library.bib

@article{Bale2019,
  title = {Highly Structured Slow Solar Wind Emerging from an Equatorial Coronal Hole},
  author = {Bale, S D and Badman, S T and Bonnell, J W and Bowen, T A and Burgess, D and Case, A W and Cattell, C A and Chandran, B D G and Chaston, C C and Chen, C H K and Drake, J F and {de Wit}, T Dudok and Eastwood, J P and Ergun, R E and Farrell, W M and Fong, C and Goetz, K and Goldstein, M and Goodrich, K A and Harvey, P R and Horbury, T S and Howes, G G and Kasper, J C and Kellogg, P J and Klimchuk, J A and Korreck, K E and Krasnoselskikh, V V and Krucker, S and Laker, R and Larson, D E and MacDowall, R J and Maksimovic, M and Malaspina, D M and {Martinez-Oliveros}, J and McComas, D J and {Meyer-Vernet}, N and Moncuquet, M and Mozer, F S and Phan, T D and Pulupa, M and Raouafi, N E and Salem, C and Stansby, D and Stevens, M and Szabo, A and Velli, M and Woolley, T and Wygant, J R},
  year = {2019},
  journal = {Nature},
  volume = {576},
  number = {7786},
  pages = {237--242},
  publisher = {{Springer US}},
  issn = {14764687},
  doi = {10.1038/s41586-019-1818-7},
  abstract = {During the solar minimum, when the Sun is at its least active, the solar wind1,2 is observed at high latitudes as a predominantly fast (more than 500 kilometres per second), highly Alfv\'enic rarefied stream of plasma originating from deep within coronal holes. Closer to the ecliptic plane, the solar wind is interspersed with a more variable slow wind3 of less than 500 kilometres per second. The precise origins of the slow wind streams are less certain4; theories and observations suggest that they may originate at the tips of helmet streamers5,6, from interchange reconnection near coronal hole boundaries7,8, or within coronal holes with highly diverging magnetic fields9,10. The heating mechanism required to drive the solar wind is also unresolved, although candidate mechanisms include Alfv\'en-wave turbulence11,12, heating by reconnection in nanoflares13, ion cyclotron wave heating14 and acceleration by thermal gradients1. At a distance of one astronomical unit, the wind is mixed and evolved, and therefore much of the diagnostic structure of these sources and processes has been lost. Here we present observations from the Parker Solar Probe15 at 36 to 54 solar radii that show evidence of slow Alfv\'enic solar wind emerging from a small equatorial coronal hole. The measured magnetic field exhibits patches of large, intermittent reversals that are associated with jets of plasma and enhanced Poynting flux and that are interspersed in a smoother and less turbulent flow with a near-radial magnetic field. Furthermore, plasma-wave measurements suggest the existence of electron and ion velocity-space micro-instabilities10,16 that are associated with plasma heating and thermalization processes. Our measurements suggest that there is an impulsive mechanism associated with solar-wind energization and that micro-instabilities play a part in heating, and we provide evidence that low-latitude coronal holes are a key source of the slow solar wind.},
  keywords = {ObsCite},
  annotation = {283 citations (Crossref) [2022-12-19] 267 citations (Semantic Scholar/DOI) [2022-12-19]},
  file = {C\:\\Users\\Ronan\\Zotero\\storage\\N3P8G5DX\\Bale et al. - 2019 - Highly structured slow solar wind emerging from an equatorial coronal hole.pdf}
}

@article{Bale2021,
  title = {A {{Solar Source}} of {{Alfv\'enic Magnetic Field Switchbacks}}: {{In Situ Remnants}} of {{Magnetic Funnels}} on {{Supergranulation Scales}}},
  author = {Bale, S D and Horbury, T S and Velli, M and Desai, M I and Halekas, J S and McManus, M D and Panasenco, O and Badman, S T and Bowen, T A and Chandran, B D G and Drake, J F and Kasper, J C and Laker, R and Mallet, A and Matteini, L and Phan, T D and Raouafi, N E and Squire, J and Woodham, L D and Woolley, T},
  year = {2021},
  month = dec,
  journal = {The Astrophysical Journal},
  volume = {923},
  number = {2},
  pages = {174},
  publisher = {{American Astronomical Society}},
  doi = {10.3847/1538-4357/ac2d8c},
  abstract = {One of the striking observations from the Parker Solar Probe (PSP) spacecraft is the prevalence in the inner heliosphere of large amplitude, Alfv\'enic magnetic field reversals termed switchbacks. These ) fluctuations occur over a range of timescales and in patches separated by intervals of quiet, radial magnetic field. We use measurements from PSP to demonstrate that patches of switchbacks are localized within the extensions of plasma structures originating at the base of the corona. These structures are characterized by an increase in alpha particle abundance, Mach number, plasma {$\beta$} and pressure, and by depletions in the magnetic field magnitude and electron temperature. These intervals are in pressure balance, implying stationary spatial structure, and the field depressions are consistent with overexpanded flux tubes. The structures are asymmetric in Carrington longitude with a steeper leading edge and a small ({$\sim$}1\textdegree ) edge of hotter plasma and enhanced magnetic field fluctuations. Some structures contain suprathermal ions to {$\sim$}85 keV that we argue are the energetic tail of the solar wind alpha population. The structures are separated in longitude by angular scales associated with supergranulation. This suggests that these switchbacks originate near the leading edge of the diverging magnetic field funnels associated with the network magnetic field\textemdash the primary wind sources. We propose an origin of the magnetic field switchbacks, hot plasma and suprathermals, alpha particles in interchange reconnection events just above the solar transition region and our measurements represent the extended regions of a turbulent outflow exhaust.},
  keywords = {ObsCite},
  annotation = {25 citations (Crossref) [2022-12-19] 22 citations (Semantic Scholar/DOI) [2022-12-19]},
  file = {C\:\\Users\\Ronan\\Zotero\\storage\\TV8XKQVN\\Bale et al_2021_A Solar Source of Alfvénic Magnetic Field Switchbacks.pdf}
}

