A5062709132- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Astro and Planetary Science
- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Geomagnetism and Paleomagnetism Studies
- Solar Radiation and Photovoltaics
- Earthquake Detection and Analysis
- Magnetic confinement fusion research
- Laser-Plasma Interactions and Diagnostics
- Fluid Dynamics and Turbulent Flows
- Tropical and Extratropical Cyclones Research
- Space Satellite Systems and Control
- Geophysics and Gravity Measurements
- Software Testing and Debugging Techniques
- Planetary Science and Exploration
- Gas Dynamics and Kinetic Theory
- Anomaly Detection Techniques and Applications
- Automotive and Human Injury Biomechanics
- Laser-induced spectroscopy and plasma
- GNSS positioning and interference
- Dark Matter and Cosmic Phenomena
- Lightning and Electromagnetic Phenomena
Imperial College London
2022-2025
European Space Astronomy Centre
2024-2025
European Space Agency
2024
University of Calabria
2020-2022
University of Arizona
2020
Queen Mary University of London
2018-2020
The Solar MAgnetic Connection HAUS 1 tool (Solar-MACH) is an open-source completely written in Python that derives and visualizes the spatial configuration solar magnetic connection of different observers (i.e., spacecraft or planets) heliosphere at times. For doing this, interplanetary space obtained by classic Parker Heliospheric Magnetic Field (HMF). In close vicinity Sun, a Potential Source Surface (PFSS) model can be applied to connect HMF photosphere. Solar-MACH especially aimed...
Context. A complex and long-lasting solar eruption on 17 April 2021 produced a widespread energetic particle (SEP) event that was observed by five longitudinally well-separated observers in the inner heliosphere covered distances to Sun from 0.42 1 au: BepiColombo, Parker Solar Probe, Orbiter, STEREO A, near-Earth spacecraft. The second SEP detected cycle 25, it relativistic electrons protons. It associated with hard X-ray flare showed multiple peaks over duration of one hour. further...
Abstract The Parker Solar Probe (PSP) and Orbiter (SolO) missions opened a new observational window in the inner heliosphere, which is finally accessible to direct measurements. On 2022 September 5, coronal mass ejection (CME)-driven interplanetary (IP) shock was observed as close 0.07 au by PSP. CME then reached SolO, radially well-aligned at 0.7 au, thus providing us with opportunity study properties different heliocentric distances. We characterize shock, investigate its typical...
The complex interaction between shocks and plasma turbulence is extremely important to address crucial features of energy conversion in a broad range astrophysical systems. We study the supercritical, perpendicular shock pre-existing, fully-developed turbulence, employing novel combination magnetohydrodynamic (MHD) small-scale, hybrid-kinetic simulations where propagating through turbulent medium. variability front unperturbed case for two levels upstream fluctuations addressed.We find that...
Shock accelerated electrons are found in many astrophysical environments, and the mechanisms by which they to high energies still not completely clear. For relatively Mach numbers, shock is supercritical, its front exhibit broadband fluctuations, or ripples. surface fluctuations have been object of observational theoretical studies, known be important for electron acceleration. We employ a combination hybrid Particle-In-Cell test-particle methods study how influence acceleration suprathermal...
Significance Shocks and turbulence are spectacular, ubiquitous phenomena. In this work, we investigate, by kinetic simulations, the interaction between a supercritical shock fully developed plasma turbulence. We demonstrate how dramatically changes phase space transport due to complex interaction. Two main findings presented: 1) paradigm for modeling shocks, including natural with surrounding turbulence, 2) an analysis method, based on coarse-grained equations, able characterize (and...
Spacecraft missions provide the unique opportunity to study properties of collisionless shocks utilising in situ measurements. In past years, several diagnostics have been developed address key shock parameters using time series magnetic field (and plasma) data collected by a single spacecraft crossing front. A critical aspect such is averaging process involved evaluation upstream/downstream quantities. this work, we discuss these techniques, with particular focus on obliquity (defined as...
Collisionless shocks and plasma turbulence are crucial ingredients for a broad range of astrophysical systems. The shock-turbulence interaction, in particular the transmission fully developed across quasi-perpendicular Earth's bow shock, is here addressed using combination spacecraft observations local numerical simulations. An alignment between Wind (upstream) MMS (downstream) used to study turbulent structures revealing an increase their magnetic helicity content its downstream. Local...
ABSTRACT Interplanetary (IP) shocks are fundamental building blocks of the heliosphere, and possibility to observe them in situ is crucial address important aspects energy conversion for a variety astrophysical systems. Steepened waves known as shocklets be structures planetary bow shocks, but they very rarely observed related IP shocks. We present here first multi-spacecraft observations by upstream an unusually strong shock on 3 November 2021 several spacecraft at L1 near-Earth solar wind....
Abstract As both Parker Solar Probe (PSP) and Orbiter (SolO) reach heliocentric distances closer to the Sun, they present an exciting opportunity study structure of coronal mass ejections (CMEs) in inner heliosphere. We analysis global flux rope 2022 September 5 CME event that impacted PSP at a distance only 0.07 au SolO 0.69 au. compare situ measurements determine local expansion measures, finding good agreement between magnetic field relationships with distance, but significant differences...
Abstract Collisionless shock waves, ubiquitous in the Universe, are crucial for particle acceleration various astrophysical systems. Currently, heliosphere is only natural environment available their situ study. In this work, we showcase collective of electrons and ions by one fastest shocks ever recorded, observed pioneering Parker Solar Probe at 34.5 million km from Sun. Our analysis unprecedented, near-parallel shows electron up to 6 MeV amidst intense multiscale electromagnetic wave...
