Search Publications
The Solar and Geomagnetic Storms in 2024 May: A Flash Data Report
Miyoshi, Yoshizumi; Akiyama, Sachiko; Yashiro, Seiji +16 more
In 2024 May, the scientific community observed intense solar eruptions that resulted in a great geomagnetic storm and auroral extensions, highlighting the need to document and quantify these events. This study mainly focuses on their quantification. The source active region (AR; NOAA Active Region 13664) evolved from 113 to 2761 millionths of the …
Radial evolution of interplanetary coronal mass ejection-associated particle acceleration observed by Solar Orbiter and ACE
Li, Gang; Kouloumvakos, Athanasios; Wimmer-Schweingruber, Robert F. +5 more
On 2022 March 10 a coronal mass ejection erupted from the Sun, resulting in Solar Orbiter observations at 0.45 au of both dispersive solar energetic particles arriving prior to the interplanetary coronal mass ejection (ICME) and locally accelerated particles near the ICME-associated shock structure as it passed the spacecraft on 2022 March 11. Thi…
Solar energetic particles injected inside and outside a magnetic cloud: The widespread solar energetic particle event on 2022 January 20
Palmerio, E.; Jebaraj, I. C.; Laitinen, T. +22 more
Context. On 2022 January 20, the Energetic Particle Detector (EPD) on board Solar Orbiter measured a solar energetic particle (SEP) event showing unusual first arriving particles from the anti-Sun direction. Near-Earth spacecraft separated by 17° in longitude to the west of Solar Orbiter measured classic anti-sunward-directed fluxes. STEREO-A and …
Deconstructing the Properties of Solar Super Active Region 13664 in the Context of the Historic Geomagnetic Storm of 2024 May 10–11
Nandy, Dibyendu; Jaswal, Priyansh; Sinha, Suvadip
Active regions (ARs) are sites of strong magnetic fields on the solar surface whose size can be several times that of Earth. They spawn dynamic activity, sometimes resulting in severe space weather. Some ARs characterized by extraordinary magnetic properties and exhibiting extreme activity are termed as super active regions (SARs). Recently, solar…
On the Nature of the Dark Cavity of Solar Coronal Mass Ejections
Chen, Yao; Xia, Lidong; Li, Leping +2 more
Earlier studies have shown that less than one-third of coronal mass ejections (CMEs) possess the archetypical three-part (bright core, dark cavity, and bright front) structure in the outer corona (e.g., 2–6 R⊙). In the traditional opinion, the core, cavity, and front correspond to the erupted filament, magnetic flux rope (MFR), and plas…
SIP-IFVM: Efficient time-accurate magnetohydrodynamic model of the corona and coronal mass ejections
Poedts, S.; Guo, Y.; Guo, J. H. +7 more
Context. Coronal mass ejections (CMEs) are one of the main drivers of space weather. However, robust and efficient numerical modelling applications of the initial stages of CME propagation and evolution process in the sub-Alfvénic corona are still lacking. Aims. Magnetohydrodynamic (MHD) solar coronal models are critical in the Sun-to-Earth model …
Shock and SEP Modeling Study for the 2022 September 5 SEP Event
Lario, D.; Jebaraj, I. C.; Mitchell, D. G. +10 more
On 2022 September 5, during Parker Solar Probe's (PSP) 13th encounter, a fast shock wave and a related solar energetic particle (SEP) event were observed as the spacecraft approached the perihelion of its orbit. Observations from the Integrated Science Investigation of the Sun (IS⊙IS) instrument suite show that SEPs arrived at the spacecraft with …
The Magnetic Field Structure of Coronal Mass Ejections: A More Realistic Representation
Lugaz, Noé; Al-Haddad, Nada
It is often accepted that the magnetic field structure of coronal mass ejections (CMEs) is accurately represented by the highly twisted circular cross-section magnetic flux rope model, which is the basis of all most commonly used sketches and representations of CMEs. This paradigm has been developed based on studies in the 1970s and 1980s, and it …
Determining the acceleration regions of in situ electrons using remote radio and X-ray observations
Jebaraj, I. C.; Vainio, R.; Kilpua, E. K. J. +13 more
Context. Solar energetic particles in the heliosphere are produced by flaring processes on the Sun or by shocks driven by coronal mass ejections. These particles are regularly detected remotely as electromagnetic radiation (X-rays or radio emission), which they generate through various processes, or in situ by spacecraft monitoring the Sun and the…
Radio dimming associated with filament eruptions in the meter and decimeter wavebands
Feng, Li; Tian, Hui; Madjarska, Maria S. +12 more
Filament eruptions are considered to be a common phenomenon on the Sun and other stars, yet they are rarely directly imaged in the meter and decimeter wavebands. Using imaging data from the DAocheng solar Radio Telescope (DART) in the 150‑450 MHz frequency range, we present two eruptive filaments that manifest as radio dimmings (i.e., emission dep…