Explanipedia

Switchbacks and Associated Magnetic Holes Observed near the Alfvén Critical Surface Open

Anthony P. Rasca, W. M. Farrell, J. Gruesbeck, R. J. MacDowall, S. D. Bale , et al. · 2023

During recent solar encounters, the Parker Solar Probe (PSP) began its initial dips below the Alfvén critical surface to measure in situ the sub-Alfvénic coronal wind. While the near-Sun super-Alfvénic solar wind is shown to be dominated b…

Are Switchback Boundaries Observed by Parker Solar Probe Closed? Open

Nina Bizien, Thierry Dudok de Wit, C. Froment, M. Velli, A. W. Case , et al. · 2023

Switchbacks are sudden and large deflections in the magnetic field that Parker Solar Probe frequently observes in the inner heliosphere. Their ubiquitous occurrence has prompted numerous studies to determine their nature and origin. Our go…

Are Switchback boundaries observed by Parker Solar Probe closed? Open

Nina Bizien, Thierry Dudok de Wit, C. Froment, M. Velli, A. W. Case , et al. · 2023

Switchbacks are sudden and large deflections in the magnetic field that Parker Solar Probe frequently observes in the inner heliosphere. Their ubiquitous occurrence has prompted numerous studies to determine their nature and origin. Our go…

On the Evolution of the Anisotropic Scaling of Magnetohydrodynamic Turbulence in the Inner Heliosphere Open

Nikos Sioulas, M. Velli, Zesen Huang, Chen Shi, Trevor A. Bowen , et al. · 2023

We analyze a merged Parker Solar Probe (PSP) and Solar Orbiter (SO) data set covering heliocentric distances 13 R ⊙ ≲ R ≲ 220 R ⊙ to investigate the radial evolution of power and spectral index anisotropy in the wavevector space of solar w…

New Observations of Solar Wind 1/f Turbulence Spectrum from Parker Solar Probe Open

Zesen Huang, Nikos Sioulas, Chen Shi, M. Velli, Trevor A. Bowen , et al. · 2023

The trace magnetic power spectrum in the solar wind is known to be characterized by a double power law at scales much larger than the proton gyro-radius, with flatter spectral exponents close to −1 found at the lower frequencies below an i…

New Observations of Solar Wind 1/f Turbulence Spectrum from Parker Solar Probe Open

Zesen Huang, Nikos Sioulas, Chen Shi, M. Velli, Trevor A. Bowen , et al. · 2023

The trace magnetic power spectrum in the solar wind is known to be characterized by a double power law at scales much larger than the proton gyro-radius, with flatter spectral exponents close to -1 found at the lower frequencies below an i…

On the evolution of the Anisotropic Scaling of Magnetohydrodynamic Turbulence in the Inner Heliosphere Open

Nikos Sioulas, M. Velli, Zesen Huang, Chen Shi, Trevor A. Bowen , et al. · 2023

We analyze a merged Parker Solar Probe ($PSP$) and Solar Orbiter ($SO$) dataset covering heliocentric distances $13 \ R_{\odot} \lesssim R \lesssim 220$ $R_{\odot}$ to investigate the radial evolution of power and spectral-index anisotropy…

Magnetic Field Spectral Evolution in the Inner Heliosphere Open

Nikos Sioulas, Zesen Huang, Chen Shi, M. Velli, Anna Tenerani , et al. · 2023

Parker Solar Probe and Solar Orbiter data are used to investigate the radial evolution of magnetic turbulence between 0.06 ≲ R ≲ 1 au. The spectrum is studied as a function of scale, normalized to the ion inertial scale d i . In the vicini…

Observations of Quiescent Solar Wind Regions with Near-f ce Wave Activity Open

Benjamin Short, D. Malaspina, J. S. Halekas, Orlando Romeo, J. L. Verniero , et al. · 2022

In situ measurements in the near-Sun solar wind from the Parker Solar Probe have revealed the existence of quiescent solar wind regions: extended regions of solar wind with low-amplitude turbulent magnetic field fluctuations compared to ad…

Observation and Modeling of the Solar Wind Turbulence Evolution in the Sub-Mercury Inner Heliosphere Open

Daniele Telloni, L. Adhikari, G. P. Zank, Lina Hadid, Beatriz Sánchez‐Cano , et al. · 2022

This letter exploits the radial alignment between the Parker Solar Probe and BepiColombo in late 2022 February, when both spacecraft were within Mercury’s orbit. This allows the study of the turbulent evolution, namely, the change in spect…

