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213 results on '"Andris Vaivads"'

1. Alpha-to-proton Temperature Ratio Distributions Using Parker Solar Probe Measurements

Author: Mário B. Amaro and Andris Vaivads
Subjects: Solar energetic particles, Solar wind, Space weather, Astrophysics, QB460-466
Abstract: The distributions of the temperature excess of alphas to protons ( ε ) were studied using Parker Solar Probe measurements for Encounters 2 through 14. The distributions were mapped based on heliographic distance, Coulomb number, plasma β , and Alfvén Mach number ( M _A ). The importance of collisional effects in the thermalization of solar wind is observed for a wide range of Coulomb numbers. The distributions correlate better with N β and NM _A than just N . Furthermore, evidence was found for a narrow region immediately above the Alfvén surface (1 < M _A < 2) where ε has values much higher than the mass ratio.
Published: 2024
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2. Electric Sail Test Cube–Lunar Nanospacecraft, ESTCube-LuNa: Solar Wind Propulsion Demonstration Mission Concept

Author: Andris Slavinskis, Mario F. Palos, Janis Dalbins, Pekka Janhunen, Martin Tajmar, Nickolay Ivchenko, Agnes Rohtsalu, Aldo Micciani, Nicola Orsini, Karl Mattias Moor, Sergei Kuzmin, Marcis Bleiders, Marcis Donerblics, Ikechukwu Ofodile, Johan Kütt, Tõnis Eenmäe, Viljo Allik, Jaan Viru, Pätris Halapuu, Katriin Kristmann, Janis Sate, Endija Briede, Marius Anger, Katarina Aas, Gustavs Plonis, Hans Teras, Kristo Allaje, Andris Vaivads, Lorenzo Niccolai, Marco Bassetto, Giovanni Mengali, Petri Toivanen, Iaroslav Iakubivskyi, Mihkel Pajusalu, and Antti Tamm
Subjects: electric solar wind sail, lunar orbit, cubesat, in-orbit demonstration, interplanetary nanospacecraft, Motor vehicles. Aeronautics. Astronautics, TL1-4050
Abstract: The electric solar wind sail, or E-sail, is a propellantless interplanetary propulsion system concept. By deflecting solar wind particles off their original course, it can generate a propulsive effect with nothing more than an electric charge. The high-voltage charge is applied to one or multiple centrifugally deployed hair-thin tethers, around which an electrostatic sheath is created. Electron emitters are required to compensate for the electron current gathered by the tether. The electric sail can also be utilised in low Earth orbit, or LEO, when passing through the ionosphere, where it serves as a plasma brake for deorbiting—several missions have been dedicated to LEO demonstration. In this article, we propose the ESTCube-LuNa mission concept and the preliminary cubesat design to be launched into the Moon’s orbit, where the solar wind is uninterrupted, except for the lunar wake and when the Moon is in the Earth’s magnetosphere. This article introduces E-sail demonstration experiments and the preliminary payload design, along with E-sail thrust validation and environment characterisation methods, a cis-lunar cubesat platform solution and an early concept of operations. The proposed lunar nanospacecraft concept is designed without a deep space network, typically used for lunar and deep space operations. Instead, radio telescopes are being repurposed for communications and radio frequency ranging, and celestial optical navigation is developed for on-board orbit determination.
Published: 2024
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3. Downstream high-speed plasma jet generation as a direct consequence of shock reformation

Author: Savvas Rapitis, Tomas Karlsson, Andris Vaivads, Craig Pollock, Ferdinand Plaschke, Andreas Johlander, Henriette Trollvik, and Per-Arne Lindqvist
Subjects: Science
Abstract: Several mechanisms exist for formation of jets observed in Earth’s magnetosheath. Here, the authors show evidence of high-speed downstream flows generated at the Earth’s bow shock as a direct consequence of shock reformation, which is different than the proposed mechanisms.
Published: 2022
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4. Auroral Spiral Structure Formation Through Magnetic Reconnection in the Auroral Acceleration Region

Author: Kai Huang, Yi‐Hsin Liu, Quanming Lu, Zejun Hu, Kristina A. Lynch, Michael Hesse, Andris Vaivads, and Huigen Yang
Subjects: Geophysics. Cosmic physics, QC801-809
Abstract: Abstract Auroral spiral is one of the auroral vortex structures. Here, we propose a model to explain the formation of auroral spiral structure based on three‐dimensional particle‐in‐cell simulations. In our model, an auroral arc develops through precipitations of electrons accelerated during magnetic reconnection in the auroral acceleration region. The arc morphology at low altitudes can be modified by electron‐scale magnetic flux ropes, which are generated through secondary oblique tearing modes in the intensified current sheet along one particular branch of the primary reconnection separatrices. The resulting vortex structures agree well with high‐resolution observations of auroral spirals. We find that the rotational sense of these spirals is determined by electron kinetic processes and controlled by the guide field direction. Our study further suggests that when the field‐aligned length of the auroral acceleration region is shorter than a critical length, these auroral spiral structures will not form.
Published: 2022
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5. Electric Sail Mission Expeditor, ESME: Software Architecture and Initial ESTCube Lunar Cubesat E-Sail Experiment Design

Author: Mario F. Palos, Pekka Janhunen, Petri Toivanen, Martin Tajmar, Iaroslav Iakubivskyi, Aldo Micciani, Nicola Orsini, Johan Kütt, Agnes Rohtsalu, Janis Dalbins, Hans Teras, Kristo Allaje, Mihkel Pajusalu, Lorenzo Niccolai, Marco Bassetto, Giovanni Mengali, Alessandro A. Quarta, Nickolay Ivchenko, Joan Stude, Andris Vaivads, Antti Tamm, and Andris Slavinskis
Subjects: electric propulsion, electric sail, solar wind propulsion, Coulomb drag, lunar mission, ESTCube lunar nanospacecraft, Motor vehicles. Aeronautics. Astronautics, TL1-4050
Abstract: The electric solar wind sail, or E-sail, is a novel deep space propulsion concept which has not been demonstrated in space yet. While the solar wind is the authentic operational environment of the electric sail, its fundamentals can be demonstrated in the ionosphere where the E-sail can be used as a plasma brake for deorbiting. Two missions to be launched in 2023, Foresail-1p and ESTCube-2, will attempt to demonstrate Coulomb drag propulsion (an umbrella term for the E-sail and plasma brake) in low Earth orbit. This paper presents the next step of bringing the E-sail to deep space—we provide the initial modelling and trajectory analysis of demonstrating the E-sail in solar wind. The preliminary analysis assumes a six-unit cubesat being inserted in the lunar orbit where it deploys several hundred meters of the E-sail tether and charges the tether at 10–20 kV. The spacecraft will experience acceleration due to the solar wind particles being deflected by the electrostatic sheath around the charged tether. The paper includes two new concepts: the software architecture of a new mission design tool, the Electric Sail Mission Expeditor (ESME), and the initial E-sail experiment design for the lunar orbit. Our solar-wind simulation places the Electric Sail Test Cube (ESTCube) lunar cubesat with the E-sail tether in average solar wind conditions and we estimate a force of 1.51×10−4 N produced by the Coulomb drag on a 2 km tether charged to 20 kV. Our trajectory analysis takes the 15 kg cubesat from the lunar back to the Earth orbit in under three years assuming a 2 km long tether and 20 kV. The results of this paper are used to set scientific requirements for the conceptional ESTCube lunar nanospacecraft mission design to be published subsequently in the Special Issue “Advances in CubeSat Sails and Tethers”.
Published: 2023
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6. Electron Kinetic Entropy across Quasi-Perpendicular Shocks

Author: Martin Lindberg, Andris Vaivads, Savvas Raptis, Per-Arne Lindqvist, Barbara L. Giles, and Daniel Jonathan Gershman
Subjects: space plasma, electron kinetic entropy, quasi-perpendicular shock, adiabatic index, Science, Astrophysics, QB460-466, Physics, QC1-999
Abstract: We use Magnetospheric Multiscale (MMS) data to study electron kinetic entropy per particle Se across Earth’s quasi-perpendicular bow shock. We have selected 22 shock crossings covering a wide range of shock conditions. Measured distribution functions are calibrated and corrected for spacecraft potential, secondary electron contamination, lack of measurements at the lowest energies and electron density measurements based on plasma frequency measurements. All crossings display an increase in electron kinetic entropy across the shock ΔSe being positive or zero within their error margin. There is a strong dependence of ΔSe on the change in electron temperature, ΔTe, and the upstream electron plasma beta, βe. Shocks with large ΔTe have large ΔSe. Shocks with smaller βe are associated with larger ΔSe. We use the values of ΔSe, ΔTe and density change Δne to determine the effective adiabatic index of electrons for each shock crossing. The average effective adiabatic index is ⟨γe⟩=1.64±0.07.
Published: 2022
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7. Author Correction: Downstream high-speed plasma jet generation as a direct consequence of shock reformation

Author: Savvas Raptis, Tomas Karlsson, Andris Vaivads, Craig Pollock, Ferdinand Plaschke, Andreas Johlander, Henriette Trollvik, and Per-Arne Lindqvist
Subjects: Science
Published: 2022
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8. Collisionless Magnetic Reconnection and Waves: Progress Review

Author: Yuri V. Khotyaintsev, Daniel B. Graham, Cecilia Norgren, and Andris Vaivads
Subjects: magnetic reconnection, turbulence, waves, instabilities, kinetic plasma processes, Astronomy, QB1-991, Geophysics. Cosmic physics, QC801-809
Abstract: Magnetic reconnection is a fundamental process whereby microscopic plasma processes cause macroscopic changes in magnetic field topology, leading to explosive energy release. Waves and turbulence generated during the reconnection process can produce particle diffusion and anomalous resistivity, as well as heat the plasma and accelerate plasma particles, all of which can impact the reconnection process. We review progress on waves related to reconnection achieved using high resolution multi-point in situ observations over the last decade, since early Cluster and THEMIS observations and ending with recent Magnetospheric Multiscale results. In particular, we focus on the waves most frequently observed in relation to reconnection, ranging from low-frequency kinetic Alfvén waves (KAW), to intermediate frequency lower hybrid and whistler-mode waves, electrostatic broadband and solitary waves, as well as the high-frequency upper hybrid, Langmuir, and electron Bernstein waves. Significant progress has been made in understanding localization of the different wave modes in the context of the reconnection picture, better quantification of generation mechanisms and wave-particle interactions, including anomalous resistivity. Examples include: temperature anisotropy driven whistlers in the flux pileup region, anomalous effects due to lower-hybrid waves, upper hybrid wave generation within the electron diffusion region, wave-particle interaction of electrostatic solitary waves. While being clearly identified in observations, some of the wave processes remain challenging for reconnection simulations (electron Bernstein, upper hybrid, Langmuir, whistler), as the instabilities (streaming, loss-cone, shell) which drive these waves require high resolution of distribution functions in phase space, and realistic ratio of Debye to electron inertia scales. We discuss how reconnection configuration, i.e., symmetric vs. asymmetric, guide-field vs. antiparallel, affect wave occurrence, generation, effect on particles, and feedback on the overall reconnection process. Finally, we outline some of the major open questions, such as generation of electromagnetic radiation by reconnection sites and role of waves in triggering/onset of reconnection.
Published: 2019
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9. Evidence that Interaction with the Spacecraft Plasma Wake Generates Plasma Waves Close to the Electron Cyclotron Frequency in the Near-Sun Solar Wind

Author: David M. Malaspina, Sabrina F. Tigik, and Andris Vaivads
Published: 2022
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10. The Formation of a Magnetosphere with Implicit Particle-in-Cell Simulations.

