Related papers: Solar and Galactic Cosmic Rays observed by SOHO
We study solar modulation of galactic cosmic rays (GCRs) during the deep solar minimum, including the declining phase, of solar cycle 23 and compare the results of this unusual period with the results obtained during similar phases of the…
Solar Energetic Particles (SEPs) and radio bursts are indicators of particle acceleration on the Sun and in the heliosphere. The accelerated particles have energies significantly higher than thermal particles up to several orders of…
Using the SIT instrument aboard STEREO we have examined the abundance of the 3He during the ascending phase of solar cycle 24 from January 2010 through December 2012. We report on several cases when 3He-rich solar energetic particle events…
We present the association rates between solar energetic particles (SEPs) and the radio emission signatures in the corona and IP space during the entire solar cycle 23. We selected SEPs associated with X and M-class flares from the visible…
We have statistically analyzed a set of 115 low frequency (Deca- Hectometer wavelengths range) type II and type III bursts associated with major Solar Energetic Particle (SEP: Ep > 10 MeV) events and their solar causes such as solar flares…
We probe the spectral hardening of solar flares emission in view of associated solar proton events (SEPs) at earth and coronal mass ejection (CME) acceleration as a consequence. In this investigation we undertake 60 SEPs of the Solar Cycle…
Solar energetic particle (SEP) events are one of the most crucial aspects of space weather that require continuous monitoring and forecasting. Their prediction depends on various factors including source eruptions. In the present work, we…
After providing an overview of solar activity as measured by the sunspot number (SSN) and space weather events during solar cycles (SCs) 21-24, we focus on the weak solar activity in SC 24. The weak solar activity reduces the number of…
We decompose the monthly cosmic-ray data, using several neutron monitor count rates, of Cycles 19-24 with principal component analysis (PCA). We show using different cycle limits that the first and second PC of cosmic-ray (CR) data explain…
Ions and electrons accelerated to high energies during flares and coronal mass ejections at the Sun may escape the solar atmosphere and, guided by the interplanetary magnetic fields, propagate through space to near-Earth locations. These…
We report on a study of all major solar eruptions that occurred on the front-side of the Sun during the rise to peak phase of cycle 24 (first 62 months) in order to understand the key factors affecting the occurrence of large solar…
During the recent solar minimum between cycles 23 and 24 (solar minimum $P_{23/24}$) the intensity of Galactic Cosmic Rays (GCRs) measured at the Earth was the highest ever recorded since space age. It is the purpose of this paper to…
Observations over the past two solar cycles show a highly irregular pattern of occurrence for major solar flares, gamma-ray events, and solar energetic particle (SEP) fluences. Such phenomena do not appear to follow the direct indices of…
We study the solar energetic particle (SEP) event observed on 9 October 2021, by multiple spacecraft including Solar Orbiter (SolO). The event was associated with an M1.6 flare, a coronal mass ejection (CME) and a shock wave. During the…
Extreme Solar Energetic Particle Events (ESPEs) were identified almost a decade ago, providing context for super events unleashed by our host star, the Sun. Their assumed solar origin drives the question of their ``worst-case" impact, which…
The twin STEREO A and B spacecraft were launched in October 2006 into heliocentric orbits at around 1 AU, advancing ahead of or lagging behind Earth, respectively, at around 22 deg./year. The spacecraft provide in-situ observations of the…
The Solar energetic particle analysis platform for the inner heliosphere (SERPENTINE) project presents it's new multi-spacecraft SEP event catalog for events observed in solar cycle 25. Observations from five different viewpoints are…
After a prolong and deep solar minimum at the end of solar cycle 23, the current cycle 24 is one of the lowest cycles. The two periods of deep minimum and mini-maximum of the cycle 24 are connected by a period of increasing solar activity.…
A shower of secondary Cosmic Ray (CR) particles is produced at high altitudes in the Earth's atmosphere, so the primordial Galactic Cosmic Rays (GCRs) are never directly measured outside the Earth magnetosphere and atmosphere. They approach…
The need for quantitative characterization of the solar energetic particle (SEP) dynamics goes beyond being an academic discipline only. It has numerous practical implications related to human activity in space. The terrestrial magnetic…