MMS星座对磁层顶磁通量绳内离子惯性尺度结构的观测

刘杨; 濮祖荫; 谢伦; 郭瑞龙; 王晓钢; 肖池阶; 史全岐; DUNLOP M; BOGDANOVA Y V; MOORE T E; RUSSELL C T; LINDQVIST P A; TORBERT R B; POLLOCK C; ZHAO Cong

doi:10.11728/cjss2018.02.147

MMS星座对磁层顶磁通量绳内离子惯性尺度结构的观测

doi: 10.11728/cjss2018.02.147

1. 北京大学地球与空间科学学院北京 100871;
2. 中国科学院地质与地球物理研究所北京 100029;
3. 哈尔滨工业大学物理系哈尔滨 150001;
4. 北京大学物理学院北京 100871;
5. 山东大学空间科学与物理学院威海 264209;
6. RAL Space, Rutherford Appleton Laboratory, STFC, Didcot, OX11 0QX, UK;
7. Goddard Space Flight Center, NASA, Greenbelt, MD, USA;
8. University of California, Los Angeles, CA, USA;
9. Royal Institute of Technology, Stockholm, Sweden;
10. University of New Hampshire, Durham, NH, USA

基金项目:

国家自然科学基金项目资助（41274167，41674164）

详细信息

作者简介:
刘杨,E-mail:xijubear@163.com

中图分类号: P353
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出版历程
- 收稿日期: 2017-11-03
- 修回日期: 2017-11-24
- 刊出日期: 2018-03-15

Ion-scale Structures in Flux Ropes Observed by MMS at the Magnetopause

1. School of Earth and Space Sciences, Peking University, Beijing 100871;
2. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029;
3. Department of Physics, Harbin Institute of Technology, Haerbin 150001;
4. Institute of Plasma Physics and Fusion Studies, Peking University, Beijing 100871;
5. School of Space Science and Physics, Shandong University, Weihai 264209;
6. RAL Space, Rutherford Appleton Laboratory, STFC, Didcot, OX110 QX, UK;
7. Goddard Space Flight Center, NASA, Greenbelt, MD, USA;
8. University of California, Los Angeles, CA, USA;
9. Royal Institute of Technology, Stockholm, Sweden;
10. University of New Hampshire, Durham, NH, USA

摘要

摘要: 利用MMS观测数据，对磁层顶通量绳内离子惯性尺度（d_i）的结构进行分析研究.结果发现，许多不同尺度（约1d_i至数十d_i）的通量绳内都存在具有d_i尺度的电流 j _m，其方向在磁层顶局地坐标系的-M方向，即与磁层顶查普曼-费拉罗电流同向，由电子在+M方向的运动（ v _em）携带.这些电流结构具有以下特征：磁鞘与磁层成分混合，磁场为开放形态；离子去磁化，电子与磁场冻结；N方向（即垂直于磁层顶电流片方向）的电场 E _n显著增大，幅度达到约20mV·m^-1，并伴有明显的尖峰状起伏，该增强和尖峰状起伏的电场对应于霍尔电场.分析表明，电流、电子与离子运动的偏离以及霍尔电场之间遵从广义欧姆定律，三者密切关联.进一步对磁层顶磁重联的探测数据进行分析发现，在很多重联区内也存在与通量绳内相似的结构，其尺度约为d_i量级，其中霍尔电场 E _N、电流 j _M和电子速度 v _eM均与通量绳内对应物理量的方向相同且幅度相近.基于上述观测事实，采用经典FTE通量绳模型，对通量绳内电流、电子运动和霍尔电场的起源进行了初步探讨，认为其来源于磁层顶无碰撞磁重联区内的相应结构，并且后者在离子尺度通量绳的形成过程中起到重要作用.
- 磁通量绳 /
- 离子尺度电流 /
- 霍尔电场 /
- 磁层顶 /
- 磁重联
Abstract: In this paper the structures with scale of ion inertial length (d_i) in flux ropes at the magnetopause are studied based on MMS measurements. The results show that currents ( j _m) of d_i scale are found to exist in many flux ropes with different scales, which flow in the -M direction in magnetopause local coordinates (i.e., in the same direction of the Chapman-Ferraro current at the magnetopause) and are carried by electrons' motion in the +M direction ( v _em). Within the current structures, magnetosheath and magnetospheric plasma populations are mixed; the magnetic field has open topology; ions are non-magnetized, while electrons are frozen-in with the magnetic field lines; the N-component of electric field ( E _n), which is Hall electric field in nature, substantially enhances (up to about 20mV·m^-1), accompanying with notable fluctuations. Detailed analysis shows that the current, separation of electrons' motion from ions and the Hall electric field are closely related to each other, and obey the general Ohm's Law. In addition, we have also analyzed the MMS measurements of magnetic reconnection events at the magnetopause. It is found that structures similar to those in flux ropes are also present inside the reconnection region in many cases. Their scales are of d_i length. The directions (magnitudes) of the Hall electric field E _N, current filament j _M and electron velocity v _eM are as same as (close to) those in flux ropes. On the bases of above observations and making use of the classical flux rope models, how the d_i-scale structures in flux ropes are formed is studied. It is suggested that they are likely to originate from the corresponding structures in the reconnection region at the magnetopause which play an essential role in the formation process of d_i-scale flux ropes.
- Magnetic flux ropes /
- Ion-scale current /
- Hall electric field /
- Magnetopause /
- Magnetic reconnection

