Mangeney André | Observatoire de Paris (original) (raw)

Papers by Mangeney André

Journal of Geophysical Research, 2009

The presence of a background magnetic field induces anisotropy in magnetic turbulence. Understand... more The presence of a background magnetic field induces anisotropy in magnetic turbulence. Understanding properties of anisotropy is important to characterize turbulence power spectrum. This paper presents a case study of anisotropy by using a minimum variance analysis, in three different regions of the heliosphere, namely in the solar wind, and in the Earth&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#x27;s foreshock and magnetosheath behind a quasiparallel bow

Physical Review Letters, 2010

We investigate the scaling laws of a signed measure derived from the reduced magnetic helicity wh... more We investigate the scaling laws of a signed measure derived from the reduced magnetic helicity which has been determined from Cluster data in the solar wind. This quantifies the handedness of the magnetic field; namely, it can be related to the polarization of the magnetic field fluctuations (right or left hand). The measure results to be sign-singular; that is, we do not observe any scale-dependent effect at the ion-and at electron-cyclotron frequencies. Cancellations between right-and left-hand polarizations go on in the dispersive or dissipative range, beyond the electron-cyclotron frequency. This means that the mechanism responsible for the generation of the dispersive or dissipative range is rather insensitive to the polarization of the magnetic field fluctuations.

Journal of Geophysical Research, 1985

Electrostatic waves are observed However, Gurnett et al. [1981] have noted that around the plasma... more Electrostatic waves are observed However, Gurnett et al. [1981] have noted that around the plasma frequency f in the electron this electrostatic noise is made up of an intense e foreshock, together with elec•ons backstreaming emission line, at f e' and of emissions above and from the bow shock Using data from the sounder below f that the• call the "sidebands". They ' pe aboard ISEE 1, we show that this noise, previ-have incerpreted the whole as Langmuir waves with ously understood as narrow band Langmuir waves a bandwidth due to Doppler shift and non-linear more or less widened by Doppler shift or non-effects. present observations of the associated solar wind burst noise by Harvey et al. [1979], are gene-not exactly equal to f-e' and If-f-^l may b• as rally considered as emitted by a beam-plasma large as 5 kHz. The shaPpe c •= of the spectrum depends instability at the electron plasma frequency f•e. on the connexion depth, and the wave number tends [see, for example, Fitzenreiter et al., 198 to increase with the observed frequency.

Journal of Geophysical Research, 1990

To study the problem of electron heating in quasi-perpendicular shocks, under the combined effect... more To study the problem of electron heating in quasi-perpendicular shocks, under the combined effects of &amp;amp;amp;#39;reversible&amp;amp;amp;#39; motion, in the shock electric potential and magnetic field, and wave-particle interactions a diffusion equation was derived, in the drift (adiabatic) approximation and it was solved by using a Monte Carlo method. The results show that most of the observations can be explained within

Annales Geophysicae, 2007

The STAFF-SC observations complemented by the data from other instruments on Cluster spacecraft w... more The STAFF-SC observations complemented by the data from other instruments on Cluster spacecraft were used to study the main properties of magnetospheric lion roars: sporadic bursts of whistler emissions at f~0.1-0.2fe where fe is the electron gyrofrequency. Magnetospheric lion roars are shown to be similar to the emissions in the magnetosheath while the conditions for their generation are much less favorable: the growth rate of the cyclotron temperature anisotropy instability is much smaller due to a smaller number of the resonant electrons. This implies a nonlinear mechanism of generation of the observed wave emissions. It is shown that the observed whistler turbulence, in reality, consists of many nearly monochromatic wave packets. It is suggested that these structures are nonlinear Gendrin's whistler solitary waves. Properties of these waves are widely discussed. Since the group velocity of Gendrin's waves is aligned with the magnetic field, these well guided wave packets can propagate through many magnetic "bottles" associated with mirror structures, without being trapped.

Annales Geophysicae, 1995

Geophysical Research Letters, 1992

The radio receiver of the Unified Radio and Plasma (URAP) experiment aboard the Ulysses spacecraf... more The radio receiver of the Unified Radio and Plasma (URAP) experiment aboard the Ulysses spacecraft records spectra of the quasi-thermal plasma noise. The interpretation of these spectra allows the determination of the total electron density Ne and of the cold (core) electron temperature Tc in the solar wind. A single power law does not fit the variations of Ne which result from the contribution from different solar wind structures. The distribution of the values of Tc suggests that, on the average, the solar wind is nearly isothermal.

