Superthin current sheets supported by anisotropic electrons

Current sheets with strong transverse (cross field) currents are commonly observed in planetary magnetospheres and serve as a natural energy source for magnetic reconnection. As the most investigated current sheet, the current sheet in the Earth's magnetotail forms in a high-β plasma, with hot ions dominantly contributing to the diamagnetic currents. Spacecraft observations have shown, however, that a superthin electron dominated current sheet can be embedded in the Earth's magnetotail current sheet. In this paper, we develop a model of such superthin current sheets with strong currents produced by anisotropic electrons. We also compare the model with spacecraft observations, which shows reasonable agreement in spatial profiles and magnitudes of the current density. The spatial scale (thickness) of the superthin current sheet is controlled by the equatorial magnetic field component, whereas the current density magnitude is controlled by the electron fire-hose parameter at the equator. Although the current density peak within the superthin current sheet can significantly exceed the background (embedding) current density, the magnetic field magnitude at the superthin current sheet boundary does not exceed 10% of the total magnetic field magnitude. These superthin current sheets are sub-ion (or even electron-scale) structures, which are not sufficiently large/intense to perturb ion dynamics. We discuss applications of the proposed model for the analysis of plasma instabilities in superthin electron-dominated current sheets.

[1]  I. Vasko,et al.  A model of the current sheet in the Earth's magnetotail , 2020, Physics of Plasmas.

[2]  T. Neukirch,et al.  Kinetic Models of Tangential Discontinuities in the Solar Wind , 2020, The Astrophysical Journal.

[3]  V. Angelopoulos,et al.  Contribution of Anisotropic Electron Current to the Magnetotail Current Sheet as a Function of Location and Plasma Conditions , 2020, Journal of Geophysical Research: Space Physics.

[4]  V. Angelopoulos,et al.  Near-Earth Magnetotail Reconnection Powers Space Storms , 2019, Nature physics.

[5]  D. Gershman,et al.  Pressure Tensor Elements Breaking the Frozen-In Law During Reconnection in Earth's Magnetotail. , 2019, Physical review letters.

[6]  J. Egedal,et al.  Three-dimensional stability of current sheets supported by electron pressure anisotropy , 2019, Physics of Plasmas.

[7]  V. Angelopoulos,et al.  Ion Anisotropy in Earth's Magnetotail Current Sheet: Multicomponent Ion Population , 2019, Journal of Geophysical Research: Space Physics.

[8]  V. Angelopoulos,et al.  The Hall Electric Field in Earth's Magnetotail Thin Current Sheet , 2019, Journal of Geophysical Research: Space Physics.

[9]  J. G. Sample,et al.  The Space Physics Environment Data Analysis System (SPEDAS) , 2019, Space Science Reviews.

[10]  J P Eastwood,et al.  Electron-scale dynamics of the diffusion region during symmetric magnetic reconnection in space , 2018, Science.

[11]  M. Velli,et al.  Nonlinear Firehose Relaxation and Constant-B Field Fluctuations , 2018, The Astrophysical Journal.

[12]  P. Hellinger,et al.  Electron mirror instability: particle-in-cell simulations , 2018, Journal of Plasma Physics.

[13]  C. Russell,et al.  An Electron‐Scale Current Sheet Without Bursty Reconnection Signatures Observed in the Near‐Earth Tail , 2018 .

[14]  C. Russell,et al.  Electron magnetic reconnection without ion coupling in Earth’s turbulent magnetosheath , 2018, Nature.

[15]  A. Lui.  Review on the Characteristics of the Current Sheet in the Earth's Magnetotail , 2018 .

[16]  P. Cassak,et al.  Spacecraft Observations of Oblique Electron Beams Breaking the Frozen-In Law During Asymmetric Reconnection. , 2018, Physical Review Letters.

[17]  M. Velli,et al.  The Parametric Instability of Alfvén Waves: Effects of Temperature Anisotropy , 2017, 1711.06371.

[18]  G. Reeves,et al.  Electron‐acoustic solitons and double layers in the inner magnetosphere , 2017 .

[19]  V. Angelopoulos,et al.  Mars's magnetotail: Nature's current sheet laboratory , 2017 .

[20]  A. Runov,et al.  Electron currents supporting the near‐Earth magnetotail during current sheet thinning , 2017 .

[21]  D. Blake,et al.  Atmospheric benzene observations from oil and gas production in the Denver‐Julesburg Basin in July and August 2014 , 2016 .

