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Koller F, Plaschke F, Temmer M, Preisser L, Roberts OW, Vörös Z. Magnetosheath Jet Formation Influenced by Parameters in Solar Wind Structures. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2023; 128:e2023JA031339. [PMID: 38440351 PMCID: PMC10909547 DOI: 10.1029/2023ja031339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/16/2023] [Accepted: 03/23/2023] [Indexed: 03/06/2024]
Abstract
Magnetosheath jets are dynamic pressure enhancements observed in the terrestrial magnetosheath. Their generation mechanisms are currently debated but the majority of jets can be linked to foreshock processes. Recent results showed that jets are less numerous when coronal mass ejections (CMEs) cross the magnetosheath and more numerous when stream interaction regions (SIRs) cross it. Here, we show for the first time how the pronounced substructures of CMEs and SIRs are related to jet production. We distinguish between compression and magnetic ejecta (ME) regions for the CME as well as compression region associated with the stream interface and high-speed streams (HSSs) for the SIR. Based on THEMIS and OMNI data covering 2008-2021, we show the 2D probability distribution of jet occurrence using the cone angle and Alfvén Mach number. We compare this distribution with the values within each solar wind (SW) structure. We find that both high cone angles and low Alfvén Mach numbers within CME-MEs are unfavorable for jet production as they may inhibit a well-defined foreshock region. 1D histograms of all parameters show, which SW parameters govern jet occurrence in each SW structure. In terms of the considered parameters the most favorable conditions for jet generation are found for HSSs due to their associated low cone angles, low densities, and low magnetic field strengths.
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Affiliation(s)
| | - Ferdinand Plaschke
- Institut für Geophysik und Extraterrestrische PhysikTU BraunschweigBraunschweigGermany
| | | | - Luis Preisser
- Space Research InstituteAustrian Academy of SciencesGrazAustria
| | - Owen W. Roberts
- Space Research InstituteAustrian Academy of SciencesGrazAustria
| | - Zoltan Vörös
- Space Research InstituteAustrian Academy of SciencesGrazAustria
- Institute of Earth Physics and Space ScienceELRNSopronHungary
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Turc L, Roberts OW, Verscharen D, Dimmock AP, Kajdič P, Palmroth M, Pfau-Kempf Y, Johlander A, Dubart M, Kilpua EKJ, Soucek J, Takahashi K, Takahashi N, Battarbee M, Ganse U. Transmission of foreshock waves through Earth's bow shock. NATURE PHYSICS 2022; 19:78-86. [PMID: 36687291 PMCID: PMC9845118 DOI: 10.1038/s41567-022-01837-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 10/14/2022] [Indexed: 06/17/2023]
Abstract
The Earth's magnetosphere and its bow shock, which is formed by the interaction of the supersonic solar wind with the terrestrial magnetic field, constitute a rich natural laboratory enabling in situ investigations of universal plasma processes. Under suitable interplanetary magnetic field conditions, a foreshock with intense wave activity forms upstream of the bow shock. So-called 30 s waves, named after their typical period at Earth, are the dominant wave mode in the foreshock and play an important role in modulating the shape of the shock front and affect particle reflection at the shock. These waves are also observed inside the magnetosphere and down to the Earth's surface, but how they are transmitted through the bow shock remains unknown. By combining state-of-the-art global numerical simulations and spacecraft observations, we demonstrate that the interaction of foreshock waves with the shock generates earthward-propagating, fast-mode waves, which reach the magnetosphere. These findings give crucial insight into the interaction of waves with collisionless shocks in general and their impact on the downstream medium.
