# PSP Bibliography

 Notice: Clicking on the title will open a new window with all details of the bibliographic entry. Clicking on the DOI link will open a new window with the original bibliographic entry from the publisher. Clicking on a single author will show all publications by the selected author. Clicking on a single keyword, will show all publications by the selected keyword.

## Found 864 entries in the Bibliography.

### Showing entries from 251 through 300

 2021 Plasma Properties, Switchback Patches and Low \ensuremath\alpha-Particle Abundance in Slow Alfv\ enic Coronal Hole Wind at 0.13 au The Parker Solar Probe (PSP) mission presents a unique opportunity to study the near-Sun solar wind closer than any previous spacecraft. During its fourth and fifth solar encounters, PSP had the same orbital trajectory, meaning that solar wind was measured at the same latitudes and radial distances. We identify two streams measured at the same heliocentric distance (\raisebox-0.5ex\textasciitilde0.13au) and latitude (\raisebox-0.5ex\textasciitilde-3.5$^○$) across these encounters to reduce spatial evolution effects. By com ... Woolley, Thomas; Matteini, Lorenzo; McManus, Michael; Ber\vci\vc, Laura; Badman, Samuel; Woodham, Lloyd; Horbury, Timothy; Bale, Stuart; Laker, Ronan; Stawarz, Julia; Larson, Davin; Published by: \mnras      Published on: aug YEAR: 2021     DOI: 10.1093/mnras/stab2281 Assessing the Role of Interchange Reconnection in Forming Switchbacks Abrupt deflections of the magnetic field in the solar wind, so called switchbacks, are frequently observed by the Parker Solar Probe (PSP) during its first two orbits and are believed to play an important role in unveiling the nature of solar corona heating and solar wind acceleration in the inner heliosphere. Many attempts were made recently to understand the nature of switchbacks. However, the origin, propagation, and evolution of switchbacks are still under debate. In this study, we attempt to use the linear theory of ... Liang, H.; Zank, G.~P.; Nakanotani, M.; Zhao, L.; Published by: \apj      Published on: aug YEAR: 2021     DOI: 10.3847/1538-4357/ac0a73 Evolution of Interplanetary Coronal Mass Ejection Complexity: A Numerical Study through a Swarm of Simulated Spacecraft In-situ measurements carried out by spacecraft in radial alignment are critical to advance our knowledge on the evolutionary behavior of coronal mass ejections (CMEs) and their magnetic structures during propagation through interplanetary space. Yet, the scarcity of radially aligned CME crossings restricts investigations on the evolution of CME magnetic structures to a few case studies, preventing a comprehensive understanding of CME complexity changes during propagation. In this Letter, we perform numerical simulations of C ... Scolini, Camilla; Winslow, Reka; Lugaz, No\; Poedts, Stefaan; Published by: \apjl      Published on: aug YEAR: 2021     DOI: 10.3847/2041-8213/ac0d58 Dynamics of nanodust in the vicinity of a stellar corona: Effect of plasma corotation Context. In the vicinity of the Sun or other stars, the motion of the coronal and stellar wind plasma must include some amount of corotation, which could affect the dynamics of charged dust particles. In the case of the Sun, this region is now investigated in situ by the Parker Solar Probe. Charged dust particles coming from the vicinity of the Sun can also reach, and possibly be detected by, the Solar Orbiter. \ Aims: We use numerical simulations and theoretical models to study the effect of plasma corotation on the motion ... Czechowski, A.; Mann, I.; Published by: \aap      Published on: aug YEAR: 2021     DOI: 10.1051/0004-6361/202141048 Large Amplitude Switchback Turbulence: Possible Magnetic Velocity Alignment Structures Switchbacks are widely acknowledged phenomena observed by the Parker Solar Probe and appear to occur in patches. Previous studies focused on the fluctuations at the magnetic reversals. However, the nature of the fluctuations inside the switchbacks remains unknown. Here we utilize the magnetic field data and plasma data measured by the Parker Solar Probe in the first four encounters. We investigate the fluctuations in the switchback intervals of 100 s with $B_R 0$ at every instant and compare them to the fluctuations in the n ... Wu, Honghong; Tu, Chuanyi; Wang, Xin; Yang, Liping; Published by: The Astrophysical Journal      Published on: 06/2021 YEAR: 2021     DOI: 10.3847/1538-4357/abec6c Flux Ropes, Turbulence, and Collisionless Perpendicular Shock Waves: High Plasma Beta Case With the onset of solar maximum and the expected increased prevalence of interplanetary shock waves, Parker Solar Probe is likely to observe numerous shocks in the next few years. An outstanding question that has received surprisingly little attention has been how turbulence interacts with collisionless shock waves. Turbulence in the supersonic solar wind is described frequently as a superposition of a majority 2D and a minority slab component. We formulate a collisional perpendicular shock-turbulence transmission problem in ... Zank, G.; Nakanotani, M.; Zhao, L.; Du, S.; Adhikari, L.; Che, H.; le Roux, J.; Published by: The Astrophysical Journal      Published on: 06/2021 YEAR: 2021     DOI: 10.3847/1538-4357/abf7c8 A Focused Transport-based Kinetic Fractional Diffusion-advection Equation for Energetic Particle Trapping and Reconnection-related Acceleration by Small-scale Magnetic Flux Ropes in the Solar Wind Analysis of energetic particle inner heliospheric