A5025991509- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Astro and Planetary Science
- Geomagnetism and Paleomagnetism Studies
- Stellar, planetary, and galactic studies
- Geophysics and Gravity Measurements
- Solar Radiation and Photovoltaics
- Energy Load and Power Forecasting
- Spacecraft Design and Technology
- Planetary Science and Exploration
- Interconnection Networks and Systems
- Parallel Computing and Optimization Techniques
- Advanced Data Storage Technologies
- Earthquake Detection and Analysis
- Astronomy and Astrophysical Research
- Atmospheric Ozone and Climate
- Complex Systems and Time Series Analysis
- Gamma-ray bursts and supernovae
- Space Science and Extraterrestrial Life
- Radiation Therapy and Dosimetry
- Photovoltaic System Optimization Techniques
- History and Developments in Astronomy
- Distributed and Parallel Computing Systems
- Smart Grid Energy Management
- Space Satellite Systems and Control
Université de Toulouse
2015-2024
Université Toulouse III - Paul Sabatier
2015-2024
Astrophysique, Instrumentation et Modélisation
2011-2024
Centre National de la Recherche Scientifique
2015-2024
Institut de Recherche sur les Lois Fondamentales de l'Univers
2010-2024
CEA Paris-Saclay
2011-2024
Université Paris-Saclay
2010-2024
Roche (France)
2016-2024
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2011-2024
Institut de Recherche en Astrophysique et Planétologie
2016-2024
Stellar winds are thought to be the main process responsible for spin down of main-sequence stars. The extraction angular momentum by a magnetized wind has been studied decades, leading several formulations resulting torque. However, previous studies generally consider simple dipole or split monopole stellar magnetic topologies. Here we in addition dipolar field, both quadrupolar and octupolar configurations, while also varying rotation rate field strength. 60 simulations made with 2.5D,...
Abstract The physical mechanisms behind accelerating solar and stellar winds are a long-standing astrophysical mystery, although recent breakthroughs have come from models invoking the turbulent dissipation of Alfvén waves. existence waves far Sun has been known since 1970s, recently presence ubiquitous Alfvénic throughout atmosphere confirmed. However, atmospheric does not, alone, provide sufficient support for wave-based models; counter-propagating is crucial development turbulence. Here,...
ABSTRACT We study the link between an expanding coronal shock and energetic particles measured near Earth during ground level enhancement of 2012 May 17. developed a new technique based on multipoint imaging to triangulate three-dimensional (3D) expansion forming in corona. It uses images from three vantage points by mapping outermost extent region perturbed pressure front. derive for first time 3D velocity vector distribution Mach numbers, M FM , entire front as function time. Our approach...
The Coronal Multi-channel Polarimeter (CoMP) has previously demonstrated the presence of Doppler velocity fluctuations in solar corona. observed are thought to be transverse waves, i.e. highly incompressible motions whose restoring force is dominated by magnetic tension, some which demonstrate clear periodicity. We aim exploit CoMP's ability provide high cadence observations off-limb corona investigate properties a range coronal features, providing insight into how(if) waves influenced...
Context. The Solar Orbiter spacecraft will be equipped with a wide range of remote-sensing (RS) and in situ (IS) instruments to record novel unprecedented measurements the solar atmosphere inner heliosphere. To take full advantage these new datasets, tools techniques must developed ease multi-instrument multi-spacecraft studies. In particular currently inaccessible low corona below two radii can only observed remotely. Furthermore used retrieve coronal plasma properties time three...
The physical mechanisms that produce the slow solar wind are still highly debated. Parker Solar Probe's (PSP's) second encounter provided a new opportunity to relate in situ measurements of nascent with white-light images streamer flows. We exploit data taken by and Heliospheric Observatory (SOHO), TErrestrial RElations (STEREO) Wide Imager on Probe reveal for first time close link between imaged flows high-density plasma measured Wind Electrons Alphas Protons (SWEAP) experiment. identify...
Abstract We present heliospheric current sheet (HCS) and plasma (HPS) observations during Parker Solar Probe’s (PSP) first orbit around the Sun. focus on eight intervals that display a true sector boundary (TSB; based suprathermal electron pitch angle distributions) with one or several associated sheets. The analysis shows (1) main density enhancements in vicinity of TSB HCS are typically strahl dropouts, implying magnetic disconnection from Sun, (2) just about twice surrounding regions,...
Context. On 2020 November 29, an eruptive event occurred in active region located behind the eastern solar limb as seen from Earth. The consisted of M4.4 class flare, a coronal mass ejection, extreme ultraviolet (EUV) wave, and white-light (WL) shock wave. eruption gave rise to first widespread energetic particle (SEP) cycle 25, which was observed at four widely separated heliospheric locations (∼230°). Aims. Our aim is better understand source this SEP event, examine role wave wide...
The ISWAT (International Space Weather Action Teams) heliosphere clusters H1 and H2 have a focus on interplanetary space its characteristics, especially the large-scale co-rotating transient structures impacting Earth. Solar wind stream interaction regions, generated by between high-speed solar originating in open coronal magnetic fields slower from closed fields, are regions of compressed plasma field followed streams that recur at ∼27 day rotation period. Short-term reconfigurations lower...
We study the connections between Sun's convection zone and evolution of solar wind corona. let magnetic fields generated by a 2.5-dimensional (2.5D) axisymmetric kinematic dynamo code (STELEM) evolve in 2.5D coronal isothermal magnetohydrodynamic (DIP). The computations cover an 11 year activity cycle. wind's asymptotic velocity varies latitude time good agreement with available observations. polarity reversal happens at different paces heights. Overall mass-loss rate, momentum flux, braking...