[22]  V. Angelopoulos,et al.  Effects of electron pressure anisotropy on current sheet configuration , 2016 .

[23]  V. Merkin,et al.  Generalized magnetotail equilibria: Effects of the dipole field, thin current sheets, and magnetic flux accumulation , 2016 .

[24]  R. Nakamura,et al.  Formation of sub-ion scale filamentary force-free structures in the vicinity of reconnection region , 2016 .

[25]  U. Gliese,et al.  Fast Plasma Investigation for Magnetospheric Multiscale , 2016 .

[26]  William Daughton,et al.  Hybrid simulations of magnetic reconnection with kinetic ions and fluid electron pressure anisotropy , 2016 .

[27]  Thomas E. Moore,et al.  Magnetospheric Multiscale Overview and Science Objectives , 2016 .

[28]  Wolfgang Baumjohann,et al.  The Magnetospheric Multiscale Magnetometers , 2016 .

[29]  M. Shay,et al.  The competition of electron and ion heating during magnetic reconnection , 2015 .

[30]  B. Jakosky,et al.  Magnetotail dynamics at Mars: Initial MAVEN observations , 2015 .

[31]  J. Egedal,et al.  Double layer electric fields aiding the production of energetic flat-top distributions and superthermal electrons within magnetic reconnection exhausts , 2015 .

[32]  T. Neukirch,et al.  On the theory of translationally invariant magnetohydrodynamic equilibria with anisotropic pressure and magnetic shear , 2015 .

[33]  S. Barabash,et al.  The flapping motion of the Venusian magnetotail: Venus Express observations , 2015 .

[34]  R. Nakamura,et al.  Statistics of intense dawn‐dusk currents in the Earth's magnetotail , 2015 .

[35]  P. Sulem,et al.  Variational approach for static mirror structures , 2015 .

[36]  Rumi Nakamura,et al.  Current Sheets in the Earth Magnetotail: Plasma and Magnetic Field Structure with Cluster Project Observations , 2015 .

[37]  Wolfgang Baumjohann,et al.  Electron pitch angle/energy distribution in the magnetotail , 2014 .

[38]  S. Kasahara,et al.  Thin current sheets in the Jovian magnetotail , 2014 .

[39]  H. Karimabadi,et al.  Current sheets and pressure anisotropy in the reconnection exhaust , 2014 .

[40]  P. Hellinger,et al.  Oblique electron fire hose instability: Particle‐in‐cell simulations , 2014 .

[41]  I. J. Rae,et al.  Sources of electron pitch angle anisotropy in the magnetotail plasma sheet , 2013 .

[42]  William Daughton,et al.  A review of pressure anisotropy caused by electron trapping in collisionless plasma, and its implications for magnetic reconnection , 2013 .

[43]  A. Neishtadt,et al.  Quasiadiabatic dynamics of charged particles in a space plasma , 2013 .

[44]  J. Birn,et al.  Kinetic Model of Electric Potentials in Localized Collisionless Plasma Structures under Steady Quasi-gyrotropic Conditions , 2012 .

[45]  William Daughton,et al.  Large-scale electron acceleration by parallel electric fields during magnetic reconnection , 2011, Nature Physics.

[46]  Wolfgang Baumjohann,et al.  Proton/electron temperature ratio in the magnetotail , 2011 .

[47]  R. Nakamura,et al.  Cluster statistics of thin current sheets in the Earth magnetotail: Specifics of the dawn flank, proton temperature profiles and electrostatic effects , 2011 .

[48]  H. Malova,et al.  Thin current sheets in collisionless plasma: Equilibrium structure, plasma instabilities, and particle acceleration , 2011 .

[49]  C. Owen,et al.  Average magnetotail electron and proton pitch angle distributions from Cluster PEACE and CIS observations , 2011 .

[50]  R. Nakamura,et al.  Proton velocity distribution in thin current sheets: Cluster observations and theory of transient trajectories , 2010 .

[51]  M. Sitnov,et al.  Tearing stability of a multiscale magnetotail current sheet , 2010 .

[52]  J. Egedal,et al.  Cluster observations of bidirectional beams caused by electron trapping during antiparallel reconnection , 2010 .

[53]  R. Nakamura,et al.  Thin embedded current sheets: Cluster observations of ion kinetic structure and analytical models , 2009 .

[54]  R. Nakamura,et al.  Comparison of multi-point measurements of current sheet structure and analytical models , 2008 .

