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Notice:
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Found 287 entries in the Bibliography.
Showing entries from 51 through 100
| 2022 |
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The Imprint of Intermittent Interchange Reconnection on the Solar Wind The solar wind is known to be highly structured in space and time. Observations from Parker Solar Probe have revealed an abundance of so-called magnetic switchbacks within the near-Sun solar wind. In this Letter, we use a high-resolution, adaptive-mesh, magnetohydrodynamics simulation to explore the disturbances launched into the solar wind by intermittent/bursty interchange reconnection and how they may be related to magnetic switchbacks. We find that repeated ejection of plasmoid flux ropes into the solar wind produces a c ... Wyper, Peter; DeVore, C.~R.; Antiochos, S.~K.; Pontin, D.~I.; Higginson, Aleida; Scott, Roger; Masson, Sophie; Pelegrin-Frachon, Theo; Published by: \apjl Published on: dec YEAR: 2022 DOI: 10.3847/2041-8213/aca8ae Parker Data Used; Solar corona; Solar coronal holes; Solar wind; Solar magnetic reconnection; Solar magnetic fields; Solar Physics; 1483; 1484; 1534; 1504; 1503; 1476 |
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Thermal Energy Budget of Electrons in the Inner Heliosphere: Parker Solar Probe Observations We present an observational analysis of the electron thermal energy budget using data from Parker Solar Probe. We use the macroscopic moments, obtained from our fits to the measured electron distribution function, to evaluate the thermal energy budget based on the second moment of the Boltzmann equation. We separate contributions to the overall budget from reversible and irreversible processes. We find that an irreversible thermal energy source must be present in the inner heliosphere over the heliocentric distance range fro ... Abraham, Joel; Verscharen, Daniel; Wicks, Robert; Rueda, Jeffersson; Owen, Christopher; Nicolaou, Georgios; Jeong, Seong-Yeop; Published by: \apj Published on: dec YEAR: 2022 DOI: 10.3847/1538-4357/ac9fd8 Parker Data Used; The Sun; Solar wind; Heliosphere; Plasma physics; 1693; 1534; 711; 2089; Astrophysics - Solar and Stellar Astrophysics; Physics - Geophysics; Physics - Plasma Physics; Physics - Space Physics |
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Statistical classification of the Helios solar wind observations into several populations sorted by bulk speed has revealed an outward acceleration of the wind. The faster the wind, the smaller this acceleration in the 0.3-1 au radial range. In this paper, we show that recent measurements from the Parker Solar Probe (PSP) are compatible with an extension closer to the Sun of the latter Helios classification. For instance, the well-established bulk speed/proton temperature (u, T $_p$) correlation and bulk speed/electron tempe ... Dakeyo, Jean-Baptiste; Maksimovic, Milan; emoulin, Pascal; Halekas, Jasper; Stevens, Michael; Published by: \apj Published on: dec YEAR: 2022 DOI: 10.3847/1538-4357/ac9b14 Parker Data Used; Solar wind; Interplanetary particle acceleration; Slow solar wind; Astronomy data modeling; 1534; 826; 1873; 1859 |
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We study the radial evolution, from 0.1 AU to the Earth, of a homogeneous recurrent fast wind, coming from the same source on the Sun, by means of new measurements by both Solar Orbiter and Parker Solar Probe. With respect to previous radial studies, we extend, for the first time, the analysis of a recurrent fast stream at distances never reached prior to the Parker Solar Probe mission. Confirming previous findings, the observations show: (i) a decrease in the radial trend of the proton density that is slower than the one ex ... Perrone, D.; Perri, S.; Bruno, R.; Stansby, D.; Amicis, R.; Jagarlamudi, V.~K.; Laker, R.; Toledo-Redondo, S.; Stawarz, J.~E.; Telloni, D.; De Marco, R.; Owen, C.~J.; Raines, J.~M.; Settino, A.; Lavraud, B.; Maksimovic, M.; Vaivads, A.; Phan, T.~D.; Fargette, N.; Louarn, P.; Zouganelis, I.; Published by: \aap Published on: dec YEAR: 2022 DOI: 10.1051/0004-6361/202243989 |
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As a key feature, NASA s Parker Solar Probe (PSP) and ESA-NASA s Solar Orbiter (SO) missions cooperate to trace solar wind and transients from their sources on the Sun to the inner interplanetary space. The goal of this work is to accurately reconstruct the interplanetary Parker spiral and the connection between coronal features observed remotely by the Metis coronagraph on-board SO and those detected in situ by PSP at the time of the first PSP-SO quadrature of January 2021. We use the Reverse in situ and MHD Approach (RIMAP ... Biondo, Ruggero; Bemporad, Alessandro; Pagano, Paolo; Telloni, Daniele; Reale, Fabio; Romoli, Marco; Andretta, Vincenzo; Antonucci, Ester; Da Deppo, Vania; De Leo, Yara; Fineschi, Silvano; Heinzel, Petr; Moses, Daniel; Naletto, Giampiero; Nicolini, Gianalfredo; Spadaro, Daniele; Stangalini, Marco; Teriaca, Luca; Landini, Federico; Sasso, Clementina; Susino, Roberto; Jerse, Giovanna; Uslenghi, Michela; Pancrazzi, Maurizio; Published by: \aap Published on: dec YEAR: 2022 DOI: 10.1051/0004-6361/202244535 Parker Data Used; magnetohydrodynamics (MHD); methods: numerical; Solar wind; Sun: heliosphere; Sun: corona; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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Modeling the 2020 November 29 solar energetic particle event using EUHFORIA and iPATH models \ Aims: We present the implementation of a coupling between EUropean Heliospheric FORcasting Information Asset (EUHFORIA) and improved Particle Acceleration and Transport in the Heliosphere (iPATH) models. In this work, we simulate the widespread solar energetic particle (SEP) event of 2020 November 29 and compare the simulated time-intensity profiles with measurements at Parker Solar Probe (PSP), the Solar Terrestrial Relations Observatory (STEREO)-A, SOlar and Heliospheric Observatory (SOHO), and Solar Orbiter. We focus on ... Ding, Zheyi; Wijsen, Nicolas; Li, Gang; Poedts, Stefaan; Published by: \aap Published on: dec YEAR: 2022 DOI: 10.1051/0004-6361/202244732 Parker Data Used; Solar wind; Sun: magnetic fields; Sun: coronal mass ejections (CMEs); acceleration of particles; Sun: particle emission; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics |