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Affiliation(s)
- L. Turc
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - O. W. Roberts
- Space Research Institute, Austrian Academy of Sciences, Graz, Austria
| | - D. Verscharen
- Mullard Space Science Laboratory, University College London, Dorking, UK
| | | | - P. Kajdič
- Departamento de Ciencias Espaciales, Instituto de Geofísica, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - M. Palmroth
- Department of Physics, University of Helsinki, Helsinki, Finland
- Finnish Meteorological Institute, Helsinki, Finland
| | - Y. Pfau-Kempf
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - A. Johlander
- Department of Physics, University of Helsinki, Helsinki, Finland
- Swedish Institute of Space Physics, Uppsala, Sweden
| | - M. Dubart
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - E. K. J. Kilpua
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - J. Soucek
- Institute of Atmospheric Physics, Czech Academy of Sciences, Prague, Czech Republic
| | - K. Takahashi
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - N. Takahashi
- Department of Earth and Planetary Science, Graduate School of Science, University of Tokyo, Tokyo, Japan
- Radio Research Institute, National Institute of Information and Communication Technology, Tokyo, Japan
| | - M. Battarbee
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - U. Ganse
- Department of Physics, University of Helsinki, Helsinki, Finland
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3
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Ala‐Lahti M, Pulkkinen TI, Pfau‐Kempf Y, Grandin M, Palmroth M. Energy Flux Through the Magnetopause During Flux Transfer Events in Hybrid-Vlasov 2D Simulations. GEOPHYSICAL RESEARCH LETTERS 2022; 49:e2022GL100079. [PMID: 36591573 PMCID: PMC9788168 DOI: 10.1029/2022gl100079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 09/02/2022] [Accepted: 09/23/2022] [Indexed: 06/17/2023]
Abstract
Solar wind-magnetosphere coupling drives magnetospheric dynamic phenomena by enabling energy exchange between magnetospheric and solar wind plasmas. In this study, we examine two-dimensional noon-midnight meridional plane simulation runs of the global hybrid-Vlasov code Vlasiator with southward interplanetary magnetic field driving. We compute the energy flux, which consists of the Poynting flux and hydrodynamic energy flux components, through the Earth's magnetopause during flux transfer events (FTEs). The results demonstrate the spatiotemporal variations of the energy flux along the magnetopause during an FTE, associating the FTE leading (trailing) edge with an energy injection into (escape from) the magnetosphere on the dayside. Furthermore, FTEs traveling along the magnetopause transport energy to the nightside magnetosphere. We identify the tail lobes as a primary entry region for solar wind energy into the magnetosphere, consistent with results from global magnetohydrodynamic simulations and observations.
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Affiliation(s)
- Matti Ala‐Lahti
- Department of Climate and Space Sciences and EngineeringUniversity of MichiganAnn ArborMIUSA
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - Tuija I. Pulkkinen
- Department of Climate and Space Sciences and EngineeringUniversity of MichiganAnn ArborMIUSA
| | | | - Maxime Grandin
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - Minna Palmroth
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
- Space and Earth Observation CentreFinnish Meteorological InstituteHelsinkiFinland
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4
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Ye E, Loureiro NFG. Quantum-inspired method for solving the Vlasov-Poisson equations. Phys Rev E 2022; 106:035208. [PMID: 36266832 DOI: 10.1103/physreve.106.035208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 09/08/2022] [Indexed: 06/16/2023]
Abstract
Kinetic simulations of collisionless (or weakly collisional) plasmas using the Vlasov equation are often infeasible due to high-resolution requirements and the exponential scaling of computational cost with respect to dimension. Recently, it has been proposed that matrix product state (MPS) methods, a quantum-inspired but classical algorithm, can be used to solve partial differential equations with exponential speed-up, provided that the solution can be compressed and efficiently represented as a MPS within some tolerable error threshold. In this work, we explore the practicality of MPS methods for solving the Vlasov-Poisson equations for systems with one coordinate in space and one coordinate in velocity, and find that important features of linear and nonlinear dynamics, such as damping or growth rates and saturation amplitudes, can be captured while compressing the solution significantly. Furthermore, by comparing the performance of different mappings of the distribution functions onto the MPS, we develop an intuition of the MPS representation and its behavior in the context of solving the Vlasov-Poisson equations, which will be useful for extending these methods to higher-dimensional problems.
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Affiliation(s)
- Erika Ye
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139, USA
| | - Nuno F G Loureiro
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139, USA
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Alho M, Battarbee M, Pfau‐Kempf Y, Khotyaintsev YV, Nakamura R, Cozzani G, Ganse U, Turc L, Johlander A, Horaites K, Tarvus V, Zhou H, Grandin M, Dubart M, Papadakis K, Suni J, George H, Bussov M, Palmroth M. Electron Signatures of Reconnection in a Global eVlasiator Simulation. GEOPHYSICAL RESEARCH LETTERS 2022; 49:e2022GL098329. [PMID: 36249284 PMCID: PMC9541212 DOI: 10.1029/2022gl098329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 05/13/2022] [Accepted: 06/02/2022] [Indexed: 06/16/2023]
Abstract
Geospace plasma simulations have progressed toward more realistic descriptions of the solar wind-magnetosphere interaction from magnetohydrodynamic to hybrid ion-kinetic, such as the state-of-the-art Vlasiator model. Despite computational advances, electron scales have been out of reach in a global setting. eVlasiator, a novel Vlasiator submodule, shows for the first time how electromagnetic fields driven by global hybrid-ion kinetics influence electrons, resulting in kinetic signatures. We analyze simulated electron distributions associated with reconnection sites and compare them with Magnetospheric Multiscale (MMS) spacecraft observations. Comparison with MMS shows that key electron features, such as reconnection inflows, heated outflows, flat-top distributions, and bidirectional streaming, are in remarkable agreement. Thus, we show that many reconnection-related features can be reproduced despite strongly truncated electron physics and an ion-scale spatial resolution. Ion-scale dynamics and ion-driven magnetic fields are shown to be significantly responsible for the environment that produces electron dynamics observed by spacecraft in near-Earth plasmas.
