scholarly journals Solar energetic particle characteristics and their dependence on longitude in solar cycle 24

2013 ◽  
Author(s):  
C. M. S. Cohen ◽  
G. M. Mason ◽  
R. A. Mewaldt ◽  
T. T. von Rosenvinge
Keyword(s):  
Solar Cycle ◽  
Energetic Particle ◽  
Solar Energetic Particle ◽  
Particle Characteristics ◽  
Solar Cycle 24 ◽  
Cycle 24

Solar flares, CMEs and solar energetic particle events during solar cycle 24

2018 ◽  
Vol 61 (2) ◽  
pp. 777-785 ◽  
Author(s):  
Bimal Pande ◽  
Seema Pande ◽  
Ramesh Chandra ◽  
Mahesh Chandra Mathpal
Keyword(s):  
Solar Cycle ◽  
Solar Flares ◽  
Energetic Particle ◽  
Solar Energetic Particle ◽  
Solar Energetic Particle Events ◽  
Solar Cycle 24 ◽  
Cycle 24

3He rich periods measured by the Suprathermal Ion Telescope (SIT) on STEREO-A during solar cycle 24

2021 ◽  
Author(s):  
Marlon Köberle ◽  
Radoslav Bucik ◽  
Nina Dresing ◽  
Bernd Heber ◽  
Andreas Klassen ◽  
...  
Keyword(s):  
Solar Cycle ◽  
Heavy Ions ◽  
Energetic Particle ◽  
Solar Energetic Particle ◽  
Detection Algorithm ◽  
Solar Cycle 24 ◽  
Time Periods ◽  
Cycle 24 ◽  
Automatic Detection Algorithm

<p><sup>3</sup>He-rich solar energetic particle (SEP) events are characterized by a peculiar elemental composition with rare species like <sup>3</sup>He or ultra-heavy ions tremendously enhanced over the solar system abundances.<br>We report on <sup>3</sup>He rich SEP periods measured by the Suprathermal Ion Telescope (SIT) onboard STEREO-A beginning in 2007 until 2020, covering the whole solar cycle 24.<br>The mass resolution capabilities of SIT do not allow to easily distinguish between <sup>3</sup>He and <sup>4</sup>He especially in cases of a low <sup>3</sup>He to <sup>4</sup>He ratio.<br>We therefore developed a semi-automatic detection algorithm to find time periods during which a <sup>3</sup>He enhancement can be statistically determined.<br>Using this method we found 112 <sup>3</sup>He rich periods.<br>These periods were further examined in regards of their <sup>3</sup>He/<sup>4</sup>He and Fe/O ratio. <br>Previously about ten <sup>3</sup>He-rich SEP periods measured by SIT on STEREO-A have been reported.<br>An association with in-situ electron measurements by STEREO-SEPT and STEREO-STE showed that ~60% of the 112 periods are accompanied with electron events.<br>The here presented catalogue of <sup>3</sup>He rich periods is intended to serve as a reference for the community.</p>

scholarly journals SOLAR SOURCES OF3He-RICH SOLAR ENERGETIC PARTICLE EVENTS IN SOLAR CYCLE 24

2015 ◽  
Vol 806 (2) ◽  
pp. 235 ◽  
Author(s):  
Nariaki V. Nitta ◽  
Glenn M. Mason ◽  
Linghua Wang ◽  
Christina M. S. Cohen ◽  
Mark E. Wiedenbeck
Keyword(s):  
Solar Cycle ◽  
Energetic Particle ◽  
Solar Energetic Particle ◽  
Solar Energetic Particle Events ◽  
Solar Cycle 24 ◽  
Cycle 24

scholarly journals Observations of the longitudinal spread of solar energetic particle events in solar cycle 24

