A5027426239- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Geomagnetism and Paleomagnetism Studies
- Astro and Planetary Science
- Fluid Dynamics and Turbulent Flows
- Geophysics and Gravity Measurements
- Solar Radiation and Photovoltaics
- Global Energy and Sustainability Research
- Earthquake Detection and Analysis
- Magnetic confinement fusion research
- Spacecraft Design and Technology
- History and Developments in Astronomy
- Ocean Waves and Remote Sensing
- Planetary Science and Exploration
- Meteorological Phenomena and Simulations
- Oil, Gas, and Environmental Issues
- Stellar, planetary, and galactic studies
- Medicinal Plants and Bioactive Compounds
- Diverse Industrial Engineering Technologies
- Atmospheric chemistry and aerosols
- Market Dynamics and Volatility
- Atmospheric aerosols and clouds
- Industrial Engineering and Technologies
- Atmospheric Ozone and Climate
- Laser-induced spectroscopy and plasma
Observatoire de Paris
2014-2024
Laboratoire d’études spatiales et d’instrumentation en astrophysique
2015-2024
Sorbonne Université
2013-2024
Université de Versailles Saint-Quentin-en-Yvelines
2010-2024
Université Paris Cité
2013-2024
Délégation Paris 7
2008-2024
Centre National de la Recherche Scientifique
2009-2024
Université Paris Sciences et Lettres
2016-2024
Peter the Great St. Petersburg Polytechnic University
2024
Sorbonne Paris Cité
2016-2022
To investigate the universality of magnetic turbulence in space plasmas, we analyze seven time periods free solar wind under different plasma conditions. Three instruments on Cluster spacecraft operating frequency ranges give us possibility to resolve spectra up 300 Hz. We show that form a quasiuniversal spectrum following Kolmogorov's law approximately k(-5/3) at MHD scales, k(-2.8) power ion and an exponential exp[-sqrt[k(rho)e]] scales k(rho)e [0.1,1], where rho(e) is electron gyroradius....
Solar wind is probably the best laboratory to study turbulence in astrophysical plasmas. In addition presence of magnetic field, differences with neutral fluid isotropic are: weakness collisional dissipation and several characteristic space time scales. this paper we discuss observational properties solar a large range from MHD electron At scales, within inertial range, cascade fluctuations develops mostly plane perpendicular mean field. compressible nature. The spectrum velocity do not...
Magnetic fluctuations in the solar wind are distributed according to Kolmogorov's power law f−5/3 below ion cyclotron frequency fci. Above this frequency, observed steeper is usually interpreted two different ways, as a dissipative range of turbulence, or another turbulent cascade, nature which still an open question. Using Cluster magnetic data we show that after spectral break intermittency increases toward higher frequencies, indicating presence nonlinear interactions inherent new...
The anisotropy of turbulence in the fast solar wind, between ion and electron gyroscales, is directly observed using a multispacecraft analysis technique. Second order structure functions are calculated at different angles to local magnetic field, for fluctuations both perpendicular parallel mean field. In components, function value large field ${S}_{\ensuremath{\perp}}$ greater than small ${S}_{\ensuremath{\parallel}}$: component...
The description of the turbulent spectrum magnetic fluctuations in solar wind kinetic range scales is not yet completely established. Here, we perform a statistical study 100 spectra measured by STAFF instrument on Cluster mission, which allows us to resolve from ion down fraction electron scales, i.e., ∼102 km ∼300 m. We show that for k⊥ρe ∈ [0.03, 3] (which corresponds approximately frequency spacecraft frame f [3, 300] Hz), all observed can be described general law E(k⊥)∝k−8/3⊥exp (−...
The Radio and Plasma Waves (RPW) instrument on the ESA Solar Orbiter mission is described in this paper. This designed to measure in-situ magnetic electric fields waves from continuous a few hundreds of kHz. RPW will also observe solar radio emissions up 16 MHz. primary importance science requirements since it essential answer three four overarching objectives. In addition exchange on-board data with other instruments order process algorithms for interplanetary shocks type III langmuir detections.
In this paper we investigate spectral and phase coherence properties of magnetic fluctuations in the vicinity transition from large, magnetohydrodynamic (MHD) to sub-ion scales using in-situ measurements Wind spacecraft a fast stream. For time interval investigated by Leamon et al. (1998) phase-coherence analysis shows presence sporadic quasi-parallel Alfvén Ion Cyclotron (AIC) waves as well coherent structures form large-amplitude, quasi-perpendicular vortex-like current sheets. These...
ABSTRACT We present a study of magnetic field fluctuations in slow solar wind stream, close to ion scales, where an increase the level compressibility is observed. Here, nature these compressive found be characterized by coherent structures. Although previous studies have shown that current sheets can considered principal cause intermittency at here we show for first time that, case wind, large variety structures contributes proton and are not most common. Specifically, find ( <?CDATA...
Solar Orbiter is the first space mission observing solar plasma both in situ and remotely, from a close distance, out of ecliptic. The ultimate goal to understand how Sun produces controls heliosphere, filling System driving planetary environments. With six remote-sensing four in-situ instrument suites, coordination planning operations are essential address following top-level science questions: (1) What drives wind where does coronal magnetic field originate? (2) How do transients drive...
HelioSwarm (HS) is a NASA Medium-Class Explorer mission of the Heliophysics Division designed to explore dynamic three-dimensional mechanisms controlling physics plasma turbulence, ubiquitous process occurring in heliosphere and plasmas throughout universe. This will be accomplished by making simultaneous measurements at nine spacecraft with separations spanning magnetohydrodynamic sub-ion spatial scales variety near-Earth plasmas. In this paper, we describe scientific background for HS...