@article{Eastwood2021,
  title = {Solar {{Orbiter}} Observations of an Ion-Scale Flux Rope Confined to a Bifurcated Solar Wind Current Sheet},
  author = {Eastwood, J. P. and Stawarz, J. E. and Phan, T. D. and Laker, R. and Robertson, S. and Zhao, L.-L. and Zank, G. P. and Lavraud, B. and Shay, M. A. and Evans, V. and Angelini, V. and O'Brien, H. and Horbury, T. S.},
  year = {2021},
  month = dec,
  journal = {Astronomy \& Astrophysics},
  volume = {656},
  pages = {A27},
  publisher = {{EDP Sciences}},
  issn = {0004-6361, 1432-0746},
  doi = {10.1051/0004-6361/202140949},
  abstract = {\emph{Context.{$<$}i/{$>$} Flux ropes in the solar wind are a key element of heliospheric dynamics and particle acceleration. When associated with current sheets, the primary formation mechanism is magnetic reconnection and flux ropes in current sheets are commonly used as tracers of the reconnection process.\emph{Aims.{$<$}i/{$>$} Whilst flux ropes associated with reconnecting current sheets in the solar wind have been reported, their occurrence, size distribution, and lifetime are not well understood.\emph{Methods.{$<$}i/{$>$} Here we present and analyse new Solar Orbiter magnetic field data reporting novel observations of a flux rope confined to a bifurcated current sheet in the solar wind. Comparative data and large-scale context is provided by Wind.\emph{Results.{$<$}i/{$>$} The Solar Orbiter observations reveal that the flux rope, which does not span the current sheet, is of ion scale, and in a reconnection formation scenario, existed for a prolonged period of time as it was carried out in the reconnection exhaust. Wind is also found to have observed clear signatures of reconnection at what may be the same current sheet, thus demonstrating that reconnection signatures can be found separated by as much as {$\sim$}2000 Earth radii, or 0.08 au.\emph{Conclusions.{$<$}i/{$>$} The Solar Orbiter observations provide new insight into the hierarchy of scales on which flux ropes can form, and show that they exist down to the ion scale in the solar wind. The context provided by Wind extends the spatial scale over which reconnection signatures have been found at solar wind current sheets. The data suggest the local orientations of the current sheet at Solar Orbiter and Wind are rotated relative to each other, unlike reconnection observed at smaller separations; the implications of this are discussed with reference to patchy vs. continuous reconnection scenarios.}}}}}},
  copyright = {\textcopyright{} ESO 2021},
  langid = {english},
  annotation = {3 citations (Crossref) [2022-12-19] 4 citations (Semantic Scholar/DOI) [2022-12-19]},
  file = {C\:\\Users\\Ronan\\Zotero\\storage\\9LBTWTEF\\Eastwood et al_2021_Solar Orbiter observations of an ion-scale flux rope confined to a bifurcated.pdf;C\:\\Users\\Ronan\\Zotero\\storage\\4GFMAMTD\\aa40949-21.html}
}

