A5014276607- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Earthquake Detection and Analysis
- Astro and Planetary Science
- Geomagnetism and Paleomagnetism Studies
- Non-Destructive Testing Techniques
- Sensor Technology and Measurement Systems
- High voltage insulation and dielectric phenomena
- Laser-Plasma Interactions and Diagnostics
- High-pressure geophysics and materials
- Machine Fault Diagnosis Techniques
- Electrostatic Discharge in Electronics
- Atomic and Subatomic Physics Research
- Astrophysics and Cosmic Phenomena
- Seismology and Earthquake Studies
- earthquake and tectonic studies
- Astrophysics and Star Formation Studies
- GNSS positioning and interference
- Vacuum and Plasma Arcs
- Gamma-ray bursts and supernovae
- Radiation Effects in Electronics
- Plasma Diagnostics and Applications
- Diamond and Carbon-based Materials Research
- Fluid Dynamics and Turbulent Flows
- Magnetic confinement fusion research
Swedish Institute of Space Physics
2020-2025
Uppsala University
2020-2025
Northumbria University
2024-2025
American University of Beirut
2019
Identifying collisionless shock crossings in data sent from spacecraft has so far been done manually. It is a tedious job that physicists have to go through if they want conduct case studies or perform statistical studies. We use machine learning approach automatically identify the Magnetospheric Multiscale (MMS) spacecraft. compile database of those including various related and parameters for each event. Furthermore, we show shocks properties are spread out both real space parameter space....
Collisionless shock waves, found in supernova remnants, interstellar, stellar, and planetary environments, laboratories, are one of nature's most powerful particle accelerators. This study combines situ satellite measurements with recent theoretical developments to establish a reinforced acceleration model for relativistic electrons. Our incorporates transient structures, wave-particle interactions, variable stellar wind conditions, operating collectively multiscale set processes. We show...
Ion-acoustic waves are routinely observed at collisionless shocks and could be an important source of resistivity. The instability the effects not fully understood. We show, using Magnetospheric Multiscale (MMS) mission observations numerical modeling, that across low Mach number a large relative drift between protons alpha particles develops, which can unstable to proton-alpha streaming instability. results from linear analysis simulation show resulting agree with wave properties. generated...
Abstract A thorough understanding of collisionless shocks requires knowledge how different ion species are accelerated across the shock. We investigate a bow shock crossing using Magnetospheric Multiscale spacecraft after coronal mass ejection crossed Earth, which led to solar wind consisting protons, alpha particles, and singly charged helium ions. The three resolved upstream low Mach number enabled ions be partly distinguished downstream due relatively heating. Some protons specularly...
Abstract Electron heating at collisionless shocks in space is a combination of adiabatic due to large‐scale electric and magnetic fields non‐adiabatic scattering by high‐frequency fluctuations. The scales which happens hints what physical processes are taking place. In this letter, we study electron with data from the Magnetospheric Multiscale (MMS) spacecraft Earth's quasi‐perpendicular bow shock. We utilize tight tetrahedron formation high‐resolution plasma measurements MMS directly...
Abstract Shock-generated transients, such as hot flow anomalies (HFAs), upstream of planetary bow shocks, play a critical role in electron acceleration. Using multimission data from NASA’s Magnetospheric Multiscale and ESA’s Cluster missions, we demonstrate the transmission HFAs through Earth’s quasi-parallel shock, accelerating electrons to relativistic energies process. Energetic initially accelerated are shown remain broadly confined within transmitted transient structures downstream,...
Collisionless shock waves are ubiquitous in astrophysical plasmas, from supernova remnants and planetary atmospheres to coronal mass ejections laboratory experiments. These shocks known be efficient particle accelerators, crucial for understanding the origin of cosmic rays, including ultra-relativistic particles. This study presents a novel model reinforced acceleration electrons, integrating in-situ data NASA's Magnetospheric Multiscale (MMS) Acceleration, Reconnection, Turbulence,...
The response of the outer radiation belt to large-scale variations in solar wind is an active field research. In this work, we use electron flux measurement from full 7 years Van Allen probes mission along with properties measurements OMNI database at L1 and THEMIS/ARTEMIS spacecraft investigate how responds parameters across temporal scales. We find that has multiple periodicities correlated those wind. At largest scales, observe 0.5-year, 27-days, 13.5-days which are most prominent near...
Quasi-perpendicular collisionless shocks are fundamental structures in space plasmas, where the absence of collisions necessitates electromagnetic fields to mediate energy dissipation and particle dynamics. The Magnetospheric Multiscale (MMS) mission, with its high-resolution measurements multi-point capabilities, provides unique insights into these complex processes. We present MMS observations ion reflection, electron heating, non-stationarity, wave-particle interactions at...
Abstract Ion‐acoustic waves are routinely observed at collisionless shocks and could be an important source of resistivity. The instability the effects not fully understood. We show, using Magnetospheric Multiscale mission observations numerical modeling, that across low Mach number a large relative drift between protons alpha particles develops, which can unstable to proton‐alpha streaming instability. Linear analysis simulation show resulting agree with wave properties. generated...
Solar Orbiter, a mission developed by the European Space Agency, explores in situ plasma across inner heliosphere while providing remote-sensing observations of Sun. Our study examines particle for 30 October 2021 shock. The particles provide clear evidence ion reflection up to several minutes upstream Additionally, magnetic and electric field contain complex electromagnetic structures near shock, we aim investigate how they are connected dynamics. main goal this is advance our understanding...