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Parker Solar Probe (PSP) and SolO data are utilized to investigate magnetic field intermittency in the solar wind (SW). Small-scale intermittency (20-100 d $_ i $) is observed to radially strengthen when methods relying on higher-order moments are considered (SF$_ q $; SDK), but no clear trend is observed at larger scales. However, lower-order moment-based methods (e.g., partial variance of increments; PVI) are deemed more appropriate for examining the evolution of the bulk of coherent structures (CSs), PVI \ensuremath\geq 3 ... Sioulas, Nikos; Huang, Zesen; Velli, Marco; Chhiber, Rohit; Cuesta, Manuel; Shi, Chen; Matthaeus, William; Bandyopadhyay, Riddhi; Vlahos, Loukas; Bowen, Trevor; Qudsi, Ramiz; Bale, Stuart; Owen, Christopher; Louarn, P.; Fedorov, A.; c, Milan; Stevens, Michael; Case, Anthony; Kasper, Justin; Larson, Davin; Pulupa, Marc; Livi, Roberto; Published by: \apj Published on: aug YEAR: 2022 DOI: 10.3847/1538-4357/ac7aa2 Parker Data Used; Solar wind; interplanetary turbulence; Magnetohydrodynamics; Space plasmas; Plasma astrophysics; Solar Physics; 1534; 830; 1964; 1544; 1261; 1476; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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Tracking of magnetic helicity evolution in the inner heliosphere. A radial alignment study Context. Magnetic helicity is one of the invariants in ideal magnetohydrodynamics, and its spectral evolution has a substantial amount of information to reveal the mechanism that are behind turbulence in space and astrophysical plasmas. \ Aims: The goal of our study is to observationally characterize the magnetic helicity evolution in the inner heliosphere by resolving the helicity transport in a scale-wise fashion in the spectral domain. \ Methods: The evolution of the magnetic helicity spectrum in the inner heliosphere was ... Alberti, T.; Narita, Y.; Hadid, L.~Z.; Heyner, D.; Milillo, A.; Plainaki, C.; Auster, H.; Richter, I.; Published by: \aap Published on: aug YEAR: 2022 DOI: 10.1051/0004-6361/202244314 Parker Data Used; Solar wind; Sun: fundamental parameters; Sun: heliosphere |
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Small-Scale Magnetic Holes in the Solar Wind Observed by Parker Solar Probe The small-scale magnetic hole (SSMH), characterized by magnetic field depression, is a structure with the size in the order of proton gyro-radius. SSMHs near the Earth or other planets have been widely observed in recent years. However, SSMHs in the solar wind near the Sun are rarely investigated due to mission constraints. In the present study, SSMHs in the pristine solar wind within a wide heliocentric distance range are analyzed based on the Parker Solar Probe (PSP) Mission measurements. A total of 2,416 SSMHs are success ... Yu, L.; Huang, S.~Y.; Yuan, Z.~G.; Jiang, K.; Wei, Y.~Y.; Zhang, J.; Xu, S.~B.; Xiong, Q.~Y.; Wang, Z.; Lin, R.~T.; Li, Y.~J.; Wang, C.~M.; Song, G.~J.; Published by: Journal of Geophysical Research (Space Physics) Published on: aug YEAR: 2022 DOI: 10.1029/2022JA030505 Parker Data Used; Solar wind; small-scale magnetic hole; PSP |
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Solar Chromospheric Network as a Source for Solar Wind Switchbacks Recent studies suggest that the magnetic switchbacks (SBs) detected by the Parker Solar Probe carry information on the scales of solar supergranulation (large scale) and granulation (medium scale). We test this claim using high-resolution H\ensuremath\alpha images obtained with the visible spectropolarimeters of the Goode Solar Telescope in Big Bear Solar Observatory. As possible solar sources, we count all the spicule-like features standing along the chromospheric networks near the coronal hole boundary visible in the H\ens ... Lee, Jeongwoo; Yurchyshyn, Vasyl; Wang, Haimin; Yang, Xu; Cao, Wenda; Oliveros, Juan; Published by: \apjl Published on: aug YEAR: 2022 DOI: 10.3847/2041-8213/ac86bf Parker Data Used; Solar magnetic fields; Solar chromosphere; Solar wind; interplanetary magnetic fields; 1503; 1479; 1534; 824 |
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The solar wind undergoes significant heating as it propagates away from the Sun; the exact mechanisms responsible for this heating remain unclear. Using data from the first perihelion of the Parker Solar Probe mission, we examine the properties of proton and electron heating occurring within magnetic coherent structures identified by means of the Partial Variance of Increments (PVI) method. Statistically, regions of space with strong gradients in the magnetic field, PVI \ensuremath\geq 1, are associated with strongly enhance ... Sioulas, Nikos; Shi, Chen; Huang, Zesen; Velli, Marco; Published by: \apjl Published on: aug YEAR: 2022 DOI: 10.3847/2041-8213/ac85de Parker Data Used; Solar wind; Solar coronal heating; interplanetary turbulence; Magnetohydrodynamics; 1534; 1989; 830; 1964; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
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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 coronal outflows observed near the ecliptic by Metis on 2021 January 17 at 16:30 UT, between 3.5 and 6.3 R $_\ensuremath\odot$ above the eastern solar limb, can be associated with the streams sampled by PSP at 0.11 and 0.26 au from the Sun, in two time intervals almost 5 days apart. The two pla ... Telloni, Daniele; Zank, Gary; Sorriso-Valvo, Luca; Amicis, Raffaella; Panasenco, Olga; Susino, Roberto; Bruno, Roberto; Perrone, Denise; Adhikari, Laxman; Liang, Haoming; Nakanotani, Masaru; Zhao, Lingling; Hadid, Lina; anchez-Cano, Beatriz; Verscharen, Daniel; Velli, Marco; Grimani, Catia; Marino, Raffaele; Carbone, Francesco; Mancuso, Salvatore; Biondo, Ruggero; Pagano, Paolo; Reale, Fabio; Bale, Stuart; Kasper, Justin; Case, Anthony; de Wit, Thierry; Goetz, Keith; Harvey, Peter; Korreck, Kelly; Larson, Davin; Livi, Roberto; MacDowall, Robert; Malaspina, David; Pulupa, Marc; Stevens, Michael; Whittlesey, Phyllis; Romoli, Marco; Andretta, Vincenzo; Da