@article{Horbury2020,
  title = {Sharp {{Alfv\'enic Impulses}} in the {{Near-Sun Solar Wind}}},
  author = {Horbury, Timothy S and Woolley, Thomas and Laker, Ronan and Matteini, Lorenzo and Eastwood, Jonathan and Bale, Stuart D and Velli, Marco and Chandran, Benjamin D G and Phan, Tai and Raouafi, Nour E and Goetz, Keith and Harvey, Peter R and Pulupa, Marc and Klein, K G and {de Wit}, Thierry Dudok and Kasper, Justin C and Korreck, Kelly E and Case, A W and Stevens, Michael L and Whittlesey, Phyllis and Larson, Davin and MacDowall, Robert J and Malaspina, David M and Livi, Roberto},
  year = {2020},
  month = feb,
  journal = {The Astrophysical Journal Supplement Series},
  volume = {246},
  number = {2},
  pages = {45},
  publisher = {{American Astronomical Society}},
  doi = {10.3847/1538-4365/ab5b15},
  abstract = {Measurements of the near-Sun solar wind by the Parker Solar Probe have revealed the presence of large numbers of discrete Alfv\'enic impulses with an anti-sunward sense of propagation. These are similar to those previously observed near 1 au, in high speed streams over the Sun's poles and at 60 solar radii. At 35 solar radii, however, they are typically shorter and sharper than seen elsewhere. In addition, these spikes occur in ``patches'' and there are also clear periods within the same stream when they do not occur; the timescale of these patches might be related to the rate at which the spacecraft magnetic footpoint tracks across the coronal hole from which the plasma originated. While the velocity fluctuations associated with these spikes are typically under 100 km s-1, due to the rather low Alfv\'en speeds in the streams observed by the spacecraft to date, these are still associated with large angular deflections of the magnetic field\textemdash and these deflections are not isotropic. These deflections do not appear to be related to the recently reported large-scale, pro-rotation solar wind flow. Estimates of the size and shape of the spikes reveal high aspect ratio flow-aligned structures with a transverse scale of {$\approx$}104 km. These events might be signatures of near-Sun impulsive reconnection events.},
  keywords = {ObsCite},
  annotation = {79 citations (Crossref) [2022-12-19] 74 citations (Semantic Scholar/DOI) [2022-12-19]},
  file = {C\:\\Users\\Ronan\\Zotero\\storage\\6GWEQKH5\\Horbury et al_2020_Sharp Alfvénic Impulses in the Near-Sun Solar Wind.pdf}
}

@article{Laker2021,
  title = {Statistical Analysis of Orientation, Shape, and Size of Solar Wind Switchbacks},
  author = {Laker, R. and Horbury, T. S. and Bale, S. D. and Matteini, L. and Woolley, T. and Woodham, L. D. and Badman, S. T. and Pulupa, M. and Kasper, J. C. and Stevens, M. and Case, A. W. and Korreck, K. E.},
  year = {2021},
  journal = {Astronomy \& Astrophysics},
  volume = {650},
  pages = {A1},
  doi = {10.1051/0004-6361/202039354},
  abstract = {One of the main discoveries from the first two orbits of Parker Solar Probe (PSP) was the presence of magnetic switchbacks, whose deflections dominated the magnetic field measurements. Determining their shape and size could provide evidence of their origin, which is still unclear. Previous work with a single solar wind stream has indicated that these are long, thin structures although the direction of their major axis could not be determined. We investigate if this long, thin nature extends to other solar wind streams, while determining the direction along which the switchbacks within a stream were aligned. We try to understand how the size and orientation of the switchbacks, along with the flow velocity and spacecraft trajectory, combine to produce the observed structure durations for past and future orbits. We searched for the alignment direction that produced a combination of a spacecraft cutting direction and switchback duration that was most consistent with long, thin structures. The expected form of a long, thin structure was fitted to the results of the best alignment direction, which determined the width and aspect ratio of the switchbacks for that stream. The switchbacks had a mean width of \$50,000 \textbackslash, \textbackslash rmkm\$, with an aspect ratio of the order of \$10\$. We find that switchbacks are not aligned along the background flow direction, but instead aligned along the local Parker spiral, perhaps suggesting that they propagate along the magnetic field. Since the observed switchback duration depends on how the spacecraft cuts through the structure, the duration alone cannot be used to determine the size or influence of an individual event. For future PSP orbits, a larger spacecraft transverse component combined with more radially aligned switchbacks will lead to long duration switchbacks becoming less common.},
  keywords = {ObsCite,parker solar probe -,switchbacks},
  annotation = {26 citations (Crossref) [2022-12-19] 20 citations (Semantic Scholar/DOI) [2022-12-19] \_eprint: 2010.10211},
  file = {C\:\\Users\\Ronan\\Zotero\\storage\\FHVEM9FD\\Laker et al. - 2021 - Statistical analysis of orientation, shape, and size of solar wind switchbacks.pdf}
}

@article{Laker2021a,
  title = {Multi-Spacecraft Study of the Solar Wind at Solar Minimum: {{Dependence}} on Latitude and Transient Outflows},
  author = {Laker, R and Horbury, T S and Bale, S D and Matteini, L and Woolley, T and Woodham, L D and Stawarz, J E and Davies, E E and Eastwood, J P and Owens, M J and O'Brien, H and Evans, V and Angelini, V and Richter, I and Heyner, D and Owen, C J and Louarn, P and Fedorov, A},
  year = {2021},
  journal = {A\&A},
  volume = {652},
  doi = {10.1051/0004-6361/202140679},
  keywords = {ObsCite},
  annotation = {5 citations (Crossref) [2022-12-19] 1 citations (Semantic Scholar/DOI) [2022-12-19]},
  file = {C\:\\Users\\Ronan\\Zotero\\storage\\8QVDR7CW\\Laker et al_2021_Multi-spacecraft study of the solar wind at solar minimum.pdf}
}

