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Related papers: Characteristics of SEPs during Solar Cycle 21-24

200 papers

Geomagnetic field variations during five major Solar Energetic Particle (SEP) events of solar cycle 23 have been investigated in the present study. The SEP events of 01 oct 2001, 04 Nov 2001, 21 Apr 2002 and 14 May 2005 have been selected…

Earth and Planetary Astrophysics · Physics 2015-06-17 Parvaiz A. Khan , Sharad C. Tripathi , O. A. Troshichev , Malik A. Waheed , Aslam A. M. , A. K. Gwal

3He-rich solar energetic particles (SEPs) are believed to be accelerated in solar flares or jets by a mechanism that depends on the ion charge-to-mass (Q/M) ratio. It implies that the flare plasma characteristics (e.g., temperature) may be…

Solar and Stellar Astrophysics · Physics 2021-03-10 R. Bucik , S. M. Mulay , G. M. Mason , N. V. Nitta , M. I. Desai , M. A. Dayeh

We review recent work on 111 Fe-rich impulsive solar energetic ($\sim$ 3 MeV/nuc) particle (SEP) events observed from 1994 to 2013. Strong elemental abundance enhancements scale with A/Q, the ion mass-to-charge ratio, as (A/Q)$^{\alpha}$,…

Solar and Stellar Astrophysics · Physics 2015-10-01 Stephen Kahler , Donald Reames , Edward Cliver

Solar energetic particles (SEPs), including protons and heavy ions, are believed to be accelerated either by CME shock or by magnetic reconnection. The latter also produces solar flares, in which the white light flares (WLFs) are among the…

Solar and Stellar Astrophysics · Physics 2018-01-16 Nengyi Huang , Yan Xu , Haimin Wang

Solar energetic particles (SEPs) affect the solar-terrestrial space environment and become a very important aspect in space weather research. In this work, we numerically investigate the transport processes of SEPs in three-dimensional…

Solar and Stellar Astrophysics · Physics 2015-06-04 H. -Q. He , W. Wan

We study the large solar energetic particle (SEP) events that were detected by GOES in the $>$ 10 MeV energy channel during December 2006 to March 2014. We derive and compare solar particle release (SPR) times for the 0.25--10.4 MeV…

Solar and Stellar Astrophysics · Physics 2016-10-26 Hong Xie , Pertti Makela , Nat Gopalswamy , Orville St. Cyr

Solar energetic particles (SEPs), accelerated during solar eruptions, propagate in turbulent solar wind before being observed with in situ instruments. In order to interpret their origin through comparison with remote-sensing observations…

Solar and Stellar Astrophysics · Physics 2020-01-08 T. Laitinen , S. Dalla

Solar energetic particles are a result of intense solar events such as solar flares and Coronal Mass Ejections (CMEs). These latter events all together can cause major disruptions to spacecraft that are in Earth's orbit and outside of the…

Solar and Stellar Astrophysics · Physics 2017-12-13 Soukaina Filali Boubrahimi , Berkay Aydin , Petrus Martens , Rafal Angryk

Widespread solar energetic particle (SEP) events remain poorly understood phenomena in space weather. These events are often linked to coronal mass ejections (CMEs) and their shocks, but the mechanisms governing their global particle…

Space Physics · Physics 2025-07-02 N. Wijsen , I. C. Jebaraj , N. Dresing , A. Kouloumvakos , E. Palmerio , L. Rodríguez-García

Small 3He-rich solar energetic particle (SEP) events have been commonly associated with extreme-ultraviolet (EUV) jets and narrow coronal mass ejections (CMEs) which are believed to be the signatures of magnetic reconnection involving field…

Solar and Stellar Astrophysics · Physics 2016-12-14 Radoslav Bucik , Davina E. Innes , Glenn M. Mason , Mark E. Wiedenbeck

The familiar correlation between the speed and angular width of coronal mass ejections (CMEs) is also found in solar cycle 24, but the regression line has a larger slope: for a given CME speed, cycle 24 CMEs are significantly wider than…

Solar and Stellar Astrophysics · Physics 2014-08-18 Nat Gopalswamy , Sachiko Akiyama , Seiji Yashiro , Hong Xie , Pertti Mäkelä , Grzegorz Michalek

The solar irradiance in the Extreme Ultraviolet (EUV) spectral bands has been observed with a 15 sec cadence by the SOHO Solar EUV Monitor (SEM) since 1995. During remarkably intense solar flares the SEM EUV measurements are saturated in…

Astrophysics · Physics 2009-11-11 L. V. Didkovsky , D. L. Judge , A. R. Jones , S. Wieman , B. T. Tsurutani , D. McMullin

The coronal mass ejections (CMEs) from the Sun are known for their space weather and geomagnetic consequences. Among all CMEs, so-called radio-loud (RL) and halo CMEs are considered the most energetic in the sense that they are usually…

Solar and Stellar Astrophysics · Physics 2021-05-05 A. Shanmugaraju , P. Pappa Kalaivani , Y. -J. Moon , O. Prakash

We report on a remarkable finding that the halo coronal mass ejections (CMEs) in cycle 24 are more abundant than in cycle 23, although the sunspot number in cycle 24 has dropped by about 40%. We also find that the distribution of halo-CME…

Solar and Stellar Astrophysics · Physics 2015-06-24 N. Gopalswamy , H. Xie , S. Akiyama , P. Mäkelä , S. Yashiro , G. Michalek

The space weather is extremely mild during solar cycle 24: the number of major geomagnetic storms and high-energy solar energetic particle events are at the lowest since the dawn of the space age. Solar wind measurements at 1 AU using Wind…

Solar and Stellar Astrophysics · Physics 2015-08-10 Nat Gopalswamy , Sachiko Akiyama , Seiji Yashiro , Hong Xie , Pertti Makela , Grzegorz Michalek

The Energetic Particle Radiation Environment Model (EPREM) solves the focused transport equation (FTE) on a Lagrangian grid in a frame co-moving with the solar wind plasma and simulates the acceleration and transport of solar energetic…

Solar and Stellar Astrophysics · Physics 2026-03-18 Matthew A. Young , Bala Poduval

Coronal Mass Ejections (CMEs) are highly dynamic events originating in the solar atmosphere, that show a wide range of kinematic properties and are the major drivers of the space weather. The angular width of the CMEs is a crucial parameter…

Solar and Stellar Astrophysics · Physics 2021-04-28 V. Pant , R. Majumdar , R. Patel , A. Chauhan , D. Banerjee , N. Gopalswamy

We study the clustering properties of fast Coronal Mass Ejections (CMEs) that occurred during solar cycles 23 and 24. We apply two methods: the Max spectrum method can detect the predominant clusters and the de-clustering threshold time…

Context: Parameters of solar energetic particle (SEP) event profiles such as the onset time and peak time have been researched extensively to obtain information on acceleration and transport of SEPs. Corotation of particle-filled magnetic…

Solar and Stellar Astrophysics · Physics 2025-02-21 R. A. Hyndman , S. Dalla , T. Laitinen , A. Hutchinson , C. M. S. Cohen , R. F. Wimmer-Schweingruber