Deppo, Vania; Fineschi, Silvano; Heinzel, Petr; Moses, John; Naletto, Giampiero; Nicolini, Gianalfredo; Spadaro, Daniele; Stangalini, Marco; Teriaca, Luca; Capobianco, Gerardo; Capuano, Giuseppe; Casini, Chiara; Casti, Marta; Chioetto, Paolo; Corso, Alain; De Leo, Yara; Fabi, Michele; Frassati, Federica; Frassetto, Fabio; Giordano, Silvio; Guglielmino, Salvo; Jerse, Giovanna; Landini, Federico; Liberatore, Alessandro; Magli, Enrico; Massone, Giuseppe; Messerotti, Mauro; Pancrazzi, Maurizio; Pelizzo, Maria; Romano, Paolo; Sasso, Clementina; Schühle, Udo; Slemer, Alessandra; Straus, Thomas; Uslenghi, Michela; Volpicelli, Cosimo; Zangrilli, Luca; Zuppella, Paola; Abbo, Lucia; Auchère, Fr\; Cuadrado, Regina; Berlicki, Arkadiusz; Ciaravella, Angela; Lamy, Philippe; Lanzafame, Alessandro; Malvezzi, Marco; Nicolosi, Piergiorgio; o, Giuseppe; Peter, Hardi; Solanki, Sami; Strachan, Leonard; Tsinganos, Kanaris; Ventura, Rita; Vial, Jean-Claude; Woch, Joachim; Zimbardo, Gaetano; Published by: \apj Published on: aug YEAR: 2022 DOI: 10.3847/1538-4357/ac8103 Parker Data Used; H II regions; Alfven waves; Space plasmas; interplanetary turbulence; Solar corona; Heliosphere; Solar wind; 694; 23; 1544; 830; 1483; 711; 1534 |
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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 increase inside the switchbacks, \ensuremath\midB\ensuremath\mid exhibits very brief dropouts only at the switchback boundaries. Brief intensifications in spectral density measurements near the electron plasma frequency, f $_pe$, were also observed at these boundaries, indicating the presenc ... Rasca, Anthony; Farrell, William; Whittlesey, Phyllis; MacDowall, Robert; Bale, Stuart; Kasper, Justin; Published by: \apj Published on: aug YEAR: 2022 DOI: 10.3847/1538-4357/ac80c3 Parker Data Used; Solar magnetic fields; Plasma physics; Solar wind; 1503; 2089; 1534 |
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New Insights into the First Two PSP Solar Encounters Enabled by Modeling Analysis with ADAPT-WSA Parker Solar Probe s (PSP s) unique orbital path allows us to observe the solar wind closer to the Sun than ever before. Essential to advancing our knowledge of solar wind and energetic particle formation is identifying the sources of PSP observations. We report on results for the first two PSP solar encounters derived using the Wang-Sheeley-Arge (WSA) model driven by Air Force Data Assimilative Photospheric Flux Transport (ADAPT) model maps. We derive the coronal magnetic field and the 1 R $_\ensuremath\odot$ source regions ... Wallace, Samantha; Jones, Shaela; Arge, Nick; Viall, Nicholeen; Henney, Carl; Published by: \apj Published on: aug YEAR: 2022 DOI: 10.3847/1538-4357/ac731c Parker Data Used; Solar wind; Solar magnetic fields; Solar corona; 1534; 1503; 1483; Astrophysics - Solar and Stellar Astrophysics |
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During its 10th orbit around the Sun, the Parker Solar Probe sampled two intervals where the local Alfv\ en speed exceeded the solar wind speed, lasting more than 10 hours in total. In this paper, we analyze the turbulence and wave properties during these periods. The turbulence is observed to be Alfv\ enic and unbalanced, dominated by outward-propagating modes. The power spectrum of the outward-propagating Elsässer z $^+$ mode steepens at high frequencies while that of the inward- propagating z $^-$ mode flattens. The obse ... Zhao, L.; Zank, G.~P.; Adhikari, L.; Telloni, D.; Stevens, M.; Kasper, J.~C.; Bale, S.~D.; Raouafi, N.~E.; Published by: \apjl Published on: aug YEAR: 2022 DOI: 10.3847/2041-8213/ac8353 Parker Data Used; Solar Coronal Waves; interplanetary turbulence; Solar wind; 1995; 830; 1534 |
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Patches of Magnetic Switchbacks and Their Origins 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 tend to come in patches, with a large-scale modulation that appears to have a spatial scale size comparable to supergranulation on the Sun. Here we inspect data from the first 10 encounters of PSP focusing on different time intervals when clear switchback patches were observed by PSP. We s ... Shi, Chen; Panasenco, Olga; Velli, Marco; Tenerani, Anna; Verniero, Jaye; Sioulas, Nikos; Huang, Zesen; Brosius, A.; Bale, Stuart; Klein, Kristopher; Kasper, Justin; de Wit, Thierry; Goetz, Keith; Harvey, Peter; MacDowall, Robert; Malaspina, David; Pulupa, Marc; Larson, Davin; Livi, Roberto; Case, Anthony; Stevens, Michael; Published by: \apj Published on: aug YEAR: 2022 DOI: 10.3847/1538-4357/ac7c11 Parker Data Used; Solar wind; Solar corona; Solar prominences; interplanetary turbulence; 1534; 1483; 1519; 830; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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The Turbulent Properties of the Sub-Alfv\ enic Solar Wind Measured by the Parker Solar Probe For the first time, Parker Solar Probe (PSP) observed the sub- Alfv\ enic solar wind where the solar wind bulk speed drops below the local Alfv\ en speed for an extended period of time. Here, we report on the turbulent properties of the sub- Alfv\ enic region. We analyze the turbulence correlation length and the energy transfer and compare the results with nearby super-Alfv\ enic regions. As the Alfv\ en speed is larger or comparable to the solar wind speed in the intervals studied, we use a modified Taylor s hypothesis to a ... Zhao, L.; Zank, G.~P.; Telloni, D.; Stevens, M.; Kasper, J.~C.; Bale, S.~D.; Published by: \apjl Published on: apr YEAR: 2022 DOI: 10.3847/2041-8213/ac5fb0 Parker Data Used; Solar wind; interplanetary turbulence; 1534; 830 |
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Using Single-view Observations of Cometary Plasma Tails to Infer Solar Wind Speed A comet plasma tail is a product of the interaction between the solar wind and the comet s coma, and has long been studied as a natural probe of the solar wind condition. We previously developed a method to derive the solar wind speed from dual-view observations of comet plasma tails. Here we improve the method to use single-view observations by assuming a radially propagating solar wind and apply it to two comets, C/2011 W3 (Lovejoy) and C/2012 S1 (ISON) observed by coronagraphs on board the Solar and Heliospheric Observato ... Cheng, Long; Wang, Yuming; Li, Xiaolei; Published by: \apj Published on: apr YEAR: 2022 DOI: 10.3847/1538-4357/ac5410 |