@article{Laker2022,
  title = {Switchback Deflections beyond the Early Parker Solar Probe Encounters},
  author = {Laker, R and Horbury, T S and Matteini, L and Bale, S D and Stawarz, J E and Woodham, L D and Woolley, T},
  year = {2022},
  month = sep,
  journal = {Monthly Notices of the Royal Astronomical Society},
  pages = {stac2477},
  issn = {0035-8711, 1365-2966},
  doi = {10.1093/mnras/stac2477},
  abstract = {Abstract             Switchbacks are Aflv\'enic fluctuations in the solar wind, which exhibit large rotations in the magnetic field direction. Observations from Parker Solar Probe's (PSP's) first two solar encounters have formed the basis for many of the described switchback properties and generation mechanisms. However, this early data may not be representative of the typical near-Sun solar wind, biasing our current understanding of these phenomena. One defining switchback property is the magnetic deflection direction. During the first solar encounter, this was primarily in the tangential direction for the longest switchbacks, which has since been discussed as evidence, and a testable prediction, of several switchback generation methods. In this study, we re-examine the deflection direction of switchbacks during the first eight PSP encounters to confirm the existence of a systematic deflection direction. We first identify switchbacks exceeding a threshold deflection in the magnetic field and confirm a previous finding that they are arc-polarized. In agreement with earlier results from PSP's first encounter, we find that groups of longer switchbacks tend to deflect in the same direction for several hours. However, in contrast to earlier studies, we find that there is no unique direction for these deflections, although several solar encounters showed a non-uniform distribution in deflection direction with a slight preference for the tangential direction. This result suggests a systematic magnetic configuration for switchback generation, which is consistent with interchange reconnection as a source mechanism, although this new evidence does not rule out other mechanisms, such as the expansion of wave modes.},
  copyright = {All rights reserved},
  langid = {english},
  keywords = {ObsCite},
  annotation = {0 citations (Crossref) [2022-12-19] 1 citations (Semantic Scholar/DOI) [2022-12-19]},
  file = {C\:\\Users\\Ronan\\Zotero\\storage\\KUSNECYR\\Laker et al_2022_Switchback deflections beyond the early parker solar probe encounters.pdf}
}

@article{Lavraud2021,
  title = {Magnetic Reconnection as a Mechanism to Produce Multiple Thermal Proton Populations and Beams Locally in the Solar Wind},
  author = {Lavraud, B. and Kieokaew, R. and Fargette, N. and Louarn, P. and Fedorov, A. and Andr{\'e}, N. and Fruit, G. and G{\'e}not, V. and R{\'e}ville, V. and Rouillard, A. P. and Plotnikov, I. and Penou, E. and Barthe, A. and Prech, L. and Owen, C. J. and Bruno, R. and Allegrini, F. and Berthomier, M. and Kataria, D. and Livi, S. and Raines, J. M. and D'Amicis, R. and Eastwood, J. P. and Froment, C. and Laker, R. and Maksimovic, M. and Marcucci, F. and Perri, S. and Perrone, D. and Phan, T. D. and Stansby, D. and Stawarz, J. and {Toledo-Redondo}, S. and Vaivads, A. and Verscharen, D. and Zouganelis, I. and Angelini, V. and Evans, V. and Horbury, T. S. and O'Brien, H.},
  year = {2021},
  month = dec,
  journal = {Astronomy \& Astrophysics},
  volume = {656},
  pages = {A37},
  issn = {0004-6361, 1432-0746},
  doi = {10.1051/0004-6361/202141149},
  abstract = {Context.               Spacecraft data revealed early on the frequent observation of multiple near-thermal proton populations in the solar wind. Decades of research on their origin have focused on processes such as magnetic reconnection in the low corona and wave-particle interactions in the corona and locally in the solar wind.                                         Aims.               This study aims to highlight the fact that such multiple thermal proton populations and beams are also produced by magnetic reconnection occurring locally in the solar wind.                                         Methods.               We used high-resolution Solar Orbiter proton velocity distribution function measurements, complemented by electron and magnetic field data, to analyze the association of multiple thermal proton populations and beams with magnetic reconnection during a period of slow Alfv\'enic solar wind on 16 July 2020.                                         Results.               At least six reconnecting current sheets with associated multiple thermal proton populations and beams, including a case of magnetic reconnection at a switchback boundary, were found on this day. This represents 2\% of the measured distribution functions. We discuss how this proportion may be underestimated, and how it may depend on solar wind type and distance from the Sun.                                         Conclusions.               Although suggesting a likely small contribution, but which remains to be quantitatively assessed, Solar Orbiter observations show that magnetic reconnection must be considered as one of the mechanisms that produce multiple thermal proton populations and beams locally in the solar wind.},
  copyright = {All rights reserved},
  annotation = {2 citations (Crossref) [2022-12-19] 2 citations (Semantic Scholar/DOI) [2022-12-19]},
  file = {C\:\\Users\\Ronan\\Zotero\\storage\\Q7KKKIF9\\Lavraud et al_2021_Magnetic reconnection as a mechanism to produce multiple thermal proton.pdf}
}

