Search Publications
Sun-to-Earth MHD Simulation of the 2000 July 14 “Bastille Day” Eruption
Downs, Cooper; Riley, Pete; Linker, Jon A. +6 more
Solar eruptions are the main driver of space-weather disturbances at Earth. Extreme events are of particular interest, not only because of the scientific challenges they pose, but also because of their possible societal consequences. Here we present a magnetohydrodynamic (MHD) simulation of the 2000 July 14 “Bastille Day” eruption, which produced …
Deep Learning Based Solar Flare Forecasting Model. I. Results for Line-of-sight Magnetograms
Xu, Long; Huang, Xin; Wang, Huaning +3 more
Solar flares originate from the release of the energy stored in the magnetic field of solar active regions, the triggering mechanism for these flares, however, remains unknown. For this reason, the conventional solar flare forecast is essentially based on the statistic relationship between solar flares and measures extracted from observational dat…
Observations of Turbulent Magnetic Reconnection within a Solar Current Sheet
Cheng, X.; Ding, M. D.; Zhang, J. +4 more
Magnetic reconnection is a fundamental physical process in various astrophysical, space, and laboratory environments. Many pieces of evidence for magnetic reconnection have been uncovered. However, its specific processes that could be fragmented and turbulent have been short of direct observational evidence. Here, we present observations of a supe…
Genesis and Impulsive Evolution of the 2017 September 10 Coronal Mass Ejection
Veronig, Astrid M.; Temmer, Manuela; Dissauer, Karin +7 more
The X8.2 event of 2017 September 10 provides unique observations to study the genesis, magnetic morphology, and impulsive dynamics of a very fast coronal mass ejection (CME). Combining GOES-16/SUVI and SDO/AIA EUV imagery, we identify a hot (T ≈ 10-15 MK) bright rim around a quickly expanding cavity, embedded inside a much larger CME shell (T ≈ 1-…
Successive X-class Flares and Coronal Mass Ejections Driven by Shearing Motion and Sunspot Rotation in Active Region NOAA 12673
Feng, X. S.; Yan, X. L.; Xue, Z. K. +5 more
We present a clear case study on the occurrence of two successive X-class flares, including a decade-class flare (X9.3) and two coronal mass ejections (CMEs) triggered by shearing motion and sunspot rotation in active region NOAA 12673 on 2017 September 6. A shearing motion between the main sunspots with opposite polarities began on September 5 an…
Extreme Kinematics of the 2017 September 10 Solar Eruption and the Spectral Characteristics of the Associated Energetic Particles
Gopalswamy, N.; Yashiro, S.; Mäkelä, P. +3 more
We report on the 2017 September 10 ground-level enhancement (GLE) event associated with a coronal mass ejection whose initial acceleration (∼9.1 km s-2) and initial speed (∼4300 km s-1) were among the highest observed in the Solar and Heliospheric Observatory era. The GLE event was of low intensity (∼4.4% above background) an…
Solar Energetic Particle Events Observed by the PAMELA Mission
de Nolfo, G. A.; Christian, E. R.; Ryan, J. M. +55 more
Despite the significant progress achieved in recent years, the physical mechanisms underlying the origin of solar energetic particles (SEPs) are still a matter of debate. The complex nature of both particle acceleration and transport poses challenges to developing a universal picture of SEP events that encompasses both the low-energy (from tens of…
On the Detection of Coronal Dimmings and the Extraction of Their Characteristic Properties
Temmer, M.; Veronig, A. M.; Vanninathan, K. +2 more
Coronal dimmings are distinct phenomena associated with coronal mass ejections (CMEs). The study of coronal dimmings and the extraction of their characteristic parameters help us to obtain additional information regarding CMEs, especially on the initiation and early evolution of Earth-directed CMEs. We present a new approach to detect coronal dimm…
Why the Shock-ICME Complex Structure Is Important: Learning from the Early 2017 September CMEs
Wang, Yuming; Shen, Chenglong; Luo, Bingxian +2 more
In the early days of 2017 September, an exceptionally energetic solar active region AR 12673 aroused great interest in the solar physics community. It produced four X class flares, more than 20 coronal mass ejections (CMEs), and an intense geomagnetic storm, for which the peak value of the Dst index reached up to -142 nT at 2017 September 8 02:00 …
Application of the Deep Convolutional Neural Network to the Forecast of Solar Flare Occurrence Using Full-disk Solar Magnetograms
Moon, Yong-Jae; Lim, Daye; Lee, Harim +4 more
In this study, we present the application of the Convolutional Neural Network (CNN) to the forecast of solar flare occurrence. For this, we consider three CNN models (two pretrained models, AlexNet and GoogLeNet, and one newly proposed model). Our inputs are SOHO/Michelson Doppler Imager (from 1996 May to 2010 December) and SDO/Helioseismic and Ma…