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Quasi-Thermal Noise (QTN) spectroscopy is a reliable diagnostic routinely used for measuring electron density and temperature in space plasmas. The observed spectrum depends on both antenna geometry and plasma kinetic properties. Parker solar probe (PSP), launched in 2018, is equipped with an antenna system consisting of two linear dipoles with a significant gap between the antenna arms. Such a configuration, not utilized on previous missions, cannot be completely described by current models of the antenna response function. ... c, Mihailo; c, Antonije; Klein, Kristopher; c, Milan; Issautier, Karine; Liu, Mingzhe; Pulupa, Marc; Bale, Stuart; Halekas, Jasper; McManus, Michael; Published by: Journal of Geophysical Research (Space Physics) Published on: apr YEAR: 2022 DOI: 10.1029/2021JA030182 Parker Data Used; quasi-thermal noise; Solar wind; antenna response |
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First Results From the SCM Search-Coil Magnetometer on Parker Solar Probe 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 components of the fluctuating magnetic field between 3 Hz and 1 MHz. After more than 3 years of operation, the SCM has revealed a multitude of different wave phenomena in the solar wind. Here we present an overview of some of the discoveries made so far. These include oblique and sunward propaga ... de Wit, Dudok; Krasnoselskikh, V.~V.; Agapitov, O.; Froment, C.; Larosa, A.; Bale, S.~D.; Bowen, T.; Goetz, K.; Harvey, P.; Jannet, G.; Kretzschmar, M.; MacDowall, R.~J.; Malaspina, D.; Martin, P.; Page, B.; Pulupa, M.; Revillet, C.; Published by: Journal of Geophysical Research (Space Physics) Published on: apr YEAR: 2022 DOI: 10.1029/2021JA030018 Parker Data Used; Solar wind; magnetic field; search-coil; plasma waves |
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Solar Wind Model Supported by Parker Solar Probe Observations During Faint Venusian Auroral Emission The encounter of the Parker Solar Probe (PSP) with Venus during the Venus Gravity Assist 3 on 2020 July 11 provided a unique opportunity to gather in situ solar wind data in the Venusian environment while also being able to observe Venus from ground- based facilities on Earth. The Wang-Sheeley-Arge (WSA) model was used to make accurate predictions of solar wind velocity and interplanetary magnetic field polarity at Earth and STEREO-A, as compared to in situ data at each spacecraft. The same model was then used to predict sol ... Kovac, Sarah; Gray, Candace; Arge, Nick; Chanover, Nancy; Churchill, Christopher; Szabo, Adam; Hill, Matthew; McAteer, James; Published by: \apj Published on: apr YEAR: 2022 DOI: 10.3847/1538-4357/ac58f4 Parker Data Used; Solar wind; Venus; Aurorae; 1534; 1763; 2192 |
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Markovian Features of the Solar Wind at Subproton Scales The interplanetary magnetic field carried out from the Sun by the solar wind displays fluctuations over a wide range of scales. While at large scales, say at frequencies lower than 0.1-1 Hz, fluctuations display the universal character of fully developed turbulence with a well-defined Kolmogorov-like inertial range, the physical and dynamical properties of the small-scale regime as well as their connection with the large-scale ones are still a debated topic. In this work we investigate the near-Sun magnetic field fluctuation ... Benella, Simone; Stumpo, Mirko; Consolini, Giuseppe; Alberti, Tommaso; Carbone, Vincenzo; Laurenza, Monica; Published by: \apjl Published on: apr YEAR: 2022 DOI: 10.3847/2041-8213/ac6107 Parker Data Used; Solar wind; interplanetary turbulence; Magnetohydrodynamics; Heliosphere; Interplanetary physics; Space plasmas; 1534; 830; 1964; 711; 827; 1544; Physics - Space Physics; Physics - Data Analysis; Statistics and Probability; Physics - Plasma Physics |
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Using the Parker Solar Probe data taken in the inner heliosphere, we investigate the power and spatial anisotropy of magnetic field spectra at kinetic scales (i.e., around sub-ion scales) in solar wind turbulence in the inner heliosphere. We find that strong anisotropy of the magnetic spectra occurs at kinetic scales with the strongest power in the perpendicular direction with respect to the local magnetic field (forming an angle \ensuremath\theta $_B$ with the mean flow velocity). The spectral index of the magnetic spectra ... Huang, S.~Y.; Xu, S.~B.; Zhang, J.; Sahraoui, F.; es, Andr\; He, J.~S.; Yuan, Z.~G.; Deng, X.~H.; Jiang, K.; Wei, Y.~Y.; Xiong, Q.~Y.; Wang, Z.; Yu, L.; Lin, R.~T.; Published by: \apjl Published on: apr YEAR: 2022 DOI: 10.3847/2041-8213/ac5f02 Parker Data Used; Solar wind; interplanetary turbulence; Heliosphere; Space plasmas; 1534; 830; 711; 1544; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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We present statistical analysis of 11,200 proton kinetic-scale current sheets (CS) observed by the Parker Solar Probe during 10 days around the first perihelion. The CS thickness {\ensuremath{\lambda}} is in the range from a few to 200 km with the typical value around 30 km, while current densities are in the range from 0.1 to 10 {\ensuremath{\mu}}A m$^{-2}$ with the typical value around 0.7 {\ensuremath{\mu}}A m$^{-2}$. These CSs are resolved thanks to magnetic field measurements at 73-290 samples s$^{-1}$ resolution. In te ... Lotekar, A.~B.; Vasko, I.~Y.; Phan, T.; Bale, S.~D.; Bowen, T.~A.; Halekas, J.; Artemyev, A.~V.; Khotyaintsev, Yu.; Mozer, F.~S.; Published by: \apj Published on: apr YEAR: 2022 DOI: 10.3847/1538-4357/ac5bd9 Parker Data Used; Solar wind; interplanetary turbulence; 1534; 830; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
| 2021 |
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We report nonlinear wave-wave coupling related to whistler-mode or electron Bernstein waves in the near-Sun slow solar wind with Parker Solar Probe (PSP) data. Prominent plasma wave power enhancements usually exist near the electron gyrofrequency (f$_ce$), identified as electrostatic whistler-mode and electron Bernstein waves (Malaspina et al. 2020). We find that these plasma waves near f$_ce$ typically have a harmonic spectral structure and further classify them into three types identified by the characteristics of wave fre ... Ma, Jiuqi; Gao, Xinliang; Yang, Zhongwei; Tsurutani, Bruce; Liu, Mingzhe; Lu, Quanming; Wang, Shui; Published by: \apj Published on: sep YEAR: 2021 DOI: 10.3847/1538-4357/ac0ef4 |