@article{Matteini2021,
  title = {Solar {{Orbiter}}'s Encounter with the Tail of Comet {{C}}/2019 {{Y4}} ({{ATLAS}}): {{Magnetic}} Field Draping and Cometary Pick-up Ion Waves},
  shorttitle = {Solar {{Orbiter}}'s Encounter with the Tail of Comet {{C}}/2019 {{Y4}} ({{ATLAS}})},
  author = {Matteini, L. and Laker, R. and Horbury, T. and Woodham, L. and Bale, S. D. and Stawarz, J. E. and Woolley, T. and Steinvall, K. and Jones, G. H. and Grant, S. R. and Afghan, Q. and Galand, M. and O'Brien, H. and Evans, V. and Angelini, V. and Maksimovic, M. and Chust, T. and Khotyaintsev, Y. and Krasnoselskikh, V. and Kretzschmar, M. and Lorf{\`e}vre, E. and Plettemeier, D. and Sou{\v c}ek, J. and Steller, M. and {\v S}tver{\'a}k, {\v S} and Tr{\'a}vn{\'i}{\v c}ek, P. and Vaivads, A. and Vecchio, A. and {Wimmer-Schweingruber}, R. F. and Ho, G. C. and {G{\'o}mez-Herrero}, R. and {Rodr{\'i}guez-Pacheco}, J. and Louarn, P. and Fedorov, A. and Owen, C. J. and Bruno, R. and Livi, S. and Zouganelis, I. and M{\"u}ller, D.},
  year = {2021},
  month = dec,
  journal = {Astronomy \& Astrophysics},
  volume = {656},
  pages = {A39},
  publisher = {{EDP Sciences}},
  issn = {0004-6361, 1432-0746},
  doi = {10.1051/0004-6361/202141229},
  abstract = {\emph{Context.{$<$}i/{$>$} Solar Orbiter is expected to have flown close to the tail of comet C/2019 Y4 (ATLAS) during the spacecraft's first perihelion in June 2020. Models predict a possible crossing of the comet tails by the spacecraft at a distance from the Sun of approximately 0.5 AU.\emph{Aims.{$<$}i/{$>$} This study is aimed at identifying possible signatures of the interaction of the solar wind plasma with material released by comet ATLAS, including the detection of draped magnetic field as well as the presence of cometary pick-up ions and of ion-scale waves excited by associated instabilities. This encounter provides us with the first opportunity of addressing such dynamics in the inner Heliosphere and improving our understanding of the plasma interaction between comets and the solar wind.\emph{Methods.{$<$}i/{$>$} We analysed data from all in situ instruments on board Solar Orbiter and compared their independent measurements in order to identify and characterize the nature of structures and waves observed in the plasma when the encounter was predicted.\emph{Results.{$<$}i/{$>$} We identified a magnetic field structure observed at the start of 4 June, associated with a full magnetic reversal, a local deceleration of the flow and large plasma density, and enhanced dust and energetic ions events. The cross-comparison of all these observations support a possible cometary origin for this structure and suggests the presence of magnetic field draping around some low-field and high-density object. Inside and around this large scale structure, several ion-scale wave-forms are detected that are consistent with small-scale waves and structures generated by cometary pick-up ion instabilities.\emph{Conclusions.{$<$}i/{$>$} Solar Orbiter measurements are consistent with the crossing through a magnetic and plasma structure of cometary origin embedded in the ambient solar wind. We suggest that this corresponds to the magnetotail of one of the fragments of comet ATLAS or to a portion of the tail that was previously disconnected and advected past the spacecraft by the solar wind.}}}}}},
  copyright = {\textcopyright{} ESO 2021},
  langid = {english},
  keywords = {ObsCite},
  annotation = {2 citations (Crossref) [2022-12-19] 2 citations (Semantic Scholar/DOI) [2022-12-19]},
  file = {C\:\\Users\\Ronan\\Zotero\\storage\\6964P6H5\\Matteini et al_2021_Solar Orbiter’s encounter with the tail of comet C-2019 Y4 (ATLAS).pdf;C\:\\Users\\Ronan\\Zotero\\storage\\REV8PXQU\\aa41229-21.html}
}