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参考文献(58)

[1]	LE G, GOSLING J T, RUSSELL C T, et al. The magnetic and plasma structure of flux transfer events[J]. J. Geophys. Res., 1999, 104(A1):233-245
[2]	HAERENDEL G, PASCHMANN G, SCKOPKE N, et al. The frontside boundary layer of the magnetosphere and the problem of reconnection[J]. J. Geophys. Res., 1978, 83(A7):3195-3216
[3]	RUSSELL C T, ELPHIC R C. Initial ISEE magnetometer results:magnetopause observations[J]. Space Sci. Rev., 1978, 22(6):681-715
[4]	RIJNBEEK R P, COWLEY S W H, SOUTHWOOD D J, et al. A survey of dayside flux transfer events observed by ISEE 1 and 2 magnetometers[J]. J. Geophys. Res., 1984, 89(A2):786-800
[5]	PASCHMANN G, HAERENDEL G, PAPAMASTORAKIS I, et al. Plasma and magnetic field characteristics of magnetic flux transfer events[J]. J. Geophys. Res., 1982, 87(A4):2159-2168
[6]	ELPHIC R C. Observations of flux transfer events:A review[M]//Physics of the Magnetopause. Washington, DC:AGU, 1995:225-233
[7]	EASTWOOD J P, PHAN T D, FEAR R C, et al. Survival of Flux Transfer Event (FTE) flux ropes far along the tail magnetopause[J]. J. Geophys. Res., 2012, 117(A8):A08222
[8]	ZHANG H, KIVELSON M G, ANGELOPOULOS V, et al. Generation and properties of in vivo flux transfer events[J]. J. Geophys. Res., 2012, 117(A5):A05224
[9]	LEE L C, FU Z F. A theory of magnetic flux transfer at the earth's magnetopause[J]. Geophys. Res. Lett., 1985, 12(2):105-108
[10]	RAEDER J. Flux transfer events:1. Generation mechanism for strong southward IMF[J]. Ann. Geophys., 2006, 24(1):381-392
[11]	SCHOLER M. Strong core magnetic fields in magnetopause flux transfer events[J]. Geophys. Res. Lett., 1988, 15(8):748-751
[12]	SOUTHWOOD D J, FARRUGIA C J, SAUNDERS M A. What are flux transfer events[J]. Planet. Space Sci., 1988, 36(5):503-508
[13]	LIU Z X, HU Y D. Local magnetic reconnection caused by vortices in the flow field[J]. Geophys. Res. Lett., 1988, 15(8):752-755
[14]	PU Z Y, HOU P T, LIU Z X. Vortex-induced tearing mode instability as a source of flux transfer events[J]. J. Geophys. Res., 1990, 95(A11):18861-18869
[15]	CHEN L J, BHATTACHARJEE A, PUHL-QUINN P A, et al. Observation of energetic electrons within magnetic islands[J]. Nat. Phys., 2008, 4(1):19-23
[16]	CHEN L J, BESSHO N, LEFEBVRE B, et al. Multispacecraft observations of the electron current sheet, neighboring magnetic islands, and electron acceleration during magnetotail reconnection[J]. Phys. Plasmas, 2009, 16(5):056501. DOI: 10.1063/1.3112744
[17]	HUANG S Y, VAIVADS A, KHOTYAINTSEV Y V, et al. Electron acceleration in the reconnection diffusion region:Cluster observations[J]. Geophys. Res. Lett., 2012, 39(11):L11103. DOI: 10.1029/2012GL051946
[18]	HUANG S Y, RETINO A, PHAN T D, et al. In situ observations of flux rope at the separatrix region of magnetic reconnection[J]. J. Geophys. Res., 2016, 121(1):205-213
[19]	DAUGHTON W, ROYTERSHTEYN V, KARIMABADI H, et al. Role of electron physics in the development of turbulent magnetic reconnection in collisionless plasmas[J]. Nat. Phys., 2011, 7(7):539-542
[20]	DRAKE J F, SWISDAK M, CHE H, et al. Electron acceleration from contracting magnetic islands during reconnection[J]. Nature, 2006, 443(7111):553-556
[21]	WANG Rongsheng, LU Quanming, LI Xing, et al. Observations of energetic electrons up to 200keV associated with a secondary island near the center of an ion diffusion region:a Cluster case study[J]. J. Geophys. Res., 2010, 115(A11):A11201. DOI: 10.1029/2010JA015473