Magnetic field spectral evolution in the inner heliosphere Open

Nikos Sioulas, Zesen Huang, Chen Shi, M. Velli, Anna Tenerani , et al. · 2022

Parker Solar Probe and Solar Orbiter data are used to investigate the radial evolution of magnetic turbulence between $0.06 ~ \lesssim R ~\lesssim 1$ au. The spectrum is studied as a function of scale, normalized to the ion inertial scale …

Switchbacks in the Young Solar Wind: Electron Evolution Observed inside Switchbacks between 0.125 au and 0.25 au Open

Raaman Nair, J. S. Halekas, P. L. Whittlesey, D. E. Larson, R. Livi , et al. · 2022

Switchbacks are localized deviations from the nominal Parker spiral field in the solar wind. In this study, we investigate the electron distributions inside switchbacks, focusing primarily on the suprathermal (halo and strahl) populations.…

The Radial Evolution of the Solar Wind as Organized by Electron Distribution Parameters Open

J. S. Halekas, P. L. Whittlesey, D. E. Larson, M. Maksimović, R. Livi , et al. · 2022

We utilize observations from the Parker Solar Probe (PSP) to study the radial evolution of the solar wind in the inner heliosphere. We analyze electron velocity distribution functions observed by the Solar Wind Electrons, Alphas, and Proto…

Patches of Magnetic Switchbacks and Their Origins Open

Chen Shi, O. Panasenco, M. Velli, Anna Tenerani, J. L. Verniero , et al. · 2022

Parker Solar Probe (PSP) has shown that the solar wind in the inner heliosphere is characterized by the quasi omnipresence of magnetic switchbacks (“switchback” hereinafter), local backward bends of magnetic field lines. Switchbacks also t…

Magnetic Field Dropouts and Associated Plasma Wave Emission near the Electron Plasma Frequency at Switchback Boundaries as Observed by the Parker Solar Probe Open

Anthony P. Rasca, W. M. Farrell, P. L. Whittlesey, R. J. MacDowall, S. D. Bale , et al. · 2022

The first solar encounters by the Parker Solar Probe revealed the magnetic field to be dominated by short field reversals in the radial direction, referred to as “switchbacks.” While radial velocity and proton temperature were shown to inc…

Linking Small-scale Solar Wind Properties with Large-scale Coronal Source Regions through Joint Parker Solar Probe–Metis/Solar Orbiter Observations Open

Daniele Telloni, G. P. Zank, L. Sorriso‐Valvo, R. D’Amicis, O. Panasenco , et al. · 2022

The solar wind measured in situ by Parker Solar Probe in the very inner heliosphere is studied in combination with the remote-sensing observation of the coronal source region provided by the METIS coronagraph aboard Solar Orbiter. The coro…

Parker Solar Probe Observations of Solar Wind Energetic Proton Beams Produced by Magnetic Reconnection in the Near‐Sun Heliospheric Current Sheet Open

T. D. Phan, J. L. Verniero, D. E. Larson, B. Lavraud, J. F. Drake , et al. · 2022

We report observations of reconnection exhausts in the Heliospheric Current Sheet (HCS) during Parker Solar Probe Encounters 08 and 07, at 16 R s and 20 R s , respectively. Heliospheric current sheet (HCS) reconnection accelerated protons …

First Results From the SCM Search‐Coil Magnetometer on Parker Solar Probe Open

Thierry Dudok de Wit, V. Krasnoselskikh, O. V. Agapitov, C. Froment, A. Larosa , et al. · 2022

Parker Solar Probe is the first mission to probe in situ the innermost heliosphere, revealing an exceptionally dynamic and structured outer solar corona. Its payload includes a search‐coil magnetometer (SCM) that measures up to three compo…

Correlated Magnetic Field Dropouts and Plasma Wave Activity at Switchback Boundaries as Observed by Parker Solar Probe Open

Anthony P. Rasca, W. M. Farrell, R. J. MacDowall, S. D. Bale, J. C. Kasper · 2022

The first solar encounters by the Parker Solar Probe revealed the magnetic field to be dominated by short field reversals in the radial direction referred to as "switchbacks."  While rad…

Langmuir-Slow Extraordinary Mode Magnetic Signature Observations with Parker Solar Probe Open

A. Larosa, Thierry Dudok de Wit, V. Krasnoselskikh, S. D. Bale, O. V. Agapitov , et al. · 2022

Radio emission from interplanetary shocks, planetary foreshocks, and some solar flares occurs in the so-called “plasma emission” framework. The generally accepted scenario begins with electrostatic Langmuir waves that are driven by a supra…

Suprathermal Ion Energy Spectra and Anisotropies near the Heliospheric Current Sheet Crossing Observed by the Parker Solar Probe during Encounter 7 Open