spacecraft data increasingly suggests the existence of anomalous diffusion phenomena that should be addressed to achieve a better understanding of energetic particle transport and acceleration in the expanding solar wind medium. Related to this is fast-growing observational evidence supporting the long-standing prediction from magnetohydrodynamic (MHD) theory and simulations of the presence of an inner heliospheric, dominant quasi-two-dimensional MHD turbulence component that ... le Roux, J.; Zank, G.; Published by: The Astrophysical Journal      Published on: 06/2021 YEAR: 2021     DOI: 10.3847/1538-4357/abf3c6 Time evolution of stream interaction region energetic particle spectra in the inner heliosphere We analyze an energetic proton event associated with a stream interaction region (SIR) that was observed at Parker Solar Probe on day 320 of 2018 when the spacecraft was just 0.34 AU from the Sun. Using the Integrated Science Investigation of the Sun instrument suite, we perform a spectral analysis of the event and show how the observed spectra evolve over the course of the event. We find that the spectra from the first day of the event are much more consistent with local acceleration at a weak compression, while spectra fro ... Joyce, C.; McComas, D.; Schwadron, N.; Christian, E.; Wiedenbeck, M.; McNutt, R.; Cohen, C.; Leske, R.; Mewaldt, R.; Stone, E.; Labrador, A.; Davis, A.; Cummings, A.; Mitchell, D.; Hill, M.; Roelof, E.; Allen, R.; Szalay, J.; Rankin, J.; Desai, M.; Giacalone, J.; Matthaeus, W.; Bale, S.; Kasper, J.; Published by: Astronomy and Astrophysics      Published on: 06/2021 YEAR: 2021     DOI: 10.1051/0004-6361/202039330 Energetic particle behavior in near-Sun magnetic field switchbacks from PSP Context. The observation of numerous magnetic switchbacks and associated plasma jets in Parker Solar Probe (PSP) during its first five orbits, particularly near the Sun, has attracted considerable attention. Switchbacks have been found to be systematically associated with correlated reversals in the direction of the propagation of Alfvénic fluctuations, as well as similar reversals of the electron strahl. Aims: Here we aim to see whether the energetic particles change direction at the magnetic field switchbacks. Bandyopadhyay, R.; Matthaeus, W.; McComas, D.; Joyce, C.; Szalay, J.; Christian, E.; Giacalone, J.; Schwadron, N.; Mitchell, D.; Hill, M.; McNutt, R.; Desai, M.; Bale, S.; Bonnell, J.; de Wit, Dudok; Goetz, K.; Harvey, P.; MacDowall, R.; Malaspina, D.; Pulupa, M.; Kasper, J.; Stevens, M.; Published by: Astronomy and Astrophysics      Published on: 06/2021 YEAR: 2021     DOI: 10.1051/0004-6361/202039800 Electron Bernstein waves and narrowband plasma waves near the electron cyclotron frequency in the near-Sun solar wind Context. Recent studies of the solar wind sunward of 0.25 AU reveal that it contains quiescent regions, with low-amplitude plasma and magnetic field fluctuations, and a magnetic field direction similar to the Parker spiral. The quiescent regions are thought to have a more direct magnetic connection to the solar corona than other types of solar wind, suggesting that waves or instabilities in the quiescent regions are indicative of the early evolution of the solar wind as it escapes the corona. The quiescent solar wind regions ... Malaspina, D.; Wilson, L.; Ergun, R.; Bale, S.; Bonnell, J.; Goodrich, K.; Goetz, K.; Harvey, P.; MacDowall, R.; Pulupa, M.; Halekas, J.; Case, A.; Kasper, J.; Larson, D.; Stevens, M.; Whittlesey, P.; Published by: Astronomy and Astrophysics      Published on: 06/2021 YEAR: 2021     DOI: 10.1051/0004-6361/202140449 Thin silicon solid-state detectors for energetic particle measurements. Development, characterization, and application on NASA s Parker Solar Probe mission Context. Silicon solid-state detectors are commonly used for measuring the specific ionization, dE∕dx, in instruments designed for identifying energetic nuclei using the dE∕dx versus total energy technique in space and in the laboratory. The energy threshold and species resolution of the technique strongly depend on the thickness and thickness uniformity of these detectors. Aims: Research has been carried out to develop processes for fabricating detectors that are thinner than 15 μm, that have a thickness uniform ... Wiedenbeck, M.; Burnham, J.; Cohen, C.; Cook, W.; Crabill, R.; Cummings, A.; Davis, A.; Kecman, B.; Labrador, A.; Leske, R.; Mewaldt, R.; Rankin, J.; Rusert, M.; Stone, E.; Christian, E.; Goodwin, P.; Link, J.; Nahory, B.; Shuman, S.; von Rosenvinge, T.; Tindall, C.; Black, H.; Bullough, M.; Clarke, N.; Glasson, V.; Greenwood, N.; Hawkins, C.; Johnson, T.; Newton, A.; Richardson, K.; Walsh, S.; Wilburn, C.; Birdwell, B.; Everett, d.; McComas, D.; Weidner, S.; Angold, N.; Schwadron, N.; Published by: Astronomy and Astrophysics      Published on: 06/2021 YEAR: 2021     DOI: 10.1051/0004-6361/202039754 Parker Solar Probe observations of He/H abundance variations in SEP events inside 0.5 au Aims: The Parker Solar Probe (PSP) orbit provides an opportunity to study the inner heliosphere at distances closer to the Sun than previously possible. Due to the solar minimum conditions, the initial orbits of PSP yielded only a few solar energetic particle (SEP) events for study. Recently during the fifth orbit, at distances from 0.45 to 0.3 au, the energetic particle suite on PSP, Integrated Science Investigation of the Sun (IS⊙IS), observed a series of six SEP events, adding to the limited number of SEP events ... Cohen, C.; Christian, E.; Cummings, A.; Davis, A.; Desai, M.; de Nolfo, G.; Giacalone, J.; Hill, M.; Joyce, C.; Labrador, A.; Leske, R.; Matthaeus, W.; McComas, D.; McNutt, R.; Mewaldt, R.; Mitchell, D.; Mitchell, J.; Rankin, J.; Roelof, E.; Schwadron, N.; Stone, E.; Szalay, J.; Wiedenbeck, M.; Vourlidas, A.; Bale, S.; Pulupa, M.; MacDowall, R.; Published by: Astronomy and Astrophysics      Published on: 06/2021 YEAR: 2021     DOI: 10.1051/0004-6361/202039299 Applicability of Taylor s hypothesis during Parker Solar Probe perihelia We investigate the validity of Taylor s hypothesis (TH) in the analysis of velocity and magnetic field fluctuations in Alfvénic solar wind streams measured by Parker Solar Probe (PSP) during the first four encounters. The analysis is based on a recent model of the spacetime correlation of magnetohydrodynamic (MHD) turbulence, which has been validated in high-resolution numerical simulations of strong reduced MHD turbulence. We use PSP velocity and magnetic field measurements from 24 h intervals selected from each of the fir ... Perez, Jean; Bourouaine, Sofiane; Chen, Christopher; Raouafi, Nour; Published by: Astronomy and Astrophysics      Published on: 06/2021 YEAR: 2021     DOI: 10.1051/0004-6361/202039879 The contribution of alpha particles to the solar wind angular momentum flux in the inner heliosphere Context. An accurate assessment of the Sun s angular momentum (AM) loss rate is an independent constraint for models that describe the rotation evolution of Sun-like stars. Aims: In situ measurements of the solar wind taken by Parker Solar Probe (PSP), at radial distances of ~28−55 R⊙, are used to constrain the solar wind AM-loss rate. For the first time with PSP, this includes a measurement of the alpha particle contribution. Methods: The mechanical AM flux in the solar wind protons (core and be ... Finley, A.; McManus, M.; Matt, S.; Kasper, J.; Korreck, K.; Case, A.; Stevens, M.; Whittlesey, P.; Larson, D.; Livi, R.; Bale, S.; de Wit, Dudok; Goetz, K.; Harvey, P.; MacDowall, R.; Malaspina, D.; Pulupa, M.; Published by: Astronomy and Astrophysics      Published on: 06/2021 YEAR: 2021     DOI: 10.1051/0004-6361/202039288 Prevalence of magnetic reconnection in the near-Sun heliospheric current sheet During three of its first five orbits around the Sun, Parker Solar Probe (PSP) crossed the large-scale heliospheric current sheet (HCS) multiple times and provided unprecedented detailed plasma and field observations of the near-Sun HCS. We report the common detections by PSP of reconnection exhaust signatures in the HCS at heliocentric distances of 29.5-107 solar radii during encounters 1, 4, and 5. Both sunward and antisunward-directed reconnection exhausts were observed. In the sunward reconnection exhausts, PSP detected ... Phan, T.; Lavraud, B.; Halekas, J.; Øieroset, M.; Drake, J.; Eastwood, J.; Shay, M.; Pyakurel, P.; Bale, S.; Larson, D.; Livi, R.; Whittlesey, P.; Rahmati, A.; Pulupa, M.; McManus, M.; Verniero, J.; Bonnell, J.; Schwadron, N.; Stevens, M.; Case, A.; Kasper, J.; MacDowall, R.; Szabo, P.; Koval, A.; Korreck, K.; de Wit, Dudok; Malaspina, D.; Goetz, K.; Harvey, P.; Published by: Astronomy and Astrophysics      Published on: 06/2021 YEAR: 2021     DOI: 10.1051/0004-6361/202039863 Detection of small magnetic flux ropes from the third and fourth Parker Solar Probe encounters Context. Aims: We systematically search for magnetic flux rope structures in the solar wind to within the closest distance to the Sun of ~0.13 AU, using data from the third and fourth orbits of the Parker Solar Probe. Methods: We extended our previous magnetic helicity-based technique of identifying magnetic flux rope structures. The method was improved upon to incorporate the azimuthal flow, which becomes larger as the spacecraft approaches the Sun. Results: A total of 21 and 34 magnetic flux ropes are ... Zhao, L.; Zank, G.; Hu, Q.; Telloni, D.; Chen, Y.; Adhikari, L.; Nakanotani, M.; Kasper, J.; Huang, J.; Bale, S.; Korreck, K.; Case, A.; Stevens, M.; Bonnell, J.; de Wit, Dudok; Goetz, K.; Harvey, P.; MacDowall, R.; Malaspina, D.; Pulupa, M.; Larson, D.; Livi, R.; Whittlesey, P.; Klein, K.; Raouafi, N.; Published by: Astronomy and Astrophysics      Published on: 06/2021 YEAR: 2021     DOI: 10.1051/0004-6361/202039298 Wave-particle energy transfer directly observed in an ion cyclotron wave Context. The first studies with Parker Solar Probe (PSP) data have made significant progress toward understanding of the fundamental properties of ion cyclotron waves in the inner heliosphere. The survey mode particle measurements of PSP, however, did not make it possible to measure the coupling between electromagnetic fields and particles on the time scale of the wave periods. Aims: We present a novel approach to study wave-particle energy exchange with PSP. Methods: We used the Flux Angle operation mode of th ... Vech, D.; Martinovic, M.; Klein, K.; Malaspina, D.; Bowen, T.; Verniero, J.; Paulson, K.; de Wit, Dudok; Kasper, J.; Huang, J.; Stevens, M.; Case, A.; Korreck, K.; Mozer, F.; Goodrich, K.; Bale, S.; Whittlesey, P.; Livi, R.; Larson, D.; Pulupa, M.; Bonnell, J.; Harvey, P.; Goetz, K.; MacDowall, R.; Published by: Astronomy and Astrophysics      Published on: 06/2021 YEAR: 2021     DOI: 10.1051/0004-6361/202039296 Magnetic field line random walk and solar energetic particle path lengths. Stochastic theory and PSP/ISoIS observations Context. In 2020 May-June, six solar energetic ion events were observed by the Parker