[22]	EASTWOOD J P, PHAN T D, CASSAK P A, et al. Ion-scale secondary flux ropes generated by magnetopause reconnection as resolved by MMS[J]. Geophys. Res. Lett., 2016, 43(10):4716-4724
[23]	HWANG K J, SIBECK D J, GILES B L, et al. The substructure of a flux transfer event observed by the MMS spacecraft[J]. Geophys. Res. Lett., 2016:43(18):9434-9443
[24]	TEH W L, DENTON R E, SONNERUP B U Ö, et al. MMS observations of oblique small-scale magnetopause flux ropes near the ion diffusion region during weak guide-field reconnection[J]. Geophys. Res. Lett., 2017, 44(13):6517-6524
[25]	TEH W L, NAKAMURA T K M, NAKAMURA R, et al. Evolution of a typical ion-scale magnetic flux rope caused by thermal pressure enhancement[J]. J. Geophys. Res., 2017, 122(2):2040-2050
[26]	RUSSELL C T, ANDERSON B J, BAUMJOHANN W, et al. The magnetospheric multiscale magnetometers[J]. Space Sci. Rev., 2016, 199(1/2/3/4):189-256
[27]	TORBERT R B, RUSSELL C T, MAGNES W, et al. The FIELDS instrument suite on MMS:Scientific objectives, measurements, and data products[J]. Space Sci. Rev., 2016, 199(1/2/3/4):105-135
[28]	LINDQVIST P A, OLSSON G, TORBERT R B, et al. The spin-plane double probe electric field instrument for MMS[J]. Space Sci. Rev., 2016, 199(1/2/3/4):137-165
[29]	POLLOCK C, MOORE T, JACQUES A, et al. Fast plasma investigation for magnetospheric multiscale[J]. Space Sci. Rev., 2016, 199(1/2/3/4):331-406
[30]	SONNERUP B U Ö, SCHEIBLE M. Minimum and maximum variance analysis[M]//Analysis Methods for Multi-Spacecraft Data. ISSI Scientific Reports SR-001. Noordwijk, Netherlands:International Space Science Institute, 1998:185-220
[31]	XIAO C J, PU Z Y, MA Z W, et al. Inferring of flux rope orientation with the minimum variance analysis technique[J]. J. Geophys. Res., 2004, 109(A11):A11218. DOI: 10.1029/2004JA010594
[32]	RUSSELL C T, MELLOTT M M, SMITH E J, et al. Multiple spacecraft observations of interplanetary shocks:four spacecraft determination of shock normals[J]. J. Geophys. Res., 1983, 88(A6):4739-4748
[33]	SCHWARTZ S J. Shock and discontinuity normals, mach numbers, and related parameters[R]//Analysis Methods for Multi-Spacecraft Data. ISSI Scientific Report SR-001. Bern:International Space Science Institute, 1998:249-270
[34]	ZHOU X Z, ZONG Q G, PU Z Y, et al. Multiple triangulation analysis:another approach to determine the orientation of magnetic flux ropes[J]. Ann. Geophys., 2006, 24(6):1759-1765
[35]	ZHOU X Z, ZONG Q G, WANG J, et al. Multiple triangulation analysis:application to determine the velocity of 2-D structures[J]. Ann. Geophys., 2006, 24(11):3173-3177
[36]	SHI Q Q, SHEN C, PU Z Y, et al. Dimensional analysis of observed structures using multipoint magnetic field measurements:Application to Cluster[J]. Geophys. Res. Lett., 2005, 32(12):L12105. DOI: 10.1029/2005GL022454
[37]	SHI Q Q, SHEN C, DUNLOP M W, et al. Motion of observed structures calculated from multi-point magnetic field measurements:Application to Cluster[J]. Geophys. Res. Lett., 2006, 33(8):L08109. DOI: 10.1029/2005GL025073
[38]	DE HOFFMANN F, TELLER E. Magneto-hydrodynamic shocks[J]. Phys. Rev., 1950, 80(4):692-703.
[39]	MOZER F S. Criteria for and statistics of electron diffusion regions associated with subsolar magnetic field reconnection[J]. J. Geophys. Res., 2005, 110(A12):A12222. DOI: 10.1029/2005JA011258
