Search Publications
On the Mesoscale Structure of Coronal Mass Ejections at Mercury's Orbit: BepiColombo and Parker Solar Probe Observations
Dresing, Nina; Nieves-Chinchilla, Teresa; Weiss, Andreas J. +27 more
On 2022 February 15, an impressive filament eruption was observed off the solar eastern limb from three remote-sensing viewpoints, namely, Earth, STEREO-A, and Solar Orbiter. In addition to representing the most-distant observed filament at extreme ultraviolet wavelengths—captured by Solar Orbiter's field of view extending to above 6 R ⊙
Multispacecraft Observations of a Widespread Solar Energetic Particle Event on 2022 February 15–16
Holmström, M.; Lario, D.; Palmerio, E. +37 more
On 2022 February 15–16, multiple spacecraft measured one of the most intense solar energetic particle (SEP) events observed so far in Solar Cycle 25. This study provides an overview of interesting observations made by multiple spacecraft during this event. Parker Solar Probe (PSP) and BepiColombo were close to each other at 0.34–0.37 au (a radial …
The Width of Magnetic Ejecta Measured near 1 au: Lessons from STEREO-A Measurements in 2021–2022
Lugaz, Noé; Zhuang, Bin; Scolini, Camilla +7 more
Coronal mass ejections (CMEs) are large-scale eruptions with a typical radial size at 1 au of 0.21 au but their angular width in interplanetary space is still mostly unknown, especially for the magnetic ejecta (ME) part of the CME. We take advantage of STEREO-A angular separation of 20°–60° from the Sun–Earth line from 2020 October to 2022 August,…
Differential Rotation of the Solar Chromosphere: A Century-long Perspective from Kodaikanal Solar Observatory Ca II K Data
Chatzistergos, Theodosios; Ermolli, Ilaria; Chatterjee, Subhamoy +5 more
Chromospheric differential rotation is a key component in comprehending the atmospheric coupling between the chromosphere and the photosphere at different phases of the solar cycle. In this study, we therefore utilize the newly calibrated multidecadal Ca II K spectroheliograms (1907-2007) from the Kodaikanal Solar Observatory (KoSO) to investigate…
Observations of the 2022 September 5 Solar Energetic Particle Event at 15 Solar Radii
Mitchell, D. G.; McComas, D. J.; Bale, S. D. +27 more
On 2022 September 5, Parker Solar Probe (Parker) observed a large solar energetic particle (SEP) event at the unprecedented distance of only 15 R S from the Sun. The observations from the Integrated Science Investigation of the Sun (IS⊙IS) obtained over the course of this event are remarkably rich, and an overview is presented here. IS⊙…
A Pileup of Coronal Mass Ejections Produced the Largest Geomagnetic Storm in Two Decades
Wang, Rui; Liu, Ying D.; Hu, Huidong +2 more
The largest geomagnetic storm in two decades occurred in 2024 May with a minimum D st of ‑412 nT. We examine its solar and interplanetary origins by combining multipoint imaging and in situ observations. The source active region, NOAA AR 13664, exhibited extraordinary activity and produced successive halo eruptions, which were responsib…
Flux Rope Modeling of the 2022 September 5 Coronal Mass Ejection Observed by Parker Solar Probe and Solar Orbiter from 0.07 to 0.69 au
Hess, Phillip; Long, David M.; Möstl, Christian +19 more
As both Parker Solar Probe (PSP) and Solar Orbiter (SolO) reach heliocentric distances closer to the Sun, they present an exciting opportunity to study the structure of coronal mass ejections (CMEs) in the inner heliosphere. We present an analysis of the global flux rope structure of the 2022 September 5 CME event that impacted PSP at a heliocentr…
Solar Eruptions in Nested Magnetic Flux Systems
Antiochos, Spiro K.; Kumar, Pankaj; DeVore, C. Richard +2 more
The magnetic topology of erupting regions on the Sun is a key factor in the energy buildup and release, and the subsequent evolution of flares and coronal mass ejections (CMEs). The presence/absence of null points and separatrices dictates whether and where current sheets form and magnetic reconnection occurs. Numerical simulations show that energ…
Analysis of BMR Tilt from AutoTAB Catalog: Hinting toward the Thin Flux Tube Model?
Banerjee, Dipankar; Sreedevi, Anu; Jha, Bibhuti Kumar +1 more
One of the intriguing mechanisms of the Sun is the formation of bipolar magnetic regions (BMRs) in the solar convection zone (CZ), which are observed as regions of concentrated magnetic fields of opposite polarity on the photosphere. These BMRs are tilted with respect to the equatorial line, which statistically increases with latitude. The thin fl…
Survey of Magnetic Field Parameters Associated with Large Solar Flares
Hou, Yijun; Li, Ting; Chen, Anqin +4 more
Until now, how the magnetic fields in M/X-class flaring active regions (ARs) differ from C-class flaring ARs remains unclear. Here, we calculate the key magnetic field parameters within the area of high photospheric free energy density (HED region) for 323 ARs (217 C- and 106 M/X-flaring ARs), including total photospheric free magnetic energy dens…