Solar Probe/IS⊙IS instrument suite at ≈0.35 AU from the Sun. From standard velocity-dispersion analysis, the apparent ion path length is ≈0.625 AU at the onset of each event. Aims: We develop a formalism for estimating the path length of random-walking magnetic field lines to explain why the apparent ion path length at an event onset greatly exceeds the radial distance from the Sun for these events. Methods: We developed ... Chhiber, R.; Matthaeus, W.; Cohen, C.; Ruffolo, D.; Sonsrettee, W.; Tooprakai, P.; Seripienlert, A.; Chuychai, P.; Usmanov, A.; Goldstein, M.; McComas, D.; Leske, R.; Christian, E.; Mewaldt, R.; Labrador, A.; al., et; Published by: Astronomy and Astrophysics      Published on: 06/2021 YEAR: 2021     DOI: "10.1051/0004-6361/202039816" Whistler wave occurrence and the interaction with strahl electrons during the first encounter of Parker Solar Probe Aims: We studied the properties and occurrence of narrowband whistler waves and their interaction with strahl electrons observed between 0.17 and 0.26 au during the first encounter of Parker Solar Probe. Methods: We used Digital Fields Board band-pass filtered (BPF) data from FIELDS to detect the signatures of whistler waves. Additionally parameters derived from the particle distribution functions measured by the Solar Wind Electrons Alphas and Protons (SWEAP) instrument suite were used to investigate the plasm ... Jagarlamudi, V.; de Wit, Dudok; Froment, C.; Krasnoselskikh, V.; Larosa, A.; Bercic, L.; Agapitov, O.; Halekas, J.; Kretzschmar, M.; Malaspina, D.; Moncuquet, M.; Bale, S.; Case, A.; Kasper, J.; Korreck, K.; Larson, D.; Pulupa, M.; Stevens, M.; Whittlesey, P.; Published by: Astronomy and Astrophysics      Published on: 06/2021 YEAR: 2021     DOI: 10.1051/0004-6361/202039808 Alfvenic versus non-Alfvenic turbulence in the inner heliosphere as observed by Parker Solar Probe Context. Parker Solar Probe (PSP) measures the magnetic field and plasma parameters of the solar wind at unprecedentedly close distances to the Sun. These data provide great opportunities to study the early-stage evolution of magnetohydrodynamic (MHD) turbulence in the solar wind. Aims: In this study, we make use of the PSP data to explore the nature of solar wind turbulence focusing on the Alfvénic character and power spectra of the fluctuations and their dependence on the distance and context (i.e., large-scale sol ... Shi, C.; Velli, M.; Panasenco, O.; Tenerani, A.; eville, V.; Bale, S.; Kasper, J.; Korreck, K.; Bonnell, J.; de Wit, Dudok; Goetz, K.; Harvey, P.; MacDowall, R.; Pulupa, M.; Case, A.; Larson, D.; Verniero, J.; Livi, R.; Stevens, M.; al., et; Published by: Astronomy and Astrophysics      Published on: 06/2021 YEAR: 2021     DOI: "10.1051/0004-6361/202039818" The active region source of a type III radio storm observed by Parker Solar Probe during encounter 2 Context. We investigated the source of a type III radio burst storm during encounter 2 of NASA s Parker Solar Probe (PSP) mission. Aims: It was observed that in encounter 2 of NASA s PSP mission there was a large amount of radio activity and, in particular, a noise storm of frequent, small type III bursts from 31 March to 6 April 2019. Our aim is to investigate the source of these small and frequent bursts. Methods: In order to do this, we analysed data from the Hinode EUV Imaging Spectrometer, PSP FIELDS, and ... Harra, L.; Brooks, D.; Bale, S.; Mandrini, C.; Barczynski, K.; Sharma, R.; Badman, S.; Domínguez, Vargas; Pulupa, M.; Published by: Astronomy and Astrophysics      Published on: 06/2021 YEAR: 2021     DOI: 10.1051/0004-6361/202039514 Periodicities in an active region correlated with Type III radio bursts observed by Parker Solar Probe Context. Periodicities have frequently been reported across many wavelengths in the solar corona. Correlated periods of ~5 min, comparable to solar p-modes, are suggestive of coupling between the photosphere and the corona. Aims: Our study investigates whether there are correlations in the periodic behavior of Type III radio bursts which are indicative of nonthermal electron acceleration processes, and coronal extreme ultraviolet (EUV) emission used to assess heating and cooling in an active region when there are no l ... Cattell, Cynthia; Glesener, Lindsay; Leiran, Benjamin; Dombeck, John; Goetz, Keith; Oliveros, Juan; Badman, Samuel; Pulupa, Marc; Bale, Stuart; Published by: Astronomy and Astrophysics      Published on: 06/2021 YEAR: 2021     DOI: 10.1051/0004-6361/202039510 Direct evidence for magnetic reconnection at the boundaries of magnetic switchbacks with Parker Solar Probe Context. The first encounters of Parker Solar Probe (PSP) with the Sun revealed the presence of ubiquitous localised magnetic deflections in the inner heliosphere; these structures, often called switchbacks, are particularly striking in solar wind streams originating from coronal holes. Aims: We report the direct piece of evidence for magnetic reconnection occurring at the boundaries of three switchbacks crossed by PSP at a distance of 45 to 48 solar radii to the Sun during its first encounter. Methods: We anal ... Froment, C.; Krasnoselskikh, V.; de Wit, Dudok; Agapitov, O.; Fargette, N.; Lavraud, B.; Larosa, A.; Kretzschmar, M.; Jagarlamudi, V.; Velli, M.; Malaspina, D.; Whittlesey, P.; Bale, S.; Case, A.; Goetz, K.; Kasper, J.; Korreck, K.; Larson, D.; MacDowall, R.; Mozer, F.; Pulupa, M.; Revillet, C.; Stevens, M.; Published by: Astronomy and Astrophysics      Published on: 06/2021 YEAR: 2021     DOI: 