Author: Ivy Bo Peng, Stefano Markidis, Andris Vaivads, Juris Vencels, Jorge Amaya, Andrey Divin, Erwin Laure, and Giovanni Lapenta
Published: 2015
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11. Velocity distribution functions and non‐Maxwellianity of magnetosheath jets using MMS

Author: Savvas Raptis, Tomas Karlsson, Andris Vaivads, Martin Lindberg, and Henriette Trollvik
Abstract: The interaction between the solar wind and Earth’s magnetic field results in the formation of a supercritical bow shock. Downstream of this shock wave, the magnetosheath region emerges, in which high-speed plasma flows can be formed. These jets have been connected to several shock and foreshock properties. Moreover, due to their unique properties (i.e., higher density and velocity compared to the ambient flow), they can cause a variety of different phenomena, including magnetopause reconnection, excitation of ULF waves and electron acceleration.In this work, we use Magnetosphere Multiscale (MMS) mission to demonstrate jets’ complex structure by investigating their velocity distribution functions. Specifically, we focus on how their VDFs change over time and on whether they exhibit non-Maxwellian properties. By comparing with the VDFs taken from the background magnetosheath, we show that full particle plasma moments provide an inadequate description of jet plasma properties. Furthermore, we present different metrics to quantify the non-Maxwellian features exhibited by jet observations. Finally, we discuss how the observed kinetic properties of jets may provide insight into jets generation, wave excitation and evolution.
Published: 2023

12. Ion Temperature Anisotropy in Plasma Jets

Author: Louis Richard, Yuri V. Khotyaintsev, Daniel B. Graham, Andris Vaivads, Daniel J. Gershman, and Christopher T. Russell
Abstract: Magnetotail magnetic reconnection results in fast plasma flows referred to as jets. Reconnection jets are populated with complex non-Maxwellian ion distributions providing a source of free energy for the micro-instabilities, which contribute to the ion heating in the reconnection region. We present a statistical analysis of the ion temperature anisotropy in magnetic reconnection jets using data from the Magnetospheric Multiscale spacecraft. Compared with the quiet plasma in which the jet propagates, we often find anisotropic and non-Maxwellian ion distributions in the plasma jets. We observe magnetic field fluctuations associated with unstable ion distributions, but the wave amplitude is not large enough to scatter ions during the observed lifetime of the jet. Our estimate of the phase-space diffusion due to chaotic and quasi-adiabatic ion motion in the current sheet shows that the diffusion is sufficiently fast to be the main process leading to isotropization.
Published: 2023

13. Ion Kinetics in a Hot Flow Anomaly: MMS Observations

Author: Steven J Schwartz, Levon Avanov, Drew Turner, Hui Zhang, Imogen Gingell, Jonathan P Eastwood, Daniel J Gershman, Andreas Johlander, Christopher T Russell, James L Burch, John C Dorelli, Stefan Eriksson, Robert E Ergun, Stephen A Fuselier, Barbara L Giles, Katherine A Goodrich, Yuri V Khotyaintsev, Benoit Lavraud, Per‐Arne Lindqvist, Mitsuo Oka, Tai‐Duc Phan, Robert J Strangeway, Karlheinz J Trattner, Roy B Torbert, Andris Vaivads, Hanying Wei, and Frederick Wilder
Published: 2018
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14. The emission of near-fce harmonic waves at small radial distances from the Sun

Author: Sabrina F. Tigik, Andris Vaivads, and David M. Malaspina
Abstract: Near-fce harmonic waves are prevalent in the high-frequency electric field spectrum during Parker Solar Probe's (PSP) close encounters with the Sun. These waves are electrostatic and tend to occur in regions of a relatively stable magnetic field with low broadband magnetic fluctuation levels. We show that the emissions of near-fce harmonic waves are strongly connected to the magnetic field direction. We express the magnetic field direction in terms of spherical angles, where θB is the elevation angle and φB is the azimuthal angle. Then, we show that near-fce harmonics emissions occur when the magnetic field points in a narrow angular range, bounded by 80° ≤ θB ≤ 100° and 10° ≤ φB ≤ 30°, in most of the cases. We also show that the influence of magnetic field direction on near-fce harmonic waves goes down to the shortest time scales the FIELDS instrument can access. These results suggest that cross-scale interaction might play an essential role in the dynamics of the near-fce harmonics measured by PSP at small radial distances from the Sun. It may also provide important clues about the origin of these waves and their role at the early stages of solar wind evolution.
Published: 2022

15. Ion Acceleration at Magnetotail Turbulent Plasma Jet Fronts

Author: Louis Richard, Yuri V. Khotyaintsev, Daniel B. Graham, Andris Vaivads, Romina Nikoukar, Ian J. Cohen, Drew L. Turner, Stephen A. Fuselier, Christopher T. Russell, Barbara L. Giles, and Per-Arne Lindqvist
Subjects: Physics::Space Physics
Abstract: We investigate a series of Earthward bursty bulk flows (BBFs) observed by the Magnetospheric Multiscale (MMS) spacecraft in the Earth’s magnetotail (X ~ -24 Re, Y ~ 7 Re, Z ~ 4 Re). At the leading edges of the BBFs, we observe complex magnetic field structures. In particular, we focus on one which presents a chain of small scale (~0.5 Re) dipolarizations, and another with a large scale (~3.5 Re) dipolarization. Although the two structures have different scales, both of these structures are associated with flux increases of supra-thermal ions (Ki > 100 keV). We investigate the ion acceleration mechanism and its dependence on the mass and charge state. We show that the ions with gyroradii smaller than the scale of the structure are accelerated by the ion bulk flow. We show that whereas in the small-scale structure, ions with gyroradii comparable with the scale of the structure undergo resonance acceleration, the acceleration in the larger-scale structure is more likely due to a spatially limited electric field. In both cases, we discuss the adiabaticity of the acceleration mechanism.
Published: 2022

16. Electron Kinetic Entropy Generation at Quasi-perpendicular Collisionless Shocks: Dependence on Shock Parameters

Author: Martin Lindberg, Andris Vaivads, Savvas Raptis, Per-Arne Lindqvist, Barbara Giles, and Daniel Gershman
Abstract: We calculate the change in electron kinetic entropy, ΔSe, across 22 supercritical quasi-perpendicular Earth bow shock crossings observed by the Magnetospheric Multiscale (MMS) mission. The crossings cover a wide range of shock parameters. We calibrate the measured distribution functions measured by MMS to correct for spacecraft potential, secondary electron contamination, lack of measurements at the lowest energies and electron density measurements based on the plasma frequency measurements. The change in electron kinetic entropy displays a strong dependence on the change in electron temperature, ΔTe, and the upstream plasma beta. Shocks with a small upstream plasma beta have a large ΔSe while shocks with high upstream plasma beta have a small ΔSe.The calculated changes in kinetic entropy, density and temperature are used to estimate the proxy adiabatic index, γe, for each shock crossing. The estimated adiabatic indices are all in the vicinity of 1.6, comparable to that of a monatomic gas with three degrees of freedom.
Published: 2022

17. High-speed Magnetosheath Jet Generation due to Shock Reformation

Author: Savvas Raptis, Tomas Karlsson, Andris Vaivads, Craig Pollock, Ferdinand Plaschke, Andreas Johlander, Henriette Trollvik, and Per-Arne Lindqvist
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Physics::Space Physics
Abstract: Magnetosheath jets are transient localized structures of enhanced dynamic pressure observed downstream of the Earth’s bow shock. They may exhibit an increase of velocity reaching solar wind levels, while their density is typically much higher than typical magnetosheath and solar wind values. Jets have been associated to several magnetospheric effects such as, magnetopause reconnection, excitations of surface eigenmodes and even direct plasma penetration in the magnetosphere. While their exact origin is unknown, many mechanisms have been proposed. One of the most prominent explanations involves the interaction of solar wind with local inclinations of the bow shock (ripples) while others include solar wind discontinuities, and foreshock structures.In this work, by using Magnetosphere Multiscale (MMS) we show in-situ observations of a super-magnetosonic magnetosheath jet being generated as a direct result of the bow shock reformation cycle. The observed jet origin appears to be the result of the dynamical evolution of the shock and the emergence of a spatially de-attached compressive magnetic structure that acts as a local shock front. Due to this, the solar wind particles are effectively transferred downstream without experiencing a strong interaction with the shock, which allows compressed high velocity plasma to be observed downstream of the bow shock.The proposed mechanism does not require external phenomena (e.g., solar wind discontinuities) or specific configuration of the bow shock (e.g., ripples) to take place. On the contrary, it allows the magnetosheath jet phenomenon to directly originate from the dynamical evolution of the quasi-parallel collisionless shock.
Published: 2022

18. On magnetosheath jet kinetic structure and plasma properties

Author: Savvas Raptis, Tomas Karlsson, Andris Vaivads, Martin Lindberg, Andreas Johlander, and Henriette Trollvik
Subjects: Fusion, plasma och rymdfysik, Geophysics, Geofysik, kinetic plasma, General Earth and Planetary Sciences, plasma moments, magnetosheath jet, magnetosheath, bow shock, Fusion, Plasma and Space Physics, VDFs
Abstract: High-speed plasma jets downstream of Earth's bow shock are high velocity streams associated with a variety of shock and magnetospheric phenomena. In this work, using the Magnetosphere Multiscale mission, we study the properties of a jet found downstream of the Quasi-parallel bow shock using high-resolution (burst) data. By doing so, we demonstrate how the jet is an inherently kinetic structure described by highly variable velocity distributions. The observed distributions show the presence of two plasma population, a cold/fast jet and a hotter/slower background population. We derive partial moments for the jet population to isolate its properties. The resulting partial moments appear different from the full ones which are typically used in similar studies. These discrepancies show how jets are more similar to upstream solar wind beams compared to what was previously believed. Finally, we explore the consequences of our results and methodology regarding the characterization, origin, and evolution of jets.
Published: 2022

