Energetic and Suprathermal Particle Composition Measurements from Solar Orbiter

2020 ◽  
Author(s):  
George Ho ◽  
Glenn Mason ◽  
Robert Wimmer-Schweingruber ◽  
Javier Rodríguez-Pacheco
Keyword(s):  
Solar Energetic Particle ◽  
Solar Wind Plasma ◽  
High Time Resolution ◽  
Plasma Energy ◽  
Seed Particles ◽  
Particle Population ◽  
Seed Population ◽  
Interaction Regions ◽  
Suprathermal Ions ◽  
Inner Heliosphere

<p>Particles that have energies of a few times the solar wind plasma energy up to 100s of keV/q are called suprathermal particles. Recent studies have revealed that these particles play a significant role as seed particles for further acceleration to higher energies.  This may occur either close to the Sun in solar energetic particle (SEP) events, but also locally at 1 AU in energetic storm particle events, or even outside 1 AU as ions accelerated in Corotating Interaction Regions. The constituents of this suprathermal ion reservoir are therefore expected to vary in time and space. The composition and spectra of these ions provide us the telltale of their origin and acceleration mechanism.  It is therefore important to make high time resolution measurements of the composition and spectra of this particle population in the inner heliosphere to better characterize its origins and role as a seed population in particle acceleration processes. Because of the vastly different mass-per-charge ratios of the various possible origins of suprathermal ions, we expect to see distinct difference and radial dependencies in their abundances in low-energy accelerated particles in the inner heliosphere.  Here we describe the measurements that we will be making on Solar Orbiter that will make significant contributions to the understanding of the particle population in this largely unexplored energy range.</p>

The effect of stream interaction regions on CME structures: observations in longitudinal conjunction at Mercury and 1 AU

2021 ◽  
Author(s):  
Camilla Scolini ◽  
Reka M. Winslow ◽  
Noé Lugaz ◽  
Antoinette B. Galvin
Keyword(s):  
Solar Wind ◽  
Large Scale ◽  
Flux Rope ◽  
Solar Wind Plasma ◽  
In Situ Data ◽  
Earth Environment ◽  
Size Evolution ◽  
Interaction Regions ◽  
Plasma Measurements ◽  
Inner Heliosphere

<p>We present a study of two CMEs observed at Mercury and 1 AU by spacecraft in longitudinal conjunction. Of the two CMEs, one propagated relatively self-similarly, while the other one underwent significant changes in its properties, making them excellent case studies to investigate the following question: what causes the drastic alterations observed in some CMEs during propagation, while other CMEs remain relatively unchanged? Answering this question will also help us better understand the potential impact of CMEs on the near-Earth environment. </p><p>In this work we focus on the presence or absence of large-scale corotating structures in the propagation space between Mercury and 1 AU, that have been shown in the past to influence  the orientation  of  CME  magnetic  structures  and  the  properties  of  CME  sheaths. At both locations, we determine the CME flux rope orientation and characteristics using different fitting and classification methods. Our analysis is complemented by solar wind plasma measurements near 1 AU, by estimates of the size evolution of the sheaths and magnetic ejecta with heliocentric distance, and by the identification of solar wind structures in the CME propagation space based on in situ data, remote-sensing observations, and numerical simulations of the solar wind conditions in the inner heliosphere.</p><p>Results indicate that the changes observed in one CME were likely caused by a stream interaction region, while the CME exhibiting little change did not interact with any large-scale structure between Mercury and 1 AU. This work provides end-member examples of CME propagation in the inner heliosphere, exemplifying how interactions  with  corotating  structures  in  the  solar  wind  can  induce  essential  changes  in  CME structures. Our findings provide new fundamental insights on the propagation and evolution of CMEs, and can help lay the foundation for improved predictions of CME properties at 1 AU.</p>

Nonlinear electromagnetic wave interactions in Hall–MHD plasmas

2010 ◽  
Vol 76 (6) ◽  
pp. 893-901
Author(s):  
DASTGEER SHAIKH ◽  
P. K. SHUKŁA
Keyword(s):  
Solar Wind ◽  
Electromagnetic Wave ◽  
Three Dimensional ◽  
Solar Wind Plasma ◽  
Inertial Range ◽  
High Time Resolution ◽  
Plasma Energy ◽  
Frequency Regime ◽  
Electromagnetic Wave Interactions ◽  
Hall Mhd