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BepiColombo s cruise phase: unique opportunity for synergistic observations The investigation of multi-spacecraft coordinated observations during the cruise phase of BepiColombo (ESA/JAXA) are reported, with a particular emphasis on the recently launched missions, Solar Orbiter (ESA/NASA) and Parker Solar Probe (NASA). Despite some payload constraints, many instruments onboard BepiColombo are operating during its cruise phase simultaneously covering a wide range of heliocentric distances [0.28 AU - 0.5 AU]. Hence, the various spacecraft configurations and the combined in-situ and remote sensing meas ... Hadid, L.~Z.; enot, V.; Aizawa, S.; Milillo, A.; Zender, J.; Murakami, G.; Benkhoff, J.; Zouganelis, I.; Alberti, T.; e, Andr\; Bebesi, Z.; Califano, F.; Dimmock, A.~P.; Dosa, M.; Escoubet, C.~P.; Griton, L.; Ho, G.~C.; Horbury, T.~S.; Iwai, K.; Janvier, M.; Kilpua, E.; Lavraud, B.; Madar, A.; Miyoshi, Y.; Müller, D.; Pinto, R.~F.; Rouillard, A.~P.; Raines, J.~M.; Raouafi, N.; Sahraoui, F.; anchez-Cano, B.; Shiota, D.; Vainio, R.; Walsh, A.; Published by: Frontiers in Astronomy and Space Sciences Published on: sep YEAR: 2021 DOI: 10.3389/fspas.2021.718024 Solar wind; multi-spacecraft measurements; Inner heliosphere; Spacecraft mission; Coordinated measurements |
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Triggered Ion-acoustic Waves in the Solar Wind For more than 12 hr beginning on 2021 January 18, continuous narrowband electrostatic emissions were observed on the Parker Solar Probe near 20 solar radii. The observed <1000 Hz frequencies were well below the local ion-plasma frequency. Surprisingly, the emissions consisted of electrostatic wave packets with shock- like envelopes, appearing repetitively at a \raisebox-0.5ex\textasciitilde1.5 Hz rate. This repetitiveness correlated and was in phase with low-frequency electromagnetic fluctuations. The emissions were associat ... Mozer, F.~S.; Vasko, I.~Y.; Verniero, J.~L.; Published by: \apjl Published on: sep YEAR: 2021 DOI: 10.3847/2041-8213/ac2259 Solar Coronal Waves; Solar wind; 1995; 1534; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Parker Data Used |
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On the Origin of Switchbacks Observed in the Solar Wind The origin of switchbacks in the solar wind is discussed in two classes of theory that differ in the location of the source being either near the transition region near the Sun or in the solar wind itself. The two classes of theory differ in their predictions of the switchback rate (the number of switchbacks observed per hour) as a function of distance from the Sun. To distinguish between these theories, one-hour averages of Parker Solar Probe data were averaged over five orbits to find the following: (1) The hourly averaged ... Mozer, F.~S.; Bale, S.~D.; Bonnell, J.~W.; Drake, J.~F.; Hanson, E.~L.~M.; Mozer, M.~C.; Published by: \apj Published on: sep YEAR: 2021 DOI: 10.3847/1538-4357/ac110d Solar wind; Solar corona; Space plasmas; 1534; 1483; 1544; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics; Parker Data Used |
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The role of solar wind expansion in generating whistler waves is investigated using the EB-iPic3D code, which models solar wind expansion self-consistently within a fully kinetic semi-implicit approach. The simulation is initialized with an electron velocity distribution function modeled after observations of the Parker Solar Probe during its first perihelion at 0.166 au, consisting of a dense core and an antisunward strahl. This distribution function is initially stable with respect to kinetic instabilities. Expansion drive ... Micera, A.; Zhukov, A.~N.; opez, R.~A.; Boella, E.; Tenerani, A.; Velli, M.; Lapenta, G.; Innocenti, M.~E.; Published by: \apj Published on: sep YEAR: 2021 DOI: 10.3847/1538-4357/ac1067 Solar wind; Plasma astrophysics; Space plasmas; 1534; 1261; 1544; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics; Parker Data Used |
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The first computations of the compressible energy transfer rate from \raisebox-0.5ex\textasciitilde0.2 up to \raisebox-0.5ex\textasciitilde1.7 au is obtained using Parker Solar Probe (PSP), Time History of Events and Macroscale Interactions during Substorms (THEMIS), and Mars Atmosphere and Volatile EvolutioN (MAVEN) observations. Using a recently derived exact relation for isothermal magnetohydrodynamics turbulence, the compressible energy cascade rate, \ensuremath\varepsilon$_C$, is computed for hundred of events at differ ... es, Andr\; Sahraoui, F.; Hadid, L.~Z.; Huang, S.~Y.; Romanelli, N.; Galtier, S.; DiBraccio, G.; Halekas, J.; Published by: \apj Published on: sep YEAR: 2021 DOI: 10.3847/1538-4357/ac0af5 Solar wind; Fast solar wind; Slow solar wind; Interplanetary physics; 1534; 1872; 1873; 827; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Parker Data Used |
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Motivated by recent Parker Solar Probe (PSP) observations of switchbacks (abrupt, large-amplitude reversals in the radial magnetic field, which exhibit Alfv\ enic correlations), we examine the dynamics of large-amplitude Alfv\ en waves in the expanding solar wind. We develop an analytic model that makes several predictions: switchbacks should preferentially occur in regions where the solar wind plasma has undergone a greater expansion, the switchback fraction at radii comparable to PSP should be an increasing function of ... Mallet, Alfred; Squire, Jonathan; Chandran, Benjamin; Bowen, Trevor; Bale, Stuart; Published by: \apj Published on: sep YEAR: 2021 DOI: 10.3847/1538-4357/ac0c12 Alfven waves; Magnetohydrodynamics; Solar wind; Space plasmas; 23; 1964; 1534; 1544; Parker Data Used |