19. ICARUS: in-situ studies of the solar corona beyond Parker Solar Probe and Solar Orbiter

Author: Vladimir Krasnoselskikh, Bruce T. Tsurutani, Thierry Dudok de Wit, Simon Walker, Michael Balikhin, Marianne Balat-Pichelin, Marco Velli, Stuart D. Bale, Milan Maksimovic, Oleksiy Agapitov, Wolfgang Baumjohann, Matthieu Berthomier, Roberto Bruno, Steven R. Cranmer, Bart de Pontieu, Domingos de Sousa Meneses, Jonathan Eastwood, Robertus Erdelyi, Robert Ergun, Viktor Fedun, Natalia Ganushkina, Antonella Greco, Louise Harra, Pierre Henri, Timothy Horbury, Hugh Hudson, Justin Kasper, Yuri Khotyaintsev, Matthieu Kretzschmar, Säm Krucker, Harald Kucharek, Yves Langevin, Benoît Lavraud, Jean-Pierre Lebreton, Susan Lepri, Michael Liemohn, Philippe Louarn, Eberhard Moebius, Forrest Mozer, Zdenek Nemecek, Olga Panasenco, Alessandro Retino, Jana Safrankova, Jack Scudder, Sergio Servidio, Luca Sorriso-Valvo, Jan Souček, Adam Szabo, Andris Vaivads, Grigory Vekstein, Zoltan Vörös, Teimuraz Zaqarashvili, Gaetano Zimbardo, Andrei Fedorov, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)
Subjects: Space and Planetary Science, [SDU]Sciences of the Universe [physics], Solar wind, Solar atmosphere, Astronomy and Astrophysics, Space mission, Heliophysics
Abstract: The primary scientific goal of ICARUS (Investigation of Coronal AcceleRation and heating of solar wind Up to the Sun), a mother-daughter satellite mission, proposed in response to the ESA “Voyage 2050” Call, will be to determine how the magnetic field and plasma dynamics in the outer solar atmosphere give rise to the corona, the solar wind, and the entire heliosphere. Reaching this goal will be a Rosetta Stone step, with results that are broadly applicable within the fields of space plasma physics and astrophysics. Within ESA’s Cosmic Vision roadmap, these science goals address Theme 2: “How does the Solar System work?” by investigating basic processes occurring “From the Sun to the edge of the Solar System”. ICARUS will not only advance our understanding of the plasma environment around our Sun, but also of the numerous magnetically active stars with hot plasma coronae. ICARUS I will perform the first direct in situ measurements of electromagnetic fields, particle acceleration, wave activity, energy distribution, and flows directly in the regions in which the solar wind emerges from the coronal plasma. ICARUS I will have a perihelion altitude of 1 solar radius and will cross the region where the major energy deposition occurs. The polar orbit of ICARUS I will enable crossing the regions where both the fast and slow winds are generated. It will probe the local characteristics of the plasma and provide unique information about the physical processes involved in the creation of the solar wind. ICARUS II will observe this region using remote-sensing instruments, providing simultaneous, contextual information about regions crossed by ICARUS I and the solar atmosphere below as observed by solar telescopes. It will thus provide bridges for understanding the magnetic links between the heliosphere and the solar atmosphere. Such information is crucial to our understanding of the plasma physics and electrodynamics of the solar atmosphere. ICARUS II will also play a very important relay role, enabling the radio-link with ICARUS I. It will receive, collect, and store information transmitted from ICARUS I during its closest approach to the Sun. It will also perform preliminary data processing before transmitting it to Earth. Performing such unique in situ observations in the area where presumably hazardous solar energetic particles are energized, ICARUS will provide fundamental advances in our capabilities to monitor and forecast the space radiation environment. Therefore, the results from the ICARUS mission will be extremely crucial for future space explorations, especially for long-term crewed space missions.
Published: 2022

20. Solar Orbiter/RPW antenna calibration in the radio domain and its application to type III burst observations

Author: M. Steller, Milan Maksimovic, M. Dekkali, E. Lorfèvre, Vratislav Krupar, Antonio Vecchio, Arnaud Zaslavsky, Stuart D. Bale, Yu. V. Khotyaintsev, Vladimir Krasnoselskikh, Štěpán Štverák, Matthieu Kretzschmar, P. L. Astier, Dirk Plettemeier, Xavier Bonnin, Pavel M. Trávníček, J. Soucek, Andris Vaivads, E. Guilhem, T. Chust, Baptiste Cecconi, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), ALTRAN (FRANCE), Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), and Centre National d'Études Spatiales [Toulouse] (CNES)
Subjects: 010504 meteorology & atmospheric sciences, Astronomy, FOS: Physical sciences, Astrophysics, 01 natural sciences, law.invention, Domain (software engineering), Fusion, plasma och rymdfysik, Orbiter, Astronomi, astrofysik och kosmologi, Physics - Space Physics, law, Antenna calibration, 0103 physical sciences, Astronomy, Astrophysics and Cosmology, Aerospace engineering, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), detectors, 0105 earth and related environmental sciences, instrumentation, Physics, Sun: radio radiation, business.industry, instrumentation: detectors, Computer Science::Information Retrieval, Sun, Astronomy and Astrophysics, Fusion, Plasma and Space Physics, Space Physics (physics.space-ph), Astrophysics - Solar and Stellar Astrophysics, solar wind, Space and Planetary Science, radio radiation, Astrophysics - Instrumentation and Methods for Astrophysics, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: Context.In order to allow for a comparison with the measurements from other antenna systems, the voltage power spectral density measured by the Radio and Plasma waves receiver (RPW) on board Solar Orbiter needs to be converted into physical quantities that depend on the intrinsic properties of the radiation itself (e.g., the brightness of the source).Aims.The main goal of this study is to perform a calibration of the RPW dipole antenna system that allows for the conversion of the voltage power spectral density measured at the receiver’s input into the incoming flux density.Methods.We used space observations from the Thermal Noise Receiver (TNR) and the High Frequency Receiver (HFR) to perform the calibration of the RPW dipole antenna system. Observations of type III bursts by the Wind spacecraft are used to obtain a reference radio flux density for cross-calibrating the RPW dipole antennas. The analysis of a large sample of HFR observations (over about ten months), carried out jointly with an analysis of TNR-HFR data and prior to the antennas’ deployment, allowed us to estimate the reference system noise of the TNR-HFR receivers.Results.We obtained the effective length,leff, of the RPW dipoles and the reference system noise of TNR-HFR in space, where the antennas and pre-amplifiers are embedded in the solar wind plasma. The obtainedleffvalues are in agreement with the simulation and measurements performed on the ground. By investigating the radio flux intensities of 35 type III bursts simultaneously observed by Wind and Solar Orbiter, we found that while the scaling of the decay time as a function of the frequency is the same for the Waves and RPW instruments, their median values are higher for the former. This provides the first observational evidence that Type III radio waves still undergo density scattering, even when they propagate from the source, in a medium with a plasma frequency that is well below their own emission frequency.
Published: 2021

21. Electron kinetic entropy across quasi-perpendicular 1 shocks

Author: Martin Ulf Lindberg, Andris Vaivads, Savvas Raptis, Per Arne Lindqvist, Barbara Giles, and Daniel Gershman
Published: 2021

22. The Solar Orbiter Radio and Plasma Waves (RPW) instrument (Corrigendum)

Author: Andris Vaivads, V. Krupař, M. Chariet, Lars Bylander, L. R. Malac-Allain, J. Parisot, Mats André, W. Recart, W. Puccio, C. Agrapart, D. Bérard, V. Leray, Robert F. Wimmer-Schweingruber, K. Boughedada, Baptiste Cecconi, E. Lorfèvre, M. Steller, B. Katra, F. Chapron, Helmut O. Rucker, Stuart D. Bale, Matthieu Kretzschmar, J.-C. Pellion, Ivana Kolmasova, J. Sanisidro, N. Quéruel, Filippo Pantellini, V. Bouzid, Laurent Lamy, Milan Maksimovic, L. Guéguen, C. Fiachetti, S. Chaintreuil, Mykhaylo Panchenko, Karine Issautier, M. Dekkali, O. Krupařová, Keith Goetz, Tomas Karlsson, I. Fratter, H. Ottacher, Philippe Louarn, P. Fergeau, O. Le Contel, Christopher J. Owen, Jan Soucek, A. Retino, Mihailo M. Martinović, Y. de Conchy, Olga Alexandrova, E. Bellouard, G. T. Delory, David Pisa, S. Thijs, E. Guilhem, Anders Eriksson, L. Åhlén, Antonio Vecchio, Timothy S. Horbury, Ondrej Santolik, Eduard P. Kontar, T. Vincent, V. Cripps, Daniel Dias, I. Zouganelis, A. Jeandet, T. Dudok de Wit, Sonny Lion, L. Uhlíř, Quynh Nhu Nguyen, M. Timofeeva, Dirk Plettemeier, J. Baše, Christopher Cully, Petr Hellinger, Lorenzo Matteini, Fouad Sahraoui, C. Collin, Paul Turin, Javier Rodriguez-Pacheco, Säm Krucker, P. Plasson, J.-Y. Brochot, Vladimir Krasnoselskikh, P. Leroy, Petr Travnicek, R. Lán, Yu. V. Khotyaintsev, S.-E. Jansson, Štěpán Štverák, G. Barbary, Pierre Astier, G. Jannet, R. Piberne, E. P. G. Johansson, F. Gonzalez, P. Danto, Arnaud Zaslavsky, J. Břínek, Thomas Chust, Xavier Bonnin, C. Laffaye, G. Cassam-Chenai, S. Julien, B. Pontet, Matthieu Berthomier, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Swedish Institute of Space Physics [Uppsala] (IRF), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Technische Universität Dresden = Dresden University of Technology (TU Dresden), Commission for Astronomy of the Austrian Academy of Sciences, Austrian Academy of Sciences (OeAW), Institute of Atmospheric Physics [Prague] (IAP), Czech Academy of Sciences [Prague] (CAS), Space Research Institute of Austrian Academy of Sciences (IWF), Royal Institute of Technology [Stockholm] (KTH ), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Nexeya Conseil & Formation, Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud university [Nijmegen], Centre National d'Études Spatiales [Toulouse] (CNES), Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), Université Paul-Valéry - Montpellier 3 (UPVM)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), ALTRAN (FRANCE), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES), Univerzita Karlova v Praze, Universities Space Research Association (USRA), NASA Goddard Space Flight Center (GSFC), Department of Physics and Astronomy [Calgary], University of Calgary, School of Physics and Astronomy [Minneapolis], University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, Department of Physics [Imperial College London], Imperial College London, University of Glasgow, Fachhochschule Nordwestschweiz [Windisch] (FHNW), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, University of Belgrade [Belgrade], Mullard Space Science Laboratory (MSSL), University College of London [London] (UCL), Universidad de Alcalá - University of Alcalá (UAH), Institute of Experimental and Applied Physics [Kiel] (IEAP), Christian-Albrechts-Universität zu Kiel (CAU), European Space Astronomy Centre (ESAC), European Space Agency (ESA), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Radboud University [Nijmegen], Université Paul-Valéry - Montpellier 3 (UPVM)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro - Montpellier SupAgro, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Université de Rennes (UR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and Agence Spatiale Européenne = European Space Agency (ESA)
Subjects: Physics, 010308 nuclear & particles physics, Astronomy, Astronomy and Astrophysics, Astrophysics, Plasma, 01 natural sciences, law.invention, instrumentation: miscellaneous, Solar wind, Orbiter, solar wind, Space and Planetary Science, law, 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, addenda, ComputingMilieux_MISCELLANEOUS, errata
Abstract: Contains fulltext : 239392.pdf (Publisher’s version ) (Open Access)
Published: 2021

23. Non‐Maxwellianity of Electron Distributions Near Earth's Magnetopause

Author: Mats André, William H. Matthaeus, Andris Vaivads, Daniel B. Graham, Yuri V. Khotyaintsev, Alessandro Retinò, Alexandros Chasapis, Daniel J. Gershman, Francesco Valentini, Swedish Institute of Space Physics [Uppsala] (IRF), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, Thermodynamic equilibrium, Astrophysics::High Energy Astrophysical Phenomena, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Magnetosphere, FOS: Physical sciences, Electron, 01 natural sciences, Fusion, plasma och rymdfysik, Magnetosheath, Physics - Space Physics, Astronomi, astrofysik och kosmologi, Physics::Plasma Physics, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astronomy, Astrophysics and Cosmology, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Physics, Geofysik, electron distributions, turbulence, Plasma, plasma instabilities, Fusion, Plasma and Space Physics, Physics - Plasma Physics, Space Physics (physics.space-ph), Computational physics, Plasma Physics (physics.plasm-ph), Solar wind, Geophysics, Space and Planetary Science, 13. Climate action, Physics::Space Physics, Magnetopause, Particle, Astrophysics::Earth and Planetary Astrophysics
Abstract: Plasmas in Earth's outer magnetosphere, magnetosheath, and solar wind are essentially collisionless. This means particle distributions are not typically in thermodynamic equilibrium and deviate significantly from Maxwellian distributions. The deviations of these distributions can be further enhanced by plasma processes, such as shocks, turbulence, and magnetic reconnection. Such distributions can be unstable to a wide variety of kinetic plasma instabilities, which in turn modify the electron distributions. In this paper the deviations of the observed electron distributions from a bi-Maxwellian distribution function is calculated and quantified using data from the Magnetospheric Multiscale (MMS) spacecraft. A statistical study from tens of millions of electron distributions shows that the primary source of the observed non-Maxwellianity are electron distributions consisting of distinct hot and cold components in Earth's low-density magnetosphere. This results in large non-Maxwellianities in at low densities. However, after performing a stastical study we find regions where large non-Maxwellianities are observed for a given density. Highly non-Maxwellian distributions are routinely found are Earth's bowshock, in Earth's outer magnetosphere, and in the electron diffusion regions of magnetic reconnection. Enhanced non-Maxwellianities are observed in the turbulent magnetosheath, but are intermittent and are not correlated with local processes. The causes of enhanced non-Maxwellianities are investigated.
Published: 2021