10.1051/0004-6361/202039806 Switchbacks: statistical properties and deviations from Alfvénicity Context. Parker Solar Probe s first solar encounter has revealed the presence of sudden magnetic field deflections in the slow Alfvénic solar wind. These structures, which are often called switchbacks, are associated with proton velocity enhancements. Aims: We study their statistical properties with a special focus on their boundaries. Methods: Using data from SWEAP and FIELDS, we investigate particle and wavefield properties. The magnetic boundaries are analyzed with the minimum variance technique. Res ... Larosa, A.; Krasnoselskikh, V.; de Wit, Dudok; Agapitov, O.; Froment, C.; Jagarlamudi, V.; Velli, M.; Bale, S.; Case, A.; Goetz, K.; Harvey, P.; Kasper, J.; Korreck, K.; Larson, D.; MacDowall, R.; Malaspina, D.; Pulupa, M.; Revillet, C.; Stevens, M.; Published by: Astronomy and Astrophysics      Published on: 06/2021 YEAR: 2021     DOI: 10.1051/0004-6361/202039442 In-flight Calibration and Data Reduction for the WISPR Instrument On Board the PSP Mission We present the calibration status and data reduction methodology for the Wide Field Imager for Solar Probe (WISPR) on board the Parker Solar Probe (PSP) mission. In particular, we describe the process for converting a raw image, measured in digital numbers (DN), to a calibrated image, measured in mean solar brightness (MSB). We also discuss details of the on board image processing including bias removal, the linearity of the electronics, pointing, geometric distortion, and photometric calibration using stellar measurements, ... Hess, Phillip; Howard, Russell; Stenborg, Guillermo; Linton, Mark; Vourlidas, Angelos; Thernisien, Arnaud; Colaninno, Robin; Rich, Nathan; Wang, Dennis; Battams, Karl; Kuroda, Natsuha; Published by: Solar Physics      Published on: 06/2021 YEAR: 2021     DOI: 10.1007/s11207-021-01847-9 Stellar versus Galactic: the intensity of cosmic rays at the evolving Earth and young exoplanets around Sun-like stars Energetic particles, such as stellar cosmic rays, produced at a heightened rate by active stars (like the young Sun) may have been important for the origin of life on Earth and other exoplanets. Here, we compare, as a function of stellar rotation rate (Ω), contributions from two distinct populations of energetic particles: stellar cosmic rays accelerated by impulsive flare events and Galactic cosmic rays. We use a 1.5D stellar wind model combined with a spatially 1D cosmic ray transport model. We formulate the evolution of ... Rodgers-Lee, D.; Taylor, A.; Vidotto, A.; Downes, T.; Published by: Monthly Notices of the Royal Astronomical Society      Published on: 06/2021 YEAR: 2021     DOI: 10.1093/mnras/stab935 Turbulent Proton Heating Rate in the Solar Wind from 545 R Various remote sensing observations have been used so far to probe the turbulent properties of the solar wind. Using the recently reported density modulation indices that are derived using angular broadening observations of Crab Nebula during 19522013, we measured the solar wind proton heating using the kinetic Alfvn wave dispersion equation. The estimated heating rates vary from 1.58 1014 to 1.01 108 erg cm3 s1 in the heliocentric distance range of 545 R. Further, we found that he ... Raja, Sasikumar; Subramanian, Prasad; Ingale, Madhusudan; Ramesh, R.; Maksimovic, Milan; Published by: The Astrophysical Journal      Published on: 06/2021 YEAR: 2021     DOI: 10.3847/1538-4357/abfcd1 Could Switchbacks Originate in the Lower Solar Atmosphere? II. Propagation of Switchbacks in the Solar Corona The magnetic switchbacks observed recently by the Parker Solar Probe have raised the question about their nature and origin. One of the competing theories of their origin is the interchange reconnection in the solar corona. In this scenario, switchbacks are generated at the reconnection site between open and closed magnetic fields, and are either advected by an upflow or propagate as waves into the solar wind. In this paper we test the wave hypothesis, numerically modeling the propagation of a switchback, modeled as an embed ... Magyar, Norbert; Utz, Dominik; Erdélyi, Robertus; Nakariakov, Valery; Published by: The Astrophysical Journal      Published on: 06/2021 YEAR: 2021     DOI: 10.3847/1538-4357/abfa98 Editorial Parker Solar Probe: Ushering a new frontier in space exploration Alves, João; Forveille, Thierry; Lellouch, Emmanuel; Shore, Steve; Zouganelis, Yannis; Published by: Astronomy and Astrophysics      Published on: 06/2021 YEAR: 2021     DOI: 10.1051/0004-6361/202141385 Parker Data Used Using Parker Solar Probe observations during the first four perihelia to constrain global magnetohydrodynamic models Context. Parker Solar Probe (PSP) is providing an unprecedented view of the Sun s corona as it progressively dips closer into the solar atmosphere with each solar encounter. Each set of observations provides a unique opportunity to test and constrain global models of the solar corona and inner heliosphere and, in turn, use the model results to provide a global context for interpreting such observations. Aims: In this study, we develop a set of global magnetohydrodynamic (MHD) model solutions of varying degrees of soph ... Riley, Pete; Lionello, Roberto; Caplan, Ronald; Downs, Cooper; Linker, Jon; Badman, Samuel; Stevens, Michael; Published by: Astronomy and Astrophysics      Published on: 06/2021 YEAR: 2021     DOI: 10.1051/0004-6361/202039815 Discontinuity analysis of the leading switchback transition regions