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Context. In situ measurements by several spacecraft have revealed that the solar wind is frequently perturbed by transient structures that have been interpreted as magnetic folds, jets, waves, and flux ropes that propagate rapidly away from the Sun over a large range of heliocentric distances. Parker Solar Probe (PSP), in particular, has detected very frequent rotations of the magnetic field vector at small heliocentric radial distances, accompanied by surprisingly large solar wind rotation rates. The physical origin of such ... Pinto, R.~F.; Poirier, N.; Rouillard, A.~P.; Kouloumvakos, A.; Griton, L.; Fargette, N.; Kieokaew, R.; Lavraud, B.; Brun, A.~S.; Published by: \aap Published on: sep YEAR: 2021 DOI: 10.1051/0004-6361/202040180 Sun: corona; Sun: rotation; Solar wind; Astrophysics - Solar and Stellar Astrophysics |
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Parker Solar Probe (PSP) data recorded within a heliocentric radial distance of 0.3 au have revealed a magnetic field dominated by Alfv\ enic structures that undergo large local variations or even reversals of the radial magnetic field. They are called magnetic switchbacks, they are consistent with folds in magnetic field lines within a same magnetic sector and are associated with velocity spikes during an otherwise calmer background. They are thought to originate either in the low solar atmosphere through magnetic reconnect ... Fargette, Na; Lavraud, Benoit; Rouillard, Alexis; eville, Victor; de Wit, Thierry; Froment, Clara; Halekas, Jasper; Phan, Tai; Malaspina, David; Bale, Stuart; Kasper, Justin; Louarn, Philippe; Case, Anthony; Korreck, Kelly; Larson, Davin; Pulupa, Marc; Stevens, Michael; Whittlesey, Phyllis; Berthomier, Matthieu; Published by: \apj Published on: oct YEAR: 2021 DOI: 10.3847/1538-4357/ac1112 Solar wind; Solar Physics; Wavelet analysis; Supergranulation; Solar granulation; Solar magnetic fields; 1534; 1476; 1918; 1662; 1498; 1503; Astrophysics - Solar and Stellar Astrophysics; Parker Data Used |
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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 propagation, the same plasma volume observed remotely in the corona at altitudes between 3.5 and 6.3 solar radii above the solar limb with the Metis coronagraph on SO can be tracked to PSP, orbiting at 0.1 au, thus allowing the local properties of the solar wind to be linked to the coronal source re ... Telloni, Daniele; Andretta, Vincenzo; Antonucci, Ester; Bemporad, Alessandro; Capuano, Giuseppe; Fineschi, Silvano; Giordano, Silvio; Habbal, Shadia; Perrone, Denise; Pinto, Rui; Sorriso-Valvo, Luca; Spadaro, Daniele; Susino, Roberto; Woodham, Lloyd; Zank, Gary; Romoli, Marco; Bale, Stuart; Kasper, Justin; Auchère, Fr\; Bruno, Roberto; Capobianco, Gerardo; Case, Anthony; Casini, Chiara; Casti, Marta; Chioetto, Paolo; Corso, Alain; Da Deppo, Vania; De Leo, Yara; de Wit, Thierry; Frassati, Federica; Frassetto, Fabio; Goetz, Keith; Guglielmino, Salvo; Harvey, Peter; Heinzel, Petr; Jerse, Giovanna; Korreck, Kelly; Landini, Federico; Larson, Davin; Liberatore, Alessandro; Livi, Roberto; MacDowall, Robert; Magli, Enrico; Malaspina, David; Massone, Giuseppe; Messerotti, Mauro; Moses, John; Naletto, Giampiero; Nicolini, Gianalfredo; o, Giuseppe; Panasenco, Olga; Pancrazzi, Maurizio; Pelizzo, Maria; Pulupa, Marc; Reale, Fabio; Romano, Paolo; Sasso, Clementina; Schühle, Udo; Stangalini, Marco; Stevens, Michael; Strachan, Leonard; Straus, Thomas; Teriaca, Luca; Uslenghi, Michela; Velli, Marco; Verscharen, Daniel; Volpicelli, Cosimo; Whittlesey, Phyllis; Zangrilli, Luca; Zimbardo, Gaetano; Zuppella, Paola; Published by: \apjl Published on: oct YEAR: 2021 DOI: 10.3847/2041-8213/ac282f Parker Data Used; Magnetohydrodynamics; Space plasmas; interplanetary turbulence; Solar corona; Heliosphere; Solar wind; 1964; 1544; 830; 1483; 711; 1534; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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Alfv\ en Speed Transition Zone in the Solar Corona The Alfv\ en radius, r$_A$, at which solar wind radial outflow speed exceeds the Alfv\ en wave speed, is an important parameter in understanding solar wind evolution in the extended corona. The mean solar wind angular momentum scales with $r_A^2$ in the axisymmetric steady-state approximation, so the Alfv\ en radius is often referenced in the study of solar wind corotation and dynamics. Alfv\ en wave speed is derived from the magnetic-field intensity and plasma mass density. In the inner coronal regions, these parameters wer ... Wexler, David; Stevens, Michael; Case, Anthony; Song, Paul; Published by: \apjl Published on: oct YEAR: 2021 DOI: 10.3847/2041-8213/ac25fa |
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Evolution of Switchbacks in the Inner Heliosphere We analyze magnetic field data from the first six encounters of Parker Solar Probe, three Helios fast streams and two Ulysses south polar passes covering heliocentric distances 0.1 \ensuremath\lesssim R \ensuremath\lesssim 3 au. We use this data set to statistically determine the evolution of switchbacks of different periods and amplitudes with distance from the Sun. We compare the radial evolution of magnetic field variances with that of the mean square amplitudes of switchbacks, and quantify the radial evolution of the cum ... Tenerani, Anna; Sioulas, Nikos; Matteini, Lorenzo; Panasenco, Olga; Shi, Chen; Velli, Marco; Published by: \apjl Published on: oct YEAR: 2021 DOI: 10.3847/2041-8213/ac2606 Parker Data Used; Heliosphere; Solar wind; interplanetary turbulence; Alfven waves; Space plasmas; 711; 1534; 830; 23; 1544; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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Context. Alfv\ enic fluctuations are ubiquitous features observed in solar wind, especially in the inner heliosphere. However, strong Alfv\ enic fluctuations are recovered in the near-Earth solar wind too, mainly in fast streams, but also in some cases in slow wind intervals, as highlighted in recent studies. \ Aims: The present study focuses on a statistical comparison between different phases of solar cycles 23 and 24 with regard to the Alfv\ enic content of solar wind fluctuations. Particular attention is devoted to the A ... Amicis, R.; Alielden, K.; Perrone, D.; Bruno, R.; Telloni, D.; Raines, J.~M.; Lepri, S.~T.; Zhao, L.; Published by: \aap Published on: oct YEAR: 2021 DOI: 10.1051/0004-6361/202140600 Parker Data Used; plasmas; Sun: heliosphere; Solar wind; turbulence; methods: data analysis; Interplanetary medium |