24. Downstream Super-magnetosonic Plasma Jet Generation as a Direct Consequence of Shock Reformation

Author: P. A. Lindqvist, Craig J. Pollock, Andreas Johlander, Tomas Karlsson, Henriette Trollvik, Savvas Raptis, Andris Vaivads, and Ferdinand Plaschke
Subjects: Physics, Downstream (manufacturing), Physics::Plasma Physics, Astrophysics::High Energy Astrophysical Phenomena, Physics::Space Physics, Plasma jet, Direct consequence, Mechanics, Astrophysics::Galaxy Astrophysics, Shock (mechanics)
Abstract: Earth's bow shock, resulting from the interaction of the super-magnetosonic solar wind and Earth's magnetic field, has been studied for over 50 years and serves as an ideal astrophysical laboratory to study collisionless shocks. The Earth's bow shock offers a unique opportunity to study it through in-situ measurements. Shocks are one of nature's most powerful particle accelerators and have been connected to relativistic electron acceleration and cosmic rays. Upstream shock observations include wave generation, wave-particle interactions and SLAMS, while at the shock and downstream, particle acceleration, magnetic reconnection and plasma jets can be observed. Here, using Magnetospheric Multiscale (MMS) we show the first in-situ evidence of super-magnetosonic downstream flows (jets) generated at the Earth’s bow shock as a direct consequence of shock reformation. Jets are observed downstream due to a combined effect of upstream plasma wave evolution and an ongoing reformation cycle of the bow shock. This generation process can also be applicable to planetary and astrophysical plasmas where collisionless shocks are commonly found.
Published: 2021

25. Upper‐Hybrid Waves Driven by Meandering Electrons Around Magnetic Reconnection X Line

Author: Daniel J. Gershman, Cunguo Wang, Wangping Li, Binbin Tang, Benoit Lavraud, Christopher T. Russell, James L. Burch, Cecilia Norgren, Daniel B. Graham, P. A. Lindqvist, Ari Le, Yu. V. Khotyaintsev, Andris Vaivads, Roy B. Torbert, Quanming Lu, Stephen A. Fuselier, Kyunghwan Dokgo, Jan Egedal, Mats André, Jin He, Xiaocheng Guo, Robert E. Ergun, Ferdinand Plaschke, Keizo Fujimoto, Barbara L. Giles, O. Le Contel, State Key Laboratory of Space Weather [Beijing] (SKSW), National Space Science Center [Beijing] (NSSC), Chinese Academy of Sciences [Beijing] (CAS)-Chinese Academy of Sciences [Beijing] (CAS), Swedish Institute of Space Physics [Uppsala] (IRF), Department of Physics and Technology [Bergen] (UiB), University of Bergen (UiB), Royal Institute of Technology [Stockholm] (KTH ), Los Alamos National Laboratory (LANL), Department of Physics, University of Wisconsin—Milwaukee, P.O. Box 413, Milwaukee, Wisconsin 53201, Southwest Research Institute [San Antonio] (SwRI), School of Space and Environment [Beijing], Beihang University (BUAA), School of Earth and Space Sciences [Beijing], Peking University [Beijing], Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], University of New Hampshire (UNH), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), NASA Goddard Space Flight Center (GSFC), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut für Weltraumforschung = Space Research institute [Graz] (IWF), Osterreichische Akademie der Wissenschaften (ÖAW), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California (UC)-University of California (UC), CAS Key Laboratory of Geospace Environment, University of Science and Technology of China [Hefei] (USTC), State Key Laboratory for Space Weather [Beijing] (SKSW), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Institut für Weltraumforschung [Graz] (IWF), and University of California-University of California
Subjects: Physics, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Magnetic reconnection, Electron, 01 natural sciences, Computational physics, Geophysics, 0103 physical sciences, General Earth and Planetary Sciences, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Line (formation)
Abstract: International audience
Published: 2021

26. Ion Acceleration Efficiency at the Earth's Bow Shock : Observations and Simulation Results

Author: Minna Palmroth, Maxime Grandin, Damiano Caprioli, Maxime Dubart, Andris Vaivads, Andreas Johlander, Markus Battarbee, Yann Pfau-Kempf, S. J. Schwartz, Lucile Turc, Barbara L. Giles, Yu. V. Khotyaintsev, Colby Haggerty, Urs Ganse, Space Physics Research Group, Particle Physics and Astrophysics, and Department of Physics
Subjects: Physics, 010504 meteorology & atmospheric sciences, Astrophysics::High Energy Astrophysical Phenomena, ENERGETIC IONS, Astronomy and Astrophysics, Mechanics, FORESHOCK, Ion acceleration, UPSTREAM, MAGNETOSHEATH, 7. Clean energy, 01 natural sciences, 114 Physical sciences, 13. Climate action, Space and Planetary Science, Physics::Plasma Physics, 0103 physical sciences, Physics::Space Physics, Bow shock (aerodynamics), 010303 astronomy & astrophysics, Earth (classical element), 0105 earth and related environmental sciences
Abstract: Collisionless shocks are some of the most efficient particle accelerators in heliospheric and astrophysical plasmas. Here we study and quantify ion acceleration at Earth's bow shock with observations from NASA's Magnetospheric Multiscale (MMS) satellites and in a global hybrid-Vlasov simulation. From the MMS observations, we find that quasiparallel shocks are more efficient at accelerating ions. There, up to 15% of the available energy goes into accelerating ions above 10 times their initial energy. Above a shock-normal angle of similar to 50 degrees, essentially no energetic ions are observed downstream of the shock. We find that ion acceleration efficiency is significantly lower when the shock has a low Mach number (M ( A ) < 6) while there is little Mach number dependence for higher values. We also find that ion acceleration is lower on the flanks of the bow shock than at the subsolar point regardless of the Mach number. The observations show that a higher connection time of an upstream field line leads to somewhat higher acceleration efficiency. To complement the observations, we perform a global hybrid-Vlasov simulation with realistic solar-wind parameters with the shape and size of the bow shock. We find that the ion acceleration efficiency in the simulation shows good quantitative agreement with the MMS observations. With the combined approach of direct spacecraft observations, we quantify ion acceleration in a wide range of shock angles and Mach numbers.
Published: 2021

27. Ion‐Beam‐Driven Intense Electrostatic Solitary Waves in Reconnection Jet

Author: Andreas Johlander, Mats André, Andris Vaivads, C. M. Liu, Barbara L. Giles, Huishan Fu, Yuri V. Khotyaintsev, Daniel B. Graham, Particle Physics and Astrophysics, Department of Physics, and Space Physics Research Group
Subjects: 010504 meteorology & atmospheric sciences, Ion beam, ENERGY-CONVERSION, SEPARATRIX REGION, ACCELERATION, 114 Physical sciences, 01 natural sciences, Observational evidence, Acceleration, ROLLING-PIN DISTRIBUTION, Physics::Plasma Physics, 0103 physical sciences, Energy transformation, Anisotropy, wave-particle interations, 010303 astronomy & astrophysics, ion beam instability, 0105 earth and related environmental sciences, ANISOTROPY, TAIL, electrostatic solitary waves, Physics, Jet (fluid), DIPOLARIZATION FRONTS, ion heating, reconnection jet, BURSTY BULK FLOWS, Computational physics, PARTICLE ENERGIZATION, Geophysics, 13. Climate action, Physics::Space Physics, ONSET, dipolarization front, General Earth and Planetary Sciences
Abstract: Electrostatic solitary waves (ESWs) have been reported inside reconnection jets, but their source and role remain unclear hitherto. Here we present the first observational evidence of ESWs generation by cold ion beams inside the jet, by using high-cadence measurements from the Magnetospheric Multiscale spacecraft in the Earth's magnetotail. Inside the jet, intense ESWs with amplitude up to 30 mV m(-1) and potential up to similar to 7% of the electron temperature are observed in association with accelerated cold ion beams. Instability analysis shows that the ion beams are unstable, providing free energy for the ESWs. The waves are observed to thermalize the beams, thus providing a new channel for ion heating inside the jet. Our study suggests that electrostatic turbulence can play an important role in the jet dynamics.
Published: 2019

28. Can Reconnection be Triggered as a Solar Wind Directional Discontinuity Crosses the Bow Shock? A Case of Asymmetric Reconnection

Author: Timo Pitkänen, Maria Hamrin, Barbara L. Giles, Roy B. Torbert, J. Mukherjee, Oleksandr Goncharov, Herbert Gunell, A. De Spiegeleer, S. A. Fuselier, and Andris Vaivads
Subjects: Physics, 010504 meteorology & atmospheric sciences, Astrophysics::High Energy Astrophysical Phenomena, Geophysics, 01 natural sciences, Solar wind, Discontinuity (geotechnical engineering), Space and Planetary Science, Physics::Space Physics, Bow shock (aerodynamics), Interplanetary spaceflight, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences
Abstract: Here we present some unique observations of reconnection at a quasi-perpendicular bow shock as an interplanetary directional discontinuity (DD) is crossing it simultaneously with the Magnetospheric ...
Published: 2019

29. Evidence of Magnetic Nulls in Electron Diffusion Region

Author: Zulin Wang, Andris Vaivads, James L. Burch, Yuri V. Khotyaintsev, Huishan Fu, Shiyong Huang, J. B. Cao, and D. Cao
Subjects: Physics, 010504 meteorology & atmospheric sciences, Solar flare, Astrophysics::High Energy Astrophysical Phenomena, Null (mathematics), Magnetic reconnection, Electron, 010502 geochemistry & geophysics, 01 natural sciences, Computational physics, Geophysics, Physics::Space Physics, Astrophysics::Solar and Stellar Astrophysics, General Earth and Planetary Sciences, Astrophysics::Earth and Planetary Astrophysics, Diffusion (business), 0105 earth and related environmental sciences
Abstract: Theoretically, magnetic reconnection—the process responsible for solar flares and magnetospheric substorms—occurs at the X‐line or radial null in the electron diffusion region (EDR). However, wheth ...
Published: 2019

30. Cluster observations of energetic electron acceleration within earthward reconnection jet and associated magnetic flux rope