Context. Magnetic switchbacks are magnetic structures characterized as intervals of sudden reversal in the radial component of the pristine solar wind s magnetic field. Switchbacks comprise of magnetic spikes that are preceded and succeeded by switchback transition regions within which the radial magnetic field reverses. Determining switchback generation and evolution mechanisms will further our understanding of the global circulation and transportation of the Sun s open magnetic flux. Aims: The present study juxtapos ... Akhavan-Tafti, M.; Kasper, J.; Huang, J.; Bale, S.; Published by: Astronomy and Astrophysics      Published on: 06/2021 YEAR: 2021     DOI: 10.1051/0004-6361/202039508 Determining Threshold Instrumental Resolutions for Resolving the Velocity Space Signature of Ion Landau Damping Unraveling the physics of the entire turbulent cascade of energy in space and astrophysical plasmas from the injection of energy at large scales to the dissipation of that energy into plasma heat at small scales, represents an overarching, open question in heliophysics and astrophysics. The fast cadence and high phase space resolution of particle velocity distribution measurements on modern spacecraft missions, such as the recently launched Parker Solar Probe, presents exciting new opportunities for identifying turbulent dis ... Verniero, J.; Howes, G.; Stewart, D.; Klein, K.; Published by: Journal of Geophysical Research (Space Physics)      Published on: 05/2021 YEAR: 2021     DOI: 10.1029/2020JA028361 Statistics of Low Frequency Cutoffs for Type III Radio Bursts Observed by Parker Solar Probe during Its Encounters 1-5 The low frequency cutoffs flo and the observed plasma frequency fp of 176 type III radio bursts are investigated in this paper. These events are observed by the Parker Solar Probe when it is in the encounter phase from the first to the fifth orbit. The result shows that the distribution of cutoffs flo is widely spread between 200 kHz and 1.6 MHz. While the plasma frequency fp at the spacecraft is between 50 and 250 kHz, which is almost all smaller than flo. The result al ... Ma, Bing; Chen, Ling; Wu, Dejin; Bale, Stuart; Published by: The Astrophysical Journal      Published on: 05/2021 YEAR: 2021     DOI: 10.3847/2041-8213/abfb77 Evolution of Solar Wind Turbulence from 0.1 to 1 au during the First Parker Solar Probe-Solar Orbiter Radial Alignment The first radial alignment between Parker Solar Probe and Solar Orbiter spacecraft is used to investigate the evolution of solar wind turbulence in the inner heliosphere. Assuming ballistic propagation, two 1.5 hr intervals are tentatively identified as providing measurements of the same plasma parcels traveling from 0.1 to 1 au. Using magnetic field measurements from both spacecraft, the properties of turbulence in the two intervals are assessed. Magnetic spectral density, flatness, and high-order moment scaling laws are ca ... Telloni, Daniele; Sorriso-Valvo, Luca; Woodham, Lloyd; Panasenco, Olga; Velli, Marco; Carbone, Francesco; Zank, Gary; Bruno, Roberto; Perrone, Denise; Nakanotani, Masaru; Shi, Chen; Amicis, Raffaella; De Marco, Rossana; Jagarlamudi, Vamsee; Steinvall, Konrad; Marino, Raffaele; Adhikari, Laxman; Zhao, Lingling; Liang, Haoming; Tenerani, Anna; Laker, Ronan; Horbury, Timothy; Bale, Stuart; Pulupa, Marc; Malaspina, David; MacDowall, Robert; Goetz, Keith; de Wit, Thierry; Harvey, Peter; Kasper, Justin; Korreck, Kelly; Larson, Davin; Case, Anthony; Stevens, Michael; Whittlesey, Phyllis; Livi, Roberto; Owen, Christopher; Livi, Stefano; Louarn, Philippe; Antonucci, Ester; Romoli, Marco; Brien, Helen; Evans, Vincent; Angelini, Virginia; Published by: The Astrophysical Journal      Published on: 05/2021 YEAR: 2021     DOI: 10.3847/2041-8213/abf7d1 Plasma dynamics in low-electron-beta environments Recent in situ measurements by the MMS and Parker Solar Probe missions bring interest to small-scale plasma dynamics (waves, turbulence, magnetic reconnection) in regions where the electron thermal energy is smaller than the magnetic one. Examples of such regions are the Earth s mangetosheath and the vicinity of the solar corona, and they are also encountered in other astrophysical systems. In this brief review, we consider simple physical models describing plasma dynamics in such low-electron-beta regimes, discuss their con ... Boldyrev, Stanislav; Loureiro, Nuno; Roytershteyn, Vadim; Published by: Frontiers in Astronomy and Space Sciences      Published on: 05/2021 YEAR: 2021     DOI: 10.3389/fspas.2021.621040 A geometrical description for interplanetary propagation of Earth-directed CMEs based on radiative proxies We present a 3D geometrical model to describe the propagation and expansion of CMEs in the interplanetary space based on radiative proxies to be implemented in previous procedures that use SXR and microwave emissions to estimate the Earth-directed CME propagation speed. We carefully selected a sample of 45 well-defined CME-ICME events to evaluate our model. We computed this 3D geometrical model for each event as a tool to improve the arrival time predictions based on radiative proxies. We conducted a different analysis for e ... Salas-Matamoros, C.; Sanchez-Guevara, J.; Published by: Monthly Notices of the Royal Astronomical Society      Published on: 05/2021 YEAR: 2021     DOI: 10.1093/mnras/stab1232 Correlation of the Sunspot Number and the Waiting-time Distribution of Solar Flares, Coronal Mass Ejections, and Solar Wind Switchback Events Observed with the