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Turbulent Generation of Magnetic Switchbacks in the Alfv\ enic Solar Wind
| Author | Shoda, Munehito; Chandran, Benjamin; Cranmer, Steven; |
| Keywords | Space plasmas; Solar wind; interplanetary turbulence; Parker Data Used; Magnetohydrodynamical simulations; Alfven waves; 1544; 1534; 830; 1966; 23; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
| Abstract | One of the most important early results from the Parker Solar Probe (PSP) is the ubiquitous presence of magnetic switchbacks, whose origin is under debate. Using a three-dimensional direct numerical simulation of the equations of compressible magnetohydrodynamics from the corona to 40 solar radii, we investigate whether magnetic switchbacks emerge from granulation-driven Alfv\ en waves and turbulence in the solar wind. The simulated solar wind is an Alfv\ enic slow-solar- wind stream with a radial profile consistent with various observations, including observations from PSP. As a natural consequence of Alfv\ en-wave turbulence, the simulation reproduced magnetic switchbacks with many of the same properties as observed switchbacks, including Alfv\ enic v-b correlation, spherical polarization (low magnetic compressibility), and a volume filling fraction that increases with radial distance. The analysis of propagation speed and scale length shows that the magnetic switchbacks are large-amplitude (nonlinear) Alfv\ en waves with discontinuities in the magnetic-field direction. We directly compare our simulation with observations using a virtual flyby of PSP in our simulation domain. We conclude that at least some of the switchbacks observed by PSP are a natural consequence of the growth in amplitude of spherically polarized Alfv\ en waves as they propagate away from the Sun. |
| Year of Publication | 2021 |
| Journal | \apj |
| Volume | 915 |
| Number of Pages | 52 |
| Section | |
| Date Published | jul |
| ISBN | |
| URL | |
| DOI | 10.3847/1538-4357/abfdbc |