M. I. Desai, D. G. Mitchell, D. J. McComas, J. F. Drake, T. D. Phan , et al. · 2022

We present observations of ≳10–100 keV nucleon −1 suprathermal (ST) H, He, O, and Fe ions associated with crossings of the heliospheric current sheet (HCS) at radial distances of <0.1 au from the Sun. Our key findings are as follows: (1) v…

Erratum: “The Role of Alfvén Wave Dynamics on the Large-scale Properties of the Solar Wind: Comparing an MHD Simulation with Parker Solar Probe E1 data” (2020, ApJS, 246, 24) Open

Victor Réville, M. Velli, O. Panasenco, Anna Tenerani, Chen Shi , et al. · 2022

\nDuring Parker Solar Probe's first orbit, the solar wind plasma was observed in situ closer than ever before, the perihelion on 2018 November 6 revealing a flow that is constantly permeated by large-amplitude Alfvénic fluc…

Improving the Alfvén Wave Solar Atmosphere Model Based on Parker Solar Probe Data Open

B. van der Holst, Jia Huang, Nishtha Sachdeva, J. C. Kasper, W. B. Manchester , et al. · 2022

In van der Holst et al. (2019), we modeled the solar corona and inner heliosphere of the first encounter of NASA’s Parker Solar Probe (PSP) using the Alfvén Wave Solar atmosphere Model (AWSoM) with Air Force Data Assimilative Photospheric …

Flux Rope Merging and the Structure of Switchbacks in the Solar Wind Open

O. V. Agapitov, J. F. Drake, M. Swisdak, S. D. Bale, T. S. Horbury , et al. · 2022

A major discovery of Parker Solar Probe (PSP) was the presence of large numbers of localized increases in the radial solar wind speed and associated sharp deflections of the magnetic field—switchbacks (SBs). A possible generation mechanism…

Sub-Alfvénic Solar Wind Observed by the Parker Solar Probe: Characterization of Turbulence, Anisotropy, Intermittency, and Switchback Open

R. Bandyopadhyay, W. H. Matthaeus, D. J. McComas, Rohit Chhiber, A. V. Usmanov , et al. · 2022

In the lower solar coronal regions where the magnetic field is dominant, the Alfvén speed is much higher than the wind speed. In contrast, the near-Earth solar wind is strongly super-Alfvénic, i.e., the wind speed greatly exceeds the Alfvé…

Ambipolar Electric Field and Potential in the Solar Wind Estimated from Electron Velocity Distribution Functions Open

Laura Berčič, M. Maksimović, J. S. Halekas, Smone Landi, C. J. Owen , et al. · 2021

The solar wind escapes from the solar corona and is accelerated, over a short distance, to its terminal velocity. The energy balance associated with this acceleration remains poorly understood. To quantify the global electrostatic contribu…

Exploring the Solar Wind from Its Source on the Corona into the Inner Heliosphere during the First Solar Orbiter–Parker Solar Probe Quadrature Open

Daniele Telloni, V. Andretta, E. Antonucci, А. Бемпорад, G. Capuano , et al. · 2021

This Letter addresses the first Solar Orbiter (SO)–Parker Solar Probe (PSP) quadrature, occurring on 2021 January 18 to investigate the evolution of solar wind from the extended corona to the inner heliosphere. Assuming ballistic propagati…

Field‐Aligned Electron Density Distribution of the Inner Magnetosphere Inferred From Coordinated Observations of Arase and Van Allen Probes Open

Yuki Obana, Yukinaga Miyashita, Naomi Maruyama, Atsuki Shinbori, M. Nosé , et al. · 2021

The Radiation Belt Storm Probes (RBSP) and the Arase satellites have different inclinations and sometimes they fly both near the equator and off the equator on the same magnetic field line simultaneously. Such conjunction events give us op…

Dust Directionality and an Anomalous Interplanetary Dust Population Detected by the Parker Solar Probe Open

A. Pusack, D. Malaspina, J. R. Szalay, S. D. Bale, K. Goetz , et al. · 2021

Theory and previous space missions indicate there are several populations of zodiacal dust. The most prominent populations are grains on bound elliptic orbits ( α -meteoroids), and β -meteoroids on hyperbolic escape trajectories governed l…

Flux rope merging and the structure of switchbacks in the solar wind Open

J. F. Drake, M. Swisdak, S. D. Bale, J. C. Kasper, R. J. MacDowall , et al. · 2021

A major discovery of Parker Solar Probe (PSP) was the presence of large numbers of localized increases in the radial solar wind speed and associated sharp deflections of the magnetic field - switchbacks (SB). A possible generation mechanis…

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