Parker Solar Probe Waiting-time distributions of solar flares and coronal mass ejections (CMEs) exhibit power-law-like distribution functions with slopes in the range of ατ ≍ 1.4-3.2, as observed in annual data sets during four solar cycles (1974-2012). We find a close correlation between the waiting-time power-law slope ατ and the sunspot number (SN), i.e., ατ = 1.38 + 0.01 × SN. The waiting-time distribution can be fitted with a Pareto-type function of the form N(τ) = N0 $(\tau _0+\tau )^ ... Aschwanden, Markus; de Wit, Thierry; Published by: The Astrophysical Journal Published on: 05/2021 YEAR: 2021 DOI: 10.3847/1538-4357/abef69 Multiscale Solar Wind Turbulence Properties inside and near Switchbacks Measured by the Parker Solar Probe The Parker Solar Probe (PSP) routinely observes magnetic field deflections in the solar wind at distances less than 0.3 au from the Sun. These deflections are related to structures commonly called "switchbacks" (SBs), whose origins and characteristic properties are currently debated. Here, we use a database of visually selected SB intervals—and regions of solar wind plasma measured just before and after each SB—to examine plasma parameters, turbulent spectra from inertial to dissipation scales, and intermittency ... Martinovic, Mihailo; Klein, Kristopher; Huang, Jia; Chandran, Benjamin; Kasper, Justin; Lichko, Emily; Bowen, Trevor; Chen, Christopher; Matteini, Lorenzo; Stevens, Michael; Case, Anthony; Bale, Stuart; Published by: The Astrophysical Journal Published on: 05/2021 YEAR: 2021 DOI: 10.3847/1538-4357/abebe5 An approximate analytic solution to the coupled problems of coronal heating and solar-wind acceleration Between the base of the solar corona at$r=r_\textrm b$and the Alfvén critical point at$r=r_\textrm A$, where$r$is heliocentric distance, the solar-wind density decreases by a factor$ \mathop > \limits_∼ 10^5$, but the plasma temperature varies by a factor of only a few. In this paper, I show that such quasi-isothermal evolution out to$r=r_\textrm A$is a generic property of outflows powered by reflection-driven Alfvén-wave (AW) turbulence, in which outward-propagating AWs partially reflect, and counter-propagating ... Chandran, Benjamin; Published by: Journal of Plasma Physics Published on: 05/2021 YEAR: 2021 DOI: 10.1017/S0022377821000052 Depleted Plasma Densities in the Ionosphere of Venus Near Solar Minimum From Parker Solar Probe Observations of Upper Hybrid Resonance Emission On July 11, 2020, NASA s Parker Solar Probe made its third flyby of Venus. The upper hybrid resonance emission was observed below 1,100 km (a first at Venus), revealing electron densities an order of magnitude lower than at solar maximum. These observations are consistent with a substantial variation in the density and structure of the Venusian ionosphere over the Solar Cycle. Collinson, Glyn; Ramstad, Robin; Glocer, Alex; Wilson, Lynn; Brosius, Alexandra; Published by: Geophysical Research Letters Published on: 05/2021 YEAR: 2021 DOI: 10.1029/2020GL092243 The Dynamic Formation of Pseudostreamers Streamers and pseudostreamers structure the corona at the largest scales, as seen in both eclipse and coronagraph white-light images. Their inverted-goblet appearance encloses broad coronal loops at the Sun and tapers to a narrow radial stalk away from the star. The streamer associated with the global solar dipole magnetic field is long-lived, predominantly contains a single arcade of nested loops within it, and separates opposite-polarity interplanetary magnetic fields with the heliospheric current sheet (HCS) anchored at i ... Scott, Roger; Pontin, David; Antiochos, Spiro; DeVore, Richard; Wyper, Peter; Published by: The Astrophysical Journal Published on: 05/2021 YEAR: 2021 DOI: 10.3847/1538-4357/abec4f First Observations of Anomalous Cosmic Rays in to 36 Solar Radii NASA s Parker Solar Probe mission continues to travel closer to the Sun than any prior human-made object, with an expected closest approach of <10 solar radii (<0.046 au) by 2024. On board, the Integrated Science Investigation of the Sun instrument suite makes unprecedented in situ measurements of energetic particles in the near-Sun environment. The current low level of solar activity offers a prime opportunity to measure cosmic rays closer to the Sun than ever before. We present the first observations of anomalous cosmic ra ... Rankin, J.; McComas, D.; Leske, R.; Christian, E.; Cohen, C.; Cummings, A.; Joyce, C.; Labrador, A.; Mewaldt, R.; Posner, A.; Schwadron, N.; Strauss, R.; Stone, E.; Wiedenbeck, M.; Published by: The Astrophysical Journal Published on: 05/2021 YEAR: 2021 DOI: 10.3847/1538-4357/abec7e The Transport Equation for the Dispersal of Passive Tracers in a Nonuniform Turbulent Fluid: Numerical Simulations The random advection of passive additives in a turbulent fluid plays an important role in solar physics, astrophysics, and atmospheric sciences. We concern ourselves here with the case where the fluctuations are not statistically homogeneous in space, and, hence, where the transport coefficients vary with position. Using a numerical model in which the fluid turbulence is defined kinematically, we show that the evolution of the distribution of passive tracers in the fluid is not always governed by the ordinary diffusion equat ... Giacalone, Joe; Published by: The Astrophysical Journal Published on: 05/2021 YEAR: 2021 DOI: 10.3847/1538-4357/abf0b2 A New View of the Solar Interface Region from the Interface Region Imaging Spectrograph (IRIS) The