Publications

2016

• Observations of turbulence in a Kelvin-Helmholtz event on 8 September 2015 by the Magnetospheric Multiscale mission
  
  • Stawarz J. E.
  • Eriksson S.
  • Wilder F. D.
  • Ergun R. E.
  • Schwartz S. J.
  • Pouquet A.
  • Burch J. L.
  • Giles B. L.
  • Khotyaintsev Y. V.
  • Le Contel Olivier
  • Lindqvist P.-A.
  • Magnes W.
  • Pollock C. J.
  • Russell C. T.
  • Strangeway R. J.
  • Torbert R. B.
  • Avanov L. A.
  • Dorelli J. C.
  • Eastwood Jonathan P.
  • Gershman D. J.
  • Goodrich K. A.
  • Malaspina D. M.
  • Marklund G. T.
  • Mirioni Laurent
  • Sturner A. P.
  Journal of Geophysical Research Space Physics, American Geophysical Union/Wiley, 2016, 121 (11), pp.11,021-11,034. Spatial and high-time-resolution properties of the velocities, magnetic field, and 3-D electric field within plasma turbulence are examined observationally using data from the Magnetospheric Multiscale mission. Observations from a Kelvin-Helmholtz instability (KHI) on the Earth's magnetopause are examined, which both provides a series of repeatable intervals to analyze, giving better statistics, and provides a first look at the properties of turbulence in the KHI. For the first time direct observations of both the high-frequency ion and electron velocity spectra are examined, showing differing ion and electron behavior at kinetic scales. Temporal spectra exhibit power law behavior with changes in slope near the ion gyrofrequency and lower hybrid frequency. The work provides the first observational evidence for turbulent intermittency and anisotropy consistent with quasi two-dimensional turbulence in association with the KHI. The behavior of kinetic-scale intermittency is found to have differences from previous studies of solar wind turbulence, leading to novel insights on the turbulent dynamics in the KHI. (10.1002/2016JA023458)
  DOI : 10.1002/2016JA023458
• Introduction to Modern Magnetohydrodynamics
  
  • Galtier Sébastien
  , 2016. Preface; Table of physical quantities; Part I. Foundations: 1. Introduction; 2. Magnetohydrodynamics; 3. Conservation laws; Part II. Fundamental Processes: 4. Magnetohydrodynamic waves; 5. Dynamo; 6. Discontinuities and shocks; 7. Magnetic reconnection; Part III. Instabilities and Magnetic Confinement: 8. Static equilibrium; 9. Linear perturbation theory; 10. Study of MHD instabilities; Part IV. Turbulence: 11. Hydrodynamic turbulence; 12. MHD turbulence; 13. Advanced MHD turbulence; Appendix 1. Solutions to the exercises; Appendix 2. Formulary; References; Index.
• The 2π charged particles analyzer: All-sky camera concept and development for space missions
  
  • Vaisberg Oleg
  • Berthelier Jean-Jacques
  • Moore T.
  • Avanov L.
  • Leblanc François
  • Leblanc Frédéric
  • Moiseev Pavel P.
  • Moiseenko D.
  • Becker Joël
  • Collier Michael R.
  • Laky G.
  • Keller J.
  • Koynash G.
  • Lichtenneger H.
  • Leibov A. W.
  • Zhuravlev R.
  • Shestakov A.
  • Burch J.
  • Mccomas D.
  • Shuvalov S.
  • Chornay D.
  • Torkar K.
  Journal of Geophysical Research Space Physics, American Geophysical Union/Wiley, 2016, 121 (12), pp.11,750–11,765. Increasing the temporal resolution and instant coverage of velocity space of space plasma measurements is one of the key issues for experimentalists. Today the top-hat plasma analyzer appears to be the favorite solution due to its relative simplicity and the possibility to extend its application by adding a mass-analysis section and an electrostatic angular scanner. Similarly, great success has been achieved in MMS mission using such multiple top-hat analyzers to achieve unprecedented temporal resolution. An instantaneous angular coverage of charged particles measurements is an alternative approach to pursuing the goal of high time resolution. This was done with FONEMA 4-D and, to a lesser extent, by DYMIO instruments for Mars-96 and with the FIPS instrument for MESSENGER mission. In this paper we describe, along with precursors, a plasma analyzer with a 2π electrostatic mirror that was developed originally for the Phobos-Soil mission with a follow-up in the frame of the BepiColombo mission, and is under development for future Russian missions. Different versions of instrument are discussed along with their advantages and drawbacks. (10.1002/2016JA022568)
  DOI : 10.1002/2016JA022568
• Currents and associated electron scattering and bouncing near the diffusion region at Earth's magnetopause
  