@article{Reville2022,
  title = {Flux Rope and Dynamics of the Heliospheric Current Sheet: {{Study}} of the {{Parker Solar Probe}} and {{Solar Orbiter}} Conjunction of {{June}} 2020},
  shorttitle = {Flux Rope and Dynamics of the Heliospheric Current Sheet},
  author = {R{\'e}ville, V. and Fargette, N. and Rouillard, A. P. and Lavraud, B. and Velli, M. and Strugarek, A. and Parenti, S. and Brun, A. S. and Shi, C. and Kouloumvakos, A. and Poirier, N. and Pinto, R. F. and Louarn, P. and Fedorov, A. and Owen, C. J. and G{\'e}not, V. and Horbury, T. S. and Laker, R. and O'Brien, H. and Angelini, V. and {Fauchon-Jones}, E. and Kasper, J. C.},
  year = {2022},
  month = mar,
  journal = {Astronomy \& Astrophysics},
  volume = {659},
  pages = {A110},
  issn = {0004-6361, 1432-0746},
  doi = {10.1051/0004-6361/202142381},
  abstract = {Context.               Solar Orbiter and Parker Solar Probe jointly observed the solar wind for the first time in June 2020, capturing data from very different solar wind streams: calm, Alfv\'enic wind and also highly dynamic large-scale structures.                                         Context.               Our aim is to understand the origin and characteristics of the highly dynamic solar wind observed by the two probes, particularly in the vicinity of the heliospheric current sheet (HCS).                                         Methods.               We analyzed the plasma data obtained by Parker Solar Probe and Solar Orbiter in situ during the month of June 2020. We used the Alfv\'en-wave turbulence magnetohydrodynamic solar wind model WindPredict-AW and we performed two 3D simulations based on ADAPT solar magnetograms for this period.                                         Results.               We show that the dynamic regions measured by both spacecraft are pervaded by flux ropes close to the HCS. These flux ropes are also present in the simulations, forming at the tip of helmet streamers, that is, at the base of the heliospheric current sheet. The formation mechanism involves a pressure-driven instability followed by a fast tearing reconnection process. We further characterize the 3D spatial structure of helmet streamer born flux ropes, which appears in the simulations to be related to the network of quasi-separatrices.},
  copyright = {All rights reserved},
  annotation = {4 citations (Crossref) [2022-12-19] 2 citations (Semantic Scholar/DOI) [2022-12-19]},
  file = {C\:\\Users\\Ronan\\Zotero\\storage\\47R4K628\\Réville et al_2022_Flux rope and dynamics of the heliospheric current sheet.pdf}
}

@article{Telloni2021,
  title = {Study of Two Interacting Interplanetary Coronal Mass Ejections Encountered by {{Solar Orbiter}} during Its First Perihelion Passage - {{Observations}} and Modeling},
  author = {Telloni, D. and Scolini, C. and M{\"o}stl, C. and Zank, G. P. and Zhao, L.-L. and Weiss, A. J. and Reiss, M. A. and Laker, R. and Perrone, D. and Khotyaintsev, Y. and Steinvall, K. and {Sorriso-Valvo}, L. and Horbury, T. S. and {Wimmer-Schweingruber}, R. F. and Bruno, R. and D'Amicis, R. and Marco, R. De and Jagarlamudi, V. K. and Carbone, F. and Marino, R. and Stangalini, M. and Nakanotani, M. and Adhikari, L. and Liang, H. and Woodham, L. D. and Davies, E. E. and Hietala, H. and Perri, S. and {G{\'o}mez-Herrero}, R. and {Rodr{\'i}guez-Pacheco}, J. and Antonucci, E. and Romoli, M. and Fineschi, S. and Maksimovic, M. and Sou{\v c}ek, J. and Chust, T. and Kretzschmar, M. and Vecchio, A. and M{\"u}ller, D. and Zouganelis, I. and Winslow, R. M. and Giordano, S. and Mancuso, S. and Susino, R. and Ivanovski, S. L. and Messerotti, M. and O'Brien, H. and Evans, V. and Angelini, V.},
  year = {2021},
  month = dec,
  journal = {Astronomy \& Astrophysics},
  volume = {656},
  pages = {A5},
  publisher = {{EDP Sciences}},
  issn = {0004-6361, 1432-0746},
  doi = {10.1051/0004-6361/202140648},
  abstract = {\emph{Context.{$<$}i/{$>$} Solar Orbiter, the new-generation mission dedicated to solar and heliospheric exploration, was successfully launched on February 10, 2020, 04:03 UTC from Cape Canaveral. During its first perihelion passage in June 2020, two successive interplanetary coronal mass ejections (ICMEs), propagating along the heliospheric current sheet (HCS), impacted the spacecraft.\emph{Aims.{$<$}i/{$>$} This paper addresses the investigation of the ICMEs encountered by Solar Orbiter on June 7-8, 2020, from both an observational and a modeling perspective. The aim is to provide a full description of those events, their mutual interaction, and their coupling with the ambient solar wind and the HCS.\emph{Methods.{$<$}i/{$>$} Data acquired by the MAG magnetometer, the Energetic Particle Detector suite, and the Radio and Plasma Waves instrument are used to provide information on the ICMEs' magnetic topology configuration, their magnetic connectivity to the Sun, and insights into the heliospheric plasma environment where they travel, respectively. On the modeling side, the Heliospheric Upwind eXtrapolation model, the 3D COronal Rope Ejection technique, and the EUropean Heliospheric FORecasting Information Asset (EUHFORIA) tool are used to complement Solar Orbiter observations of the ambient solar wind and ICMEs, and to simulate the evolution and interaction of the ejecta in the inner heliosphere, respectively.\emph{Results.{$<$}i/{$>$} Both data analysis and numerical simulations indicate that the passage of two distinct, dynamically and magnetically interacting (via magnetic reconnection processes) ICMEs at Solar Orbiter is a possible scenario, supported by the numerous similarities between EUHFORIA time series at Solar Orbiter and Solar Orbiter data.\emph{Conclusions.{$<$}i/{$>$} The combination of in situ measurements and numerical simulations (together with remote sensing observations of the corona and inner heliosphere) will significantly lead to a deeper understanding of the physical processes occurring during the CME-CME interaction.}}}}}},
  copyright = {\textcopyright{} ESO 2021},
  langid = {english},
  keywords = {ObsCite},
  annotation = {4 citations (Crossref) [2022-12-19] 0 citations (Semantic Scholar/DOI) [2022-12-19]},
  file = {C\:\\Users\\Ronan\\Zotero\\storage\\Q5R7ACQW\\Telloni et al_2021_Study of two interacting interplanetary coronal mass ejections encountered by.pdf;C\:\\Users\\Ronan\\Zotero\\storage\\P3JJ5Q8S\\aa40648-21.html}
}