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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 contribution to the solar wind dynamics, we empirically estimate the ambipolar electric field (E$_\ensuremath\parallel$) and potential (\ensuremath\Phi$_r,\ensuremath\infty$). We analyze electron velocity distribution functions (VDFs) measured in the near-Sun solar wind between 20.3 R$_S$ and 85.3 ... Ber\vci\vc, Laura; c, Milan; Halekas, Jasper; Landi, Simone; Owen, Christopher; Verscharen, Daniel; Larson, Davin; Whittlesey, Phyllis; Badman, Samuel; Bale, Stuart.; Case, Anthony; Goetz, Keith; Harvey, Peter; Kasper, Justin; Korreck, Kelly; Livi, Roberto; MacDowall, Robert; Malaspina, David; Pulupa, Marc; Stevens, Michael; Published by: \apj Published on: nov YEAR: 2021 DOI: 10.3847/1538-4357/ac1f1c Parker Data Used; Solar wind; Space plasmas; Interplanetary particle acceleration; Collision processes; Space vehicle instruments; 1534; 1544; 826; 2065; 1548; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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Macro magnetic holes (MMHs), which are significant magnetic field decreases in the solar wind lasting tens of minutes, were found during the first four orbits of the Parker Solar Probe (PSP). We performed a detailed analysis of the 2020 January 30 event and found the possible cause of the MMH using coordinated remote sensing observations from STEREO A and PSP in situ measurements. The results indicate that an MMH represents a brief encounter with the rippled heliospheric current sheet (HCS). Out of the data from the first fo ... Chen, Chong; Liu, Ying; Hu, Huidong; Published by: \apj Published on: nov YEAR: 2021 DOI: 10.3847/1538-4357/ac1b2b Parker Data Used; Solar wind; Heliosphere; Solar magnetic fields; 1534; 711; 1503 |
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Impact of Switchbacks on Turbulent Cascade and Energy Transfer Rate in the Inner Heliosphere Recent Parker Solar Probe (PSP) observations of inner heliospheric plasma have shown an abundant presence of Alfv\ enic polarity reversal of the magnetic field, known as switchbacks. While their origin is still debated, their role in driving the solar wind turbulence has been suggested through analysis of the spectral properties of magnetic fluctuations. Here, we provide a complementary assessment of their role in the turbulent cascade. The validation of the third-order linear scaling of velocity and magnetic fluctuation ... andez, Carlos; Sorriso-Valvo, Luca; Bandyopadhyay, Riddhi; Chasapis, Alexandros; asconez, Christian; Marino, Raffaele; Pezzi, Oreste; Published by: \apjl Published on: nov YEAR: 2021 DOI: 10.3847/2041-8213/ac36d1 Parker Data Used; interplanetary turbulence; Solar wind; Magnetohydrodynamics; interplanetary magnetic fields; 830; 1534; 1964; 824 |
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Solar Origin of Compressive Alfv\ enic Spikes/Kinks as Observed by Parker Solar Probe The solar wind is found by the Parker Solar Probe to be abundant with Alfv\ enic velocity spikes and magnetic field kinks. Temperature enhancement is another remarkable feature associated with the Alfv\ enic spikes. How the prototype of these coincident phenomena is generated intermittently in the source region is an important and wide-ranging subject. Here we propose a new model introducing guide-field discontinuity into the interchange magnetic reconnection between open funnels and closed loops with different magnetic heli ... He, Jiansen; Zhu, Xingyu; Yang, Liping; Hou, Chuanpeng; Duan, Die; Zhang, Lei; Wang, Ying; Published by: \apjl Published on: may YEAR: 2021 DOI: 10.3847/2041-8213/abf83d Parker Data Used; Solar wind; Alfven waves; Solar atmosphere; Solar magnetic reconnection; 1534; 23; 1477; 1504 |
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Measurement of the open magnetic flux in the inner heliosphere down to 0.13 AU Context. Robustly interpreting sets of in situ spacecraft data of the heliospheric magnetic field (HMF) for the purpose of probing the total unsigned magnetic flux in the heliosphere is critical for constraining global coronal models as well as understanding the large scale structure of the heliosphere itself. The heliospheric flux (\ensuremath\Phi$_H$) is expected to be a spatially conserved quantity with a possible secular dependence on the solar cycle and equal to the measured radial component of the HMF weighted by the s ... Badman, Samuel; Bale, Stuart; Rouillard, Alexis; Bowen, Trevor; Bonnell, John; Goetz, Keith; Harvey, Peter; MacDowall, Robert; Malaspina, David; Pulupa, Marc; Published by: \aap Published on: jun YEAR: 2021 DOI: 10.1051/0004-6361/202039407 Parker Data Used; Sun: corona; Sun: magnetic fields; Sun: heliosphere; Solar wind; methods: data analysis; methods: statistical; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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The Electron Structure of the Solar Wind Time-series measurements of the number density ncore and temperature Tcore of the core-electron population of the solar wind are examined at 1 AU and at 0.13 AU using measurements from the WIND and Parker Solar Probe spacecraft, respectively. A statistical analysis of the ncore and Tcore measurements at 1 AU finds that the core-electron spatial structure of the solar wind is related to the magnetic-flux-tube structure of the solar wind; this electron structure is characterized by jumps in the values of ncore and Tcore when p ... Borovsky, Joseph; Halekas, Jasper; Whittlesey, Phyllis; Published by: Frontiers in Astronomy and Space Sciences Published on: jun YEAR: 2021 DOI: 10.3389/fspas.2021.690005 Parker Data Used; Solar wind; Heliosphere; interplanetary potential; Corona; Magnetic structure |
