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Authors: Amicis Raffaella ’, Matteini Lorenzo, and Bruno Roberto
Title: On slow solar wind with high Alfvénicity: from composition and microphysics to spectral properties
Abstract:

Alfvénic fluctuations are very common features in the solar wind and are found especially within the main portion of fast-wind streams while the slow wind usually is less Alfvénic and more variable. In general, the fast and slow winds show many differences, which span from the large-scale structure to small-scale phenomena, including also a different turbulent behaviour. Recent studies, however, have shown that even the slow wind can sometimes be highly Alfvénic, with fluctuations as large as those of the fast wind. This study is devoted to presenting many facets of this Alfvénic slow solar wind, including for example the study of the source regions and their connection to coronal structures, large-scale properties, and microscale phenomena and also impact on the spectral features. . . .
Date: 3/2019 Publisher: Monthly Notices of the Royal Astronomical Society DOI: 10.1093/mnras/sty3329 Available at: https://academic.oup.com/mnras/advance-article/doi/10.1093/mnras/sty3329/5245187http://academic.oup.com/mnras/advance-article-pdf/doi/10.1093/mnras/sty3329/27125375/sty3329.pdf
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Authors: Amicis Raffaella ’, Matteini Lorenzo, and Bruno Roberto
Title: On slow solar wind with high Alfvénicity: from composition and microphysics to spectral properties
Abstract:

Alfvénic fluctuations are very common features in the solar wind and are found especially within the main portion of fast-wind streams while the slow wind usually is less Alfvénic and more variable. In general, the fast and slow winds show many differences, which span from the large-scale structure to small-scale phenomena, including also a different turbulent behaviour. Recent studies, however, have shown that even the slow wind can sometimes be highly Alfvénic, with fluctuations as large as those of the fast wind. This study is devoted to presenting many facets of this Alfvénic slow solar wind, including for example the study of the source regions and their connection to coronal structures, large-scale properties, and microscale phenomena and also impact on the spectral features. . . .
Date: 3/2019 Publisher: Monthly Notices of the Royal Astronomical Society DOI: 10.1093/mnras/sty3329 Available at: https://academic.oup.com/mnras/advance-article/doi/10.1093/mnras/sty3329/5245187http://academic.oup.com/mnras/advance-article-pdf/doi/10.1093/mnras/sty3329/27125375/sty3329.pdf
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Authors: Allen R. C., Lario D., Odstrcil D., Ho G. C., Jian L. K., et al.
Title: Solar Wind Streams and Stream Interaction Regions Observed by the Parker Solar Probe with Corresponding Observations at 1 au
Abstract:

Several fast solar wind streams and stream interaction regions (SIRs) were observed by the Parker Solar Probe (PSP) during its first orbit (2018 September-2019 January). During this time, several recurring SIRs were also seen at 1 au at both L1 (Advanced Composition Explorer (ACE) and Wind) and the location of the Solar Terrestrial Relations Observatory-Ahead (STEREO-A). In this paper, we compare four fast streams observed by PSP at different radial distances during its first orbit. For three of these fast stream events, measurements from L1 (ACE and Wind) and STEREO-A indicated that the fast streams were observed by both PSP and at least one of the 1 au monitors. Our associations are supported by simulations made by the ENLIL model driven by GONG-(ADAPT-)WSA, which allows us to context. . .
Date: 02/2020 Publisher: The Astrophysical Journal Supplement Series Pages: 36 DOI: 10.3847/1538-4365/ab578f Available at: https://iopscience.iop.org/article/10.3847/1538-4365/ab578f
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Authors: Allen R. C., Lario D., Odstrcil D., Ho G. C., Jian L. K., et al.
Title: Solar Wind Streams and Stream Interaction Regions Observed by the Parker Solar Probe with Corresponding Observations at 1 au
Abstract:

Several fast solar wind streams and stream interaction regions (SIRs) were observed by the Parker Solar Probe (PSP) during its first orbit (2018 September─2019 January). During this time, several recurring SIRs were also seen at 1 au at both L1 (Advanced Composition Explorer (ACE) and Wind) and the location of the Solar Terrestrial Relations Observatory-Ahead (STEREO-A). In this paper, we compare four fast streams observed by PSP at different radial distances during its first orbit. For three of these fast stream events, measurements from L1 (ACE and Wind) and STEREO-A indicated that the fast streams were observed by both PSP and at least one of the 1 au monitors. Our associations are supported by simulations made by the ENLIL model driven by GONG-(ADAPT-)WSA, which allows us to conte. . .
Date: 02/2020 Publisher: The Astrophysical Journal Supplement Series Pages: 36 DOI: 10.3847/1538-4365/ab578f Available at: https://iopscience.iop.org/article/10.3847/1538-4365/ab578f
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Authors: Al-Haddad Nada, Lugaz Noé, Poedts Stefaan, Farrugia Charles J., Nieves-Chinchilla Teresa, et al.
Title: Evolution of Coronal Mass Ejection Properties in the Inner Heliosphere: Prediction for the Solar Orbiter and Parker Solar Probe
Abstract:

The evolution of the magnetic field and plasma quantities inside a coronal mass ejection (CME) with distance are known from statistical studies using data from 1 au monitors, planetary missions, Helios, and Ulysses. This does not cover the innermost heliosphere, below 0.29 au, where no data are yet publicly available. Here, we describe the evolution of the properties of simulated CMEs in the inner heliosphere using two different initiation mechanisms. We compare the radial evolution of these properties with that found from statistical studies based on observations in the inner heliosphere by Helios and MESSENGER. We find that the evolution of the radial size and magnetic field strength is nearly indistinguishable for twisted flux rope from that of writhed CMEs. The evolution of these pr. . .
Date: 10/2019 Publisher: The Astrophysical Journal Pages: 179 DOI: 10.3847/1538-4357/ab4126 Available at: https://iopscience.iop.org/article/10.3847/1538-4357/ab4126
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Authors: Al-Haddad Nada, Lugaz Noé, Poedts Stefaan, Farrugia Charles J., Nieves-Chinchilla Teresa, et al.
Title: Evolution of Coronal Mass Ejection Properties in the Inner Heliosphere: Prediction for the Solar Orbiter and Parker Solar Probe
Abstract:

The evolution of the magnetic field and plasma quantities inside a coronal mass ejection (CME) with distance are known from statistical studies using data from 1 au monitors, planetary missions, Helios, and Ulysses. This does not cover the innermost heliosphere, below 0.29 au, where no data are yet publicly available. Here, we describe the evolution of the properties of simulated CMEs in the inner heliosphere using two different initiation mechanisms. We compare the radial evolution of these properties with that found from statistical studies based on observations in the inner heliosphere by Helios and MESSENGER. We find that the evolution of the radial size and magnetic field strength is nearly indistinguishable for twisted flux rope from that of writhed CMEs. The evolution of these pr. . .
Date: 10/2019 Publisher: The Astrophysical Journal Pages: 179 DOI: 10.3847/1538-4357/ab4126 Available at: https://iopscience.iop.org/article/10.3847/1538-4357/ab4126
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Authors: Agapitov O. V., de Wit Dudok, Mozer F. S., Bonnell J. W., Drake J. F., et al.
Title: Sunward-propagating Whistler Waves Collocated with Localized Magnetic Field Holes in the Solar Wind: Parker Solar Probe Observations at 35.7 R Radii
Abstract:

Observations by the Parker Solar Probe mission of the solar wind at \~35.7 solar radii reveal the existence of whistler wave packets with frequencies below 0.1 fce (20-80 Hz in the spacecraft frame). These waves often coincide with local minima of the magnetic field magnitude or with sudden deflections of the magnetic field that are called switchbacks. Their sunward propagation leads to a significant Doppler frequency downshift from 200-300 to 20-80 Hz (from 0.2 to 0.5 fce). The polarization of these waves varies from quasi-parallel to significantly oblique with wave normal angles that are close to the resonance cone. Their peak amplitude can be as large as 2-4 nT. Such values represent approximately 10% of the background magnetic field, which is considerably more . . .
Date: 03/2020 Publisher: The Astrophysical Journal Pages: L20 DOI: 10.3847/2041-8213/ab799c Available at: https://iopscience.iop.org/article/10.3847/2041-8213/ab799c
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Authors: Agapitov O. V., de Wit Dudok, Mozer F. S., Bonnell J. W., Drake J. F., et al.
Title: Sunward-propagating Whistler Waves Collocated with Localized Magnetic Field Holes in the Solar Wind: Parker Solar Probe Observations at 35.7 R Radii
Abstract:

Observations by the Parker Solar Probe mission of the solar wind at ∼35.7 solar radii reveal the existence of whistler wave packets with frequencies below 0.1 fce (20-80 Hz in the spacecraft frame). These waves often coincide with local minima of the magnetic field magnitude or with sudden deflections of the magnetic field that are called switchbacks. Their sunward propagation leads to a significant Doppler frequency downshift from 200-300 to 20-80 Hz (from 0.2 to 0.5 fce). The polarization of these waves varies from quasi-parallel to significantly oblique with wave normal angles that are close to the resonance cone. Their peak amplitude can be as large as 2-4 nT. Such values represent approximately 10% of the background magnetic field, which is considerably more. . .
Date: 03/2020 Publisher: The Astrophysical Journal Pages: L20 DOI: 10.3847/2041-8213/ab799c Available at: https://iopscience.iop.org/article/10.3847/2041-8213/ab799c
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Authors: Adhikari L., Zank G. P., Zhao L.-L., Kasper J. C., Korreck K. E., et al.
Title: Turbulence Transport Modeling and First Orbit Parker Solar Probe ( PSP ) Observations
Abstract:

The Parker Solar Probe (PSP) achieved its first orbit perihelion on 2018 November 6, reaching a heliocentric distance of about 0.165 au (35.55 R). Here, we study the evolution of fully developed turbulence associated with the slow solar wind along the PSP trajectory between 35.55 R and 131.64 R in the outbound direction, comparing observations to a theoretical turbulence transport model. Several turbulent quantities, such as the fluctuating kinetic energy and the corresponding correlation length, the variance of density fluctuations, and the solar wind proton temperature are determined from the PSP Solar Wind Electrons Alphas and Protons (SWEAP) plasma data along its trajectory between 35.55 R and 131.64 R. The evolut. . .
Date: 02/2020 Publisher: The Astrophysical Journal Supplement Series Pages: 38 DOI: 10.3847/1538-4365/ab5852 Available at: https://iopscience.iop.org/article/10.3847/1538-4365/ab5852
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Authors: Adhikari L., Zank G. P., Zhao L.-L., Kasper J. C., Korreck K. E., et al.
Title: Turbulence Transport Modeling and First Orbit Parker Solar Probe ( PSP ) Observations
Abstract:

The Parker Solar Probe (PSP) achieved its first orbit perihelion on 2018 November 6, reaching a heliocentric distance of about 0.165 au (35.55 R). Here, we study the evolution of fully developed turbulence associated with the slow solar wind along the PSP trajectory between 35.55 R and 131.64 R in the outbound direction, comparing observations to a theoretical turbulence transport model. Several turbulent quantities, such as the fluctuating kinetic energy and the corresponding correlation length, the variance of density fluctuations, and the solar wind proton temperature are determined from the PSP Solar Wind Electrons Alphas and Protons (SWEAP) plasma data along its trajectory between 35.55 R and 131.64 R. The evolut. . .
Date: 02/2020 Publisher: The Astrophysical Journal Supplement Series Pages: 38 DOI: 10.3847/1538-4365/ab5852 Available at: https://iopscience.iop.org/article/10.3847/1538-4365/ab5852
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Authors: Adhikari L., Zank G. P., and Zhao L.-L.
Title: Does Turbulence Turn off at the Alfvén Critical Surface?
Abstract:

The Parker Solar Probe (PSP) will eventually reach and cross the Alfvén point or surface as it provides us with direct in situ measurements of the solar atmosphere. The Alfvén surface is the location at which the large-scale bulk solar wind speed ${\boldsymbol{U}}$ and the Alfvén speed ${\boldsymbol{V}}$ A are equal, and thus it separates sub-Aflvénic coronal flow $| {\boldsymbol{U}}| \ll | {{\boldsymbol{V}}}_{{\rm{A}}}| $ from super-Alfv. . .
Date: Jan-05-2019 Publisher: The Astrophysical Journal Pages: 26 DOI: 10.3847/1538-4357/ab141c Available at: https://iopscience.iop.org/article/10.3847/1538-4357/ab141c
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Authors: Adhikari L., Zank G. P., and Zhao L.-L.
Title: Does Turbulence Turn off at the Alfvén Critical Surface?
Abstract:

The Parker Solar Probe (PSP) will eventually reach and cross the Alfvén point or surface as it provides us with direct in situ measurements of the solar atmosphere. The Alfvén surface is the location at which the large-scale bulk solar wind speed $\boldsymbolU$ and the Alfvén speed $\boldsymbolV$ A are equal, and thus it separates sub-Aflvénic coronal flow $| \boldsymbolU| \ll | {\boldsymbolV_{\rmA| $ from super-Alfvénic solar wind flow&n. . .
Date: Jan-05-2019 Publisher: The Astrophysical Journal Pages: 26 DOI: 10.3847/1538-4357/ab141c Available at: https://iopscience.iop.org/article/10.3847/1538-4357/ab141c
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Authors: Abbo L., Ofman L., Antiochos S. K., Hansteen V. H., Harra L., et al.
Title: Slow Solar Wind: Observations and Modeling
Abstract:

While it is certain that the fast solar wind originates from coronal holes, where and how the slow solar wind (SSW) is formed remains an outstanding question in solar physics even in the post-SOHO era. The quest for the SSW origin forms a major objective for the planned future missions such as the Solar Orbiter and Solar Probe Plus. Nonetheless, results from spacecraft data, combined with theoretical modeling, have helped to investigate many aspects of the SSW. Fundamental physical properties of the coronal plasma have been derived from spectroscopic and imaging remote-sensing data and in situ data, and these results have provided crucial insights for a deeper understanding of the origin and acceleration of the SSW. Advanced models of the SSW in coronal streamers and other structures ha. . .
Date: 11/2016 Publisher: Space Science Reviews Pages: 55 - 108 DOI: 10.1007/s11214-016-0264-1 Available at: http://link.springer.com/10.1007/s11214-016-0264-1http://link.springer.com/content/pdf/10.1007/s11214-016-0264-1.pdfhttp://link.springer.com/content/pdf/10.1007/s11214-016-0264-1.pdfhttp://link.springer.com/article/10.1007/s11214-016-0264-1/fulltext.html
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Authors: Abbo L., Ofman L., Antiochos S. K., Hansteen V. H., Harra L., et al.
Title: Slow Solar Wind: Observations and Modeling
Abstract:

While it is certain that the fast solar wind originates from coronal holes, where and how the slow solar wind (SSW) is formed remains an outstanding question in solar physics even in the post-SOHO era. The quest for the SSW origin forms a major objective for the planned future missions such as the Solar Orbiter and Solar Probe Plus. Nonetheless, results from spacecraft data, combined with theoretical modeling, have helped to investigate many aspects of the SSW. Fundamental physical properties of the coronal plasma have been derived from spectroscopic and imaging remote-sensing data and in situ data, and these results have provided crucial insights for a deeper understanding of the origin and acceleration of the SSW. Advanced models of the SSW in coronal streamers and other structures ha. . .
Date: 11/2016 Publisher: Space Science Reviews Pages: 55 - 108 DOI: 10.1007/s11214-016-0264-1 Available at: http://link.springer.com/10.1007/s11214-016-0264-1http://link.springer.com/content/pdf/10.1007/s11214-016-0264-1.pdfhttp://link.springer.com/content/pdf/10.1007/s11214-016-0264-1.pdfhttp://link.springer.com/article/10.1007/s11214-016-0264-1/fulltext.html
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