scholarly journals Characteristics of ground-level enhancement-associated solar flares, coronal mass ejections, and solar energetic particles

2010 ◽  
Vol 115 (A9) ◽  
pp. n/a-n/a ◽  
Author(s):  
K. A. Firoz ◽  
K.-S. Cho ◽  
J. Hwang ◽  
D. V. Phani Kumar ◽  
J. J. Lee ◽  
...  
Keyword(s):  
Coronal Mass Ejections ◽  
Solar Flares ◽  
Ground Level ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Ground Level Enhancement

scholarly journals How Efficient are Coronal Mass Ejections at Accelerating Solar Energetic Particles?

2008 ◽  
Author(s):  
R. A. Mewaldt ◽  
C. M. S. Cohen ◽  
J. Giacalone ◽  
G. M. Mason ◽  
E. E. Chollet ◽  
...  
Keyword(s):  
Coronal Mass Ejections ◽  
Energetic Particles ◽  
Solar Energetic Particles

scholarly journals Sources of solar energetic particles

2019 ◽  
Vol 377 (2148) ◽  
pp. 20180095 ◽  
Author(s):  
Loukas Vlahos ◽  
Anastasios Anastasiadis ◽  
Athanasios Papaioannou ◽  
Athanasios Kouloumvakos ◽  
Heinz Isliker
Keyword(s):  
Solar Corona ◽  
Space Weather ◽  
Solar Flares ◽  
Large Scale ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Plasma Parameters ◽  
Current Sheets ◽  
Solar Eruptions ◽  
Magnetohydrodynamic Simulations

Solar energetic particles are an integral part of the physical processes related with space weather. We present a review for the acceleration mechanisms related to the explosive phenomena (flares and/or coronal mass ejections, CMEs) inside the solar corona. For more than 40 years, the main two-dimensional cartoon representing our understanding of the explosive phenomena inside the solar corona remained almost unchanged. The acceleration mechanisms related to solar flares and CMEs also remained unchanged and were part of the same cartoon. In this review, we revise the standard cartoon and present evidence from recent global magnetohydrodynamic simulations that support the argument that explosive phenomena will lead to the spontaneous formation of current sheets in different parts of the erupting magnetic structure. The evolution of the large-scale current sheets and their fragmentation will lead to strong turbulence and turbulent reconnection during solar flares and turbulent shocks. In other words, the acceleration mechanism in flares and CME-driven shocks may be the same, and their difference will be the overall magnetic topology, the ambient plasma parameters, and the duration of the unstable driver. This article is part of the theme issue ‘Solar eruptions and their space weather impact’.

scholarly journals Very narrow coronal mass ejections producing solar energetic particles

2018 ◽  
Vol 619 ◽  
pp. A34 ◽  
Author(s):  
K. Bronarska ◽  
M. S. Wheatland ◽  
N. Gopalswamy ◽  
G. Michalek
Keyword(s):  
Coronal Mass Ejections ◽  
Weather Forecasting ◽  
Coronal Holes ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Low Energy ◽  
Angular Width ◽  
Arrival Times ◽  
Kolmogorov Smirnov ◽  
Solar Particles

Aims. Our main aim is to study the relationship between low-energy solar particles (energies below 1 MeV) and very narrow coronal mass ejections (“jets” with angular width ≤ 20°). Methods. For this purpose, we considered 125 very narrow coronal mass ejections (CMEs) from 1999 to 2003 that are potentially associated with low-energy solar particles (LESPs). These events were chosen on the basis of their source location. We studied only very narrow CMEs at the western limb, which are expected to have good magnetic connectivity with Earth. Results. We found 24 very narrow CMEs associated with energetic particles such as ions (protons and 3He), electrons, or both. We show that arrival times at Earth of energetic particles are consistent with onset times of the respective CMEs, and that in the same time intervals, there are no other potential sources of energetic particles. We also demonstrate statistical differences for the angular width distributions using the Kolmogorov–Smirnov test for angular widths for these 24 events. We consider a coherent sample of jets (mostly originating from boundaries of coronal holes) to identify properties of events that produce solar energetic particles (velocities, widths, and position angles). Our study presents a new approach and result: very narrow CMEs can generate low-energy particles in the vicinity of Earth without other activity on the Sun. The results could be very useful for space weather forecasting.

scholarly journals Current status and possible extension of the global neutron monitor network

2020 ◽  
Vol 10 ◽  
pp. 17
Author(s):  
Alexander Mishev ◽  
Ilya Usoskin
Keyword(s):  
Space Weather ◽  
Neutron Monitor ◽  
Cosmic Ray ◽  
Ground Level ◽  
Solar Proton ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Current Status ◽  
Flight Altitude ◽  
Ground Level Enhancements

The global neutron monitor network has been successfully used over several decades to study cosmic ray variations and fluxes of energetic solar particles. Nowadays, it is used also for space weather purposes, e.g. alerts and assessment of the exposure to radiation. Here, we present the current status of the global neutron monitor network. We discuss the ability of the global neutron monitor network to study solar energetic particles, specifically during large ground level enhancements. We demonstrate as an example, the derived solar proton characteristics during ground level enhancements GLE #5 and the resulting effective dose over the globe at a typical commercial jet flight altitude of 40 kft (≈12,200 m) above sea level. We present a plan for improvement of space weather services and applications of the global neutron monitor network, specifically for studies related to solar energetic particles, namely an extension of the existing network with several new monitors. We discuss the ability of the optimized global neutron monitor network to study various populations of solar energetic particles and to provide reliable space weather services.

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