AbstractWe have developed a massively parallelized fully three-dimensional (3D) compressible Hall–magnetohydrodynamic (MHD) code to investigate inertial range electromagnetic wave cascades and dissipative processes in the regime, where characteristic length scales associated with plasma fluctuations are smaller than ion gyroradii. Such regime is ubiquitously present in the solar wind and many other collisionless space plasmas. Particularly, in the solar wind, the high time resolution databases depict a spectral break near the end of the 5/3 spectrum that corresponds to a high-frequency regime where the electromagnetic turbulent cascades cannot be explained by the usual MHD models. This refers to a second inertial range, where turbulent cascades follow a k−7/3 (where k is a wavenumber) spectrum in which the characteristic electromagnetic fluctuations evolve typically on kinetic Alfvén time scales. In this paper, we describe results from our 3D compressible Hall–MHD simulations that explain the observed k−7/3 spectrum in the solar wind plasma, energy cascade, anisotropy, and other spectral features.

Evolution of the MHD turbulence properties in the inner heliosphere with the PSP/SolO alignment data

2021 ◽  
Author(s):  
Daniele Telloni ◽  
Keyword(s):  
Solar Wind ◽  
High Frequency ◽  
Interplanetary Space ◽  
Solar Wind Plasma ◽  
Radial Dependence ◽  
Physical Processes ◽  
Temperature Anisotropy ◽  
Mhd Turbulence ◽  
Radial Evolution ◽  
Inner Heliosphere

<p>Radial alignments between pairs of spacecraft is the only way to observationally investigate the turbulent evolution of the solar wind as it expands throughout interplanetary space. On September 2020 Parker Solar Probe (PSP) and Solar Orbiter (SolO) were nearly perfectly radially aligned, with PSP orbiting around its perihelion at 0.1 au (and crossing the nominal Alfvén point) and SolO at 1 au. PSP/SolO joint observations of the same solar wind plasma allow the extraordinary and unprecedented opportunity to study how the turbulence properties of the solar wind evolve in the inner heliosphere over the wide distance of 0.9 au. The radial evolution of (i) the MHD properties (such as radial dependence of low- and high-frequency breaks, compressibility, Alfvénic content of the fluctuations), (ii) the polarization status, (iii) the presence of wave modes at kinetic scale as well as their distribution in the plasma instability-temperature anisotropy plane are just few instances of what can be addressed. Of furthest interest is the study of whether and how the cascade transfer and dissipation rates evolve with the solar distance, since this has great impact on the fundamental plasma physical processes related to the heating of the solar wind. In this talk I will present some of the results obtained by exploiting the PSP/SolO alignment data.</p>

scholarly journals SEED POPULATION IN LARGE SOLAR ENERGETIC PARTICLE EVENTS AND THE TWIN-CME SCENARIO

2015 ◽  
Vol 812 (2) ◽  
pp. 171 ◽  
Author(s):  
Liu-Guan Ding ◽  
Gang Li ◽  
Gui-Ming Le ◽  
Bin Gu ◽  
Xin-Xin Cao
Keyword(s):  
Energetic Particle ◽  
Solar Energetic Particle ◽  
Solar Energetic Particle Events ◽  
Seed Population

scholarly journals Dynamical evolution of the inner heliosphere approaching solar activity maximum: interpreting Ulysses observations using a global MHD model

2003 ◽  
Vol 21 (6) ◽  
pp. 1347-1357 ◽  
Author(s):  
P. Riley ◽  
Z. Mikić ◽  
J. A. Linker
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Solar Maximum ◽  
Dynamical Evolution ◽  
Solar Wind Plasma ◽  
Polar Regions ◽  
Activity Maximum ◽  
Interplanetary Magnetic Fields ◽  
Interplanetary Physics ◽  
Interaction Regions

Abstract. In this study we describe a series of MHD simulations covering the time period from 12 January 1999 to 19 September 2001 (Carrington Rotation 1945 to 1980). This interval coincided with: (1) the Sun’s approach toward solar maximum; and (2) Ulysses’ second descent to the southern polar regions, rapid latitude scan, and arrival into the northern polar regions. We focus on the evolution of several key parameters during this time, including the photospheric magnetic field, the computed coronal hole boundaries, the computed velocity profile near the Sun, and the plasma and magnetic field parameters at the location of Ulysses. The model results provide a global context for interpreting the often complex in situ measurements. We also present a heuristic explanation of stream dynamics to describe the morphology of interaction regions at solar maximum and contrast it with the picture that resulted from Ulysses’ first orbit, which occurred during more quiescent solar conditions. The simulation results described here are available at: http://sun.saic.com.Key words. Interplanetary physics (Interplanetary magnetic fields; solar wind plasma; sources of the solar wind)

