A NUMERICAL SIMULATION OF SOLAR ENERGETIC PARTICLE DROPOUTS DURING IMPULSIVE EVENTS
文献类型:期刊论文
作者 | Wang, Y.; Qin, G.![]() |
刊名 | ASTROPHYSICAL JOURNAL
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出版日期 | 2014 |
卷号 | 789期号:2页码:157 |
关键词 | Sun: flares Sun: granulation Sun: heliosphere Sun: magnetic fields Sun: particle emission |
ISSN号 | 0004-637X |
通讯作者 | Wang, Y (reprint author), Chinese Acad Sci, Natl Space Sci Ctr, State Key Lab Space Weather, Beijing 100190, Peoples R China. |
英文摘要 | This paper investigates the conditions for producing rapid variations of solar energetic particle (SEP) intensity commonly known as "dropouts." In particular, we use numerical model simulations based on solving the focused transport equation in the three-dimensional Parker interplanetary magnetic field to put constraints on the properties of particle transport coefficients in both directions perpendicular and parallel to the magnetic field. Our calculations of the temporal intensity profile of 0.5 and 5 MeV protons at the Earth show that the perpendicular diffusion must be small while the parallel mean free path is long in order to reproduce the phenomenon of SEP dropouts. When the parallel mean free path is a fraction of 1 AU and the observer is located at 1 AU, the perpendicular to parallel diffusion ratio must be below 10(-5) if we want to see the particle flux dropping by at least several times within 3 hr. When the observer is located at a larger solar radial distance, the perpendicular to parallel diffusion ratio for reproducing the dropouts should be even lower than that in the case of 1 AU distance. A shorter parallel mean free path or a larger radial distance from the source to observer will cause the particles to arrive later, making the effects of perpendicular diffusion more prominent and SEP dropouts disappear. All of these effects require the magnetic turbulence that resonates with the particles to be low everywhere in the inner heliosphere. |
收录类别 | SCI |
语种 | 英语 |
源URL | [http://ir.nssc.ac.cn/handle/122/4487] ![]() |
专题 | 国家空间科学中心_空间科学部 |
推荐引用方式 GB/T 7714 | Wang, Y.,Qin, G.,Zhang, M.,et al. A NUMERICAL SIMULATION OF SOLAR ENERGETIC PARTICLE DROPOUTS DURING IMPULSIVE EVENTS[J]. ASTROPHYSICAL JOURNAL,2014,789(2):157. |
APA | Wang, Y.,Qin, G.,Zhang, M.,&Dalla, S..(2014).A NUMERICAL SIMULATION OF SOLAR ENERGETIC PARTICLE DROPOUTS DURING IMPULSIVE EVENTS.ASTROPHYSICAL JOURNAL,789(2),157. |
MLA | Wang, Y.,et al."A NUMERICAL SIMULATION OF SOLAR ENERGETIC PARTICLE DROPOUTS DURING IMPULSIVE EVENTS".ASTROPHYSICAL JOURNAL 789.2(2014):157. |
入库方式: OAI收割
来源:国家空间科学中心
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