We present a mechanism for the formation of low-frequency 1/f magnetic spectrum based on numerical solutions shell-reduced MHD model turbulent dynamics inside sub-Alfvénic solar wind. assign reasonably realistic profiles to wind speed and density along radial direction, field. Alfvén waves short periodicity (600 s) are injected at base chromosphere, penetrate into corona, partially reflected, thus triggering cascade. The cascade is strong reflected wave while it weak outward propagating...
Abstract Solar wind slower than 300 km/s, hereafter termed very slow solar (VSSW), is seldom observed at 1 AU. It was, however, commonly measured inside 0.7 AU by the two Helios spacecraft, particularly during maximum. Magnetohydrodynamic (MHD) modeling reveals that disappearance of VSSW result its interaction with faster wind. The acceleration and compression contributes to highly variable structure usually contains heliospheric plasma sheet current sheet. has higher density lower...
Many scientists use coronal hole (CH) detections to infer open magnetic flux. Detection techniques differ in the areas that they assign as open, and may obtain different values for We characterize uncertainties of these methods, by applying six detection methods deduce area flux a near-disk center CH observed on 9/19/2010, single method five EUV filtergrams this CH. Open was calculated using maps. The standard deviation (interpreted uncertainty) estimate about 26%. However, including...
Aims : This paper presents a H2020 project aimed at developing an advanced space weather forecasting tool, combining the MagnetoHydroDynamic (MHD) solar wind and coronal mass ejection (CME) evolution modelling with energetic particle (SEP) transport acceleration model(s). The EUHFORIA 2.0 will address geoeffectiveness of impacts mitigation to avoid (part the) damage, including that extreme events, related eruptions, streams, SEPs, particular emphasis on its application forecast...
Abstract This Letter addresses the first Solar Orbiter (SO)–Parker Probe (PSP) quadrature, occurring on 2021 January 18 to investigate evolution of solar wind from extended corona inner heliosphere. Assuming ballistic propagation, same plasma volume observed remotely in at altitudes between 3.5 and 6.3 radii above limb with Metis coronagraph SO can be tracked PSP, orbiting 0.1 au, thus allowing local properties linked coronal source region where it originated. Thanks close approach PSP Sun...
Context. Solar Orbiter and PSP jointly observed the solar wind for first time in June 2020, capturing data from very different streams, calm Alfv\'enic as well many dynamic structures. Aims. The aim here is to understand origin characteristics of highly by two probes, particular vicinity heliospheric current sheet (HCS). Methods. We analyse plasma obtained situ during month 2020. use Alfv\'en-wave turbulence MHD model WindPredict-AW, perform 3D simulations based on ADAPT magnetograms this...
Abstract Interplanetary Type III bursts, generated by relativistic electron beams at solar flare reconnection sites, are explored through an investigation of 152 instances observed the Solar Terrestrial Relations Observatory mission. This study reveals that absolute values wavevector deviations from Sun–spacecraft line statistically 3.72 and 2.10 larger than predicted density model, assuming fundamental harmonic emission, respectively. Through Monte Carlo simulations, we examine impact...
I analyse the spatial distribution of solar wind sources and relate them to properties interplanetary by means an extended time series data-driven 3D simulations that cover more than two activity cycles. Magnetic connectivity jumps are related with plasma signatures topological features global magnetic field. The occurrence frequency amplitudes if such vary epoch cycle on distance ecliptic plane.The same model (Multi-VP) constitutes core SWiFT-FORECAST service, based pipeline initially...
Abstract We present a new model, MULTI-VP, which computes the three-dimensional structure of solar wind and includes chromosphere, transition region, corona low heliosphere. MULTI-VP calculates large ensemble profiles flowing along open magnetic field lines that sample entire atmosphere or, alternatively, given region interest. The radial domain starts from photosphere typically extends to about <?CDATA $30\ {R}_{\odot }$?> . elementary uni-dimensional solutions are based on mature numerical...
The solar wind speed at 1 AU shows variations in latitude and time which reflect the evolution of global background magnetic field during activity cycle. It is commonly accepted that terminal a flux-tube anti-correlated with its expansion ratio, motivated definition widely-used semi-empirical scaling laws relating one to other. In practice, such require ad-hoc corrections. A predictive law based solely on physical principles still missing. We test whether controlling factor all phases cycle...
Progress in space weather research and awareness needs community-wide strategies procedures to evaluate our modeling assets. Here we present the activities of Ambient Solar Wind Validation Team embedded COSPAR ISWAT initiative. We aim bridge gap between model developers end-users provide community with an assessment state-of-the-art solar wind forecasting. To this end, develop open online platform for validating models by comparing their solutions situ spacecraft measurements. The will allow...
Context. Twisted magnetic fields should be ubiquitous in the solar corona, particularly flare-producing active regions where are strongly non-potential. The energy contained such twisted can released during flares and other explosive phenomena. It has recently been shown that reconnection helical coronal loops results plasma heating particle acceleration distributed within a large volume, including lower chromospheric sections of loops. Hence, scenario involving helicity viable alternative...
In a recent study, we took advantage of highly tilted coronal neutral sheet to show that density structures, extending radially over several solar radii (Rs), are released in the forming slow wind approximately 4-5 Rs above surface (Sanchez-Diaz et al. 2017). We related signatures this formation process intermittent magnetic reconnection occurring continuously helmet streamers. now exploit heliospheric imagery from Solar Terrestrial Relation Observatory (STEREO) map spatial and temporal...