Magnetic Reconnection in Three Dimensions: Observations of Electromagnetic Drift Waves in the Adjacent Current Sheet

被引：7

作者：

Ergun, R. E. ^{[1
,2
]}

Hoilijoki, S. ^{[2
]}

Ahmadi, N. ^{[2
]}

Schwartz, S. J. ^{[2
]}

Wilder, F. D. ^{[2
]}

Burch, J. L. ^{[3
]}

Torbert, R. B. ^{[3
,4
]}

Lindqvist, P-A ^{[5
]}

Graham, D. B. ^{[6
]}

Strangeway, R. J. ^{[7
]}

Le Contel, O. ^{[8
]}

Holmes, J. C. ^{[9
]}

Stawarz, J. E. ^{[10
]}

Goodrich, K. A. ^{[11
]}

Eriksson, S. ^{[2
]}

Giles, B. L. ^{[12
]}

Gershman, D. ^{[12
]}

Chen, L. J. ^{[12
,13
]}

机构：

[1] Univ Colorado, Dept Astrophys & Planetary Sci, Boulder, CO 80309 USA

[2] Univ Colorado, Lab Atmospher & Space Sci, Boulder, CO 80309 USA

[3] Southwest Res Inst, San Antonio, TX USA

[4] Univ New Hampshire, Dept Phys, Durham, NH 03824 USA

[5] Royal Inst Technol, Stockholm, Sweden

[6] Swedish Inst Space Phys, Uppsala, Sweden

[7] Univ Calif Los Angeles, IGGP, Los Angeles, CA USA

[8] Lab Phys Plasmas, Palaiseau, France

[9] Austrian Acad Sci, Space Res Inst, Graz, Austria

[10] Imperial Coll London, Blackett Lab, London, England

[11] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA

[12] NASA, Goddard Space Flight Ctr, Greenbelt, MD USA

[13] Univ Maryland, IREAP, College Pk, MD 20742 USA

来源：

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS | 2019年 / 124卷 / 12期

关键词：

drift waves; magnetic reconnection; turbulence; parallel electric fields; ELECTRON-DIFFUSION REGION; HYBRID; INSTABILITY; TURBULENCE; FIELDS;

D O I：

10.1029/2019JA027228

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Magnetic reconnection at the subsolar magnetopause is persistently accompanied by strong fluctuations of the magnetic field (B), plasma density (n), and all components of the electric field (E) and current (J). The strongest fluctuations are at frequencies below the lower hybrid frequency and observed in a thin, intense current sheet adjacent to the electron diffusion region. In this current sheet, the background magnitudes of B and n are changing considerably, creating an inhomogeneous plasma environment. We show that the fluctuations in B and n are consistent with an oscillatory displacement of the current sheet in the surface normal direction. The displacement is propagating parallel to the magnetic reconnection X line. Wavelengths are on the order of or longer than the thickness of the current sheet to which they are confined, so we label these waves electromagnetic drift waves. E and J fluctuations are more complex than a simple displacement. They have significant variations in the component along B, which suggest that the drift waves also may be confined along B. The current sheet is supported by an electron drift driven by normal electric field, which, in turn, is balanced by an ion pressure gradient. We suggest that wave growth comes from an instability related to the drift between the electrons and ions. We discuss the possibility that drift waves can displace or penetrate into the electron diffusion region giving magnetic reconnection three-dimensional structure. Drift waves may corrugate the X line, possibly breaking the X line and generating turbulence.

引用

页码：10104 / 10118

页数：15

共 41 条

[1] Magnetospheric Multiscale Overview and Science Objectives [J].

Burch, J. L. ;

Moore, T. E. ;

Torbert, R. B. ;

Giles, B. L. .

SPACE SCIENCE REVIEWS, 2016, 199 (1-4) :5-21

[2] Electron-scale measurements of magnetic reconnection in space [J].

Burch, J. L. ;

Torbert, R. B. ;

Phan, T. D. ;

Chen, L. -J. ;

Moore, T. E. ;

Ergun, R. E. ;

Eastwood, J. P. ;

Gershman, D. J. ;

Cassak, P. A. ;

Argall, M. R. ;

Wang, S. ;

Hesse, M. ;

Pollock, C. J. ;

Giles, B. L. ;

Nakamura, R. ;

Mauk, B. H. ;

Fuselier, S. A. ;

Russell, C. T. ;

Strangeway, R. J. ;

Drake, J. F. ;

Shay, M. A. ;

Khotyaintsev, Yu. V. ;

Lindqvist, P. -A. ;

Marklund, G. ;

Wilder, F. D. ;

Young, D. T. ;

Torkar, K. ;

Goldstein, J. ;

Dorelli, J. C. ;

Avanov, L. A. ;

Oka, M. ;

Baker, D. N. ;

Jaynes, A. N. ;

Goodrich, K. A. ;

Cohen, I. J. ;

Turner, D. L. ;

Fennell, J. F. ;

Blake, J. B. ;

Clemmons, J. ;

Goldman, M. ;

Newman, D. ;

Petrinec, S. M. ;

Trattner, K. J. ;

Lavraud, B. ;

Reiff, P. H. ;

Baumjohann, W. ;

Magnes, W. ;

Steller, M. ;

Lewis, W. ;

Saito, Y. .

SCIENCE, 2016, 352 (6290)

[3] Scaling of asymmetric magnetic reconnection: General theory and collisional simulations [J].

Cassak, P. A. ;

Shay, M. A. .

PHYSICS OF PLASMAS, 2007, 14 (10)

[4] Electron diffusion region during magnetopause reconnection with an intermediate guide field: Magnetospheric multiscale observations [J].

Chen, L. -J. ;

Hesse, M. ;

Wang, S. ;

Gershman, D. ;

Ergun, R. E. ;

Burch, J. ;

Bessho, N. ;

Torbert, R. B. ;

Giles, B. ;

Webster, J. ;

Pollock, C. ;

Dorelli, J. ;

Moore, T. ;

Paterson, W. ;

Lavraud, B. ;

Strangeway, R. ;

Russell, C. ;

Khotyaintsev, Y. ;

Lindqvist, P. -A. ;

Avanov, L. .

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 2017, 122 (05) :5235-5246

[5] The THEMIS Digital Fields Board [J].

Cully, C. M. ;

Ergun, R. E. ;

Stevens, K. ;

Nammari, A. ;

Westfall, J. .

SPACE SCIENCE REVIEWS, 2008, 141 (1-4) :343-355

[6] Nonlinear evolution of the lower-hybrid drift instability in a current sheet [J].

Daughton, W ;

Lapenta, G ;

Ricci, P .

PHYSICAL REVIEW LETTERS, 2004, 93 (10) :105004-1

[7] Electromagnetic properties of the lower-hybrid drift instability in a thin current sheet [J].

Daughton, W .

PHYSICS OF PLASMAS, 2003, 10 (08) :3103-3119

[8] ANOMALOUS TRANSPORT PROPERTIES ASSOCIATED WITH LOWER-HYBRID-DRIFT INSTABILITY [J].

DAVIDSON, RC ;

GLADD, NT .

PHYSICS OF FLUIDS, 1975, 18 (10) :1327-1335

[9] EFFECTS OF FINITE PLASMA BETA ON LOWER-HYBRID-DRIFT INSTABILITY [J].

DAVIDSON, RC ;

GLADD, NT ;

WU, CS ;

HUBA, JD .

PHYSICS OF FLUIDS, 1977, 20 (02) :301-310

[10]

Dunlop MW, 2002, J GEOPHYS RES-SPACE, V107, DOI [10.1029/2001JA005088, 10.1029/2001JA005089]

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