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Affiliation(s)
- M. Alho
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - M. Battarbee
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - Y. Pfau‐Kempf
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | | | - R. Nakamura
- Space Research InstituteAustrian Academy of SciencesGrazAustria
| | - G. Cozzani
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - U. Ganse
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - L. Turc
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - A. Johlander
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
- Swedish Institute of Space PhysicsUppsalaSweden
| | - K. Horaites
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - V. Tarvus
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - H. Zhou
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - M. Grandin
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - M. Dubart
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - K. Papadakis
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - J. Suni
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - H. George
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - M. Bussov
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - M. Palmroth
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
- Finnish Meteorological InstituteHelsinkiFinland
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Johlander A, Battarbee M, Turc L, Ganse U, Pfau‐Kempf Y, Grandin M, Suni J, Tarvus V, Bussov M, Zhou H, Alho M, Dubart M, George H, Papadakis K, Palmroth M. Quasi-Parallel Shock Reformation Seen by Magnetospheric Multiscale and Ion-Kinetic Simulations. GEOPHYSICAL RESEARCH LETTERS 2022; 49:e2021GL096335. [PMID: 35860603 PMCID: PMC9285775 DOI: 10.1029/2021gl096335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 01/03/2022] [Accepted: 01/08/2022] [Indexed: 06/15/2023]
Abstract
Shock waves in collisionless plasmas are among the most efficient particle accelerators in space. Shock reformation is a process important to plasma heating and acceleration, but direct observations of reformation at quasi-parallel shocks have been lacking. Here, we investigate Earth's quasi-parallel bow shock with observations by the four Magnetospheric Multiscale spacecraft. The multi-spacecraft observations provide evidence of short large-amplitude magnetic structures (SLAMS) causing reformation of the quasi-parallel shock. We perform an ion-kinetic Vlasiator simulation of the bow shock and show that SLAMS reforming the bow shock recreates the multi-spacecraft measurements. This provides a method for identifying shock reformation in the future.
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Affiliation(s)
- Andreas Johlander
- Swedish Institute of Space PhysicsUppsalaSweden
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | | | - Lucile Turc
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - Urs Ganse
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | | | - Maxime Grandin
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - Jonas Suni
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - Vertti Tarvus
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - Maarja Bussov
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - Hongyang Zhou
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - Markku Alho
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - Maxime Dubart
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - Harriet George
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | | | - Minna Palmroth
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
- Finnish Meteorological InstituteHelsinkiFinland
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7
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PIC methods in astrophysics: simulations of relativistic jets and kinetic physics in astrophysical systems. LIVING REVIEWS IN COMPUTATIONAL ASTROPHYSICS 2021; 7:1. [PMID: 34722863 PMCID: PMC8549980 DOI: 10.1007/s41115-021-00012-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 05/05/2021] [Indexed: 11/04/2022]
Abstract
The Particle-In-Cell (PIC) method has been developed by Oscar Buneman, Charles Birdsall, Roger W. Hockney, and John Dawson in the 1950s and, with the advances of computing power, has been further developed for several fields such as astrophysical, magnetospheric as well as solar plasmas and recently also for atmospheric and laser-plasma physics. Currently more than 15 semi-public PIC codes are available which we discuss in this review. Its applications have grown extensively with increasing computing power available on high performance computing facilities around the world. These systems allow the study of various topics of astrophysical plasmas, such as magnetic reconnection, pulsars and black hole magnetosphere, non-relativistic and relativistic shocks, relativistic jets, and laser-plasma physics. We review a plethora of astrophysical phenomena such as relativistic jets, instabilities, magnetic reconnection, pulsars, as well as PIC simulations of laser-plasma physics (until 2021) emphasizing the physics involved in the simulations. Finally, we give an outlook of the future simulations of jets associated to neutron stars, black holes and their merging and discuss the future of PIC simulations in the light of petascale and exascale computing.
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Sorathia KA, Merkin VG, Panov EV, Zhang B, Lyon JG, Garretson J, Ukhorskiy AY, Ohtani S, Sitnov M, Wiltberger M. Ballooning-Interchange Instability in the Near-Earth Plasma Sheet and Auroral Beads: Global Magnetospheric Modeling at the Limit of the MHD Approximation. GEOPHYSICAL RESEARCH LETTERS 2020; 47:e2020GL088227. [PMID: 32999513 PMCID: PMC7507213 DOI: 10.1029/2020gl088227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/22/2020] [Accepted: 06/12/2020] [Indexed: 06/11/2023]
Abstract
Explosive magnetotail activity has long been understood in the context of its auroral manifestations. While global models have been used to interpret and understand many magnetospheric processes, the temporal and spatial scales of some auroral forms have been inaccessible to global modeling creating a gulf between observational and theoretical studies of these phenomena. We present here an important step toward bridging this gulf using a newly developed global magnetosphere-ionosphere model with resolution capturing ≲ 30 km azimuthal scales in the auroral zone. In a global magnetohydrodynamic (MHD) simulation of the growth phase of a synthetic substorm, we find the self-consistent formation and destabilization of localized magnetic field minima in the near-Earth magnetotail. We demonstrate that this destabilization is due to ballooning-interchange instability which drives earthward entropy bubbles with embedded magnetic fronts. Finally, we show that these bubbles create localized field-aligned current structures that manifest in the ionosphere with properties matching observed auroral beads.
