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 …
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…
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 …
Persistence and Burn-in in Solar Coronal Magnetic Field Simulations
Meyer, Karen A.; Yeates, Anthony R.; Hall, Eric J.
Simulations of solar phenomena play a vital role in space-weather prediction. A critical computational question for automating research workflows in the context of data-driven solar coronal magnetic field simulations is quantifying a simulation's burn-in time, after which a solar quantity has evolved away from an arbitrary initial condition to a p…
Magnetic Activity Evolution of Solar-like Stars. II. Sph–Ro Evolution of Kepler Main-sequence Targets
van Saders, Jennifer; García, Rafael A.; Breton, Sylvain N. +16 more
There is now a large sample of stars observed by the Kepler satellite with measured rotation periods and photometric activity index Sph. We use this data, in conjunction with stellar interiors models, to explore the interplay of magnetism, rotation, and convection. Stellar activity proxies other than Sph are correlated with t…
Ca II K Polar Network Index of the Sun: A Proxy for Historical Polar Magnetic Field
Chatzistergos, Theodosios; Ermolli, Ilaria; Banerjee, Dipankar +4 more
The Sun's polar magnetic field is pivotal in understanding solar dynamo processes and forecasting future solar cycles. However, direct measurements of the polar field have only been available since the 1970s. The chromospheric Ca II K polar network index (PNI; the fractional area of the chromospheric network regions above a certain latitude) has r…
Type IV-like Solar Radio Burst Consisting of a Series of Short-time Bursts Observed by PSP
Bale, Stuart D.; Ning, Zongjun; Pulupa, Marc +3 more
Solar and interplanetary radio bursts can reflect the existence and motion of energetic electrons and are therefore a kind of vital phenomenon in solar activities. The present study reported a solar radio storm observed by the Parker Solar Probe (PSP) in its eighth orbital encounter phase, and it lasted about 20 hr in a frequency range of 0.5–15 M…
Testing the Flux Rope Paradigm for Coronal Mass Ejections Using a Three-spacecraft Encounter Event
Hess, Phillip; Wood, Brian E.
We present a 3D morphological and field reconstruction of a coronal mass ejection (CME) from 2023 November 28, which hits three spacecraft near 1 au: Wind at Earth's L1 Lagrange point, STEREO-A with a longitudinal separation of 6
The Eruptive Duality of a Filament on 2023 April 21
Zhang, Jun; Fang, Yue
Here we study a filament eruption on 2023 April 21. The filament was composed of two segments, named S1 and S2. Initially, the brightening and bidirectionally plasmoid flows appeared inside S1, and then the west part of S1 (WS1) experienced rapid rising and eruption, accompanied by coronal dimming, flare ribbons, and a secondary flare ribbon. Howe…