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Small-scale Magnetic Flux Ropes with Field-aligned Flows via the PSP In Situ Observations Magnetic flux rope, formed by the helical magnetic field lines, can sometimes maintain its shape while carrying significant plasma flow that is aligned with the local magnetic field. We report the existence of such structures and static flux ropes by applying the Grad-Shafranov-based algorithm to the Parker Solar Probe in situ measurements in the first five encounters. These structures are detected at heliocentric distances, ranging from 0.13 to 0.66 au, in a 4-month time period. We find that flux ropes with field-aligned fl ... Chen, Yu; Hu, Qiang; Zhao, Lingling; Kasper, Justin; Huang, Jia; Published by: \apj Published on: jun YEAR: 2021 DOI: 10.3847/1538-4357/abfd30 Parker Data Used; Solar wind; Astronomy data analysis; interplanetary turbulence; Solar magnetic reconnection; Solar magnetic fields; 1534; 1858; 830; 1504; 1503; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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Anisotropy of Solar Wind Turbulence in the Inner Heliosphere at Kinetic Scales: PSP Observations The anisotropy of solar wind turbulence is a critical issue in understanding the physics of energy transfer between scales and energy conversion between fields and particles in the heliosphere. Using the measurement of Parker Solar Probe (PSP), we present an observation of the anisotropy at kinetic scales in the slow, Alfv\ enic, solar wind in the inner heliosphere. The magnetic compressibility behaves as expected for kinetic Alfv\ enic turbulence below the ion scale. A steepened transition range is found between the inertia ... Duan, Die; He, Jiansen; Bowen, Trevor; Woodham, Lloyd; Wang, Tieyan; Chen, Christopher; Mallet, Alfred; Bale, Stuart; Published by: \apjl Published on: jul YEAR: 2021 DOI: 10.3847/2041-8213/ac07ac Parker Data Used; Solar wind; interplanetary turbulence; Alfven waves; 1534; 830; 23; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics |
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Switchback Boundary Dissipation and Relative Age We examine Parker Solar Probe (PSP) magnetic field and plasma observations during its first encounter with the Sun in early 2018 November. During this perihelion time, impulsive reversals in the magnetic field, called switchbacks, were found in the data set characterized by a quick rotation in B along with a simultaneous increase in solar wind flow. In this work, we examine the structure and morphology of 920 switchback boundaries as PSP enters and exits the structures, specifically looking for evidence of boundary degra ... Farrell, W.~M.; Rasca, A.~P.; MacDowall, R.~J.; Gruesbeck, J.~R.; Bale, S.~D.; Kasper, J.~C.; Published by: \apj Published on: jul YEAR: 2021 DOI: 10.3847/1538-4357/ac005b Parker Data Used; Solar wind; Solar Physics; Solar magnetic flux emergence; Solar magnetic fields; 1534; 1476; 2000; 1503 |
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Energetic particle evolution during coronal mass ejection passage from 0.3 to 1 AU We provide analysis of a coronal mass ejection (CME) that passed over Parker Solar Probe (PSP) on January 20, 2020 when the spacecraft was at just 0.32 AU. The Integrated Science Investigation of the Sun instrument suite measures energetic particle populations associated with the CME before, during, and after its passage over the spacecraft. We observe a complex evolution of energetic particles, including a brief \raisebox-0.5ex\textasciitilde2 h period where the energetic particle fluxes are enhanced and the nominal orienta ... Joyce, C.~J.; McComas, D.~J.; Schwadron, N.~A.; Vourlidas, A.; Christian, E.~R.; McNutt, R.~L.; Cohen, C.~M.~S.; Leske, R.~A.; Mewaldt, R.~A.; Stone, E.~C.; Mitchell, D.~G.; Hill, M.~E.; Roelof, E.~C.; Allen, R.~C.; Szalay, J.~R.; Rankin, J.~S.; Desai, M.~I.; Giacalone, J.; Matthaeus, W.~H.; Niehof, J.~T.; de Wet, W.; Winslow, R.~M.; Bale, S.~D.; Kasper, J.~C.; Published by: \aap Published on: jul YEAR: 2021 DOI: 10.1051/0004-6361/202039933 Parker Data Used; acceleration of particles; Solar wind; magnetic fields |
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One of the key challenges in solar and heliospheric physics is to understand the acceleration of the solar wind. As a super-sonic, super-Alfv\ enic plasma flow, the solar wind carries mass, momentum, energy, and angular momentum from the Sun into interplanetary space. We present a framework based on two-fluid magnetohydrodynamics to estimate the flux of these quantities based on spacecraft data independent of the heliocentric distance of the location of measurement. Applying this method to the Ulysses dataset allows us to st ... Verscharen, Daniel; Bale, Stuart; Velli, Marco; Published by: \mnras Published on: jul YEAR: 2021 DOI: 10.1093/mnras/stab2051 Solar wind; Sun: heliosphere; Magnetohydrodynamics; plasmas; methods: data analysis |
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The Sunward Electron Deficit: A Telltale Sign of the Sun s Electric Potential As the Parker Solar Probe explores new regions of the inner heliosphere, it travels ever deeper into the electric potential of the Sun. In the near-Sun environment, a new feature of the electron distribution emerges, in the form of a deficit in the sunward suprathermal population. The lower boundary of this deficit forms a cutoff in phase space, at an energy determined by the electric potential drop between the observation point and the outer heliosphere. We explore the characteristics of the sunward deficit and the associat ... Halekas, J.~S.; Ber\vci\vc, L.; Whittlesey, P.; Larson, D.~E.; Livi, R.; Berthomier, M.; Kasper, J.~C.; Case, A.~W.; Stevens, M.~L.; Bale, S.~D.; MacDowall, R.~J.; Pulupa, M.~P.; Published by: \apj Published on: jul YEAR: 2021 DOI: 10.3847/1538-4357/ac096e |
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Various forms of exact laws governing magnetohydrodynamic (MHD) turbulence have been derived either in the incompressibility limit, or for isothermal compressible flows. Here we propose a more general method that allows us to obtain such laws for any turbulent isentropic flow (i.e., constant entropy). We demonstrate that the known MHD exact laws (incompressible and isothermal) and the new (polytropic) one can be obtained as specific cases of the general law when the corresponding closure equation is stated. We also recover a ... Published by: \apj Published on: jul YEAR: 2021 DOI: 10.3847/1538-4357/ac0337 Solar wind; Solar Physics; Parker Data Used; Magnetohydrodynamics; Plasma astrophysics; Plasma physics; interplanetary turbulence; 1534; 1476; 1964; 1261; 2089; 830; Physics - Plasma Physics; Physics - Fluid Dynamics |