Author: Yu. V. Khotyaintsev, Elena A. Kronberg, Alessandro Retinò, Huimin Fu, Andris Vaivads, Patrick W. Daly, Royal Institute of Technology [Stockholm] (KTH ), Swedish Institute of Space Physics [Uppsala] (IRF), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, Astrophysics::High Energy Astrophysical Phenomena, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astrophysics, 01 natural sciences, 7. Clean energy, 010305 fluids & plasmas, Fusion, plasma och rymdfysik, Electron acceleration, Astronomi, astrofysik och kosmologi, 0103 physical sciences, Cluster (physics), Astronomy, Astrophysics and Cosmology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Physics, Jet (fluid), energetic electrons, Magnetic reconnection, Fusion, Plasma and Space Physics, Magnetic flux, Geophysics, Space and Planetary Science, magnetic flux rope, magnetic reconnection, Physics::Space Physics, Physics::Accelerator Physics, Rope
Abstract: We study acceleration of energetic electrons in an earthward plasma jet due to magnetic reconnection in the Earth magnetotail for one case observed by Cluster. The case has been selected based on the presence of high fluxes of energetic electrons, Cluster being in the burst mode and Cluster separation being around 1,000 km that is optimal for studies of ion scale physics. We show that two characteristic acceleration mechanisms are operating during this event. First, significant acceleration is achieved inside the magnetic flux pile-up of the jet, the acceleration mechanism being consistent with betatron acceleration. Second, strong energetic electron acceleration occurs in magnetic flux rope like structure forming in front of the magnetic flux pile-up region. Energetic electrons inside the magnetic flux rope are accelerated predominantly in the field-aligned direction and the acceleration can be due to Fermi acceleration in a contracting flux rope.
Published: 2021

31. Solar Orbiter/Radio and Plasma Wave observations during the first Venus flyby

Author: Yuri V. Khotyaintsev, Antonio Vecchio, Niklas J. T. Edberg, Timothy S. Horbury, Matthieu Kretzschmar, Lina Hadid, Thomas Chust, Štěpán Štverák, V. Krasnoselskikh, Jan Soucek, M. Steller, Dirk Plettemeier, Stuart D. Bale, Andris Vaivads, E. Lorfèvre, Milan Maksimovic, Pavel M. Trávníček, Swedish Institute of Space Physics [Uppsala] (IRF), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), University of California, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Centre National d'Études Spatiales [Toulouse] (CNES), Technische Universität Dresden = Dresden University of Technology (TU Dresden), Czech Academy of Sciences [Prague] (CAS), Austrian Academy of Sciences (OeAW), Royal Institute of Technology [Stockholm] (KTH ), Radboud university [Nijmegen], and Imperial College London
Subjects: Physics, Orbiter, biology, law, Waves in plasmas, Physics::Space Physics, Astronomy, Venus, Astrophysics::Earth and Planetary Astrophysics, biology.organism_classification, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 7. Clean energy, law.invention
Abstract: We present measurements from the Radio and Plasma Wave (RPW) instrument suite onboard the Solar Orbiter mission during the first Venus encounter. RPW consists of several units and is capable of measuring both the electric and magnetic field fluctuations with three electric antennas and a search-coil magnetometer: The Low Frequency Receiver (LFR) cover the range from DC up to 10kHz when measuring the electric and magnetic waveform and spectra; the Thermal Noise and High Frequency Receiver (TNR-HFR) determines the electric power spectra and magnetic power spectra from 4kHz-20MHz, and 4kHz to 500kHz, respectively, to determine properties of the electron population; the Time Domain Sampler (TDS) measures and digitizes onboard the electric and magnetic field waveforms from 100 Hz to 250 kHz. The BIAS subunit measures DC and LF electric fields as well as the spacecraft potential, which gives a high cadence measure of the local plasma density when calibrated to the low-cadence tracking of the plasma peak from the TNR. Solar Orbiter approached Venus from the induced magnetotail and had its closest approach at an altitude of 7500 km over the north pole of Venus on 27 Dec 2020. The RPW instruments observed a tail region that extended several 10’s of Venus radii downstream of the planet. The induced magnetosphere was characterized to be a highly dynamic environment as Solar Orbiter traversed the downstream tail and magnetosheath before it crossed the Bow Shock outbound at ~12:40 UT. Polarized whistler waves, high frequency electrostatic waves, narrow-banded emissions, possible electron double layers were observed. The fine structure of the bow shock could also be investigated in detail. Solar Orbiter could hence enhance the knowledge of the structure of the solar wind-Venus interaction.
Published: 2021

32. Impact induced electric field signals observed by the Solar Orbiter/RPW

Author: Stuart D. Bale, Thomas Chust, Dirk Plettemeier, Milan Maksimovic, Matthieu Kretzschmar, M. Steller, Niklas J. T. Edberg, Antonio Vecchio, Michiko Morooka, Anders Eriksson, Štěpán Štverák, Jan Soucek, Erik M. J. Johansson, Andris Vaivads, Yuri V. Khotyaintsev, V. Krasnoselskikh, Pavel M. Trávníček, E. Lorfèvre, Swedish Institute of Space Physics [Uppsala] (IRF), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), University of California, Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université d'Orléans (UO), Centre National d'Études Spatiales [Toulouse] (CNES), Technische Universität Dresden = Dresden University of Technology (TU Dresden), Czech Academy of Sciences [Prague] (CAS), Austrian Academy of Sciences (OeAW), Royal Institute of Technology [Stockholm] (KTH ), and Radboud university [Nijmegen]
Subjects: Physics, Orbiter, Optics, law, business.industry, [SDU]Sciences of the Universe [physics], Electric field, Physics::Space Physics, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, business, law.invention
Abstract: A large-amplitude impact-induced like electric field signal is often observed by the Radio and Plasma Wave (RPW) Instrument onboard Solar Orbiter. The signal has a sharp increase followed by an exponential decay, typically observed when spacecraft experiences a dust impact. The amplitude can reach several V/m. The impact dust size can be estimated from the electric field amplitude and is similar to the characteristic dust size near the sun expected from the zodiacal-light observations. On the other hand, the signal's decay time is the order of second, unusually long compared to the dust impact signals previously reported by the other spacecraft. We will show the characteristics of these signals and discuss the origin.
Published: 2021

33. DMSP Observations of High‐Latitude Dayside Aurora (HiLDA)

Author: Yongliang Zhang, Andris Vaivads, Anita Kullen, Lei Cai, and Tomas Karlsson
Subjects: Physics, Geophysics, Space and Planetary Science, High latitude, Atmospheric sciences
Published: 2021

34. Structure of a Perturbed Magnetic Reconnection Electron Diffusion Region in the Earth's Magnetotail

Author: Andris Vaivads, Rumi Nakamura, James L. Burch, S. A. Fuselier, Christopher T. Russell, Jan Egedal, Mats André, Daniel B. Graham, Yu. V. Khotyaintsev, Alexandra Alexandrova, G. Cozzani, and O. Le Contel
Subjects: Physics, Current sheet, Plane (geometry), Physics::Space Physics, General Physics and Astronomy, Magnetic reconnection, Electron, Current (fluid), Diffusion (business), Lower hybrid oscillation, Magnetic field, Computational physics
Abstract: We report in situ observations of an electron diffusion region (EDR) and adjacent separatrix region in the Earth's magnetotail. We observe significant magnetic field oscillations near the lower hybrid frequency which propagate perpendicularly to the reconnection plane. We also find that the strong electron-scale gradients close to the EDR exhibit significant oscillations at a similar frequency. Such oscillations are not expected for a crossing of a steady 2D EDR, and can be explained by a complex motion of the reconnection plane induced by current sheet kinking propagating in the out-of-reconnection-plane direction. Thus, all three spatial dimensions have to be taken into account to explain the observed perturbed EDR crossing. These results shed light on the interplay between magnetic reconnection and current sheet drift instabilities in electron-scale current sheets and highlight the need for adopting a 3D description of the EDR, going beyond the two-dimensional and steady-state conception of reconnection.
Published: 2021

35. Large Amplitude Electrostatic Proton Plasma Frequency Waves in the Magnetospheric Separatrix and Outflow Regions During Magnetic Reconnection

Author: Daniel B. Graham, Andris Vaivads, Yuri V. Khotyaintsev, Christopher T. Russell, Mats André, and Konrad Steinvall
Subjects: Physics, 010504 meteorology & atmospheric sciences, Proton, Separatrix, Astrophysics::High Energy Astrophysical Phenomena, Magnetic reconnection, 010502 geochemistry & geophysics, Plasma oscillation, 01 natural sciences, Computational physics, Geophysics, Amplitude, Physics::Plasma Physics, Physics::Space Physics, Astrophysics::Solar and Stellar Astrophysics, General Earth and Planetary Sciences, Magnetopause, Outflow, 0105 earth and related environmental sciences
Abstract: We report Magnetospheric Multiscale observations of large amplitude, parallel, electrostatic, proton plasma frequency waves on the magnetospheric side of the reconnecting magnetopause. The waves ar...
Published: 2021

36. Solar Orbiter observations of solar wind current sheets and their deHoffman-Teller frames

Author: Yuri V. Khotyaintsev, Christopher J. Owen, Andris Vaivads, Philippe Louarn, Giulia Cozzani, A. Fedorov, and Konrad Steinvall
Subjects: Orbiter, Solar wind, law, business.industry, Physics::Space Physics, Astrophysics::Solar and Stellar Astrophysics, Environmental science, Astrophysics::Earth and Planetary Astrophysics, Aerospace engineering, Current (fluid), business, law.invention
Abstract: Solar wind current sheets have been extensively studied at 1 AU. The recent advent of Parker Solar Probe and Solar Orbiter (SolO) has enabled us to study these structures at a range of heliocentric distances.We present SolO observations of current sheets in the solar wind at heliocentric distances between 0.55 and 0.85 AU, some of which show signatures of ongoing magnetic reconnection. We develop a method to find the deHoffman-Teller frame which minimizes the Y-component (the component tangential to the spacecraft orbit) of the electric field. Using the electric field measurements from RPW and magnetic field measurements from MAG, we use our method to determine the deHoffman-Teller frame of solar wind current sheets. The same method can also be used on the Alfvénic turbulence and structures found in the solar wind to obtain a measure of the solar wind velocity.Our preliminary results show a good agreement between our modified deHoffmann-Teller analysis based on the single component E-field, and the conventional deHoffman-Teller analysis based on 3D plasma velocity measurements from PAS. This opens up the possibility to use the RPW and MAG data to obtain an estimate of the solar wind velocity when particle data is unavailable.
Published: 2021

37. Thin current sheets and the associated wave activity observed by Solar Orbiter

Author: Daniel B. Graham, Anders Eriksson, Milan Maksimovic, Thomas Chust, Yuri V. Khotyaintsev, Erik M. J. Johansson, Niklas J. T. Edberg, Konrad Steinvall, Matthieu Kretzschmar, Andris Vaivads, Swedish Institute of Space Physics [Uppsala] (IRF), Royal Institute of Technology [Stockholm] (KTH ), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES)
Subjects: [PHYS]Physics [physics], Orbiter, Optics, Materials science, 13. Climate action, business.industry, law, Physics::Space Physics, Current (fluid), business, law.invention
Abstract: Thin current sheets are routinely observed in the solar wind. Here we report observations of thin current sheets and the associated plasma waves using the Solar Orbiter spacecraft. The Radio and Plasma Waves (RPW) instrument provides high-resolution measurements of the electric field, number density perturbations, and magnetic field fluctuations, which we use to identify and characterise the observed waves, while the magnetic field provided by the MAG instrument is used to characterise the current sheets. We discuss the role of current sheets in the generation of the observed waves and the effects of the waves on the current sheets.
Published: 2021

