Influence of Magnetic Clouds on Variations of Cosmic Rays in November 2004

CORC > 高能物理研究所 > 中国科学院高能物理研究所 > 粒子天体物理中心

	Influence of Magnetic Clouds on Variations of Cosmic Rays in November 2004
	Yu XX(于晓霞); Lu H(卢红); Shi F(石峰); Yu, XX; Lu, H; Le, GM; Shi, F
刊名	SOLAR PHYSICS
	2010
卷号	263 期号:1-2 页码:#REF!
关键词	Coronal mass ejections (CMEs) Cosmic rays Forbush decreases (Fds) Magnetic cloud (MC) Magnetic fields
通讯作者	Yu, XX (reprint author), Chinese Acad Sci, Key Lab Particle Astrophys, Inst High Energy Phys, Beijing 100049, Peoples R China.
英文摘要	We investigate the effects of two magnetic clouds on hourly cosmic-ray intensity profiles in the Forbush decrease events in November 2004 observed by 47 ground-based neutron-monitor stations. By using a wavelet decomposition, the start time of the main phase in a Forbush decrease event can be defined, and then clearer definitions of initial phase, main phase, and recovery phase are proposed. Our analyses suggest that the main phase of this Fd event precedes the arrival time of the first magnetic cloud by about three hours, and the Fds observed at the majority (39/47) of the stations were found to originate from the sheath region as indicated by large fluctuations in magnetic field vectors at 19: 00 UT on 7 November 2004, regardless of the station location. In addition, about 45% of the onset times of the recovery phase in the Forbush decreases took place at 04: 00 UT on 10 November, independent of the station position. The results presented here support the hypothesis that the sheath region between the shock and the magnetic cloud, especially the enhanced turbulent magnetic field, results in the scattering of cosmic-ray particles, and causes the following Forbush decreases. Analysis of variation profiles from different neutron monitors reveals the global simultaneity of this Forbush decrease event. Moreover, we infer that the interplanetary disturbance was asymmetric when it reached the Earth, inclined to the southern hemisphere. These results provide several observational constraints for more detailed simulations of the Forbush decrease events with time-dependent cosmic-ray modulation models.
学科主题	Astronomy & Astrophysics
类目[WOS]	Astronomy & Astrophysics
收录类别	SCI
WOS记录号	WOS:000277148200016
公开日期	2016-05-03
内容类型	期刊论文
源URL	[http://ir.ihep.ac.cn/handle/311005/227041]
专题	高能物理研究所_粒子天体物理中心
推荐引用方式 GB/T 7714	Yu XX,Lu H,Shi F,et al. Influence of Magnetic Clouds on Variations of Cosmic Rays in November 2004[J]. SOLAR PHYSICS,2010,263(1-2):#REF!.
APA	于晓霞.,卢红.,石峰.,Yu, XX.,Lu, H.,...&Shi, F.(2010).Influence of Magnetic Clouds on Variations of Cosmic Rays in November 2004.SOLAR PHYSICS,263(1-2),#REF!.
MLA	于晓霞,et al."Influence of Magnetic Clouds on Variations of Cosmic Rays in November 2004".SOLAR PHYSICS 263.1-2(2010):#REF!.