Search Publications
The first ground-level enhancement of solar cycle 25 on 28 October 2021
Usoskin, I.; Vainio, R.; Gieseler, J. +8 more
Aims: The first relativistic solar proton event of solar cycle 25 was detected on 28 October 2021 by neutron monitors (NMs) on the ground and particle detectors on board spacecraft in near-Earth space. This is the first ground-level enhancement (GLE) of the current cycle. A detailed reconstruction of the NM response together with the identifi…
The first widespread solar energetic particle event of solar cycle 25 on 2020 November 29. Shock wave properties and the wide distribution of solar energetic particles
Lario, D.; Vainio, R.; Kilpua, E. K. J. +13 more
Context. On 2020 November 29, an eruptive event occurred in an active region located behind the eastern solar limb as seen from Earth. The event consisted of an M4.4 class flare, a coronal mass ejection, an extreme ultraviolet (EUV) wave, and a white-light (WL) shock wave. The eruption gave rise to the first widespread solar energetic particle (SE…
The relativistic solar particle event on 28 October 2021: Evidence of particle acceleration within and escape from the solar corona
Krucker, Säm; Dresing, Nina; Klein, Karl-Ludwig +6 more
Aims: We analyse particle, radio, and X-ray observations during the first relativistic proton event of solar cycle 25 detected on Earth. The aim is to gain insight into the relationship between relativistic solar particles detected in space and the processes of acceleration and propagation in solar eruptive events.
Methods: To this end, …
Observation-based modelling of the energetic storm particle event of 14 July 2012
Lario, D.; Vainio, R.; Poedts, S. +6 more
Aims: We model the energetic storm particle (ESP) event of 14 July 2012 using the energetic particle acceleration and transport model named `PArticle Radiation Asset Directed at Interplanetary Space Exploration' (PARADISE), together with the solar wind and coronal mass ejection (CME) model named `EUropean Heliospheric FORcasting Information A…
Theory of solar oscillations in the inertial frequency range: Linear modes of the convection zone
Gizon, Laurent; Cameron, Robert H.; Bekki, Yuto
Context. Several types of global-scale inertial modes of oscillation have been observed on the Sun. These include the equatorial Rossby modes, critical-latitude modes, and high-latitude modes. However, the columnar convective modes (predicted by simulations and also known as banana cells or thermal Rossby waves) remain elusive.
Aims: We aim t…
Characteristics and evolution of sheath and leading edge structures of interplanetary coronal mass ejections in the inner heliosphere based on Helios and Parker Solar Probe observations
Temmer, M.; Bothmer, V.
Context. We investigated the plasma and magnetic field characteristics of the upstream regions of interplanetary coronal mass ejections (ICMEs) and their evolution as function of distance to the Sun in the inner heliosphere. Results are related both to the development of interplanetary shocks, sheath regions, and compressed solar wind plasma ahead…
Prominence eruption observed in He II 304 Å up to >6 R⊙ by EUI/FSI aboard Solar Orbiter
Heinzel, P.; Mierla, M.; Zhukov, A. N. +24 more
Aims: We report observations of a unique, large prominence eruption that was observed in the He II 304 Å passband of the Extreme Ultraviolet Imager/Full Sun Imager telescope aboard Solar Orbiter on 15-16 February 2022.
Methods: Observations from several vantage points - Solar Orbiter, the Solar-Terrestrial Relations Observatory, the Sola…
Magnetic helicity and energy of emerging solar active regions and their erruptivity
Liu, Y.; Nindos, A.; Liokati, E.
Aims: We investigate the role of the accumulation of magnetic helicity and magnetic energy in the generation of coronal mass ejections (CMEs) from emerging solar active regions (ARs).
Methods: Using vector magnetic field data obtained by the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory, we calculated the magne…
Total reflection of a flare-driven quasi-periodic extreme ultraviolet wave train at a coronal hole boundary
Shen, Yuandeng; Zhou, Chengrui; Zhou, Xinping +3 more
Context. A flare-driven quasi-periodic extreme ultraviolet wave train totally reflected at a coronal hole boundary was well imaged on both temporal and spatial scales by AIA/SDO.
Aims: We aim to investigate the driving mechanisms of the quasi-periodic wave train and demonstrate the total reflection effect at the coronal hole boundary.
Me…
Evidence of a complex structure within the 2013 August 19 coronal mass ejection. Radial and longitudinal evolution in the inner heliosphere
Jian, L. K.; Rodríguez-Pacheco, J.; Zouganelis, I. +9 more
Context. Late on 2013 August 19, a coronal mass ejection (CME) erupted from an active region located near the far-side central meridian from Earth's perspective. The event and its accompanying shock were remotely observed by the STEREO-A, STEREO-B, and SOHO spacecraft. The interplanetary counterpart (ICME) was intercepted by MESSENGER near 0.3 au …