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Found 9 entries in the Bibliography.
Showing entries from 1 through 9
2022 
In this Letter, we report observations of magnetic switchback (SB) features near 1 au using data from the Wind spacecraft. These features appear to be strikingly similar to the ones observed by the Parker Solar Probe mission closer to the Sun: namely, one sided spikes (or enhancements) in the solarwind bulk speed V that correlate/anticorrelate with the spikes seen in the radial field component B $_ R $. In the solarwind streams that we analyzed, these specific SB features near 1 au are associated with largeamplitude Alf ... Bourouaine, Sofiane; Perez, Jean; Raouafi, Nour; Chandran, Benjamin; Bale, Stuart; Velli, Marco; Published by: \apjl Published on: jun YEAR: 2022 DOI: 10.3847/20418213/ac67d9 Parker Data Used; Heliosphere; Solar wind; 711; 1534; Astrophysics  Solar and Stellar Astrophysics; Physics  Space Physics 
2021 
The nearSun streamer belt solar wind: turbulence and solar wind acceleration The fourth orbit of Parker Solar Probe (PSP) reached heliocentric distances down to 27.9 R$_\ensuremath\odot$, allowing solar wind turbulence and acceleration mechanisms to be studied in situ closer to the Sun than previously possible. The turbulence properties were found to be significantly different in the inbound and outbound portions of PSP s fourth solar encounter, which was likely due to the proximity to the heliospheric current sheet (HCS) in the outbound period. Near the HCS, in the streamer belt wind, the turbulence ... Chen, C.; Chandran, B.; Woodham, L.; Jones, S.; Perez, J.; Bourouaine, S.; Bowen, T.; Klein, K.; Moncuquet, M.; Kasper, J.; Bale, S.; Published by: Astronomy and Astrophysics Published on: jun YEAR: 2021 DOI: "10.1051/00046361/202039872" 
Applicability of Taylor s hypothesis during Parker Solar Probe perihelia We investigate the validity of Taylor s hypothesis (TH) in the analysis of velocity and magnetic field fluctuations in Alfvénic solar wind streams measured by Parker Solar Probe (PSP) during the first four encounters. The analysis is based on a recent model of the spacetime correlation of magnetohydrodynamic (MHD) turbulence, which has been validated in highresolution numerical simulations of strong reduced MHD turbulence. We use PSP velocity and magnetic field measurements from 24 h intervals selected from each of the fir ... Perez, Jean; Bourouaine, Sofiane; Chen, Christopher; Raouafi, Nour; Published by: Astronomy and Astrophysics Published on: 06/2021 YEAR: 2021 DOI: 10.1051/00046361/202039879 Solar wind; Sun: heliosphere; turbulence; magnetohydrodynamics (MHD); plasmas; Astrophysics  Solar and Stellar Astrophysics; Physics  Plasma Physics; Physics  Space Physics; Parker Data Used 
2020 
Turbulence Characteristics of Switchback and Nonswitchback Intervals Observed by Parker Solar Probe We use Parker Solar Probe (PSP) in situ measurements to analyze the characteristics of solar wind turbulence during the first solar encounter covering radial distances between 35.7R and 41.7R. In our analysis we isolate socalled switchback (SB) intervals (folded magnetic field lines) from nonswitchback (NSB) intervals, which mainly follow the Parker spiral field. Using a technique based on conditioned correlation functions, we estimate the power spectra of Elsasser, magnetic, and bulk velocity fields separately in the SB an ... Bourouaine, Sofiane; Perez, Jean; Klein, Kristopher; Chen, Christopher; Martinovic, Mihailo; Bale, Stuart; Kasper, Justin; Raouafi, Nour; Published by: ASTROPHYSICAL JOURNAL LETTERS Published on: 12/2020 YEAR: 2020 DOI: 10.3847/20418213/abbd4a 
Eulerian spacetime correlation of strong magnetohydrodynamic turbulence Perez, Jean; Bourouaine, Sofiane; Published by: Physical Review Research Published on: 06/2020 YEAR: 2020 DOI: 10.1103/PhysRevResearch.2.023357 Astrophysics  Solar and Stellar Astrophysics; Physics  Plasma Physics; Physics  Space Physics 
Twotime energy spectrum of weak magnetohydrodynamic turbulence In this work a weakturbulence closure is used to determine the structure of the twotime power spectrum of weak magnetohydrodynamic (MHD) turbulence from the nonlinear equations describing the dynamics. The twotime energy spectrum is a fundamental quantity in turbulence theory from which most statistical properties of a homogeneous turbulent system can be derived. A closely related quantity, obtained via a spatial Fourier transform, is the twopoint twotime correlation function describing the spacetime correlations arisi ... Perez, Jean; Azelis, Augustus; Bourouaine, Sofiane; Published by: PHYSICAL REVIEW RESEARCH Published on: 05/2020 YEAR: 2020 DOI: 10.1103/PhysRevResearch.2.023189 
2019 
On the Interpretation of Parker Solar Probe Turbulent Signals In this Letter we propose a practical methodology to interpret future Parker Solar Probe (PSP) turbulent time signals even when Taylor s hypothesis is not valid. By extending Kraichnan s sweeping model used in hydrodynamics we derive the Eulerian spacetime correlation function in magnetohydrodynamic (MHD) turbulence. It is shown that in MHD, the temporal decorrelation of smallscale fluctuations arises from a combination of hydrodynamic sweeping induced by largescale fluid velocity delta u(0) and by the Alfvenic propagation ... Bourouaine, Sofiane; Perez, Jean; Published by: ASTROPHYSICAL JOURNAL LETTERS Published on: 07/2019 YEAR: 2019 DOI: 10.3847/20418213/ab288a 
2018 
In this Letter, we present an analysis of twopoint, twotime correlation functions from highresolution numerical simulations of Reflectiondriven Alfven Turbulence near the Alfven critical point r e . The simulations model the turbulence in a prescribed background solar wind model chosen to match observational constraints. This analysis allows us to investigate the temporal decorrelation of solar wind turbulence and the validity of Taylor s approximation near the heliocentric distance r(c), which Parker Solar Probe (PSP) i ... Bourouaine, Sofiane; Perez, Jean; Published by: ASTROPHYSICAL JOURNAL LETTERS Published on: 05/2018 YEAR: 2018 DOI: 10.3847/20418213/aabccf 
2013 
Stochastic Heating, Differential Flow, and the Alphatoproton Temperature Ratio in the Solar Wind Chandran, B.~D.~G.; Verscharen, D.; Quataert, E.; Kasper, J.~C.; Isenberg, P.~A.; Bourouaine, S.; Published by: \apj Published on: 10/2013 YEAR: 2013 DOI: 10.1088/0004637X/776/1/45 Parker Data Used; plasmas; Solar wind; Sun: corona; turbulence; waves; Astrophysics  Solar and Stellar Astrophysics; Physics  Plasma Physics; Physics  Space Physics 
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