Thin current sheets in the presence of a guiding magnetic field in Earth's magnetosphere

	Thin current sheets in the presence of a guiding magnetic field in Earth's magnetosphere
	Malova, H. V.; Popov, V. Y.; Mingalev, O. V.; Mingalev, I. V.; Mel'nik, M. N.; Artemyev, A. V.; Petrukovich, A. A.; Delcourt, D. C.; Shen, C.; Zelenyi, L. M.
刊名	JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
	2012
卷号	117 页码:A04212
ISSN号	0148-0227
通讯作者	Malova, HV (reprint author), Lomonosov Moscow State Univ, Skobeltsyn Inst Nucl Phys, GSP 1, Moscow 119991, Russia.
中文摘要	A self-consistent theory of relatively thin anisotropic current sheets (TCS) in collisionless plasma is developed, taking into account the presence of a guiding field By (all notations are used in the GSM coordinate system). TCS configurations with a finite value of guiding field By are often observed in Earth's magnetotail and are typical for Earth's magnetopause. A characteristic signature of such configurations is the existence of a magnetic field component along the direction of TCS current. A general case is considered in this paper with global sheared magnetic field B-y = const. Analytical and numerical (particle-in-cell) models for such plasma equilibria are analyzed and compared with each other as well as with Cluster observations. It is shown that, in contrast to the case with B-y = 0, the character of "particle-current sheet" interaction is drastically changed in the case of a global magnetic shear. Specifically, serpentine-like parts of ion trajectories in the neutral plane become more tortuous, leading to a thicker current sheet. The reflection coefficient of particles coming from northern and southern sources also becomes asymmetric and depends upon the value of the B-y component. As a result, the degree of asymmetry of magnetic field, plasma, and current density profiles appears characteristic of current sheets with a constant B-y. In addition, in the presence of nonzero guiding field, the curvature current of electrons in the center of the current sheet decreases, yielding an effective thickening of the sheet. Implications of these results for current sheets in Earth's magnetosphere are discussed.
英文摘要	A self-consistent theory of relatively thin anisotropic current sheets (TCS) in collisionless plasma is developed, taking into account the presence of a guiding field By (all notations are used in the GSM coordinate system). TCS configurations with a finite value of guiding field By are often observed in Earth's magnetotail and are typical for Earth's magnetopause. A characteristic signature of such configurations is the existence of a magnetic field component along the direction of TCS current. A general case is considered in this paper with global sheared magnetic field B-y = const. Analytical and numerical (particle-in-cell) models for such plasma equilibria are analyzed and compared with each other as well as with Cluster observations. It is shown that, in contrast to the case with B-y = 0, the character of "particle-current sheet" interaction is drastically changed in the case of a global magnetic shear. Specifically, serpentine-like parts of ion trajectories in the neutral plane become more tortuous, leading to a thicker current sheet. The reflection coefficient of particles coming from northern and southern sources also becomes asymmetric and depends upon the value of the B-y component. As a result, the degree of asymmetry of magnetic field, plasma, and current density profiles appears characteristic of current sheets with a constant B-y. In addition, in the presence of nonzero guiding field, the curvature current of electrons in the center of the current sheet decreases, yielding an effective thickening of the sheet. Implications of these results for current sheets in Earth's magnetosphere are discussed.
学科主题	空间物理
收录类别	SCI
资助信息	RFBR [11-02-01166, 10-05-91001, 10-02-93114, NOZ 14.740.11.0086, HIII-3200.2010.2, FP-7 269198]; RF Ministry of Education and Science [11.G34.31.0001]; SPBGU
语种	英语
公开日期	2014-12-15
内容类型	期刊论文
源URL	[http://ir.nssc.ac.cn/handle/122/3196]
专题	国家空间科学中心_空间科学部
推荐引用方式 GB/T 7714	Malova, H. V.,Popov, V. Y.,Mingalev, O. V.,et al. Thin current sheets in the presence of a guiding magnetic field in Earth's magnetosphere[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS,2012,117:A04212.
APA	Malova, H. V..,Popov, V. Y..,Mingalev, O. V..,Mingalev, I. V..,Mel'nik, M. N..,...&Zelenyi, L. M..(2012).Thin current sheets in the presence of a guiding magnetic field in Earth's magnetosphere.JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS,117,A04212.
MLA	Malova, H. V.,et al."Thin current sheets in the presence of a guiding magnetic field in Earth's magnetosphere".JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 117(2012):A04212.