  • Lavraud B.
  • Zhang Y. C.
  • Vernisse Y.
  • Gershman D. J.
  • Dorelli J. C.
  • Cassak P. A.
  • Dargent Jérémy
  • Pollock C.
  • Giles B. L.
  • Aunai Nicolas
  • Argall M.
  • Avanov L.
  • Barrie A.
  • Burch J. L.
  • Chandler Michael O.
  • Chen L.-J.
  • Clark G.
  • Cohen I.
  • Coffey Victoria
  • Eastwood Jonathan P.
  • Egedal J.
  • Eriksson S.
  • Ergun R.
  • Farrugia C. J.
  • Fuselier S. A.
  • Génot V.
  • Graham Daniel B.
  • Grigorenko E. E.
  • Hasegawa H.
  • Jacquey C.
  • Kacem I.
  • Khotyaintsev Y. V.
  • Macdonald E.
  • Magnes W.
  • Marchaudon A.
  • Mauk B.
  • Moore T. E.
  • Mukai Toshifumi
  • Nakamura R.
  • Paterson W. R.
  • Penou E.
  • Phan T. D.
  • Rager A.
  • Retinò Alessandro
  • Rong Z. J.
  • Russell C. T.
  • Saito Y.
  • Sauvaud J.-A.
  • Schwartz S. J.
  • Shen C.
  • Smith S.
  • Strangeway R. J.
  • Toledo-Redondo Sergio
  • Torbert R.
  • Turner D. L.
  • Wang S.
  • Yokota S.
  Geophysical Research Letters, American Geophysical Union, 2016, 43 (7), pp.3042-3050. Based on high-resolution measurements from NASA's Magnetospheric Multiscale mission, we present the dynamics of electrons associated with current systems observed near the diffusion region of magnetic reconnection at Earth's magnetopause. Using pitch angle distributions (PAD) and magnetic curvature analysis, we demonstrate the occurrence of electron scattering in the curved magnetic field of the diffusion region down to energies of 20 eV. We show that scattering occurs closer to the current sheet as the electron energy decreases. The scattering of inflowing electrons, associated with field-aligned electrostatic potentials and Hall currents, produces a new population of scattered electrons with broader PAD which bounce back and forth in the exhaust. Except at the center of the diffusion region the two populations are collocated and appear to behave adiabatically: the inflowing electron PAD focuses inward (toward lower magnetic field), while the bouncing population PAD gradually peaks at 90° away from the center (where it mirrors owing to higher magnetic field and probable field-aligned potentials). (10.1002/2016GL068359)
  DOI : 10.1002/2016GL068359
• Cold ion demagnetization near the X-line of magnetic reconnection
  
  • Toledo-Redondo Sergio
  • André M.
  • Khotyaintsev Y. V.
  • Vaivads A.
  • Walsh Andrew P.
  • Li Wenya
  • Graham Daniel B.
  • Lavraud Benoit
  • Masson A.
  • Aunai Nicolas
  • Divin A. V.
  • Dargent Jérémy
  • Fuselier Stephen
  • Gershman D. J.
  • Dorelli J. C.
  • Giles B. L.
  • Avanov L.
  • Pollock Craig
  • Saito Y.
  • Moore T. E.
  • Coffey Victoria
  • Chandler Michael O.
  • Lindqvist Per-Arne
  • Torbert Roy
  • Russell Christopher T.
  Geophysical Research Letters, American Geophysical Union, 2016, 43 (13), pp.6759-6767. Although the effects of magnetic reconnection in magnetospheres can be observed at planetary scales, reconnection is initiated at electron scales in a plasma. Surrounding the electron diffusion region, there is an Ion-Decoupling Region (IDR) of the size of the ion length scales (inertial length and gyroradius). Reconnection at the Earth's magnetopause often includes cold magnetospheric (few tens of eV), hot magnetospheric (10 keV), and magnetosheath (1 keV) ions, with different gyroradius length scales. We report observations of a subregion inside the IDR of the size of the cold ion population gyroradius (15 km) where the cold ions are demagnetized and accelerated parallel to the Hall electric field. Outside the subregion, cold ions follow the E × B motion together with electrons, while hot ions are demagnetized. We observe a sharp cold ion density gradient separating the two regions, which we identify as the cold and hot IDRs. (10.1002/2016GL069877)
  DOI : 10.1002/2016GL069877