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Found 6 entries in the Bibliography.
Showing entries from 1 through 6
2023 |
In this study we examine the radial dependence of the inertial and dissipation range indices, as well as the spectral break separating the inertial and dissipation range in power density spectra of interplanetary magnetic field fluctuations using Parker Solar Probe data from the fifth solar encounter between \raisebox-0.5ex\textasciitilde0.1 and \raisebox-0.5ex\textasciitilde0.7 au. The derived break wavenumber compares reasonably well with previous estimates at larger radial distances and is consistent with gyro-resonant da ... Lotz, S.; Nel, A.~E.; Wicks, R.~T.; Roberts, O.~W.; Engelbrecht, N.~E.; Strauss, R.~D.; Botha, G.~J.~J.; Kontar, E.~P.; Pit\vna, A.; Bale, S.~D.; Published by: \apj Published on: jan YEAR: 2023   DOI: 10.3847/1538-4357/aca903 Parker Data Used; Space plasmas; Solar wind; interplanetary turbulence; 1544; 1534; 830; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
2020 |
Measures of Scale-dependent Alfv\ enicity in the First PSP Solar Encounter The solar wind shows periods of highly Alfv\ enic activity, where velocity fluctuations and magnetic fluctuations are aligned or antialigned with each other. It is generally agreed that solar wind plasma velocity and magnetic field fluctuations observed by the Parker Solar Probe (PSP) during the first encounter are mostly highly Alfv\ enic. However, quantitative measures of Alfv\ enicity are needed to understand how the characterization of these fluctuations compares with standard measures from prior missions in the inner ... Parashar, T.; Goldstein, M.; Maruca, B.; Matthaeus, W.; Ruffolo, D.; Bandyopadhyay, R.; Chhiber, R.; Chasapis, A.; Qudsi, R.; Vech, D.; Roberts, D.; Bale, S.; Bonnell, J.; de Wit, Dudok; Goetz, K.; Harvey, P.; MacDowall, R.; Malaspina, D.; Pulupa, M.; Kasper, J.; Korreck, K.; Case, A.; Stevens, M.; Whittlesey, P.; Larson, D.; Livi, R.; Velli, M.; Raouafi, N.; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020   DOI: 10.3847/1538-4365/ab64e6 |
Objectively Determining States of the Solar Wind Using Machine Learning Conclusively determining the states of the solar wind will aid in tracing the origins of those states to the Sun, and in the process help to find the wind\textquoterights origin and acceleration mechanism(s). Prior studies have characterized the various states of the wind, making lists that are only partially based on objective criteria; different approaches obtain substantially different results. To uncover the unbiased states of the solar wind, we use "k-means clustering"\textemdashan unsupervised machine learning metho ... Roberts, Aaron; Karimabadi, Homa; Sipes, Tamara; Ko, Yuan-Kuen; Lepri, Susan; Published by: The Astrophysical Journal Published on: 02/2020 YEAR: 2020   DOI: 10.3847/1538-4357/ab5a7a |
2018 |
Simulated Encounters of the Parker Solar Probe with a Coronal-hole Jet Solar coronal jets are small, transient, collimated ejections most easily observed in coronal holes (CHs). The upcoming Parker Solar Probe (PSP) mission provides the first opportunity to encounter CH jets in situ near the Sun and examine their internal structure and dynamics. Using projected mission orbital parameters, we have simulated PSP encounters with a fully three-dimensional magnetohydrodynamic (MHD) model of a CH jet. We find that three internal jet regions, featuring different wave modes and levels of compressibi ... Roberts, Merrill; Uritsky, Vadim; DeVore, Richard; Karpen, Judith; Published by: The Astrophysical Journal Published on: 10/2018 YEAR: 2018   DOI: 10.3847/1538-4357/aadb41 Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Solar Probe Plus; Solar wind; Sun: activity; Sun: corona; Sun: heliosphere; Sun: magnetic fields |
Published by: Published on: 01/2018 |
2013 |
We present a new data analysis method enabling the observation of magnetic field fluctuations associated with temperature anisotropy instabilities using the Ulysses spacecraft. The movement of the spacecraft away from the Sun causes the observed plasma conditions, turbulent fluctuation amplitude, magnetic field strength and important physical scales to change. We normalize wavelet power spectra of the magnetic field using local values for the proton gyroscale and large scale magnetic field fluctuation amplitude to remove ... Wicks, Robert; Matteini, Lorenzo; Horbury, Timothy; Hellinger, Petr; Roberts, Aaron; Published by: Published on: 07/2013 YEAR: 2013   DOI: 10.1063/1.4811048 96.50.Ci; 96.60.Hv; 96.60.Tf; 96.60.Vg; astrophysical plasma; data analysis; parker solar probe; plasma instability; solar magnetism; Solar Probe Plus; solar spectra; Solar wind; Solar wind plasma; sources of solar wind; wavelet transforms |
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