@article{Telloni2021a,
  title = {Evolution of {{Solar Wind Turbulence}} from 0.1 to 1 Au during the {{First Parker Solar Probe-Solar Orbiter Radial Alignment}}},
  author = {Telloni, Daniele and {Sorriso-Valvo}, Luca and Woodham, Lloyd D and Panasenco, Olga and Velli, Marco and Carbone, Francesco and Zank, Gary P and Bruno, Roberto and Perrone, Denise and Nakanotani, Masaru and Shi, Chen and D'Amicis, Raffaella and De Marco, Rossana and Jagarlamudi, Vamsee K and Steinvall, Konrad and Marino, Raffaele and Adhikari, Laxman and Zhao, Lingling and Liang, Haoming and Tenerani, Anna and Laker, Ronan and Horbury, Timothy S and Bale, Stuart D and Pulupa, Marc and Malaspina, David M and MacDowall, Robert J and Goetz, Keith and {de Wit}, Thierry Dudok and Harvey, Peter R and Kasper, Justin C and Korreck, Kelly E and Larson, Davin and Case, Anthony W and Stevens, Michael L and Whittlesey, Phyllis and Livi, Roberto and Owen, Christopher J and Livi, Stefano and Louarn, Philippe and Antonucci, Ester and Romoli, Marco and O'Brien, Helen and Evans, Vincent and Angelini, Virginia},
  year = {2021},
  journal = {The Astrophysical Journal Letters},
  volume = {912},
  number = {2},
  pages = {L21},
  publisher = {{American Astronomical Society}},
  issn = {2041-8205},
  doi = {10.3847/2041-8213/abf7d1},
  abstract = {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 calculated. The Hilbert\textendash Huang transform is additionally used to mitigate short sample and poor stationarity effects. Results show that the plasma evolves from a highly Alfv\'enic, less-developed turbulence state near the Sun, to fully developed and intermittent turbulence at 1 au. These observations provide strong evidence for the radial evolution of solar wind turbulence.},
  keywords = {ObsCite},
  annotation = {26 citations (Crossref) [2022-12-19] 24 citations (Semantic Scholar/DOI) [2022-12-19]},
  file = {C\:\\Users\\Ronan\\Zotero\\storage\\QRT2R4PH\\Telloni et al_2021_Evolution of Solar Wind Turbulence from 0.pdf}
}

@article{Woodham2021,
  title = {Enhanced Proton Parallel Temperature inside Patches of Switchbacks in the Inner Heliosphere},
  author = {Woodham, L D and Horbury, T S and Matteini, L and Woolley, T and Laker, R and Bale, S D and Nicolaou, G and Stawarz, J E and Stansby, D and Hietala, H and Larson, D E and Livi, R and Verniero, J L and McManus, M and Kasper, J C and Korreck, K E and Raouafi, N and Moncuquet, M and Pulupa, M P},
  year = {2021},
  journal = {A\&A},
  volume = {650},
  doi = {10.1051/0004-6361/202039415},
  keywords = {ObsCite},
  annotation = {29 citations (Crossref) [2022-12-19] 25 citations (Semantic Scholar/DOI) [2022-12-19]},
  file = {C\:\\Users\\Ronan\\Zotero\\storage\\I8SZ598P\\Woodham et al_2021_Enhanced proton parallel temperature inside patches of switchbacks in the inner.pdf}
}

