Results 11 to 20 of about 1,433,455 (143)
Appearance of active regions at the end of solar cycle 24 and at the beginning of cycle 25
Solar-Terrestrial Physics, 2022 The spatial-temporal picture of appearance of active regions and the relationship of their appearance with the structure and development of a large-scale magnetic field were studied during the transition from solar cycle 24 to 25.
Grigoryev V. M. +2 more
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Solar-Terrestrial Physics, 2022 Using photospheric data and data on the longitudinal magnetic field from the SDO satellite, as well as observations in the Hα line from GONG ground stations, we have studied the flare activity of the NOAA 12673 sunspot group, which in September 2017 ...
A.V. Borovik, A.A. Zhdanov
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ON THE FORMATION OF ACTIVE REGIONS [PDF]
The Astrophysical Journal, 2012 Magneto-convection can produce an active region without an initial coherent flux tube. A simulation was performed where uniform, untwisted, horizontal magnetic field of 1 kG strenght was advected into the bottom of a computational domain 48 Mm wide by 20 Mm deep. The up and down convective motions produce a hierarchy of magnetic loops with a wide range
Stein, Robert F., Nordlund, Åke
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Subarcsecond Imaging of a Solar Active Region Filament With ALMA and IRIS
Frontiers in Astronomy and Space Sciences, 2022 Quiescent filaments appear as absorption features on the solar disk when observed in chromospheric lines and at continuum wavelengths in the millimeter (mm) range. Active region (AR) filaments are their small-scale, low-altitude analogues, but they could
J. M. da Silva Santos +6 more
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Sub-surface plasma flows and the flare productivity of solar active regions
Frontiers in Astronomy and Space Sciences, 2022 The extreme space weather conditions resulting from high energetic events likes solar flares and Coronal Mass Ejections demand for reliable space weather forecasting.
B. Lekshmi +5 more
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Deciphering solar magnetic activity: The (solar) hale cycle terminator of 2021
Frontiers in Astronomy and Space Sciences, 2023 We previously identified an event in the solar timeline that appeared to play a role in how sunspot Cycle 23 (SC23) transitioned into sunspot Cycle 24 (SC24). The timeframe for this transition was rapid, taking place over a very short time and perhaps in
Scott W. McIntosh +3 more
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Review and comparison of MHD wave characteristics at the Sun and in Earth’s magnetosphere
Solar-Terrestrial Physics, 2022 Magnetohydrodynamic (MHD) waves play a crucial role in the plasma processes of stellar atmospheres and planetary magnetospheres. Wave phenomena in both media are known to have similarities and unique traits typical of each system.
Chelpanov M. A. +6 more
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Solar-Terrestrial Physics, 2020 We study the evolution of the photospheric magnetic field at the early stage of active region development. We use data on longitudinal component of the magnetic field and line-of-sight velocities from SOHO/MDI and SDO/HMI.
V.M. Grigoryev +2 more
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Incorporating polar field data for improved solar flare prediction
Frontiers in Astronomy and Space Sciences, 2022 In this paper, we consider incorporating data associated with the sun’s north and south polar field strengths to improve solar flare prediction performance using machine learning models.
Mehmet Aktukmak +7 more
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Active longitudes and the structure of the large-scale magnetic field at solar minimum
Solar-Terrestrial Physics, 2023 We have studied deep minima of 11-year solar activity cycles 13–14, 14–15, 22–23, 23–24, 24–25, using the RGO and USAF/NOAA sunspot group catalogs. All of them have a large number of spotless days. Nonetheless, active longitudes as preferred zones, where
Grigoryev V. M., Ermakova L. V.
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