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Affiliation(s)
- K. A. Sorathia
- The Johns Hopkins University Applied Physics LaboratoryLaurelMDUSA
| | - V. G. Merkin
- The Johns Hopkins University Applied Physics LaboratoryLaurelMDUSA
| | - E. V. Panov
- Space Research InstituteAustrian Academy of SciencesGrazAustria
| | - B. Zhang
- Department of Earth SciencesUniversity of Hong KongHong Kong
- High Altitude Observatory, National Center for Atmospheric ResearchBoulderCOUSA
| | - J. G. Lyon
- Department of Physics and AstronomyDartmouth CollegeHanoverNHUSA
| | - J. Garretson
- The Johns Hopkins University Applied Physics LaboratoryLaurelMDUSA
| | - A. Y. Ukhorskiy
- The Johns Hopkins University Applied Physics LaboratoryLaurelMDUSA
| | - S. Ohtani
- The Johns Hopkins University Applied Physics LaboratoryLaurelMDUSA
| | - M. Sitnov
- The Johns Hopkins University Applied Physics LaboratoryLaurelMDUSA
| | - M. Wiltberger
- High Altitude Observatory, National Center for Atmospheric ResearchBoulderCOUSA
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Akhavan‐Tafti M, Palmroth M, Slavin JA, Battarbee M, Ganse U, Grandin M, Le G, Gershman DJ, Eastwood JP, Stawarz JE. Comparative Analysis of the Vlasiator Simulations and MMS Observations of Multiple X-Line Reconnection and Flux Transfer Events. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2020; 125:e2019JA027410. [PMID: 32999805 PMCID: PMC7507759 DOI: 10.1029/2019ja027410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 03/15/2020] [Accepted: 04/13/2020] [Indexed: 06/11/2023]
Abstract
The Vlasiator hybrid-Vlasov code was developed to investigate global magnetospheric dynamics at ion-kinetic scales. Here we focus on the role of magnetic reconnection in the formation and evolution of magnetic islands at the low-latitude magnetopause, under southward interplanetary magnetic field conditions. The simulation results indicate that (1) the magnetic reconnection ion kinetics, including the Earthward pointing Larmor electric field on the magnetospheric side of an X-point and anisotropic ion distributions, are well-captured by Vlasiator, thus enabling the study of reconnection-driven magnetic island evolution processes, (2) magnetic islands evolve due to continuous reconnection at adjacent X-points, "coalescence" which refers to the merging of neighboring islands to create a larger island, "erosion" during which an island loses magnetic flux due to reconnection, and "division" which involves the splitting of an island into smaller islands, and (3) continuous reconnection at adjacent X-points is the dominant source of magnetic flux and plasma to the outer layers of magnetic islands resulting in cross-sectional growth rates up to + 0.3 RE 2/min. The simulation results are compared to the Magnetospheric Multiscale (MMS) measurements of a chain of ion-scale flux transfer events (FTEs) sandwiched between two dominant X-lines. The MMS measurements similarly reveal (1) anisotropic ion populations and (2) normalized reconnection rate ~0.18, in agreement with theory and the Vlasiator predictions. Based on the simulation results and the MMS measurements, it is estimated that the observed ion-scale FTEs may grow Earth-sized within ~10 min, which is comparable to the average transport time for FTEs formed in the subsolar region to the high-latitude magnetopause. Future simulations shall revisit reconnection-driven island evolution processes with improved spatial resolutions.
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Affiliation(s)
- M. Akhavan‐Tafti
- Climate and Space Sciences and EngineeringUniversity of MichiganAnn ArborMIUSA
- Laboratoire de Physique des Plasmas (LPP), École Polytechnique, CNRSSorbonne Université, Institut Polytechnique de ParisPalaiseauFrance
| | - M. Palmroth
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - J. A. Slavin
- Climate and Space Sciences and EngineeringUniversity of MichiganAnn ArborMIUSA
| | - M. Battarbee
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - U. Ganse
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - M. Grandin
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - G. Le
- NASA Goddard Space Flight CenterGreenbeltMDUSA
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