2012 ◽  
Author(s):  
C.M.S. Cohen ◽  
G.M. Mason ◽  
M.E. Wiedenbeck ◽  
D.K. Haggerty ◽  
R. Gomez-Herrero ◽  
...  
Keyword(s):  
Solar Cycle ◽  
Energetic Particle ◽  
Solar Energetic Particle ◽  
Solar Energetic Particle Events ◽  
Solar Cycle 24 ◽  
Cycle 24

scholarly journals Earth-affecting solar transients: a review of progresses in solar cycle 24

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Jie Zhang ◽  
Manuela Temmer ◽  
Nat Gopalswamy ◽  
Olga Malandraki ◽  
Nariaki V. Nitta ◽  
...  
Keyword(s):  
Solar Cycle ◽  
Solar Energetic Particle ◽  
Space Environment ◽  
Energy Output ◽  
Human Society ◽  
The Sun ◽  
Efficient Manner ◽  
Solar Cycle 24 ◽  
Interaction Regions ◽  
Cycle 24

AbstractThis review article summarizes the advancement in the studies of Earth-affecting solar transients in the last decade that encompasses most of solar cycle 24. It is a part of the effort of the International Study of Earth-affecting Solar Transients (ISEST) project, sponsored by the SCOSTEP/VarSITI program (2014–2018). The Sun-Earth is an integrated physical system in which the space environment of the Earth sustains continuous influence from mass, magnetic field, and radiation energy output of the Sun in varying timescales from minutes to millennium. This article addresses short timescale events, from minutes to days that directly cause transient disturbances in the Earth’s space environment and generate intense adverse effects on advanced technological systems of human society. Such transient events largely fall into the following four types: (1) solar flares, (2) coronal mass ejections (CMEs) including their interplanetary counterparts ICMEs, (3) solar energetic particle (SEP) events, and (4) stream interaction regions (SIRs) including corotating interaction regions (CIRs). In the last decade, the unprecedented multi-viewpoint observations of the Sun from space, enabled by STEREO Ahead/Behind spacecraft in combination with a suite of observatories along the Sun-Earth lines, have provided much more accurate and global measurements of the size, speed, propagation direction, and morphology of CMEs in both 3D and over a large volume in the heliosphere. Many CMEs, fast ones, in particular, can be clearly characterized as a two-front (shock front plus ejecta front) and three-part (bright ejecta front, dark cavity, and bright core) structure. Drag-based kinematic models of CMEs are developed to interpret CME propagation in the heliosphere and are applied to predict their arrival times at 1 AU in an efficient manner. Several advanced MHD models have been developed to simulate realistic CME events from the initiation on the Sun until their arrival at 1 AU. Much progress has been made on detailed kinematic and dynamic behaviors of CMEs, including non-radial motion, rotation and deformation of CMEs, CME-CME interaction, and stealth CMEs and problematic ICMEs. The knowledge about SEPs has also been significantly improved. An outlook of how to address critical issues related to Earth-affecting solar transients concludes this article.

Regression Analysis of Sunspot Numbers for the Solar Cycle 24 in Comparison to Previous Three Cycles

2014 ◽  
Vol 4 (2) ◽  
pp. 477-483
Author(s):  
Debojyoti Halder
Keyword(s):  
Regression Analysis ◽  
Solar Cycle ◽  
Sunspot Number ◽  
The Sun ◽  
Sunspot Numbers ◽  
Solar Cycle 24 ◽  
Current Cycle ◽  
Cycle 24

Sunspots are temporary phenomena on the photosphere of the Sun which appear visibly as dark spots compared to surrounding regions. Sunspot populations usually rise fast but fall more slowly when observed for any particular solar cycle. The sunspot numbers for the current cycle 24 and the previous three cycles have been plotted for duration of first four years for each of them. It appears that the value of peak sunspot number for solar cycle 24 is smaller than the three preceding cycles. When regression analysis is made it exhibits a trend of slow rising phase of the cycle 24 compared to previous three cycles. Our analysis further shows that cycle 24 is approaching to a longer-period but with smaller occurrences of sunspot number.

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