@article{Woolley2020,
  title = {Proton Core Behaviour inside Magnetic Field Switchbacks},
  author = {Woolley, Thomas and Matteini, Lorenzo and Horbury, Timothy S and Bale, Stuart D and Woodham, Lloyd D and Laker, Ronan and Alterman, Benjamin L and Bonnell, John W and Case, Anthony W and Kasper, Justin C and Klein, Kristopher G and Martinovi{\'c}, Mihailo M and Stevens, Michael},
  year = {2020},
  journal = {Monthly Notices of the Royal Astronomical Society},
  volume = {498},
  number = {4},
  pages = {5524--5531},
  issn = {0035-8711},
  doi = {10.1093/mnras/staa2770},
  abstract = {During Parker Solar Probe's first two orbits, there are widespread observations of rapid magnetic field reversals known as switchbacks. These switchbacks are extensively found in the near-Sun solar wind, appear to occur in patches, and have possible links to various phenomena such as magnetic reconnection near the solar surface. As switchbacks are associated with faster plasma flows, we questioned whether they are hotter than the background plasma and whether the microphysics inside a switchback is different to its surroundings. We have studied the reduced distribution functions from the Solar Probe Cup instrument and considered time periods with markedly large angular deflections to compare parallel temperatures inside and outside switchbacks. We have shown that the reduced distribution functions inside switchbacks are consistent with a rigid velocity space rotation of the background plasma. As such, we conclude that the proton core parallel temperature is very similar inside and outside of switchbacks, implying that a temperature\textendash velocity (T\textendash V) relationship does not hold for the proton core parallel temperature inside magnetic field switchbacks. We further conclude that switchbacks are consistent with Alfv\'enic pulses travelling along open magnetic field lines. The origin of these pulses, however, remains unknown. We also found that there is no obvious link between radial Poynting flux and kinetic energy enhancements suggesting that the radial Poynting flux is not important for the dynamics of switchbacks.},
  keywords = {ObsCite,switchbacks},
  annotation = {19 citations (Crossref) [2022-12-19] 17 citations (Semantic Scholar/DOI) [2022-12-19]},
  file = {C\:\\Users\\Ronan\\Zotero\\storage\\L896YIF9\\Woolley et al. - 2020 - Proton core behaviour inside magnetic field switchbacks(2).pdf}
}

@article{Woolley2021,
  title = {Plasma Properties, Switchback Patches, and Low {\emph{{$\alpha$}}} -Particle Abundance in Slow {{Alfv\'enic}} Coronal Hole Wind at 0.13 Au},
  author = {Woolley, Thomas and Matteini, Lorenzo and McManus, Michael D and Ber{\v c}i{\v c}, Laura and Badman, Samuel T and Woodham, Lloyd D and Horbury, Timothy S and Bale, Stuart D and Laker, Ronan and Stawarz, Julia E and Larson, Davin E},
  year = {2021},
  month = sep,
  journal = {Monthly Notices of the Royal Astronomical Society},
  volume = {508},
  number = {1},
  pages = {236--244},
  issn = {0035-8711, 1365-2966},
  doi = {10.1093/mnras/stab2281},
  abstract = {ABSTRACT             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 ({$\sim$}0.13\,au) and latitude ({$\sim$}\textendash\$3\{\_\{.\}\^\{\textbackslash circ\}\}5\$) across these encounters to reduce spatial evolution effects. By comparing the plasma of each stream, we confirm that they are not dominated by variable transient events, despite PSP's proximity to the heliospheric current sheet. Both streams are consistent with a previous slow Alfv\'enic solar wind study once radial effects are considered, and appear to originate at the Southern polar coronal hole boundary. We also show that the switchback properties are not distinctly different between these two streams. Low {$\alpha$}-particle abundance ({$\sim$}0.6 ~per~cent) is observed in the encounter 5 stream, suggesting that some physical mechanism must act on coronal hole boundary wind to cause {$\alpha$}-particle depletion. Possible explanations for our observations are discussed, but it remains unclear whether the depletion occurs during the release or the acceleration of the wind. Using a flux tube argument, we note that an {$\alpha$}-particle abundance of {$\sim$}0.6 ~per~cent in this low-velocity wind could correspond to an abundance of {$\sim$}0.9 ~per~cent at 1\,au. Finally, as the two streams roughly correspond to the spatial extent of a switchback patch, we suggest that patches are distinct features of coronal hole wind.},
  copyright = {All rights reserved},
  langid = {english},
  annotation = {2 citations (Crossref) [2022-12-19] 3 citations (Semantic Scholar/DOI) [2022-12-19]},
  file = {C\:\\Users\\Ronan\\Zotero\\storage\\H8FZRDXN\\Woolley et al_2021_Plasma properties, switchback patches, and low iα-i -particle abundance in.pdf}
}