38. Dayside ionospheric electrodynamics in association with high-latitude dayside aurora (HiLDA)

Author: Andris Vaivads, Lei Cai, Yongliang Zhang, Tomas Karlson, and Anita Kullen
Subjects: Physics, High latitude, Astronomy, Ionosphere
Abstract: The Defense Meteorological Satellite Program (DMSP) Special Sensor Ultraviolet Spectrographic Imager (SSUSI) has observed the large-scale high-latitude dayside aurora (HiLDA) during its long lifetime of hours. HiLDA has dynamical changes in form, size, location, and development of fine structures. However, the associated electrodynamics is not fully understood. In general, HiLDA occurs in the dayside polar cap during IMF By+ (By-) prevailing conditions in the sunlit northern (southern) hemisphere. The prevailing conditions drive strong upward field-aligned current in the polar cap. Within the upward field-aligned current region, the field-aligned potential drop can be set up and accelerate the electrons, forming the monoenergetic electron precipitation (up to 10s keV) and producing HiLDA. This study investigates the ionospheric flows, currents, and auroral precipitation in association with HiLDA, benified from the simultaneous measurements from the DMSP satellites, the AMPERE project, and ground-based magnetometers and SuperDARN coherent radars. We will show HiLDA interacts with duskside oval-aligned arcs or transpolar arcs. The interactions are associated with the cusp and the dayside reconnection at the duskside flank/high latitudes. The reconnection produces strong dusk-dawn convection with flow shears in the polar cap, which generates the upward Region 0 current. We find that HiLDA is formed in the high-latitude part of the upward Region 0 current. We apply the Knight relation and identify the lobe electrons (< 0.3 cm-3) as the source of HiLDA. The fine structures revealed in the emission intensity of HiLDA may suggest the uneven distribution of the electron density in the high-latitude lobe.
Published: 2021

39. In situ evidence of ion acceleration between consecutive reconnection jet fronts

Author: Thomas E. Moore, Filomena Catapano, S. A. Fuselier, Yuri Khotyaintsev, Hugo Breuillard, Barry Mauk, Silvia Perri, Robert E. Ergun, Dominique Delcourt, Ian J. Cohen, Olivier Le Contel, Roy B. Torbert, Giulia Cozzani, Gaetano Zimbardo, Christopher Russell, Alessandro Retinò, Barbara L. Giles, James L. Burch, Drew Turner, Andris Vaivads, Alexandra Alexandrova, Per A. Lindqvist, Antonella Greco, L. Mirioni, Laboratoire de Physique des Plasmas (LPP), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Centre National de la Recherche Scientifique (CNRS), Observatoire de Paris, Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), and Swedish Institute of Space Physics [Uppsala] (IRF)
Subjects: 010504 meteorology & atmospheric sciences, Astrophysics::High Energy Astrophysical Phenomena, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, 01 natural sciences, Ion, Physics - Space Physics, Physics::Plasma Physics, 0103 physical sciences, Thermal, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Jet (fluid), Turbulence, Astronomy and Astrophysics, Plasma, Physics - Plasma Physics, Space Physics (physics.space-ph), [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], Magnetic field, Computational physics, Plasma Physics (physics.plasm-ph), Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Physics::Space Physics, Outflow, Magnetospheric Multiscale Mission, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: International audience; Processes driven by unsteady reconnection can efficiently accelerate particles in many astrophysical plasmas. An example is the reconnection jet fronts in an outflow region. We present evidence of suprathermal ion acceleration between two consecutive reconnection jet fronts observed by the Magnetospheric Multiscale mission in the terrestrial magnetotail. An earthward propagating jet is approached by a second faster jet. Between the jets, the thermal ions are mostly perpendicular to magnetic field, are trapped, and are gradually accelerated in the parallel direction up to 150 keV. Observations suggest that ions are predominantly accelerated by a Fermi-like mechanism in the contracting magnetic bottle formed between the two jet fronts. The ion acceleration mechanism is presumably efficient in other environments where jet fronts produced by variable rates of reconnection are common and where the interaction of multiple jet fronts can also develop a turbulent environment, e.g., in stellar and solar eruptions.
Published: 2021

40. Large amplitude electrostatic proton plasma frequency waves in the magnetospheric separatrix and outflow regions during magnetic reconnection

Author: Konrad Steinvall, Yuri V. Khotyaintsev, Daniel Bruce Graham, Andris Vaivads, Mats André, and Christopher T. Russell
Published: 2020

41. The Solar Orbiter Radio and Plasma Waves (RPW) instrument

Author: L. R. Malac-Allain, T. Dudok de Wit, E. Lorfèvre, C. Collin, J. Sanisidro, Mihailo M. Martinović, X. Bonnin, E. Guilhem, Milan Maksimovic, P. Leroy, A. Vecchio, Eduard P. Kontar, L. Uhlíř, N. Quéruel, H. Ottacher, K. Boughedada, Christopher Cully, G. Barbary, Pierre Astier, Anders Eriksson, L. Åhlén, O. Krupařová, B. Pontet, T. Chust, G. Jannet, J. Parisot, Mats André, Paul Turin, P. Plasson, F. Chapron, M. Steller, W. Recart, W. Puccio, Vladimir Krasnoselskikh, Robert F. Wimmer-Schweingruber, V. Bouzid, Laurent Lamy, V. Cripps, R. Lán, Keith Goetz, B. Katra, S. Chaintreuil, Gregory T. Delory, I. Fratter, Dirk Plettemeier, C. Fiachetti, V. Krupař, M. Chariet, Sonny Lion, M. Dekkali, Lars Bylander, F. Gonzalez, Jan Soucek, Christopher J. Owen, Mykhaylo Panchenko, P. Danto, David Pisa, T. Vincent, Y. de Conchy, Säm Krucker, G. Cassam-Chenai, S. Julien, Baptiste Cecconi, Olga Alexandrova, A. Retino, V. Leray, Karine Issautier, S. Thijs, E. P. G. Johansson, Filippo Pantellini, D. Bérard, J. Baše, L. Guéguen, R. Piberne, P. Fergeau, Matthieu Berthomier, Tomas Karlsson, Arnaud Zaslavsky, Quynh Nhu Nguyen, J.-Y. Brochot, E. Bellouard, Yu. V. Khotyaintsev, Lorenzo Matteini, Štěpán Štverák, Javier Rodriguez-Pacheco, Fouad Sahraoui, S.-E. Jansson, O. Le Contel, Timothy S. Horbury, J.-C. Pellion, Pavel M. Trávníček, A. Jeandet, C. Agrapart, Petr Hellinger, Ondrej Santolik, I. Zouganelis, C. Laffaye, M. Timofeeva, D. Dias, Philippe Louarn, Helmut O. Rucker, Stuart D. Bale, Ivana Kolmasova, J. Břínek, Matthieu Kretzschmar, Andris Vaivads, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Swedish Institute of Space Physics [Uppsala] (IRF), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Technische Universität Dresden = Dresden University of Technology (TU Dresden), Institute of Computing [Campinas] (IC), Universidade Estadual de Campinas = University of Campinas (UNICAMP), Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS), Centre d'Investigation Clinique [CHU Clermont-Ferrand] (CIC 1405), Institut National de la Santé et de la Recherche Médicale (INSERM)-Direction de la recherche clinique et de l’innovation [CHU Clermont-Ferrand] (DRCI), CHU Clermont-Ferrand-CHU Clermont-Ferrand, Department of Physics [Imperial College London], Imperial College London, Laboratoire Structures, Propriétés et Modélisation des solides (SPMS), Institut de Chimie du CNRS (INC)-CentraleSupélec-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Hasselt University (UHasselt), Centre National d'Études Spatiales [Toulouse] (CNES), Centre National d’Etudes Spatiales, Centre National d’Études Spatiales [Paris] (CNES), Laboratoire de physique et chimie de l'environnement (LPCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), DIREN RHONE ALPES LYON FRA, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), International Agency for Research on Cancer (IARC), Institute of Genetics and Molecular Medicine, University of Edinburgh, Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier), Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Institute of Atmospheric Physics [Prague] (IAP), Czech Academy of Sciences [Prague] (CAS), NASA Goddard Space Flight Center (GSFC), Universities Space Research Association (USRA), Jiangsu University of Science and Technology (JUST), Universidade Estadual Paulista Júlio de Mesquita Filho = São Paulo State University (UNESP), Alfven Laboratory, Royal Institute of Technology [Stockholm] (KTH ), Department of Plant Physiology, Umeå University, Umea Plant Science Centre, Umeå University-Umeå University, Swedish University of Agricultural Sciences (SLU), Department of Space and Plasma Physics [Stockholm], KTH School of Electrical Engineering, Royal Institute of Technology [Stockholm] (KTH )-Royal Institute of Technology [Stockholm] (KTH ), Swedish Institute of Space Physics [Kiruna] (IRF), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institute of Computing [Campinas] (UNICAMP), Universidade Estadual de Campinas (UNICAMP), Université d'Orléans (UO)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), University of California [Berkeley], University of California-University of California, Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), and European Space Agency (European Space Agency) (ESA)
Subjects: 010504 meteorology & atmospheric sciences, Astronomy, Astrophysics, Plasma oscillation, 01 natural sciences, law.invention, Orbiter, Astronomi, astrofysik och kosmologi, law, 0103 physical sciences, Astronomy, Astrophysics and Cosmology, Aerospace engineering, 010303 astronomy & astrophysics, miscellaneous [instrumentation], 0105 earth and related environmental sciences, Physics, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Plasma, Solar radio, instrumentation: miscellaneous, Solar wind, solar wind, Space and Planetary Science, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, Interplanetary spaceflight, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: The Radio and Plasma Waves (RPW) instrument on the ESA Solar Orbiter mission is described in this paper. This instrument is designed to measure in-situ magnetic and electric fields and waves from the continuous to a few hundreds of kHz. RPW will also observe solar radio emissions up to 16 MHz. The RPW instrument is of primary importance to the Solar Orbiter mission and science requirements since it is essential to answer three of the four mission overarching science objectives. In addition RPW will exchange on-board data with the other in-situ instruments in order to process algorithms for interplanetary shocks and type III langmuir waves detections. Correction in: Astronomy & Astrophysics, Volume 654, Article Number C2, DOI 10.1051/0004-6361/201936214e
Published: 2020