Energetic Particle Environment near the Sun from Parker Solar Probe

2020 ◽  
Author(s):  
Nathan Schwadron ◽  
Keyword(s):  
Energetic Particle ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Radiation Environment ◽  
The Sun ◽  
Particle Radiation ◽  
Integrated Science ◽  
Direct Observations ◽  
Interaction Regions ◽  
Inner Heliosphere

<p>NASA’s Parker Solar Probe (PSP) mission recently plunged through the inner heliosphere to perihelia at ~24 million km (~35 solar radii), much closer to the Sun than any prior human made object. Onboard PSP, the Integrated Science Investigation of the Sun (ISʘIS) instrument suite made groundbreaking measurements of solar energetic particles (SEPs). Here we discuss the near-Sun energetic particle radiation environment over PSP’s first two orbits, which reveal where and how energetic particles are energized and transported. We find a great variety of energetic particle events accelerated both locally and remotely. These include co-rotating interaction regions (CIRs), “impulsive” SEP events driven by acceleration near the Sun, and events related to Coronal Mass Ejections (CMEs). These ISʘIS observations made so close to the Sun provide critical information for investigating the near-Sun transport and energization of solar energetic particles that was difficult to resolve from prior observations. We discuss the physics of particle acceleration and transport in the context of various theories and models that have been developed over the past decades. This study marks a major milestone with humanity’s reconnaissance of the near-Sun environment and provides the first direct observations of the energetic particle radiation environment in the region just above the corona.</p>

scholarly journals ON THE REMOTE DETECTION OF SUPRATHERMAL IONS IN THE SOLAR CORONA AND THEIR ROLE AS SEEDS FOR SOLAR ENERGETIC PARTICLE PRODUCTION

2013 ◽  
Vol 770 (1) ◽  
pp. 73 ◽  
Author(s):  
J. Martin Laming ◽  
J. Daniel Moses ◽  
Yuan-Kuen Ko ◽  
Chee K. Ng ◽  
Cara E. Rakowski ◽  
...  
Keyword(s):  
Solar Corona ◽  
Energetic Particle ◽  
Particle Production ◽  
Solar Energetic Particle ◽  
Remote Detection ◽  
Suprathermal Ions

scholarly journals Are there current-sheet-like structures in the Earth's magnetotail as in the solar wind – results and implications from high time resolution magnetic field measurements by Cluster

2008 ◽  
Vol 26 (7) ◽  
pp. 1889-1895 ◽  
Author(s):  
G. Li ◽  
E. Lee ◽  
G. Parks
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Current Sheet ◽  
Time Resolution ◽  
Field Measurements ◽  
Solar Wind Plasma ◽  
High Time ◽  
High Time Resolution ◽  
Mhd Turbulence ◽  
Flux Tubes

Abstract. Recent studies of solar wind MHD turbulence show that current-sheet-like structures are common in the solar wind and they are a significant source of solar wind MHD turbulence intermittency. While numerical simulations have suggested that such structures can arise from non-linear interactions of MHD turbulence, a recent study by Borovsky (2006), upon analyzing one year worth of ACE data, suggests that these structures may represent the magnetic walls of flux tubes that separate solar wind plasma into distinct bundles and these flux tubes are relic structures originating from boundaries of supergranules on the surface of the Sun. In this work, we examine whether there are such structures in the Earth's magnetotail, an environment vastly different from the solar wind. We use high time resolution magnetic field data of the FGM instrument onboard Cluster C1 spacecraft. The orbits of Cluster traverse through both the solar wind and the Earth's magnetosheath and magnetotail. This makes its dataset ideal for studying differences between solar wind MHD turbulence and that inside the Earth's magnetosphere. For comparison, we also perform the same analysis when Cluster C1 is in the solar wind. Using a data analysis procedure first introduced in Li (2007, 2008), we find that current-sheet-like structures can be clearly identified in the solar wind. However, similar structures do not exist inside the Earth's magnetotail. This result can be naturally explained if these structures have a solar origin as proposed by Borovsky (2006). With such a scenario, current analysis of solar wind MHD turbulence needs to be improved to include the effects due to these curent-sheet-like structures.

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