[55]  Vassilis Angelopoulos,et al.  The THEMIS Mission , 2008 .

[56]  Y. Yung,et al.  Modeling the distribution of H2O and HDO in the upper atmosphere of Venus , 2008 .

[57]  H. Malova,et al.  Marginal stability of thin current sheets in the Earth's magnetotail , 2008 .

[58]  Wolfgang Baumjohann,et al.  Dynamics of thin current sheets: Cluster observations , 2007 .

[59]  M. Fujimoto,et al.  Dynamics of thin current sheets associated with magnetotail reconnection , 2006 .

[60]  Parvez N. Guzdar,et al.  Structure and dynamics of a new class of thin current sheets , 2006 .

[61]  Rumi Nakamura,et al.  Local structure of the magnetotail current sheet: 2001 Cluster observations , 2006 .

[62]  Wolfgang Baumjohann,et al.  Thin Current Sheets in the Magnetotail Observed by Cluster , 2006 .

[63]  K. Schindler.  Physics of Space Plasma Activity: Quiescence , 2006 .

[64]  Enrico Camporeale,et al.  Model of bifurcated current sheets in the Earth's magnetotail: Equilibrium and stability , 2005 .

[65]  Wolfgang Baumjohann,et al.  Electric current and magnetic field geometry in flapping magnetotail current sheets , 2005 .

[66]  A. Sharma,et al.  Nonlinear equilibrium structure of thin currents sheets: influence of electron pressure anisotropy , 2004 .

[67]  S. Gary,et al.  Resonant electron firehose instability: Particle-in-cell simulations , 2003 .

[68]  J. Birn,et al.  Models of two‐dimensional embedded thin current sheets from Vlasov theory , 2001 .

[69]  M. Fehringer,et al.  Introduction The Cluster mission , 2001 .

[70]  J. Birn,et al.  On the ion-scale structure of thin current sheets in the magnetotail , 1998 .

[71]  J. Phillips,et al.  Solar wind velocity jumps across tangential discontinuities: Ulysses observations and kinetic interpretation , 1997 .

[72]  P. Diamond,et al.  Fluid models for kinetic effects on coherent nonlinear Alfvén waves. II. Numerical solutions , 1996, physics/9612018.

[73]  C. M. Hammond,et al.  Theoretical plasma distributions consistent with Ulysses magnetic field observations in a solar wind tangential discontinuity , 1996 .

[74]  T. Speiser,et al.  Particle chaos and pitch angle scattering , 1995 .

[75]  M. Ashour‐Abdalla,et al.  Consequences of magnetotail ion dynamics , 1994 .

[76]  L. Hau.  Anisotropic magnetotail equilibrium and convection , 1993 .

[77]  R. Puetter,et al.  A two-dimensional, time-dependent, near-earth magnetotail , 1991 .

[78]  Lev M. Zelenyi,et al.  Regular and chaotic charged particle motion in magnetotaillike field reversals: 1. Basic theory of trapped motion , 1989 .

[79]  J. Birn,et al.  On the cause of approximate pressure isotropy in the quiet near-earth plasma sheet , 1985 .

[80]  W. Zwingmann.  Self‐consistent magnetotail theory: Equilibrium structures including arbitrary variation along the tail axis , 1983 .

[81]  René Pellat,et al.  Stability of a thick two‐dimensional quasineutral sheet , 1982 .

[82]  L. Burlaga,et al.  The Jovian magnetotail and its current sheet , 1981 .

[83]  S. Syrovatskii.  Pinch Sheets and Reconnection in Astrophysics , 1981 .

[84]  J. Birn.  Self‐consistent magnetotail theory: General solution for the quiet tail with vanishing field‐aligned currents , 1979 .

[85]  S. Cowley.  The effect of pressure anisotropy on the equilibrium structure of magnetic current sheets , 1978 .

[86]  J. Dungey.  Magnetospheric physics , 1978, Nature.

[87]  J. Birn,et al.  Self‐consistent theory of the quiet magnetotail in three dimensions , 1977 .

[88]  K. Schindler.  A SELF-CONSISTENT THEORY OF THE TAIL OF THE MAGNETOSPHERE , 1972 .

[89]  P. D. Hudson,et al.  Discontinuities in an anisotropic plasma and their identification in the solar wind , 1970 .

[90]  E. G. Harris.  On a plasma sheath separating regions of oppositely directed magnetic field , 1962 .