Interface Region Imaging Spectrograph (IRIS) has been obtaining near- and far-ultraviolet images and spectra of the solar atmosphere since July 2013. IRIS is the highest resolution observatory to provide seamless coverage of spectra and images from the photosphere into the low corona. The unique combination of near- and far-ultraviolet spectra and images at sub-arcsecond resolution and high cadence allows the tracing of mass and energy through the critical interface between the surface and the corona or solar wind. IRIS ... De Pontieu, Bart; Polito, Vanessa; Hansteen, Viggo; Testa, Paola; Reeves, Katharine; Antolin, Patrick; Nóbrega-Siverio, Daniel; Kowalski, Adam; Martinez-Sykora, Juan; Carlsson, Mats; McIntosh, Scott; Liu, Wei; Daw, Adrian; Kankelborg, Charles; Published by: Solar Physics Published on: 05/2021 YEAR: 2021 DOI: 10.1007/s11207-021-01826-0 On the violation of the zeroth law of turbulence in space plasmas The zeroth law of turbulence states that, for fixed energy input into large-scale motions, the statistical steady state of a turbulent system is independent of microphysical dissipation properties. This behaviour, which is fundamental to nearly all fluid-like systems from industrial processes to galaxies, occurs because nonlinear processes generate smaller and smaller scales in the flow, until the dissipation - no matter how small - can thermalise the energy input. Using direct numerical simulations and theoretical arguments ... Meyrand, R.; Squire, J.; Schekochihin, A.; Dorland, W.; Published by: Journal of Plasma Physics Published on: 05/2021 YEAR: 2021 DOI: 10.1017/S0022377821000489 PATCH: Particle Arrival Time Correlation for Heliophysics The ability to understand the fundamental nature of the physics that governs the heliosphere requires spacecraft instrumentation to measure energy transfer at kinetic scales. This translates to a time cadence resolving the proton kinetic timescales, typically of the order of the proton gyrofrequency. The downlinked survey mode data from modern spacecraft are often much lower resolution than this criterion, meaning that the higher resolution, burst mode data must be captured to study an event at kinetic time scales. Telemetry ... Verniero, J.; Howes, G.; Stewart, D.; Klein, K.; Published by: Journal of Geophysical Research (Space Physics) Published on: 05/2021 YEAR: 2021 DOI: 10.1029/2020JA028940 Parker Solar Probe FIELDS Instrument Charging in the Near Sun Environment: Part 2: Comparison of In Flight Data and Modeling Results This research shows Part II of the Spacecraft Interaction Plasma Software (SPIS) used to model the parker solar probe (PSP) FIELDS instrument and its interactions with the Solar Wind. Flight data were used to run the PSP model and compared with models using past predicted parameters. The effect of voltage biasing between the antenna, its shield, and the spacecraft on the current balance of each surface was investigated at first perihelion (0.16AU). The model data were reduced to I-V curves to find current saturations (analys ... Diaz-Aguado, M.; Bonnell, J.; Bale, S.; Wang, J.; Gruntman, M.; Published by: Journal of Geophysical Research (Space Physics) Published on: 05/2021 YEAR: 2021 DOI: 10.1029/2020JA028689 On Alfvénic Slow Wind: A Journey From the Earth Back to the Sun Comparative studies of fast and slow solar wind streams performed over the past decades have illustrated several differences between the plasma regimes for these different flows, examples including features such as temperatures, particle distribution function anisotropies, and the nature of the embedded turbulence, specifically the Alfvénicity of the fluctuations. Though this two state classification of the solar wind primarily based on flow speed has been widely adopted, more in depth studies have found that slow solar win ... Amicis, R.; Perrone, D.; Bruno, R.; Velli, M.; Published by: Journal of Geophysical Research (Space Physics) Published on: 04/2021 YEAR: 2021 DOI: 10.1029/2020JA028996 Nonlinear Ion-acoustic Waves, Ion Holes, and Electron Holes in the Near-Sun Solar Wind Nonlinear ion-acoustic waves, ion holes, and electron holes have been observed on the Parker Solar Probe at a heliocentric distance of 35 solar radii. These time domain structures contain millisecond duration electric field spikes of several mV m-1. They are observed inside or at boundaries of switchbacks in the background magnetic field. Their presence in switchbacks indicates that both electron- and ion-streaming electrostatic instabilities occur there to thermalize electron and ion beams. Mozer, F.; Bonnell, J.; Hanson, E.; Gasque, L.; Vasko, I; Published by: The Astrophysical Journal Published on: 04/2021 YEAR: 2021 DOI: 10.3847/1538-4357/abed52 How Alfvén waves energize the solar wind: heat versus work A growing body of evidence suggests that the solar wind is powered to a large extent by an Alfvén-wave (AW) energy flux. AWs energize the solar wind via two mechanisms: heating and work. We use high-resolution direct numerical simulations of reflection-driven AW turbulence (RDAWT) in a fast-solar-wind stream emanating from a coronal hole to investigate both mechanisms. In particular, we compute the fraction of the AW power at the coronal base ($P_\textrm AWb\$) that is transferred to solar-wind particles via heating between ... Perez, Jean; Chandran, Benjamin; Klein, Kristopher; Martinovic, Mihailo; Published by: Journal of Plasma Physics      Published on: 04/2021 YEAR: 2021     DOI: 10.1017/S0022377821000167