenzo   +7 more
doaj   +1 more source

Full-disk spectroscopy of the solar corona across a solar cycle with Hinode/EIS

Frontiers in Astronomy and Space Sciences
The structure and dynamics of the solar corona evolve with the Sun’s magnetic cycle, yet how this variability manifests in the disk-integrated, Sun-as-a-star observables used in stellar activity studies remains poorly constrained. We compile 18 full-disk
James McKevitt, James McKevitt, Ignacio Ugarte-Urra, Peter R. Young, Peter R. Young   +4 more
doaj   +1 more source

Comparing Solar Structure Detection Methods in SDO/AIA Observations and the Application to Raw Uncalibrated Data

Journal of Geophysical Research: Machine Learning and Computation
Recent advances in solar physics increasingly rely on automated identification of coronal structures using machine learning. Yet most studies emphasize scientific performance without evaluating feasibility for onboard deployment to prioritize downlink ...
P. Gonidakis, F. Carella, E. Dineva, H‐J. Jeong, P. Antunes, A. Podobas, S. Raptis, V. Toy‐Edens, M. Jin, S. Poedts, J. Magdalenic, G. Miloshevich   +11 more
doaj   +1 more source

Self-reported domain-specific and accelerometer-based physical activity and sedentary behaviour in relation to psychological distress among an urban Asian population

International Journal of Behavioral Nutrition and Physical Activity, 2018
Background The interpretation of previous studies on the association of physical activity and sedentary behaviour with psychological health is limited by the use of mostly self-reported physical activity and sedentary behaviour, and a focus on Western ...
A. H. Y. Chu, R. M. van Dam, S. J. H. Biddle, C. S. Tan, D. Koh, F. Müller-Riemenschneider   +5 more
doaj   +1 more source