Submicrometer sea salt aerosol (SSA) particles are routinely observed in the remote marine boundary layer (MBL); these aerosols include cloud condensation nuclei and so affect earth's radiative balance. Here foams designed to mimic oceanic whitecaps were generated laboratory using a range of bubbling flow rates aqueous media: unfiltered seawater, filtered artificial mixtures seawater. The number sizes dried foam droplets particle diameter, D p , 15–673 nm measured. Particle size...
We investigate the spectral shape, anisotropy of wave vector distributions and amplitudes magnetic fluctuations in Earth's magnetosheath within a broad range frequencies. present first observations Kolmogorov-like inertial Alfvenic flanks, below fci. In vicinity fci, break is observed, like solar wind turbulence. Above break, energy compressive generally follow power law with index between -3 -2. Concerning distribution, we observe change its nature ion characteristic scales: if at MHD...
We analyze the radial variation of power spectra magnetic field from 0.3 to about 0.9 AU, using Helios 2 spacecraft measurements in fast solar wind. The time resolution data allows us study up Hz. Generally, corresponding spectral break frequency fb and Doppler-shifted frequencies, which are related proton gyroradius inertial scales, close a f 0.5 Hz at distance 1 AU Sun. However, studying evolution offers possibility distinguish between those scales. Recent Ulysses observations show that,...
Abstract. In this paper we give firstly a broad review of the space plasma turbulence around ion characteristic and temporal scales within two natural laboratories, solar wind Earth magnetosheath. both regions power law spectra magnetic fluctuations are observed. these have break in vicinity cyclotron frequency. A distinctive feature magnetosheath is presence Alfvén vortices at spectral break. The multi-scale nonlinear structures. We main theoretical features incompressible vortsices second...
The nature of the magnetic field fluctuations in solar wind between ion and electron scales is still under debate. Using Cluster/STAFF instrument, we make a survey power spectral density polarization these at frequencies $f\in[1,400]$ Hz, during five years (2001-2005), when Cluster was free wind. In $\sim 10\%$ selected data, observe narrow-band, right-handed, circularly polarized fluctuations, with wave vectors quasi-parallel to mean field, superimposed on spectrum permanent background...
Abstract We investigate the nature of magnetic turbulent fluctuations, around ion characteristic scales, in a fast solar wind stream, by using Cluster data. Contrarily to slow wind, where both Alfvénic ( <?CDATA $\delta {b}_{\perp }\gg \delta {b}_{\parallel }$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>δ</mml:mi> <mml:msub> <mml:mrow> <mml:mi>b</mml:mi> </mml:mrow> <mml:mo>⊥</mml:mo> </mml:msub> <mml:mo>≫</mml:mo> <mml:mo stretchy="false">∥</mml:mo>...
The Universe is permeated by hot, turbulent, magnetized plasmas. Turbulent plasma a major constituent of active galactic nuclei, supernova remnants, the intergalactic and interstellar medium, solar corona, wind Earth’s magnetosphere, just to mention few examples. Energy dissipation turbulent fluctuations plays key role in heating energization, yet we still do not understand underlying physical mechanisms involved. THOR mission designed answer questions how heated particles accelerated,...
Magnetic field fluctuations in the frequency range [0.02–12.5] Hz are studied with four Cluster satellites Earth magnetosheath downstream of a quasi‐perpendicular bow shock. The turbulent spectrum presents spectral break accompanied by broad maximum usually interpreted as due to Alfvén ion cyclotron waves. In this paper we establish that knee corresponds space‐localized coherent magnetic structures form vortices. vortex is nonlinear cylindrical wave, quasi‐parallel mean B 0 and propagating...
We investigate the transition of turbulence from large to kinetic scales using Cluster observations. Simultaneous spectra magnetic and electric fields in Earth's magnetosheath magnetohydrodynamic (MHD) electron are presented for first time. While two have approximatively similar behaviour fluid-MHD regime, they show different trends range. As field spectrum steepens at ion scales, is characterized by a shallower power law continuing down scales. Such an evolution consistent with theoretical...
ABSTRACT We perform the first statistical study of effects interaction suprathermal electrons with narrow-band whistler mode waves in solar wind (SW). show that this does occur and it is associated enhanced widths so-called strahl component. The latter directed along interplanetary magnetic field away from Sun. do by comparing pitch angle SW at 1 AU absence large scale discontinuities transient structures, such as shocks, coronal mass ejections, stream regions, etc. during times when were...
Abstract This study focuses on a radial alignment between Parker Solar Probe (PSP) and Orbiter (SolO) 2021 April 29 (during solar minimum), when the two spacecraft were, respectively, located at ∼0.075 ∼0.9 au from Sun. A previous of this allowed identification same density enhancement (with timescale ∼1.5 hr) substructures (timescales ∼20–30 minutes), passing first by PSP then SolO after ∼138 hr propagation time in inner heliosphere. We show here that structure belongs to large-scale...
Electromagnetic fluctuations in the solar wind cover a wide range of scales, from sun-rotation period to sub-electron scales. We study Cluster Guest Investigator data when 2 satellites were at 7 km distance, that corresponds few electron Larmor radius. find typical spectral shape within kinetic and signatures intermittency up Local analysis magnetic scales indicates presence vortex-like coherent structures, which can be interpreted terms scale Alfven vortices. discuss possible connection...
We present the study of a radial alignment between Parker Solar Probe and Orbiter occurring at end April 2021. The two spacecraft were respectively ~0.075 ~0.9 au from Sun. With help propagation method, we identified same density structure crossing both spacecraft, with time delay ~138 h two. This is part heliospheric plasma sheet. found that for this event, in-situ measurements concordant gradients, while magnetic field more longitudinal gradients. moreover inferred to have been generated...