Scientific 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
• Solar quiet current response in the African sector due to a 2009 sudden stratospheric warming event
  
  • Bolaji O. S.
  • Oyeyemi E. O.
  • Owolabi O. P.
  • Yamazaki Y.
  • Rabiu A. B.
  • Okoh D.
  • Fujimoto A.
  • Amory-Mazaudier Christine
  • Seemala G. K.
  • Yoshikawa A.
  • Onanuga O. K.
  Journal of Geophysical Research Space Physics, American Geophysical Union/Wiley, 2016. We present solar quiet (S q) variation of the horizontal (H) magnetic field intensity deduced from Magnetic Data Acquisition System (MAGDAS) records over Africa during an unusual strong and prolonged 2009 sudden stratospheric warming (SSW) event. A reduction in the S q H magnitude that enveloped the geomagnetic latitudes between 21.13°N (Fayum FYM) in Egypt and 39.51°S (Durban DRB) in South Africa was observed, while the stratospheric polar temperature was increasing and got strengthened when the stratospheric temperature reached its maximum. Another novel feature associated with the hemispheric reduction is the reversal in the north-south asymmetry of the S q H, which is indicative of higher S q H magnitude in the Northern Hemisphere compared to the Southern Hemisphere during SSW peak phase. The reversal of the equatorial electrojet (EEJ) or the counter electrojet (CEJ) was observed after the polar stratospheric temperature reached its maximum. The effect of additional currents associated with CEJ was observed in the Southern Hemisphere at middle latitude. Similar changes were observed in the EEJ at the South America, Pacific Ocean, and Central Asia sectors. The effect of the SSW is largest in the South American sector and smallest in the Central Asian sector. (10.1002/2016JA022857)
  DOI : 10.1002/2016JA022857
• Turbulence Heating ObserveR - satellite mission proposal
  
  • Vaivads A.
  • Retinò Alessandro
  • Soucek J.
  • Khotyaintsev Yu. V. V
  • Valentini F.
  • Escoubet C. Philippe
  • Alexandrova Olga
  • André M.
  • Bale S. D.
  • Balikhin M. A.
  • Burgess D.
  • Camporeale E.
  • Caprioli D.
  • Chen C. H. K.
  • Clacey E.
  • Cully C. M.
  • de Keyser J.
  • Eastwood Jonathan P.
  • Fazakerley A. N.
  • Eriksson S.
  • Goldstein M. L.
  • Graham D. B.
  • Haaland S.
  • Hoshino M.
  • Ji H.
  • Karimabadi H.
  • Kucharek H.
  • Lavraud B.
  • Marcucci F.
  • Matthaeus W. H.
  • Moore T. E.
  • Nakamura R.
  • Narita Y.
  • Nemecek Z.
  • Norgren C.
  • Opgenoorth H.
  • Palmroth M.
  • Perrone D.
  • Pinçon Jean-Louis
  • Rathsman P.
  • Rothkaehl H.
  • Sahraoui Fouad
  • Servidio S.
  • Sorriso-Valvo L.
  • Vainio R.
  • Vörös Z.
  • Wimmer-Schweingruber R. F.
  Journal of Plasma Physics, Cambridge University Press (CUP), 2016, 82 (5), pp.905820501 (16 pages). The Universe is permeated by hot, turbulent, magnetized plasmas. Turbulent plasma is a major constituent of active galactic nuclei, supernova remnants, the intergalactic and interstellar medium, the solar corona, the solar wind and the Earth's magnetosphere, just to mention a few examples. Energy dissipation of turbulent fluctuations plays a key role in plasma heating and energization, yet we still do not understand the underlying physical mechanisms involved. THOR is a mission designed to answer the questions of how turbulent plasma is heated and particles accelerated, how the dissipated energy is partitioned and how dissipation operates in different regimes of turbulence. THOR is a single-spacecraft mission with an orbit tuned to maximize data return from regions in near-Earth space - magnetosheath, shock, foreshock and pristine solar wind - featuring different kinds of turbulence. Here we summarize the THOR proposal submitted on 15 January 2015 to the `Call for a Medium-size mission opportunity in ESAs Science Programme for a launch in 2025 (M4)'. THOR has been selected by European Space Agency (ESA) for the study phase. (10.1017/S0022377816000775)
  DOI : 10.1017/S0022377816000775