[40]	ZHONG J, PU Z Y, DUNLOP M W, et al. Three-dimensional magnetic flux rope structure formed by multiple sequential X-line reconnection at the magnetopause[J]. J. Geophys. Res., 2013, 118(5):1904-1911
[41]	PU Z Y, RAEDER J, ZHONG J, et al. Magnetic topologies of an in vivo FTE observed by Double Star/TC-1 at Earth's magnetopause[J]. Geophys. Res. Lett., 2013, 40(14):3502-3506
[42]	LÜ Leiqi, PU Zuyin, XIE Lun. Multiple magnetic topologies in flux transfer events:THEMIS measurements[J]. Sci. China Technol. Sci., 2016, 59(8):1283-1293
[43]	ROSSI B OLBERT S. Introduction to the Physics of Space[M]. New York:McGraw-Hill, 1970
[44]	EASTWOOD J P, PHAN T D, MOZER F S, et al. Multi-point observations of the Hall electromagnetic field and secondary island formation during magnetic Reconnection[J]. J. Geophys. Res., 2007, 112(A6):A06235. DOI: 10.1029/2006JA012158
[45]	SHAY M A, DRAKE J F SWISDAK M. Two-scale structure of the electron dissipation region during collisionless magnetic reconnection[J]. Phys. Rev. Lett., 2007, 99(15):155002. DOI: 10.1103/PhysRevLett.99.155002
[46]	MOZER F S, BALE S D, PHAN T D. Evidence of diffusion regions at a subsolar magnetopause crossing[J]. Phys. Rev. Lett., 2002, 89(1):015002
[47]	EASTWOOD J P, PHAN T D, ØIEROSET M, et al. Average properties of the magnetic reconnection ion diffusion region in the Earth's magnetotail:the 2001-2005 Cluster observations and comparison with simulations[J]. J. Geophys. Res., 2010, 115(A8):A08215. DOI: 10.1029/2009JA014962
[48]	PRITCHETT P L, MOZER F S. Asymmetric magnetic reconnection in the presence of a guide field[J]. J. Geophys. Res., 2009, 114(A11):A11210. DOI: 10.1029/2009JA014343
[49]	HESSE M, LIU Y H, CHEN L J, et al. On the electron diffusion region in asymmetric reconnection with a guide magnetic field[J]. Geophys. Res. Lett., 2016, 43(6):2359-2364
[50]	BURCH J L, TORBERT R B, PHAN T D, et al. Electron-scale measurements of magnetic reconnection in space[J]. Science, 2016, 352(6290):aaf2939. DOI:10.1126/science. aaf2939
[51]	CHEN L J, HESSE M, WANG Shan, et al. Electron energization and mixing observed by MMS in the vicinity of an electron diffusion region during magnetopause reconnection[J]. Geophys. Res. Lett., 2016, 43(12):6036-6043
[52]	WANG Rongsheng, NAKAMURA R, LU Quanming, et al. Electron-scale quadrants of the Hall magnetic field observed by the Magnetospheric Multiscale spacecraft during asymmetric reconnection[J]. Phys. Rev. Lett., 2017, 118(17):175101
[53]	PENG F Z, FU H S, CAO J B, et al. Quadrupolar pattern of the asymmetric guide-field reconnection[J]. J. Geophys. Res., 2017, 122(6):6349-6356
[54]	BURCH J L, PHAN T D. Magnetic reconnection at the dayside magnetopause:Advances with MMS[J]. Geophys. Res. Lett., 2016, 43(16):8327-8338
[55]	PHAN T D, EASTWOOD J P, CASSAK P A, et al. MMS observations of electron-scale filamentary currents in the reconnection exhaust and near the X line[J]. Geophys. Res. Lett., 2016, 43(12):6060-6069
[56]	ERGUN R E, CHEN L J, WILDER F D, et al. Drift waves, intense parallel electric fields, and turbulence associated with asymmetric magnetic reconnection at the magnetopause[J]. Geophys. Res. Lett., 2017, 44(7):2978-2986
[57]	DRAKE J F, SWISDAK M, SCHOEFFLER K M, et al. Formation of secondary islands during magnetic reconnection[J]. Geophys. Res. Lett., 2006, 33(13):L13105. DOI: 10.1029/2006GL025957
[58]	TREUMANN R A, BAUMJOHANN W. Collisionless magnetic reconnection in space plasmas[J]. Front. Phys., 2013, 1:31