In Situ Observation of Intermittent Dissipation at Kinetic Scales in the Earth's Magnetosheath

被引：64

作者：

Chasapis, Alexandros ^{[1
]}

Matthaeus, W. H. ^{[1
]}

Parashar, T. N. ^{[1
]}

Wan, M. ^{[2
]}

Haggerty, C. C. ^{[1
]}

Pollock, C. J. ^{[3
]}

Giles, B. L. ^{[3
]}

Paterson, W. R. ^{[3
]}

Dorelli, J. ^{[3
]}

Gershman, D. J. ^{[3
]}

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

Russell, C. T. ^{[5
]}

Lindqvist, P. -A. ^{[6
]}

Khotyaintsev, Y. ^{[7
]}

Moore, T. E. ^{[3
]}

Ergun, R. E. ^{[8
]}

Burch, J. L. ^{[9
]}

机构：

[1] Univ Delaware, Newark, DE 19716 USA

[2] South Univ Sci & Technol China, Shenzhen, Guangdong, Peoples R China

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

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

[5] Univ Calif Los Angeles, Los Angeles, CA USA

[6] Royal Inst Technol, Stockholm, Sweden

[7] Swedish Inst Space Phys, Uppsala, Sweden

[8] Univ Colorado, Lab Atmospher & Space Phys, Boulder, CO 80309 USA

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

来源：

ASTROPHYSICAL JOURNAL LETTERS | 2018年 / 856卷 / 01期

基金：

中国国家自然科学基金;

关键词：

acceleration of particles - magnetic reconnection - plasmas - turbulence - waves; MAGNETIC RECONNECTION; TURBULENCE; PLASMA; WIND;

D O I：

10.3847/2041-8213/aaadf8

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present a study of signatures of energy dissipation at kinetic scales in plasma turbulence based on observations by the Magnetospheric Multiscale mission (MMS) in the Earth's magnetosheath. Using several intervals, and taking advantage of the high-resolution instrumentation on board MMS, we compute and discuss several statistical measures of coherent structures and heating associated with electrons, at previously unattainable scales in space and time. We use the multi-spacecraft Partial Variance of Increments (PVI) technique to study the intermittent structure of the magnetic field. Furthermore, we examine a measure of dissipation and its behavior with respect to the PVI as well as the current density. Additionally, we analyze the evolution of the anisotropic electron temperature and non-Maxwellian features of the particle distribution function. From these diagnostics emerges strong statistical evidence that electrons are preferentially heated in subproton-scale regions of strong electric current density, and this heating is preferentially in the parallel direction relative to the local magnetic field. Accordingly, the conversion of magnetic energy into electron kinetic energy occurs more strongly in regions of stronger current density, a finding consistent with several kinetic plasma simulation studies and hinted at by prior studies using lower resolution Cluster observations.

引用

页数：6

共 24 条

[1] Spectral energy transfer and dissipation of magnetic energy from fluid to kinetic scales [J].