42. The Solar Orbiter Science Activity Plan: Translating solar and heliospheric physics questions into action

Author: Jack Jenkins, A. Vecchio, Georgios Nicolaou, Robert T. Wicks, Sarah A. Matthews, Matthieu Berthomier, T. Chust, Johann Hirzberger, L. Dolla, R. Carr, Spiros Patsourakos, O. Alexandrova, R. De Marco, V. Da Deppo, Angelos Vourlidas, Vincent Génot, Martin M. Roth, Alessandro Bemporad, Eduard P. Kontar, Susan T. Lepri, Lucie M. Green, Pedro Osuna, Jon A. Linker, Sergio Toledo-Redondo, D. Orozco Suárez, Denise Perrone, I. Carrasco-Blazquez, Manolis K. Georgoulis, Achim Gandorfer, Hardi Peter, Daniele Spadaro, Dirk Plettemeier, N. J. Fox, Luciano Rodriguez, Olga Malandraki, Andrei Zhukov, Teresa Nieves-Chinchilla, A. Giunta, Natasha L. S. Jeffrey, L. Etesi, Karine Bocchialini, Davina Innes, Kévin Dalmasse, Jim M. Raines, Jesper Schou, J. C. del Toro Iniesta, Jonathan Eastwood, Lucia Abbo, P. Rochus, T. Dudok de Wit, T. Appourchaux, Stuart D. Bale, C. Watson, Milan Maksimovic, F. Espinosa Lara, Sami K. Solanki, Paulett C. Liewer, Matthieu Kretzschmar, Vincenzo Andretta, L. R. Bellot Rubio, C. Plainaki, C. Terasa, V. Martinez-Pillet, C. Gontikakis, Säm Krucker, S. Parenti, David Long, I. Zouganelis, Silvano Fineschi, Gary Graham, Sophie Musset, Daniel Müller, L. Sanchez, Robert F. Wimmer-Schweingruber, Lakshmi Pradeep Chitta, Xavier Bonnin, Hamish A. S. Reid, Stefano Livi, Thomas Wiegelmann, Andreas Lagg, N. Vilmer, David Berghmans, D. Fontaine, Arnaud Masson, Francesco Valentini, Fernando Carcaboso, Laurence Rezeau, Luca Sorriso-Valvo, I. Cernuda Cangas, David R. Williams, Shane A. Maloney, M. Haberreiter, Miho Janvier, Andrei Fedorov, Luca Teriaca, Timothy S. Horbury, Philippe Louarn, Benoit Lavraud, Christopher J. Owen, Donald M. Hassler, Georgia Tsiropoula, Etienne Pariat, L. van Driel-Gesztelyi, Athanasios Papaioannou, Nicole Meyer-Vernet, Daniel Verscharen, D. N. Baker, Federico Landini, Cis Verbeeck, S. Gissot, Louise K. Harra, L. Rodriguez-Garcia, Andrea Verdini, Baptiste Cecconi, Ioannis Kontogiannis, C. N. Arge, Andrew Walsh, Richard Morton, Marco Romoli, Daniele Telloni, Lorenzo Matteini, Eric Buchlin, Fouad Sahraoui, Roberto Bruno, Christopher H. K. Chen, Radoslav Bučík, Nicolas Labrosse, J. Lefort, K. Moraitis, N. Janitzek, Gethyn R. Lewis, M. Steller, Kostas Tziotziou, Holly Gilbert, Angels Aran, F. Felix-Redondo, Mathew J. Owens, A. S. Brun, Alexander Nindos, Alexander W. James, K. Issautier, Laurent Gizon, N. E. Raouafi, B. Fleck, Javier Rodriguez-Pacheco, Alexis P. Rouillard, Raul Gomez-Herrero, George C. Ho, R. A. Howard, G. J. Hurford, Raffaella D'Amicis, F. Auchère, Helen O'Brien, Andrzej Fludra, J. Büchner, A. Tsounis, Roberto Susino, C. Krafft, Yu. V. Khotyaintsev, Udo Schühle, Štěpán Štverák, Mihailo M. Martinović, Maurizio Pancrazzi, Guillaume Aulanier, S. P. Plunkett, Marco Stangalini, Rui F. Pinto, A. De Groof, David Stansby, Jan Soucek, S. Dolei, Andris Vaivads, Marina Battaglia, Antoine Strugarek, Anastasios Anastasiadis, K.-L. Klein, Peter R. Young, Clementina Sasso, Marco Velli, V. Krasnoselskikh, A. Retino, T. Grundy, I. Leon, O. C. St. Cyr, Ester Antonucci, European Space Agency (European Space Agency) (ESA), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay-Sorbonne Université-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École polytechnique (X)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU), Centre National D'Etudes Spatiales (France), Agenzia Spaziale Italiana, Czech Grant Agency, National Aeronautics and Space Administration (US), Ministerio de Ciencia e Innovación (España), European Commission, Science and Technology Facilities Council (UK), and Science and Technology Facilities Council (STFC)
Subjects: Solar System, instruments [space vehicles], 010504 meteorology & atmospheric sciences, Astronomy, observational [methods], Astrophysics, 01 natural sciences, 7. Clean energy, law.invention, Methods: observational, law, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], general [Sun], Astrophysics::Solar and Stellar Astrophysics, Space vehicles: instruments, space vehicles: instruments, methods: observational, Sun: general, Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, MISSION, Physics, COORDINATION, INSTRUMENT, Astrophysics::Instrumentation and Methods for Astrophysics, Solar wind, Astrophysics - Solar and Stellar Astrophysics, Physics::Space Physics, Physical Sciences, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, PAYLOAD, Sun: general, astro-ph.SR, TELESCOPE, F300, FOS: Physical sciences, F500, Astronomy & Astrophysics, Computer Science::Digital Libraries, REGION, Orbiter, 0201 Astronomical and Space Sciences, 0103 physical sciences, Aerospace engineering, Solar dynamo, Instrumentation and Methods for Astrophysics (astro-ph.IM), Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences, Science & Technology, Spacecraft, business.industry, Ecliptic, Astronomy and Astrophysics, WIND, Physics::History of Physics, 13. Climate action, Space and Planetary Science, Orbit (dynamics), business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Heliosphere, astro-ph.IM
Abstract: All authors: Zouganelis, I.; De Groof, A.; Walsh, A. P.; Williams, D. R.; Müller, D.; St Cyr, O. C.; Auchère, F.; Berghmans, D.; Fludra, A.; Horbury, T. S.; Howard, R. A.; Krucker, S.; Maksimovic, M.; Owen, C. J.; Rodríguez-Pacheco, J.; Romoli, M.; Solanki, S. K.; Watson, C.; Sanchez, L.; Lefort, J.; Osuna, P.; Gilbert, H. R.; Nieves-Chinchilla, T.; Abbo, L.; Alexandrova, O.; Anastasiadis, A.; Andretta, V.; Antonucci, E.; Appourchaux, T.; Aran, A.; Arge, C. N.; Aulanier, G.; Baker, D.; Bale, S. D.; Battaglia, M.; Bellot Rubio, L.; Bemporad, A.; Berthomier, M.; Bocchialini, K.; Bonnin, X.; Brun, A. S.; Bruno, R.; Buchlin, E.; Büchner, J.; Bucik, R.; Carcaboso, F.; Carr, R.; Carrasco-Blázquez, I.; Cecconi, B.; Cernuda Cangas, I.; Chen, C. H. K.; Chitta, L. P.; Chust, T.; Dalmasse, K.; D'Amicis, R.; Da Deppo, V.; De Marco, R.; Dolei, S.; Dolla, L.; Dudok de Wit, T.; van Driel-Gesztelyi, L.; Eastwood, J. P.; Espinosa Lara, F.; Etesi, L.; Fedorov, A.; Félix-Redondo, F.; Fineschi, S.; Fleck, B.; Fontaine, D.; Fox, N. J.; Gandorfer, A.; Génot, V.; Georgoulis, M. K.; Gissot, S.; Giunta, A.; Gizon, L.; Gómez-Herrero, R.; Gontikakis, C.; Graham, G.; Green, L.; Grundy, T.; Haberreiter, M.; Harra, L. K.; Hassler, D. M.; Hirzberger, J.; Ho, G. C.; Hurford, G.; Innes, D.; Issautier, K.; James, A. W.; Janitzek, N.; Janvier, M.; Jeffrey, N.; Jenkins, J.; Khotyaintsev, Y.; Klein, K. -L.; Kontar, E. P.; Kontogiannis, I.; Krafft, C.; Krasnoselskikh, V.; Kretzschmar, M.; Labrosse, N.; Lagg, A.; Landini, F.; Lavraud, B.; Leon, I.; Lepri, S. T.; Lewis, G. R.; Liewer, P.; Linker, J.; Livi, S.; Long, D. M.; Louarn, P.; Malandraki, O.; Maloney, S.; Martinez-Pillet, V.; Martinovic, M.; Masson, A.; Matthews, S.; Matteini, L.; Meyer-Vernet, N.; Moraitis, K.; Morton, R. J.; Musset, S.; Nicolaou, G.; Nindos, A.; O'Brien, H.; Orozco Suarez, D.; Owens, M.; Pancrazzi, M.; Papaioannou, A.; Parenti, S.; Pariat, E.; Patsourakos, S.; Perrone, D.; Peter, H.; Pinto, R. F.; Plainaki, C.; Plettemeier, D.; Plunkett, S. P.; Raines, J. M.; Raouafi, N.; Reid, H.; Retino, A.; Rezeau, L.; Rochus, P.; Rodriguez, L.; Rodriguez-Garcia, L.; Roth, M.; Rouillard, A. P.; Sahraoui, F.; Sasso, C.; Schou, J.; Schühle, U.; Sorriso-Valvo, L.; Soucek, J.; Spadaro, D.; Stangalini, M.; Stansby, D.; Steller, M.; Strugarek, A.; Štverák, Š.; Susino, R.; Telloni, D.; Terasa, C.; Teriaca, L.; Toledo-Redondo, S.; del Toro Iniesta, J. C.; Tsiropoula, G.; Tsounis, A.; Tziotziou, K.; Valentini, F.; Vaivads, A.; Vecchio, A.; Velli, M.; Verbeeck, C.; Verdini, A.; Verscharen, D.; Vilmer, N.; Vourlidas, A.; Wicks, R.; Wimmer-Schweingruber, R. F.; Wiegelmann, T.; Young, P. R.; Zhukov, A. N., Solar Orbiter is the first space mission observing the solar plasma both in situ and remotely, from a close distance, in and out of the ecliptic. The ultimate goal is to understand how the Sun produces and controls the heliosphere, filling the Solar System and driving the planetary environments. With six remote-sensing and four in-situ instrument suites, the coordination and planning of the operations are essential to address the following four top-level science questions: (1) What drives the solar wind and where does the coronal magnetic field originate?; (2) How do solar transients drive heliospheric variability?; (3) How do solar eruptions produce energetic particle radiation that fills the heliosphere?; (4) How does the solar dynamo work and drive connections between the Sun and the heliosphere? Maximising the mission's science return requires considering the characteristics of each orbit, including the relative position of the spacecraft to Earth (affecting downlink rates), trajectory events (such as gravitational assist manoeuvres), and the phase of the solar activity cycle. Furthermore, since each orbit's science telemetry will be downloaded over the course of the following orbit, science operations must be planned at mission level, rather than at the level of individual orbits. It is important to explore the way in which those science questions are translated into an actual plan of observations that fits into the mission, thus ensuring that no opportunities are missed. First, the overarching goals are broken down into specific, answerable questions along with the required observations and the so-called Science Activity Plan (SAP) is developed to achieve this. The SAP groups objectives that require similar observations into Solar Orbiter Observing Plans, resulting in a strategic, top-level view of the optimal opportunities for science observations during the mission lifetime. This allows for all four mission goals to be addressed. In this paper, we introduce Solar Orbiter's SAP through a series of examples and the strategy being followed. © 2020 ESO., Solar Orbiter is a space mission of international collaboration between ESA and NASA with contributions from national agencies of ESA member states. The spacecraft has been developed by Airbus and is being operated by ESA from the European Space Operations Centre (ESOC) in Darmstadt, Germany. Science operations are carried out at ESA's European Space Astronomy Centre (ESAC) in Villafranca del Castillo, Spain. SWA is an international collaboration which has been funded by the UKSA, CNES, ASI, NASA and the Czech contribution to the ESA PRODEX programme. UAH authors want to thanks the Spanish MINECO-FPI-2016 predoctoral grant with FSE, and its project FEDER/MCIU-AEEI/Proyecto ESP2017-88436-R. The Spanish contribution to SO/PHI has been funded by the Spanish Ministry of Science and Innovation through several projects, the last one being RTI2018-096886-B-C5, and by "Centro de Excelencia Severo Ochoa" programme under grant SEV-2017-0709. RAH, RCC, DMM, SPP, and AV acknowledge the support of the NASA Heliophysics Division, Solar Orbiter Collaboration Office under IAT NNG09EK11I. JEP acknowledges grant UKRI/STFC ST/N000692/1. All French involvements are supported by CNES and CNRS. DV is supported by the STFC Ernest Rutherford Fellowship ST/P003826/1 and STFC Consolidated Grant ST/S000240/1. The authors thank the referee for her constructive comments and suggestions, which led to the substantial improvement of this paper.
Published: 2020