Abstract We present the first observational evidence of irregular surface interplanetary (IP) shocks by using multispacecraft observations Cluster mission. In total we discuss four IP that exhibit moderate Alfvénic Mach numbers ( M A ≤ 6.5). Three them are high- β with upstream = 2.2–3.7. During times when these were observed, spacecraft formed constellations inter-spacecraft separations ranging from less than one ion inertial length d i ) up to 100 . Expressed in kilometers, distances...
Abstract Solar Orbiter's four in situ instruments have recorded numerous energetic electron events at heliocentric distances between 0.5 and 1 au. We analyze fluxes, spectra, pitch-angle distributions, associated Langmuir waves, type III solar radio bursts for three to understand what causes modifications the flux identify origin characteristics of features observed spectrum. investigate beam properties wind conditions are with wave growth spectral breaks peak as a function energy. observe...
ABSTRACT Localized dynamic pressure enhancements arising from kinetic processes are frequently observed downstream of the Earth’s bow shock. These structures, called jets, modify their plasma surroundings and participate in particle energization. Here, we report first observations jet-like structures a non-planetary shock environment: interplanetary shocks. We introduce an analysis approach suitable for such conditions apply it to Wind spacecraft data. present one event with Mach number...
Abstract We report direct observations of a fast magnetosonic forward–reverse shock pair observed by Solar Orbiter on 2022 March 8 at the short heliocentric distance 0.5 au. The structure, sharing some features with fully-formed stream interaction regions, is due to between two successive coronal mass ejections (CMEs), never previously give rise pair. scenario supported remote from extreme ultraviolet cameras and coronagraphs, where candidate eruptions compatible in situ signatures have been...
Abstract Helium nuclei (alpha particles) strongly influence the momentum and energy balance in solar wind, comprising up to 20% of wind mass density. In fast Alfvénic at heliocentric distances greater than 0.3 au, alpha particles’ bulk flow speed is systematically different that protons. This relative drift unknown origin often close local Alfvén wave speed. Novel Parker Solar Probe measurements below au show that, closer Sun, alpha–proton remains on order 100–200 km s −1 , even where 600 ....
Abstract Interplanetary (IP) shocks are fundamental constituents of the heliosphere, where they form as a result solar activity. We use previously unavailable measurements IP in inner heliosphere provided by Solar Orbiter, and present survey first 100 observed situ at different heliocentric distances during rising phase cycle 25. The shock parameters (shock normals, normal angles, speeds, compression ratios, Mach numbers) have been estimated studied function distance, revealing rich scenario...
It was the best of times, it worst times – for two traveling interplanetary shocks observed by Solar Orbiter on November 29 and 30 in 2023. We investigate these very dissimilar which were within less than 27 hours to elucidate obviously present non-equilibrium features test assumption gyrotropy. find different behavior particles at are course due differences shocks.The first 07:51:17 Nov. 29, 2023, quasi-parallel (θBn ≈ 33°) weaker (fast magnetosonic...
Interplanetary (IP) shocks are important sites of particle acceleration in the Heliosphere and can be observed in-situ utilizing spacecraft measurements. Solar Orbiter provides observations interplanetary at different locations inner heliosphere with unprecedented time energy resolution suprathermal (usually above 50 keV) range, thus opening a new observational window to study acceleration.We first discuss behaviour strong IP shock as close 0.07 AU by Parker Probe then 0.7, highlighting how...
Interplanetary (IP) shocks can be driven in the solar wind by fast coronal mass ejections, and interaction of with slow streams plasma. These preceded extended wave suprathermal ion foreshocks perturbing large extensions heliosphere. In a recent study (Trotta et al., 2024 it was shown that between two interplanetary ejections (ICMEs) drive forward reverse shock similarities to those bounding stream regions (SIRs). this work we analyse microstructure event observed Solar Orbiter on March 8th,...
Populations of energetic particles, ranging from solar particles to incredibly high-energy cosmic rays, are ubiquitous in space and astrophysical plasmas. Several intertwined phenomena, including shocks, magnetic reconnection, jets, turbulence, responsible for the efficient energization determining their transport properties.Plasma turbulence produces patchy coherent structures, such as reconnecting current sheets, plasmoids, vortices across a vast range spatial scales. Under some...
In space plasma, due to the absence of collisions, phase present a complex structuring and strong deviations from thermal equilibrium. Previous works have highlighted this aspect in both magnetosheath data numerical simulation through an hermite decomposition ion velocity distribution function. The spectrum vdf is expected precise spectral slope anisotropy magnetic field dominated environment. Such tool particularly suited for representation since each order corresponds moment vdf.In work we...
Since Parker, the existence of solar wind has been ascribed to fact that corona is not in hydrostatic equilibrium and thus constantly expanding. However, mechanism responsible for accelerating/heating widely debated, even though there evidence it magnetic nature. New space missions like Parker Solar Probe (PSP), Orbiter (SolO) BepiColombo (BC), being much closer Sun, allow observations less evolved mixed wind. Thus, example, observed streams can be easily back-propagated their source on...
The role of kinetic electrons in the excitation and sustainment ion-bulk electrostatic waves collisionless plasmas is investigated, with a focus on physical mechanisms responsible for generation small-scale structures space plasmas. Building work Valentini et al. [Phys. Rev. Lett. 106, 165002 (2011)], we numerically solve Vlasov–Poisson system one spatial velocity dimension both ions electrons. Our findings reveal that significant fraction energy supplied by an external driving electric...
Abstract Magnetosheath jets and plasmoids are very common phenomena downstream of Earth’s quasi-parallel bow shock. As the increase dynamic pressure is one principal characteristics magnetosheath jets, embedded paramagnetic have been considered as an special case former. Although properties both types structures widely studied during last 20 years, their formation mechanisms not examined thoroughly. In this work we perform a 2D local hybrid simulation (kinetic ions – fluid electrons) ( θ Bn...