Whistler waves are thought to play an essential role in the dynamics of collisionless shocks. We use magnetospheric multiscale (MMS) spacecraft study whistler around lower hybrid frequency, upstream 11 quasi-perpendicular super-critical apply 4-spacecraft timing method unambiguously determine wave vector $\mathbf{k}$ waves. find that oblique background magnetic field with a wave-normal angle between $20^{\circ}$ and $42^{\circ}$, wavelength 100 km which is close ion inertial length. also...
Context. Solar Orbiter is a European Space Agency mission with suite of in situ and remote sensing instruments to investigate the physical processes across inner heliosphere. During mission, spacecraft expected perform multiple Venus gravity assist maneuvers while providing measurements Venusian plasma environment. The first these occurred on 27 December 2020, which measured regions such as distant near magnetotail, magnetosheath, bow shock. Aims. This study aims outbound shock crossing by...
Determination of the wave mode short-wavelength electrostatic waves along with their generation mechanism requires reliable measurement electric field. We investigate reliability field for observed by MMS. develop a method, based on spin-plane interferometry, to reliably determine full 3D vector waves. test method synthetic data and then apply it ion acoustic bursts measured in situ solar wind. By studying statistical properties wind we retrieve known results that propagation is...
Abstract The relative contribution of adiabatic and non‐adiabatic processes to electron heating across collisionless shocks remains an open question. We analyze the evolution suprathermal electrons 310 quasi‐perpendicular with Alfvénic Mach numbers in normal‐incidence frame ranging from 1.7 48, using situ measurements Earth's bow shock by Magnetospheric Multiscale (MMS) spacecraft. introduce a novel non‐adiabaticity measure derived distribution function based on Liouville's theorem. Our...
We show that the axial symmetry of a shallow rotating flow is spontaneously broken in absence an externally forced velocity gradient. It caused by instability excited gradients arise from axisymmetric counter-rotating vortices. The experimental setup consists electrolyte poured into cylindrical container with radius R and height h subject to electromagnetic forcing magnetic field radial current (J) leading azimuthal rotation Vθ. motion considered be two-dimensional at large aspect ratio...
Adiabatic and non-adiabatic electron dynamics have been proposed to explain heating across collisionless shocks. We analyze the evolution of suprathermal electrons 310 quasi-perpendicular shocks with $1.7<M_A<48$ using in-situ measurements. show that mechanism shifts from predominantly adiabatic for Alfv\'enic Mach number in de Hoffman-Teller $\gtrsim 30$ latter constituting 48\% analyzed The observed is consistent stochastic shock drift acceleration mechanism.
The mechanism of electron heating across collisionless shocks remains an open question. mechanisms suggested to address this problem revolve around the adiabatic or non-adiabatic\stochastic dynamics electrons shock. In letter, we analyze evolution velocity distribution function observed 313 with 1.7<MA<48. We use a Liouville mapping technique show that shifts from predominantly non-adiabatic as Alfvenic Mach number in de Hoffmann-Teller frame increases. also for electrons, is...
Reflection of a fraction incoming ions is vital dissipation mechanism for super-critical shocks. Such reflected provide significant contribution to the downstream ion temperature increase. Understanding dynamics crucial characterization It needed an equation state that connects upstream and parameters given shock parameters. The reflection depends on detailed structure electromagnetic fields in transition region. ion-scale strongly affected by non-stationarity. To characterize spatiotemporal...
Abstract Despite more than half a century of Collisionless shock (CS) research, our understanding the processes energy dissipation into charge particle heating and acceleration remains incomplete. To help to address problem rate data analysis on CSs being well below acquisition, an open‐source high‐level database shocks centralized source advanced tools for purpose analyzing structure dynamics have been developed. The is called SHARP by name project (Shocks: structure, AcceleRation,...
<title>Abstract</title> Collisionless shock waves, found in supernova remnants, interstellar, stellar, and planetary environments, laboratories, are one of nature's most powerful particle accelerators. This study combines in-situ satellite measurements with recent theoretical developments to establish a novel reinforced acceleration model for relativistic electrons. Our incorporates transient structures, wave-particle interactions, variable stellar wind conditions, operating collectively...
Shock-generated transients, such as hot flow anomalies (HFAs), upstream of planetary bow shocks, play a critical role in electron acceleration. Using multi-mission data from NASA's Magnetospheric Multiscale (MMS) and ESA's Cluster missions, we demonstrate the transmission HFAs through Earth's quasi-parallel shock, associated with acceleration electrons up to relativistic energies. Energetic electrons, initially accelerated upstream, are shown remain broadly confined within transmitted...
We investigate the properties of ion sky maps produced by Dual Ion Spectrometers (DIS) from Fast Plasma Investigation (FPI). have trained a convolutional neural network classifier to predict four regions crossed MMS on dayside magnetosphere: solar wind, foreshock, magnetosheath, and magnetopause using solely DIS spectrograms. The accuracy is >98%. use detect mixed plasma regions, in particular find bow shock regions. A similar approach can be used identify crossings reveal prone magnetic...
Collisionless shocks exist across diverse plasma environments. Examples are supernova remnants, comets, near planets, and interplanetary (IP) in the solar wind. As shock Mach number increases, so does complexity of ion distribution functions at front due to features such as whistler precursors, reflection, ripples, nonstationarity.&#160;Experimental studies dynamics supercritical high (>5) typically conducted using planetary bow crossings since these higher while speeds with respect...
MMS can resolve the fine structure of shock ramp, which often shows holes in reduced ion-phase space distributions (integrated along tangential plane shock). This is possible due to high temporal resolutions FPI/DIS. Such have been associated with ripples propagating surface but also be related reformation. We statistically characterize ion phase-space at Earth&#8217;s bow using observations. establish a systematic procedure find shocks exhibiting holes. apply ~500 crossings for burst...