43. The RPW Low Frequency Receiver (LFR) on Solar Orbiter: in-situ LF electric and magnetic field measurements of the solar wind expansion

Author: Thomas Chust, Olivier Le Contel, Matthieu Berthomier, Alessandro Retinò, Fouad Sahraoui, Alexis Jeandet, Paul Leroy, Jean-Christophe Pellion, Bouzid, V., Bruno Katra, Rodrigue Piberne, Yuri Khotyaintsev, Andris Vaivads, Volodya Krasnoselskikh, Matthieu Kretzschmar, Jan Souček, Ondrej Santolík, Milan Maksimovic, Bale, Stuart D., Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire de Paris, Swedish Institute of Space Physics [Kiruna] (IRF), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Institute of Atmospheric Physics [Prague] (IAP), Czech Academy of Sciences [Prague] (CAS), Observatoire de Paris - Site de Paris (OP), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)
Subjects: [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], [SDU]Sciences of the Universe [physics], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2020

44. Reconnection site and ion scale turbulence generation

Author: Andris Vaivads, Daniel J. Gershman, Roy B. Torbert, Barbara L. Giles, Yuri V. Khotyaintsev, James L. Burch, C. M. Liu, Daniel B. Graham, Christopher T. Russell, Per-Arne Lindqvist, Olivier Le Contel, Swedish Institute of Space Physics [Uppsala] (IRF), Beihang University (BUAA), Royal Institute of Technology [Stockholm] (KTH ), University of New Hampshire (UNH), Southwest Research Institute [San Antonio] (SwRI), Institute of Geophysics and Planetary Physics [Los Angeles] (IGPP), University of California [Los Angeles] (UCLA), University of California-University of California, Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and NASA Goddard Space Flight Center (GSFC)
Subjects: Scale (ratio), Turbulence, Physics::Plasma Physics, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Physics::Space Physics, Environmental science, Mechanics, Ion
Abstract: We analyze in detail a reconnection site observed by the Magnetospheric Multiscale (MMS) mission in the magnetotail. The interval around the X-line is identified based on the ion jet reversal, Hall electric fields and other reconnection signatures. At the reconnection site strong electric fields with amplitudes above 100mV/m are observed. In addition, the region shows strong turbulent variations on ion scales, including magnetic island-like structures. We discuss the cause of strong electric fields, their relation to ion scale structures and associated particle acceleration in this region. Of particular interest is the relation of the reconnection site to the generation of kinetic Alfven waves.
Published: 2020

45. Electron Bernstein Waves driven by Electron Crescents near the Electron Diffusion Region

Author: Wenya Li, Daniel Graham, Binbin Tang, Andris Vaivads, Mats Andre, Kyungguk Min, Kaijun Liu, Keizo Fujimoto, Per Arne Lindqvist, Kyunghwan Dokgo, Chi Wang, and James Burch
Subjects: Physics::Plasma Physics, Physics::Space Physics
Abstract: The Magnetospheric Multiscale spacecraft encounter an electron diffusion region (EDR) of asymmetric magnetic reconnection at Earth's magnetopause. The EDR is characterized by agyrotropic electron velocity distributions on both sides of the neutral line. Various types of plasma waves are produced by the magnetic reconnection in and near the EDR. Here we report large-amplitude electron Bernstein waves (EBWs) at the electron-scale boundary of the Hall current reversal. The finite gyroradius effect of the outflow electrons generates the crescent-shaped agyrotropic electron distributions, which drive the EBWs. The EBWs propagate toward the central EDR. The amplitude of the EBWs is sufficiently large to thermalize and diffuse electrons around the EDR. Our analysis shows that the EBWs contribute to the cross-field diffusion of the electron-scale boundary of the Hall current reversal near the EDR.
Published: 2020

46. Initial in-flight performance results from Solar Orbiter RPW/BIAS

Author: Yuri V. Khotyaintsev, Andris Vaivads, Daniel B. Graham, Niklas J. T. Edberg, Erik P. G. Johansson, Milan Maksimovic, Stuart D. Bale, Thomas Chust, Matthieu Kretzschmar, and Jan Soucek
Abstract: The BIAS subsystem is a part of the Radio and Plasma Waves (RPW) instrument on the ESA Solar Orbiter mission. It allows sending bias current to each of the three RPW antennas. By setting the appropriate bias current the antenna potential can be shifted closer to the local plasma potential. This allows us to measure the floating potential of the spacecraft, as well as the electric field in the DC/LF frequency range with higher accuracy and lower noise level. Here we present the very initial results on RPW/BIAS in-flight performance based on the operations during the instrument commissioning.
Published: 2020

47. DMSP/SSUSI observations of the high-latitude dayside aurora (HiLDA

Author: Andris Vaivads, Anita Kullen, Tomas Karlsson, Yongliang Zhang, and Lei Cai
Subjects: High latitude, Atmospheric sciences, Geology
Abstract: High-latitude dayside aurora (HiLDA) are large-scale discrete arcs or spot-like aurora poleward of the cusp, observed previously in the northern hemisphere by the Viking UV imager [Murphree et al., 1990] and by the IMAGE FUV [Frey et al., 2003]. The particular interest on HiLDA is to understand its formation related to the dayside reconnection and the resulted field-aligned currents (FACs) configuration in the polar cap (open field line region). In addition, the occurrence of HiLDA in the southern hemisphere is not well known.In this study, we investigate the properties of HiLDA using DMSP/SSUSI images from the satellites F16, F17, F18, and F19. The combined data with auroral images from DMSP/SSUSI, ion drift velocity from SSIES, magnetic field perturbations from SSM, and energetic particle spectrum from SSJ make it possible to study the electrodynamics in the vicinity of the HiLDA and its connection the dayside cusp. HiLDA is formed due to monoenergetic electron precipitation (inverted-V structures) with the absence of ion precipitation. The field-aligned potential drop can be up to tens of keV. Applying the current-voltage relation, we suggest accelerated polar rain as the source of HiLDA, indirectly controlled by the solar wind/magnetosheath plasma population. The upward field-aligned current associated with the potential drop is a part of the cusp current system, produced by the dayside reconnection. Both lobe reconnection and reconnection on the duskside flanks play a role in the formation of HiLDA.The occurrence of HiLDA is highly associated with the sunlit hemisphere and IMF By dominated conditions. Our results agree with previous observations, which show that HiLDA occurs during positive By dominated conditions in the northern summer hemisphere. We also confirmed that HiLDA occurs during negative By dominated conditions in the southern hemisphere. In addition, the fine structures of HiLDA are studied.ReferencesMurphree, J. S., Elphinstone, R. D., Hearn, D., and Cogger, L. L. ( 1990), Large‐scale high‐latitude dayside auroral emissions, J. Geophys. Res., 95( A3), 2345– 2354, doi:.Frey, H. U., Immel, T. J., Lu, G., Bonnell, J., Fuselier, S. A., Mende, S. B., Hubert, B., Østgaard, N., and Le, G. ( 2003), Properties of localized, high latitude, dayside aurora, J. Geophys. Res., 108, 8008, doi:, A4.
Published: 2020

48. Effect of whistler precursor waves on energy dissipation in supercritical quasi-perpendicular collisionless shocks

Author: Ahmad Lalti, Yuri Khotyaintsev, Daniel Graham, Andris Vaivads, Andreas Johlander, Roy Torbert, Barbara Giles, Chris Russell, and Jim Burch
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Physics::Space Physics
Abstract: The process of transforming the bulk kinetic energy of solar wind into the random motion of the plasma particles is still an open question. One of the proposed mechanisms for energy dissipation in such shocks is wave-particle interactions. Specifically reflected ions at the foot of the shock could interact with the solar wind plasma in an unstable way causing an increase in the temperature of the upstream plasma. Phase standing Whistler precursor waves upstream of the shock front could play a major role in enhancing energy dissipation. We analyze multiple shock crossing events encountered by the Magnetospheric Multiscale (MMS) multi-spacecraft Mission, with Alfvenic Mach numbers around 4 and a θBn around 80 degrees. We use these events to study the effect of such waves on energy dissipation at quasi perpendicular shocks. Using spectral analysis and by calculating the poynting flux of the waves, we investigate the upstream shock energy transport by whistler waves, then we discuss the consequences of these results on the wave particle interaction as a mechanism for stabilizing such high Mach number shocks.
Published: 2020

49. The Icy Giants & Triton’s Ionospheres – lessons learned from Cassini observations within Saturn’s and Titan’s ionospheres

Author: Jan-Erik Wahlund, Michiko W. Morooka, David Andrews, Mats André, Jan Bergman, Niklas Edberg, Anders I. Eriksson, Lina Hadid, Yuri Khotyaintsev, Andris Vaivads, and Erik Vigren
Subjects: Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics
Abstract: We discuss the importance to determine the structure and composition of the upper atmospheres and ionospheres of the Icy Giants (Uranus & Neptune) as well as Triton’s ionosphere in the light of numerous recently obtained Cassini results. The ionizing radiation and charging environment within the upper atmospheres of Saturn and Titan creates a very complex organic chemistry leading to charged sub-nm-sized to 100 nm-sized aerosols. The charged dust has a profound effect on the ionospheric structure and related chemistry, enhancing the ion number density well above photochemical equilibrium levels, while the electrons tend to become attached to the dust population. The organic chemistry leads to compounds reaching above 50,000 amu diffusing downward and possibly creating a pre-biotic chemistry. This process, involving nitrogen, methane and water may very well be a more general process, also applicable for the cases of Uranus, Neptune and Triton, were all have these starting species abundant in their upper atmospheres. We therefore propose that a future mission to the Ice Giants and the moon Triton has Langmuir probe, electron spectrometer, dust, ion- and neutral mass spectrometers onboard to make detailed in-situ measurements on both the orbiter and atmospheric probe in order to investigate this fundamental chemistry and aerosol formation.
Published: 2020

50. Asymmetric reconnection at the bow shock

Author: Herbert Gunell, Maria Hamrin, Oleksandr Goncharov, Alexandre De Spiegeleer, Stephen Fuselier, Joey Mukherjee, and Andris Vaivads
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Physics::Space Physics, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: Can reconnection be triggered as a directional discontinuity (DD) crosses the bow shock? Here we present some unique observations of asymmetric reconnection at a quasi-perpendicular bow shock as an interplanetary DD is crossing it simultaneously with the Magnetospheric Multiscale (MMS) mission. The data show indications of ongoing reconnection at the bow shock southward of the spacecraft. The DD is also observed by several upstream spacecraft (ACE, WIND, Geotail, and THEMIS B) and one downstream in the magnetosheath (Cluster 4), but none of them resolve signatures of ongoing reconnection. We therefore suggest that reconnection was temporarily triggered as the DD was compressed by the shock. Bow shock reconnection is inevitably asymmetric with both the density and the magnetic field strength being higher on one side of the X-line (the magneosheath side) than on the other side where the plasma flow also is supersonic (the solar wind side). Asymmetric reconnection of the bow shock type has never been studied before, and the data discussed here are hence unique.
Published: 2020

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