Physical Review Letters, 1980

... an asymmetric state does take place also in the absence of a background magnetic field the ef... more ... an asymmetric state does take place also in the absence of a background magnetic field the effect of which is then replaced by the magnetic field of the ... Earth, having overtaken the critical Alfvd'nic point, must be necessarily all propagating outwards with respect to the sun. ...

Physical Review Letters, 1993

... PHYSICAL REVIEW LETTERS Nonlinear Wave Evolution in the Expanding Solar Wind Roland Grappin, ... more ... PHYSICAL REVIEW LETTERS Nonlinear Wave Evolution in the Expanding Solar Wind Roland Grappin, Marco Velli, and Andre Mangeney Observatoire de Paris-Meudon ... Parker's spiral [5]). In the absence of dissipation, the average temperature (T=P/p) falls as (T) a:a 2(y 1) oc ...

Space Science Reviews, 2008

This paper introduces and describes the radio and plasma wave investigation on the STEREO Mission... more This paper introduces and describes the radio and plasma wave investigation on the STEREO Mission: STEREO/WAVES or S/WAVES. The S/WAVES instrument includes a suite of state-of-the-art experiments that provide comprehensive measurements of the three components of the fluctuating electric field from a fraction of a hertz up to 16 MHz, plus a single frequency channel near 30 MHz. The instrument has a direction finding or goniopolarimetry capability to perform 3D localization and tracking of radio emissions associated with streams of energetic electrons and shock waves associated with Coronal Mass Ejections (CMEs). The scientific objectives include: (i) remote observation and measurement of radio waves excited by energetic particles throughout the 3D heliosphere that are associated with the CMEs and with solar flare phenomena, and (ii) in-situ measurement of the properties of CMEs and interplanetary shocks, such as their electron density and temperature and the associated plasma waves near 1 Astronomical Unit (AU). Two companion papers provide details on specific aspects of the S/WAVES instrument, namely the electric antenna system (Bale et al., Space Sci. Rev., 2007) and the direction finding technique (Cecconi et al., Space Sci. Rev., 2007).

Physical Review Letters, 2009

To investigate the universality of magnetic turbulence in space plasmas we analyze seven time per... more To investigate the universality of magnetic turbulence in space plasmas we analyze seven time periods in the free solar wind under different plasma conditions. Three instruments on Cluster spacecraft operating in different frequency ranges give us the possibility to resolve spectra up to 300 Hz. We show that the spectra form a quasiuniversal spectrum following the Kolmogorov's law ∼ k −5/3 at MHD scales, a ∼ k −2.8 power-law at ion scales and an exponential ∼ e −(kρe) 1/2 at scales kρe ∼ [0.1, 1], where ρe is the electron gyroradius. This is the first observation of an exponential magnetic spectrum in space plasmas, that may indicate the onset of dissipation. We distinguish for the first time between the role of different spatial kinetic plasma scales and show that the electron Larmor radius plays the role of a dissipation scale in space plasma turbulence. PACS numbers: 52.35.Ra,94.05.-a,96.60.Vg,95.30.Qd

Journal of Geophysical Research, 2006

Magnetic field fluctuations in the frequency range [0.02−12.5] Hz are studied with the four Clust... more Magnetic field fluctuations in the frequency range [0.02−12.5] Hz are studied with the four Cluster satellites in the Earth magnetosheath downstream of a quasiperpendicular bow-shock. The turbulent spectrum presents a spectral break accompanied by a broad maximum usually interpreted as due to Alfvén Ion Cyclotron waves. In this paper we establish that this spectral knee corresponds to space-localized coherent magnetic structures in the form of Alfvén vortices. The Alfvén vortex is a non-linear cylindrical Alfvén wave, quasi-parallel to the mean magnetic field B 0 and propagating in a plane perpendicular to B 0 . In this plane, the observed vortices are localized within 20c/ω pi . The frequent observations of such structures indicate their stability in the plasma. Therefore, the Alfvén vortices can be an important element in the magnetosheath turbulence. The possible origins of these vortices, such as a strong turbulence or the filamentation instability of an Alfvén wave, are discussed.